A power supply control method, device, air conditioner, and storage medium for an outdoor unit of an air conditioner.

Abstract

This invention discloses a power supply control method, device, air conditioner, and storage medium for an air conditioner outdoor unit. The method includes: during the operation of the air conditioner outdoor unit, based on the voltage sampling signal of the power input side of the air conditioner outdoor unit, if it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, then based on the voltage sampling signal of the power input side of the air conditioner outdoor unit, the voltage low-pass filter signal of the power input side of the air conditioner outdoor unit, and the maximum resonance voltage detection value of the power input side of the air conditioner outdoor unit, determining the compensation duty cycle of the current loop of the PFC circuit; adding the compensation duty cycle of the current loop of the PFC circuit to the control of the current loop of the PFC circuit to suppress the voltage resonance on the power input side of the air conditioner outdoor unit. This solution, by suppressing the resonance amplitude within a small controllable range when voltage resonance occurs on the power input side of the air conditioner outdoor unit, without reducing the power factor or increasing the current harmonic content, improves the reliability of air conditioner operation and user experience.

Description

Technical Field

[0001] This invention belongs to the field of air conditioning technology, specifically relating to a power supply control method, device, air conditioner, and storage medium for an outdoor unit of an air conditioner, and particularly to a voltage resonance detection and suppression method, device, variable frequency air conditioner, and storage medium for an outdoor unit of a variable frequency air conditioner. Background Technology

[0002] For the outdoor and indoor units of air conditioners (such as inverter air conditioners), when the peak resonant voltage on the power input side of the outdoor unit is too high, it will cause the DC bus voltage of the indoor unit after uncontrolled rectification to be too high, which will lead to problems such as the indoor unit resetting under excessively high voltage, thus affecting the reliability of the inverter air conditioner and the user experience.

[0003] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention

[0004] The purpose of this invention is to provide a power supply control method, device, air conditioner, and storage medium for an outdoor unit of an air conditioner. This addresses the problem that when the peak resonant voltage on the power input side of an air conditioner (such as an inverter air conditioner) is too high, it can lead to excessively high DC bus voltage after uncontrolled rectification of the indoor unit, causing the indoor unit to reset under excessively high voltage. This affects the reliability of the inverter air conditioner and the user experience. The invention aims to suppress the resonant amplitude of the voltage resonance on the power input side of the inverter air conditioner's outdoor unit within a small, controllable range without reducing the power factor or increasing the current harmonic content, thereby improving the reliability of the inverter air conditioner and the user experience.

[0005] This invention provides a power supply control method for an air conditioner outdoor unit. In the power supply circuit of the air conditioner outdoor unit, the AC power from the power input side of the air conditioner outdoor unit passes sequentially through a first filter unit, a rectifier unit, a second filter unit, and a PFC circuit before being output to the DC bus. The power supply control method for the air conditioner outdoor unit includes: during the operation of the air conditioner outdoor unit, acquiring the voltage across the second filter unit at a set sampling period to obtain a voltage sampling signal from the power input side of the air conditioner outdoor unit; filtering the voltage sampling signal from the power input side of the air conditioner outdoor unit within a set frequency range to obtain a low-pass filtered signal from the power input side of the air conditioner outdoor unit; and determining that the power input side of the air conditioner outdoor unit is in voltage resonance. In the given state, the maximum resonant voltage detection value of the power input side of the air conditioner outdoor unit is obtained; based on the voltage sampling signal of the power input side of the air conditioner outdoor unit, it is determined whether the power input side of the air conditioner outdoor unit is in a voltage resonance state; if it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, then based on the voltage sampling signal of the power input side of the air conditioner outdoor unit, the voltage low-pass filter signal of the power input side of the air conditioner outdoor unit, and the maximum resonant voltage detection value of the power input side of the air conditioner outdoor unit, the compensation duty cycle of the current loop of the PFC circuit is determined; the compensation duty cycle of the current loop of the PFC circuit is added to the control of the current loop of the PFC circuit to suppress the voltage resonance of the power input side of the air conditioner outdoor unit.

[0006] In some embodiments, determining whether the power input side of the air conditioner outdoor unit is in a voltage resonance state based on the voltage sampling signal of the power input side includes: according to a set resonance detection period, within the current resonance detection period, for the voltage sampling signals of the power input side of the air conditioner outdoor unit sampled in two adjacent sampling periods, determining the difference between the voltage sampling signal of the power input side of the air conditioner outdoor unit sampled in the current sampling period and the voltage sampling signal of the power input side of the air conditioner outdoor unit sampled in the previous sampling period, and recording it as the voltage sampling signal difference of the power input side of the air conditioner outdoor unit in two adjacent periods; wherein, the set resonance detection period is large Within a set sampling period, determine whether the difference between the voltage sampling signals of the power input side of the air conditioner outdoor unit in two adjacent sampling periods is greater than a set resonant voltage detection threshold; if the difference between the voltage sampling signals of the power input side of the air conditioner outdoor unit in two adjacent sampling periods is greater than the set resonant voltage detection threshold, then determine that the AC voltage of the power input side of the air conditioner outdoor unit is oscillating, and accumulate the number of oscillations of the AC voltage of the power input side of the air conditioner outdoor unit to obtain the accumulated value of the voltage oscillation count of the power input side of the air conditioner outdoor unit; based on the accumulated value of the voltage oscillation count of the power input side of the air conditioner outdoor unit, determine whether the power input side of the air conditioner outdoor unit is in a voltage resonance state.

[0007] In some implementations, determining whether the power input side of the air conditioner outdoor unit is in a voltage resonance state based on the accumulated value of the voltage oscillation count on the power input side includes: determining whether the accumulated value of the voltage oscillation count on the power input side of the air conditioner outdoor unit has accumulated to a value greater than or equal to a set oscillation count threshold; if it is determined that the accumulated value of the voltage oscillation count on the power input side of the air conditioner outdoor unit has accumulated to a value greater than or equal to the set oscillation count threshold, then it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state in the current resonance detection cycle; if it is determined that the accumulated value of the voltage oscillation count on the power input side of the air conditioner outdoor unit has not accumulated to a value greater than or equal to the set oscillation count threshold, then it is determined whether to enter the next resonance detection cycle; if it is determined that the next resonance detection cycle has been entered, then it is determined that the power input side of the air conditioner outdoor unit is not in a voltage resonance state in the current resonance detection cycle, and the accumulated value of the voltage oscillation count on the power input side of the air conditioner outdoor unit is cleared to zero; if it is determined that the next resonance detection cycle has not been entered, then it returns to continue determining whether the difference between the voltage sampling signals of the power input side of the air conditioner outdoor unit in two adjacent sampling cycles is greater than the set resonance voltage detection threshold.

[0008] In some implementations, the compensation duty cycle of the current loop of the PFC circuit is determined based on the voltage sampling signal of the power input side of the air conditioner outdoor unit, the voltage low-pass filter signal of the power input side of the air conditioner outdoor unit, and the maximum resonant voltage detection value of the power input side of the air conditioner outdoor unit. This includes: determining the difference between the voltage sampling signal of the power input side of the air conditioner outdoor unit and the voltage low-pass filter signal of the power input side of the air conditioner outdoor unit, denoted as the voltage signal difference of the power input side of the air conditioner outdoor unit; extracting the resonant signal component from the voltage signal difference of the power input side of the air conditioner outdoor unit as a compensation signal for suppressing voltage resonance on the power input side of the air conditioner outdoor unit, denoted as the compensation signal of the power input side of the air conditioner outdoor unit; determining the set maximum hysteresis comparison accumulation value based on the compensation signal of the power input side of the air conditioner outdoor unit, and determining the controller of the PFC circuit in digital control. The hysteresis parameters in the circuit are adjusted according to the set maximum hysteresis comparison accumulation value and the maximum resonant voltage detection value on the power input side of the air conditioner outdoor unit. The adjusted value of the hysteresis parameters in the digital control of the PFC circuit controller is obtained and used as the phase adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit. And / or, the amplitude gain adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit is determined according to the maximum resonant voltage detection value on the power input side of the air conditioner outdoor unit. The compensation signal on the power input side of the air conditioner outdoor unit is phase-adjusted by the phase adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit, and / or amplitude-gain-adjusted by the amplitude gain adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit, to obtain the compensation duty cycle of the current loop of the PFC circuit.

[0009] In some implementations, based on the compensation signal at the power input side of the air conditioner outdoor unit, a set maximum hysteresis comparison accumulation value is determined, and the hysteresis parameter of the PFC circuit controller in digital control is determined, including: determining whether the compensation signal at the power input side of the air conditioner outdoor unit is greater than a set positive hysteresis comparison voltage threshold; if it is determined that the compensation signal at the power input side of the air conditioner outdoor unit is greater than the set positive hysteresis comparison voltage threshold, then the count value of the compensation signal at the power input side of the air conditioner outdoor unit being greater than the set positive hysteresis comparison voltage threshold is accumulated to obtain the accumulated value of the count value of the compensation signal at the power input side of the air conditioner outdoor unit being greater than the set positive hysteresis comparison voltage threshold, which is recorded as the hysteresis comparison accumulation value at the power input side of the air conditioner outdoor unit; if it is determined that the compensation signal at the power input side of the air conditioner outdoor unit is not greater than the set positive hysteresis comparison voltage threshold, then if the hysteresis comparison accumulation value at the power input side of the air conditioner outdoor unit is not 0, the maximum hysteresis comparison accumulation value is determined, and ... The system checks whether the compensation signal at the outdoor unit's power input side is less than the negative value of the set positive threshold for hysteresis comparison voltage. If it is determined that the compensation signal at the outdoor unit's power input side is not less than the negative value of the set positive threshold for hysteresis comparison voltage, the system continues to accumulate the accumulated value of the hysteresis comparison on the outdoor unit's power input side. If it is determined that the compensation signal at the outdoor unit's power input side is less than the negative value of the set positive threshold for hysteresis comparison voltage, the system sets the maximum accumulated value of hysteresis comparison to the accumulated value of the outdoor unit's power input side, and then sets the accumulated value of the hysteresis comparison on the outdoor unit's power input side to zero. Based on the maximum accumulated value of hysteresis comparison and the set sampling period, the system determines the resonant frequency at which voltage resonance occurs at the outdoor unit's power input side, and records it as the resonant frequency of the outdoor unit's power input side. Furthermore, based on the set sampling period and the resonant frequency of the outdoor unit's power input side, the system determines the hysteresis parameters of the PFC circuit's controller in digital control.

[0010] In some implementations, the hysteresis parameter of the PFC circuit controller in digital control is adjusted based on a set maximum hysteresis comparison accumulation value and the maximum resonant voltage detection value on the power input side of the air conditioner outdoor unit. This adjustment value of the hysteresis parameter is then used as the phase adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit. This includes: determining the maximum resonant voltage detection value on the power input side of the air conditioner outdoor unit sampled in the current sampling period and the maximum resonant voltage detection value on the power input side of the air conditioner outdoor unit sampled in the previous sampling period, based on the maximum resonant voltage detection values ​​sampled in two adjacent sampling periods. The difference between the measured values ​​is recorded as the difference in the maximum resonant voltage detected on the power input side of the air conditioner outdoor unit. It is then determined whether the difference in the maximum resonant voltage detected on the power input side of the air conditioner outdoor unit is greater than or equal to the set phase adjustment sensitivity. If the difference in the maximum resonant voltage detected on the power input side of the air conditioner outdoor unit is greater than or equal to the set phase adjustment sensitivity, it is then determined whether the phase adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is negative. If so, the lag parameter of the PFC circuit controller in digital control is increased according to the set cycle value, and the phase adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is made positive. Otherwise, the phase adjustment direction of the PFC circuit is adjusted according to the set cycle value. The hysteresis parameter of the PFC circuit controller in digital control is reduced, and the phase adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is made negative. If it is determined that the difference in the maximum resonant voltage detection value on the power input side of the air conditioner outdoor unit is less than the set phase adjustment sensitivity, then if the difference in the maximum resonant voltage detection value on the power input side of the air conditioner outdoor unit is less than or equal to the negative value of the set phase adjustment sensitivity, it is determined whether the phase adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is negative. If so, the hysteresis parameter of the PFC circuit controller in digital control is reduced according to the set cycle value, and the phase adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is made negative. If the PFC circuit controller is positive, then according to the set cycle value, the hysteresis parameter of the PFC circuit controller in digital control is increased, and the phase adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is made positive; determine whether the hysteresis parameter of the PFC circuit controller in digital control is 0: if yes, then the hysteresis parameter of the PFC circuit controller in digital control is made 0; otherwise, the hysteresis parameter of the PFC circuit controller in digital control is made to be a set coefficient multiple of the set maximum hysteresis comparison accumulation value, so as to obtain the adjustment value of the hysteresis parameter of the PFC circuit controller in digital control, which is used as the phase adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit.

[0011] In some implementations, determining the amplitude gain adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit based on the detected maximum resonant voltage on the power input side includes: for the detected maximum resonant voltage on the power input side of the air conditioner outdoor unit sampled in two adjacent sampling periods, determining the difference between the detected maximum resonant voltage on the power input side of the air conditioner outdoor unit sampled in the current sampling period and the detected maximum resonant voltage on the power input side of the air conditioner outdoor unit sampled in the previous sampling period, and recording it as the difference in the detected maximum resonant voltage on the power input side of the air conditioner outdoor unit; determining whether the difference in the detected maximum resonant voltage on the power input side of the air conditioner outdoor unit is... If the difference in the maximum resonant voltage detected on the power input side of the air conditioner outdoor unit is greater than or equal to the set amplitude gain adjustment sensitivity, then determine whether the amplitude gain adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is negative: if yes, then increase the current amplitude gain of the PFC circuit controller according to the set gain adjustment step size, and make the amplitude gain adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit positive; otherwise, then decrease the current amplitude gain of the PFC circuit controller according to the set gain adjustment step size, and make the compensation signal on the power input side of the air conditioner outdoor unit negative. The amplitude gain adjustment direction is negative; if it is determined that the difference in the maximum resonant voltage detection value on the power input side of the air conditioner outdoor unit is less than the set amplitude gain adjustment sensitivity, then if the difference in the maximum resonant voltage detection value on the power input side of the air conditioner outdoor unit is less than or equal to the negative value of the set amplitude gain adjustment sensitivity, determine whether the amplitude gain adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is negative: if yes, then reduce the current amplitude gain of the controller of the PFC circuit according to the set gain adjustment step size, and make the amplitude gain adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit negative; otherwise, then reduce the current amplitude gain of the controller of the PFC circuit according to the set gain adjustment step size. The current amplitude gain of the PFC circuit controller is increased, and the amplitude gain adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is made positive. It is determined whether the current amplitude gain of the PFC circuit controller is 0: if so, the current amplitude gain of the PFC circuit controller is made 0; otherwise, if the current amplitude gain of the PFC circuit controller is greater than the set maximum amplitude gain, the current amplitude gain of the PFC circuit controller is made to the set maximum amplitude gain, so as to obtain the adjustment value of the current amplitude gain of the PFC circuit controller, which is used as the amplitude gain adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit.

[0012] In some embodiments, the compensation signal at the power input side of the air conditioner outdoor unit is phase-adjusted by a phase adjustment value and / or amplitude-gain adjusted by an amplitude-gain adjustment value to obtain the compensation duty cycle of the current loop of the PFC circuit. This includes: phase-adjusting the compensation signal at the power input side of the air conditioner outdoor unit by a fixed phase of the controller of the PFC circuit, and then amplitude-gain adjusting the compensation signal at the power input side of the air conditioner outdoor unit by an amplitude-gain adjustment value to obtain the compensation duty cycle of the current loop of the PFC circuit; or, phase-adjusting the compensation signal at the power input side of the air conditioner outdoor unit by a phase adjustment value and / or amplitude-gain adjustment value to obtain the compensation duty cycle of the current loop of the PFC circuit; or, phase-adjusting the compensation signal at the power input side of the air conditioner outdoor unit by a phase adjustment value and / or amplitude-gain adjustment value to obtain the compensation duty cycle of the current loop of the PFC circuit. After phase adjustment of the phase adjustment value of the signal, the amplitude gain is adjusted by the fixed amplitude gain of the PFC circuit controller to obtain the compensation duty cycle of the current loop of the PFC circuit; or, the compensation signal of the power input side of the air conditioner outdoor unit is phase adjusted by the phase adjustment value of the compensation signal of the power input side of the air conditioner outdoor unit, and then the amplitude gain is adjusted by the amplitude gain adjustment value of the compensation signal of the power input side of the air conditioner outdoor unit to obtain the compensation duty cycle of the current loop of the PFC circuit; wherein, the phase adjustment value of the compensation signal of the power input side of the air conditioner outdoor unit is determined within a first set time period; the amplitude gain adjustment value of the compensation signal of the power input side of the air conditioner outdoor unit is determined within a second set time period.

[0013] In accordance with the above method, another aspect of the present invention provides a power supply control device for an air conditioner outdoor unit. In the power supply circuit of the air conditioner outdoor unit, the AC power from the power input side of the air conditioner outdoor unit passes sequentially through a first filter unit, a rectifier unit, a second filter unit, and a PFC circuit before being output to the DC bus. The power supply control device for the air conditioner outdoor unit includes: an acquisition unit configured to acquire the voltage across the second filter unit at a set sampling period during the operation of the air conditioner outdoor unit, thereby obtaining a voltage sampling signal from the power input side of the air conditioner outdoor unit; to perform filtering processing on the voltage sampling signal from the power input side of the air conditioner outdoor unit within a set frequency range, thereby obtaining a low-pass filtered voltage signal from the power input side of the air conditioner outdoor unit; and, when it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state... The control unit is configured to obtain the maximum resonant voltage detection value of the power input side of the air conditioner outdoor unit; the control unit is configured to determine whether the power input side of the air conditioner outdoor unit is in a voltage resonance state based on the voltage sampling signal of the power input side of the air conditioner outdoor unit; the control unit is further configured to determine the compensation duty cycle of the current loop of the PFC circuit based on the voltage sampling signal of the power input side of the air conditioner outdoor unit, the voltage low-pass filter signal of the power input side of the air conditioner outdoor unit, and the maximum resonant voltage detection value of the power input side of the air conditioner outdoor unit if it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state; the control unit is further configured to add the compensation duty cycle of the current loop of the PFC circuit to the control of the current loop of the PFC circuit to suppress the voltage resonance of the power input side of the air conditioner outdoor unit.

[0014] In some embodiments, the control unit determines whether the power input side of the air conditioner outdoor unit is in a voltage resonance state based on the voltage sampling signal of the power input side of the air conditioner outdoor unit. This includes: according to a set resonance detection period, within the current resonance detection period, for the voltage sampling signals of the power input side of the air conditioner outdoor unit sampled in two adjacent sampling periods, determining the difference between the voltage sampling signal of the power input side of the air conditioner outdoor unit sampled in the current sampling period and the voltage sampling signal of the power input side of the air conditioner outdoor unit sampled in the previous sampling period, and recording this difference as the voltage sampling signal difference of the power input side of the air conditioner outdoor unit in two adjacent periods; wherein, the set resonance detection... The sampling period is greater than the set sampling period; it is determined whether the difference between the voltage sampling signals of the power input side of the air conditioner outdoor unit in two adjacent sampling periods is greater than the set resonant voltage detection threshold; if it is determined that the difference between the voltage sampling signals of the power input side of the air conditioner outdoor unit in two adjacent sampling periods is greater than the set resonant voltage detection threshold, it is determined that the AC voltage of the power input side of the air conditioner outdoor unit is oscillating, and the number of oscillations of the AC voltage of the power input side of the air conditioner outdoor unit is accumulated to obtain the accumulated value of the voltage oscillation count of the power input side of the air conditioner outdoor unit; based on the accumulated value of the voltage oscillation count of the power input side of the air conditioner outdoor unit, it is determined whether the power input side of the air conditioner outdoor unit is in a voltage resonance state.

[0015] In some implementations, the control unit determines whether the power input side of the air conditioner outdoor unit is in a voltage resonance state based on the accumulated value of the voltage oscillation count on the power input side of the air conditioner outdoor unit. This includes: determining whether the accumulated value of the voltage oscillation count on the power input side of the air conditioner outdoor unit has accumulated to a value greater than or equal to a set oscillation count threshold; if it is determined that the accumulated value of the voltage oscillation count on the power input side of the air conditioner outdoor unit has accumulated to a value greater than or equal to the set oscillation count threshold, then it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state in the current resonance detection cycle; if it is determined that the accumulated value of the voltage oscillation count on the power input side of the air conditioner outdoor unit has not accumulated to a value greater than or equal to the set oscillation count threshold, then it is determined whether to enter the next resonance detection cycle; if it is determined that the next resonance detection cycle has been entered, then it is determined that the power input side of the air conditioner outdoor unit is not in a voltage resonance state in the current resonance detection cycle, and the accumulated value of the voltage oscillation count on the power input side of the air conditioner outdoor unit is cleared to zero; if it is determined that the next resonance detection cycle has not been entered, then it returns to continue determining whether the difference between the voltage sampling signals of the power input side of the air conditioner outdoor unit in two adjacent sampling cycles is greater than the set resonance voltage detection threshold.

[0016] In some embodiments, the control unit determines the compensation duty cycle of the current loop of the PFC circuit based on the voltage sampling signal of the power input side of the air conditioner outdoor unit, the voltage low-pass filter signal of the power input side of the air conditioner outdoor unit, and the maximum resonant voltage detection value of the power input side of the air conditioner outdoor unit. This includes: determining the difference between the voltage sampling signal of the power input side of the air conditioner outdoor unit and the voltage low-pass filter signal of the power input side of the air conditioner outdoor unit, denoted as the voltage signal difference of the power input side of the air conditioner outdoor unit; extracting the resonant signal component from the voltage signal difference of the power input side of the air conditioner outdoor unit as a compensation signal for suppressing voltage resonance on the power input side of the air conditioner outdoor unit, denoted as the compensation signal of the power input side of the air conditioner outdoor unit; determining a set maximum hysteresis comparison accumulation value based on the compensation signal of the power input side of the air conditioner outdoor unit, and determining the controller of the PFC circuit in a certain number of steps. The hysteresis parameter in digital control; based on the set maximum hysteresis comparison accumulation value and the maximum resonant voltage detection value on the power input side of the air conditioner outdoor unit, the hysteresis parameter of the PFC circuit controller in digital control is adjusted to obtain the adjustment value of the hysteresis parameter of the PFC circuit controller in digital control, which is used as the phase adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit; and / or, based on the maximum resonant voltage detection value on the power input side of the air conditioner outdoor unit, the amplitude gain adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit is determined; the compensation signal on the power input side of the air conditioner outdoor unit is phase-adjusted after being adjusted by the phase adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit, and / or amplitude-gain-adjusted after being adjusted by the amplitude gain adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit, to obtain the compensation duty cycle of the current loop of the PFC circuit.

[0017] In some embodiments, the control unit determines a set maximum hysteresis comparison accumulation value based on the compensation signal from the power input side of the air conditioner outdoor unit, and determines the hysteresis parameter of the PFC circuit controller in digital control, including: determining whether the compensation signal from the power input side of the air conditioner outdoor unit is greater than a set positive hysteresis comparison voltage threshold; if it is determined that the compensation signal from the power input side of the air conditioner outdoor unit is greater than the set positive hysteresis comparison voltage threshold, then the count value of the compensation signal from the power input side of the air conditioner outdoor unit being greater than the set positive hysteresis comparison voltage threshold is accumulated to obtain the accumulated value of the count value of the compensation signal from the power input side of the air conditioner outdoor unit being greater than the set positive hysteresis comparison voltage threshold, which is recorded as the hysteresis comparison accumulation value from the power input side of the air conditioner outdoor unit; if it is determined that the compensation signal from the power input side of the air conditioner outdoor unit is not greater than the set positive hysteresis comparison voltage threshold, then if the hysteresis comparison accumulation value from the power input side of the air conditioner outdoor unit is not 0, then... If the compensation signal at the power input side of the air conditioner outdoor unit is less than the negative value of the set positive threshold for hysteresis comparison voltage, then if it is determined that the compensation signal at the power input side of the air conditioner outdoor unit is not less than the negative value of the set positive threshold for hysteresis comparison voltage, then the accumulated value of the hysteresis comparison at the power input side of the air conditioner outdoor unit continues to be accumulated; if it is determined that the compensation signal at the power input side of the air conditioner outdoor unit is less than the negative value of the set positive threshold for hysteresis comparison voltage, then the set maximum accumulated value of hysteresis comparison is made equal to the accumulated value of the hysteresis comparison at the power input side of the air conditioner outdoor unit, and then the accumulated value of the hysteresis comparison at the power input side of the air conditioner outdoor unit is cleared to zero; based on the set maximum accumulated value of hysteresis comparison and the set sampling period, the resonant frequency at which voltage resonance occurs at the power input side of the air conditioner outdoor unit is determined, and recorded as the resonant frequency of the power input side of the air conditioner outdoor unit; furthermore, based on the set sampling period and the resonant frequency of the power input side of the air conditioner outdoor unit, the hysteresis parameters of the PFC circuit controller in digital control are determined.

[0018] In some embodiments, the control unit adjusts the hysteresis parameter of the PFC circuit controller in digital control based on a set maximum hysteresis comparison accumulation value and the maximum resonant voltage detection value of the air conditioner outdoor unit power input side. This adjustment value of the hysteresis parameter of the PFC circuit controller in digital control is used as the phase adjustment value of the compensation signal on the air conditioner outdoor unit power input side. This includes: determining the maximum resonant voltage detection value of the air conditioner outdoor unit power input side sampled in the current sampling period and the maximum resonant voltage detection value of the air conditioner outdoor unit power input side sampled in the previous sampling period, based on the maximum resonant voltage detection values ​​of the air conditioner outdoor unit power input side sampled in two adjacent sampling periods. The difference in the resonant voltage detection values ​​is recorded as the difference in the maximum resonant voltage detection values ​​on the power input side of the air conditioner outdoor unit. It is determined whether the difference in the maximum resonant voltage detection values ​​on the power input side of the air conditioner outdoor unit is greater than or equal to the set phase adjustment sensitivity. If it is determined that the difference in the maximum resonant voltage detection values ​​on the power input side of the air conditioner outdoor unit is greater than or equal to the set phase adjustment sensitivity, then it is determined whether the phase adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is negative. If so, the hysteresis parameter of the PFC circuit controller in digital control is increased according to the set cycle value, and the phase adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is made positive. Otherwise, the hysteresis parameter of the PFC circuit controller is increased according to the set cycle value. The hysteresis parameter of the PFC circuit controller in digital control is reduced, and the phase adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is made negative. If it is determined that the difference in the maximum resonant voltage detection value on the power input side of the air conditioner outdoor unit is less than the set phase adjustment sensitivity, then if the difference in the maximum resonant voltage detection value on the power input side of the air conditioner outdoor unit is less than or equal to the negative value of the set phase adjustment sensitivity, it is determined whether the phase adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is negative. If so, the hysteresis parameter of the PFC circuit controller in digital control is reduced according to the set beat value, and the phase adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is made negative. If the value is negative, then according to the set cycle value, the hysteresis parameter of the PFC circuit controller in digital control is increased, and the phase adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is made positive; determine whether the hysteresis parameter of the PFC circuit controller in digital control is 0: if yes, then the hysteresis parameter of the PFC circuit controller in digital control is made 0; otherwise, the hysteresis parameter of the PFC circuit controller in digital control is made to be a set coefficient multiple of the set maximum hysteresis comparison accumulation value, so as to obtain the adjustment value of the hysteresis parameter of the PFC circuit controller in digital control, which is used as the phase adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit.

[0019] In some embodiments, the control unit determines the amplitude gain adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit based on the detected maximum resonant voltage value on the power input side of the air conditioner outdoor unit. This includes: for the detected maximum resonant voltage values ​​on the power input side of the air conditioner outdoor unit sampled in two adjacent sampling periods, determining the difference between the detected maximum resonant voltage value on the power input side of the air conditioner outdoor unit sampled in the current sampling period and the detected maximum resonant voltage value on the power input side of the air conditioner outdoor unit sampled in the previous sampling period, and recording this difference as the difference in the detected maximum resonant voltage value on the power input side of the air conditioner outdoor unit; and determining the maximum resonant voltage detection value on the power input side of the air conditioner outdoor unit. The system checks whether the difference in amplitude gain is greater than or equal to the set amplitude gain adjustment sensitivity. If the difference in amplitude gain is greater than or equal to the set amplitude gain adjustment sensitivity, the system checks whether the amplitude gain adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is negative. If yes, the system increases the current amplitude gain of the PFC circuit controller by the set gain adjustment step size and makes the amplitude gain adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit positive. Otherwise, the system decreases the current amplitude gain of the PFC circuit controller by the set gain adjustment step size and makes the amplitude gain adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit positive. The amplitude gain adjustment direction of the compensation signal is negative. If it is determined that the difference in the maximum resonant voltage detection value on the power input side of the air conditioner outdoor unit is less than the set amplitude gain adjustment sensitivity, then if the difference in the maximum resonant voltage detection value on the power input side of the air conditioner outdoor unit is less than or equal to the negative value of the set amplitude gain adjustment sensitivity, it is determined whether the amplitude gain adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is negative: if yes, then the current amplitude gain of the controller of the PFC circuit is reduced according to the set gain adjustment step size, and the amplitude gain adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is made negative; otherwise, then according to the set gain adjustment step size, The current amplitude gain of the PFC circuit controller is increased, and the amplitude gain adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is made positive. It is then determined whether the current amplitude gain of the PFC circuit controller is 0: if so, the current amplitude gain of the PFC circuit controller is set to 0; otherwise, if the current amplitude gain of the PFC circuit controller is greater than the set maximum amplitude gain, the current amplitude gain of the PFC circuit controller is set to the set maximum amplitude gain, thus obtaining the adjustment value of the current amplitude gain of the PFC circuit controller, which is used as the amplitude gain adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit.

[0020] In some embodiments, the control unit adjusts the phase of the compensation signal at the power input side of the air conditioner outdoor unit by a phase adjustment value and / or adjusts the amplitude gain of the compensation signal at the power input side of the air conditioner outdoor unit by an amplitude gain adjustment value to obtain the compensation duty cycle of the current loop of the PFC circuit. This includes: adjusting the phase of the compensation signal at the power input side of the air conditioner outdoor unit by a fixed phase of the controller of the PFC circuit, and then adjusting the amplitude gain of the compensation signal at the power input side of the air conditioner outdoor unit by an amplitude gain adjustment value to obtain the compensation duty cycle of the current loop of the PFC circuit; or, adjusting the compensation signal at the power input side of the air conditioner outdoor unit by a phase adjustment value and / or adjusting the amplitude gain of ... After phase adjustment of the compensation signal's phase adjustment value, and then amplitude gain adjustment of the fixed amplitude gain of the PFC circuit's controller, the compensation duty cycle of the PFC circuit's current loop is obtained; or, the compensation signal on the power input side of the air conditioner's outdoor unit is phase adjusted by the phase adjustment value of the compensation signal on the power input side of the air conditioner's outdoor unit, and then amplitude gain adjustment of the compensation signal on the power input side of the air conditioner's outdoor unit, to obtain the compensation duty cycle of the PFC circuit's current loop; wherein, the phase adjustment value of the compensation signal on the power input side of the air conditioner's outdoor unit is determined within a first set time period; and the amplitude gain adjustment value of the compensation signal on the power input side of the air conditioner's outdoor unit is determined within a second set time period.

[0021] In conjunction with the above-mentioned device, the present invention further provides an air conditioner, including: the power supply control device for the outdoor unit of the air conditioner described above.

[0022] In conjunction with the above method, the present invention further provides a storage medium comprising a stored program, wherein, when the program is executed, the device containing the storage medium is controlled to perform the power supply control method for the outdoor unit of an air conditioner described above.

[0023] Therefore, the solution of this invention, targeting the power input side of the outdoor unit of an air conditioner (such as an inverter air conditioner) and the PFC circuit, involves the AC power input terminals (such as N terminals and L terminals) sequentially passing through a first capacitor module (such as capacitor C1), a first inductor module (such as inductor L1), a second capacitor module (such as capacitor C2), an uncontrolled rectifier module (such as a rectifier bridge DB1 composed of diodes), and a third capacitor module (such as capacitor C3), before being output to the bus capacitor module (such as capacitor C4) after passing through the PFC circuit. The PFC circuit includes a second inductor module (such as inductor L2), a diode module (such as diode D1), and a switching transistor module (such as switching transistor G1). A sampling resistor module (such as sampling resistor RS1) is connected between the end of the third capacitor module furthest from the second inductor module and the emitter of the switching transistor module. During the operation of the outdoor unit of the air conditioner (such as an inverter air conditioner), the voltage across the third capacitor module is sampled at a set time interval ΔT as the detection period to obtain the voltage sampling. The voltage sampling signal is low-pass filtered to obtain a voltage low-pass filtered signal. When the difference between the voltage sampling signal of the current cycle and the voltage sampling signal of the previous cycle in two adjacent cycles is greater than or equal to the set resonant voltage detection threshold, it is considered that the power input side of the outdoor unit of the air conditioner (such as an inverter air conditioner) is in a voltage resonance state. At this time, the resonant signal component is extracted from the difference between the voltage sampling signal and the voltage low-pass filtered signal as a compensation signal for voltage resonance suppression. After phase adjustment and / or gain adjustment of the compensation signal for voltage resonance suppression, the compensation duty cycle is obtained. The compensation duty cycle is introduced into the current loop control of the PFC circuit. Thus, when voltage resonance occurs on the power input side of the inverter air conditioner outdoor unit, its resonance amplitude can be suppressed within a small controllable range without reducing the power factor or increasing the current harmonic content, thereby improving the reliability of the inverter air conditioner operation and the user experience.

[0024] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention.

[0025] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0026] Figure 1 This is a flowchart illustrating an embodiment of the power supply control method for an air conditioner outdoor unit according to the present invention.

[0027] Figure 2 This is a flowchart illustrating an embodiment of the method of the present invention for determining whether the power input side of the outdoor unit of the air conditioner is in a state of voltage resonance based on the voltage sampling signal;

[0028] Figure 3This is a flowchart illustrating an embodiment of the method of the present invention for determining whether the power input side of the air conditioner outdoor unit is in a state of voltage resonance based on the cumulative value of the number of voltage oscillations;

[0029] Figure 4 This is a flowchart illustrating an embodiment of the method of the present invention for determining the compensation duty cycle of the current loop of the PFC circuit.

[0030] Figure 5 This is a flowchart illustrating an embodiment of the method of the present invention for determining the set maximum hysteresis comparison accumulation value and the hysteresis parameter of the controller of the PFC circuit in digital control based on the compensation signal.

[0031] Figure 6 This is a flowchart illustrating an embodiment of the method of the present invention for determining the phase adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit;

[0032] Figure 7 This is a flowchart illustrating an embodiment of the method of the present invention for determining the amplitude gain adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit;

[0033] Figure 8 This is a schematic diagram of a structure of an embodiment of the power supply control device for the outdoor unit of an air conditioner according to the present invention;

[0034] Figure 9 A schematic diagram of an embodiment of the power input side and PFC circuit of an outdoor unit of a variable frequency air conditioner;

[0035] Figure 10 A schematic flowchart illustrating an embodiment of a voltage resonance detection and suppression method for an outdoor unit of a variable frequency air conditioner;

[0036] Figure 11 This is a schematic diagram of the curve between voltage sampling time and voltage.

[0037] Figure 12 Table for calculating resonance detection parameters;

[0038] Figure 13 This is a schematic diagram of the voltage sampling signal change curve during the PFC startup process;

[0039] Figure 14 This is a schematic diagram of the voltage resonance detection process;

[0040] Figure 15 This is a schematic diagram of the resonance compensation curve, where, Figure 15 Figure a shows a schematic diagram of the uncompensated resonant voltage curve. Figure 15 Figure b in the middle is a schematic diagram of the compensation signal curve without phase shift. Figure 15 Figure c in the middle is a schematic diagram of the compensated signal curve after phase shifting;

[0041] Figure 16 This is a schematic diagram of the resonant frequency detection process;

[0042] Figure 17 This is a schematic diagram of the phase compensation adaptive adjustment process;

[0043] Figure 18 A schematic diagram of the adaptive adjustment process for compensating for amplitude gain;

[0044] Figure 19 To introduce the current loop control block diagram for the compensation stage;

[0045] Figure 20 This is a schematic diagram of the measured voltage resonance waveform;

[0046] Figure 21 A schematic diagram of the actual test waveform after compensation is introduced.

[0047] Referring to the accompanying drawings, the reference numerals in the embodiments of the present invention are as follows:

[0048] 102 - Acquisition unit; 104 - Control unit. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0050] Considering that when the peak resonant voltage on the power input side of the outdoor unit of an air conditioner (such as an inverter air conditioner) is too high, it will cause the DC bus voltage of the indoor unit after uncontrolled rectification to be too high, which will lead to problems such as the indoor unit resetting under excessively high voltage, thus affecting the reliability of the inverter air conditioner and the user experience.

[0051] Figure 9 A schematic diagram of an embodiment of the power input side and PFC circuit of an inverter air conditioner outdoor unit. Figure 9As shown, the power input side and PFC (Power Factor Correction) circuit of the inverter air conditioner outdoor unit include: capacitors C1, C2, C3, and C4; inductors L1 and L2; rectifier bridge DB1; switching transistor G1; diode D1; and sampling resistor RS1. The live wire input terminal (L terminal) and neutral wire input terminal (N terminal) of the AC power supply constitute the power input side of the inverter air conditioner outdoor unit. The L terminal is connected to the N terminal via capacitor C1. The L terminal is also connected to the same-name terminal of the first coil of inductor L1, and the N terminal is also connected to the same-name terminal of the second coil of inductor L1. The opposite-name terminal of the first coil of inductor L1 is connected to the opposite-name terminal of the second coil of inductor L1 via capacitor C2. The opposite-name terminal of the first coil of inductor L1 is also connected to the first connection terminal of the input side of rectifier bridge DB1; the opposite-name terminal of the second coil of inductor L1 is also connected to the second connection terminal of the input side of rectifier bridge DB1. The first terminal on the output side of rectifier bridge DB1 is connected to the second terminal on the output side of rectifier bridge DB1 via capacitor C3. The first terminal on the output side of rectifier bridge DB1 is also connected to the collector C of switching transistor G1 via inductor L2. The emitter E of switching transistor G1 is grounded to GND. Sampling resistor RS1 is connected between the second terminal on the output side of rectifier bridge DB1 and the emitter E of switching transistor G1. The first terminal on the output side of rectifier bridge DB1 is also connected to the anode of diode D1. The cathode of diode D1 is connected to the positive terminal of capacitor C4. The negative terminal of capacitor C4 is grounded to GND.

[0052] like Figure 9 As shown, when the power input side of the inverter air conditioner outdoor unit (i.e. Figure 9 The L and N terminals in the circuit are inductive, and when the PFC circuit is in operation, the current loop control in the PFC control loop will generate an oscillation excitation source, inducing an oscillation on the power input side of the inverter air conditioner outdoor unit. Figure 9 The equivalent inductance between the L and N terminals and the X capacitor (in the figure) Figure 9 (Capacitors C1 and C2). In Figure 9 A voltage resonance occurs between the L and N terminals. The closer the frequency of the oscillation excitation source is to the power input side of the inverter air conditioner outdoor unit (… Figure 9 The equivalent inductance between the L and N terminals and the X capacitor (in the figure) Figure 9 The greater the resonant frequency of capacitors C1 and C2, the larger the resonant amplitude. (This refers to the power input side of the inverter air conditioner outdoor unit.) Figure 9 The equivalent inductance between the L and N terminals varies with the grid-side load, therefore the actual input inductance (between the L and N terminals) varies with the grid-side load. Figure 9 The equivalent inductance between the L and N terminals and the X capacitor (in the figure) Figure 9 The resonant frequencies of capacitors C1 and C2 also change with the grid-side load.

[0053] In relevant solutions, there are generally two approaches to solving voltage resonance in actual product development: increasing the X capacitor ( Figure 9 Reducing the capacitance values ​​of capacitors C1 and C2 to lower the voltage resonance peak is ineffective and increases hardware costs. Reducing the current loop gain in the PFC control loop can only reduce the voltage resonance peak within a limited range, and it will also reduce the power factor and increase the current harmonic content.

[0054] Therefore, the present invention proposes a power supply control method for an air conditioner outdoor unit, specifically a voltage resonance detection and suppression method for a variable frequency air conditioner outdoor unit. This method determines whether the power input side of the variable frequency air conditioner outdoor unit is in a voltage resonance state based on the rate of change of the rising edge of the AC voltage on the power input side. When the maximum number of periods with a rising edge change greater than a preset value exceeds an upper limit, the power input side of the variable frequency air conditioner outdoor unit is considered to be in a voltage resonance state. When the power input side of the variable frequency air conditioner outdoor unit is in a voltage resonance state, the resonance signal component is extracted by subtracting the original sampled signal of the voltage across capacitor C3 from the low-pass filtered signal. The compensation signal is corrected through phase adaptive adjustment and amplitude gain adaptive adjustment. The corrected signal is then introduced into the current loop feedforward control stage to suppress voltage resonance on the power input side of the inverter air conditioner outdoor unit. When voltage resonance occurs on the power input side of the inverter air conditioner outdoor unit, its resonance amplitude can be suppressed within a small controllable range without reducing the power factor or increasing the current harmonic content. This avoids problems such as excessively high DC bus voltage after uncontrolled rectification of the indoor unit due to excessively high peak resonant voltage on the power input side of the inverter air conditioner outdoor unit, which could lead to the indoor unit resetting under excessively high voltage. This improves the reliability of air conditioner operation and enhances the user experience.

[0055] According to an embodiment of the present invention, a power supply control method for an air conditioner outdoor unit is provided, such as... Figure 1 The diagram shows a flowchart of an embodiment of the method of the present invention. In the power supply circuit of the outdoor unit of the air conditioner, the AC power from the power input side of the outdoor unit passes sequentially through a first filter unit, a rectifier unit, a second filter unit, and a PFC circuit before being output to the DC bus; the first filter unit may consist of an X capacitor, etc. Figure 9 The capacitor C1 and common-mode inductor shown are as follows: Figure 9 The inductor L1 and capacitor X shown are as follows: Figure 9 The π-type filter formed by capacitor C2 shown has a second filtering unit as follows: Figure 9 The capacitor C3 shown has a DC bus as shown. Figure 9 The busbar connected to capacitor C4 as shown; in the embodiment of the present invention, as... Figure 1 As shown, the power supply control method for the outdoor unit of the air conditioner includes steps S110 to S140.

[0056] In step S110, during the operation of the outdoor unit of the air conditioner, the voltage across the second filter unit is acquired according to a set sampling period, such as a set time interval ΔT, to obtain the voltage sampling signal of the power input side of the outdoor unit of the air conditioner. For example, the voltage across capacitor C3 can accurately reflect the voltage across capacitor X ( Figure 9 Voltage u across capacitors C1 and C2 i After filtering the voltage sampling signal from the power input side of the air conditioner outdoor unit within a set frequency range, a low-pass filtered voltage signal from the power input side of the air conditioner outdoor unit is obtained. For example, the voltage sampling signal u... i After performing a 1kHz low-pass filter, the smoothed resonant voltage low-pass filtered signal u is obtained. iLPF ; and if it is determined that the power input side of the air conditioner outdoor unit is in a state of voltage resonance, obtain the maximum resonant voltage detection value of the power input side of the air conditioner outdoor unit, such as obtaining the maximum resonant voltage detection value ΔV. max .

[0057] Specifically, during the operation of the outdoor unit of a variable frequency air conditioner, a voltage sampling circuit (such as a sampling circuit composed of voltage divider resistors) is used to... Figure 9 The voltage across capacitor C3 is sampled. When the PFC circuit is in operation, the voltage across capacitor C3 accurately reflects the voltage across capacitor X. Figure 9 The voltage across capacitors C1 and C2 is denoted as u. i Since the resonant frequency is generally greater than 1kHz, the voltage sampling signal u... i Perform a 1kHz low-pass filter (the filter bandwidth can be adjusted according to the actual circuit conditions) to obtain the smoothed resonant voltage low-pass filtered signal u. iLPF .

[0058] In step S120, based on the voltage sampling signal of the power input side of the air conditioner outdoor unit, it is determined whether the power input side of the air conditioner outdoor unit is in a voltage resonance state. Specifically, Figure 10 This is a schematic flowchart illustrating an embodiment of a method for detecting and suppressing voltage resonance in the outdoor unit of a variable frequency air conditioner. Figure 10 As shown, the method for detecting and suppressing voltage resonance in the outdoor unit of a variable frequency air conditioner includes: Step 11: During the operation of the outdoor unit, the voltage resonance state on the power input side of the outdoor unit is detected to determine whether the power input side is in a voltage resonance state; if so, step 12 is executed to extract the voltage resonance compensation signal; otherwise, the process ends. Specifically, in step 11, the voltage resonance detection method and the basis for determining its detection parameters can be found in the following exemplary description.

[0059] Figure 11 This is a schematic diagram showing the relationship between voltage sampling time and voltage. From Figure 11It can be seen that during normal operation (without voltage resonance), the largest difference between two adjacent voltage samples (i.e., the largest voltage slope) occurs at the voltage zero-crossing point. Let the effective value of the AC voltage be U, the frequency be f, the detection time interval be ΔT, and the maximum difference between adjacent voltage samples be Um, then:

[0060]

[0061] Figure 12 A table for calculating resonance detection parameters is provided. Taking a PFC algorithm interrupt execution cycle ΔT = 50µs as an example, the power supply range for inverter air conditioners is generally 130-265V, 50 / 60Hz. The maximum difference between adjacent voltage samples under different power supply voltages and frequencies is theoretically calculated using the above formula, and the results are as follows: Figure 12 As shown. From Figure 12 Theoretical calculations show that, under a power supply with an effective AC voltage of 300V and a frequency of 100Hz, the maximum difference between two adjacent AC voltage samples does not exceed 14V. Actual sampling is affected by filtering devices and zero-crossing clamping, so this value will be even lower.

[0062] Figure 13 This is a schematic diagram of the voltage sampling signal change curve during the PFC startup process. When the power input side of the inverter air conditioner outdoor unit ( Figure 9 When voltage resonance occurs between the L and N terminals (in the circuit), the difference between two adjacent AC voltage samples can be much greater than 14V. Considering the voltage sampling signal waveform during the initial PFC activation phase, as shown below... Figure 13 As shown, there may be cases where the voltage slope is too large. To avoid false detection, only the voltage sample value during the rising edge stage is judged.

[0063] In some embodiments, the specific process of determining whether the power input side of the air conditioner is in a voltage resonance state based on the voltage sampling signal of the power input side of the air conditioner outdoor unit in step S120 is illustrated in the following exemplary description.

[0064] The following is combined with Figure 2 The flowchart shown is a schematic diagram of an embodiment of the method of the present invention for determining whether the power input side of the air conditioner outdoor unit is in a voltage resonance state based on the voltage sampling signal. The specific process of determining whether the power input side of the air conditioner outdoor unit is in a voltage resonance state based on the voltage sampling signal in step S120 is further explained, including steps S210 to S240.

[0065] Step S210: According to the set resonance detection period, under the current resonance detection period, for the voltage sampling signals of the power input side of the air conditioner outdoor unit sampled in the current sampling period and the voltage sampling signals of the power input side of the air conditioner outdoor unit sampled in the previous sampling period, determine the difference between the voltage sampling signals of the power input side of the air conditioner outdoor unit sampled in the current sampling period and the voltage sampling signals of the power input side of the air conditioner outdoor unit sampled in the previous sampling period, and record it as the voltage sampling signal difference of the power input side of the air conditioner outdoor unit in the two adjacent periods; wherein, the set resonance detection period is greater than the set sampling period.

[0066] Step S220: Under the current resonance detection cycle, determine whether the voltage sampling signal difference between the power input side of the air conditioner outdoor unit in two adjacent sampling cycles is greater than the set resonance voltage detection threshold.

[0067] Step S230: In the current resonance detection period, if it is determined that the voltage sampling signal difference between the power input side of the air conditioner outdoor unit in two adjacent sampling periods is greater than the set resonance voltage detection threshold, then it is determined that the AC voltage on the power input side of the air conditioner outdoor unit oscillates. The number of times the AC voltage on the power input side of the air conditioner outdoor unit oscillates is accumulated to obtain the accumulated value of the voltage oscillation count on the power input side of the air conditioner outdoor unit.

[0068] Step S240: Under the current resonance detection period, determine whether the power input side of the air conditioner outdoor unit is in a voltage resonance state based on the cumulative value of the voltage oscillation count on the power input side of the air conditioner outdoor unit.

[0069] Specifically, Figure 14 This is a schematic diagram of the voltage resonance detection process. Figure 14 In the definition, the resonance detection parameter is: the resonance voltage detection threshold ΔV. th oscillation threshold N th .like Figure 14 As shown, the voltage resonance detection process includes:

[0070] Step 21: Update the voltage sampling signal u1(i-1) = u1(i) of the previous cycle, and then execute step 22.

[0071] Step 22: Update the voltage sampling signal u1(i) = u1 for the current cycle, and then execute step 23.

[0072] Step 23: In each PFC algorithm cycle (e.g., ΔT), calculate the difference u1(i) - u1(i-1) between the current voltage sample value u1(i) and the voltage sample value u1(i-1) of the previous cycle, and determine whether the difference u1(i) - u1(i-1) between the current voltage sample value u1(i) and the voltage sample value u1(i-1) of the previous cycle is greater than the resonant voltage detection threshold ΔV. thIf the condition is met, proceed to step 24; otherwise, proceed to step 25.

[0073] Step 24: If the difference between the current voltage sample value u1(i) and the voltage sample value u1(i-1) of the previous cycle, u1(i)-u1(i-1), is greater than the resonant voltage detection threshold ΔV th The number of oscillations N in the AC voltage is accumulated, i.e., let N = N + 1; then it is determined whether the accumulated value of the number of oscillations N within a certain detection period reaches a value greater than or equal to the oscillation number threshold N. th .

[0074] In some implementations, the specific process of determining whether the power input side of the air conditioner outdoor unit is in a voltage resonance state based on the cumulative value of the number of voltage oscillations on the power input side of the air conditioner outdoor unit during the current resonance detection cycle in step S240 is illustrated in the following exemplary description.

[0075] The following is combined with Figure 3 The flowchart shown is a schematic diagram of an embodiment of the method of the present invention for determining whether the power input side of the air conditioner outdoor unit is in a voltage resonance state based on the cumulative value of the number of voltage oscillations. The specific process of determining whether the power input side of the air conditioner outdoor unit is in a voltage resonance state based on the cumulative value of the number of voltage oscillations in step S240 is further explained, including steps S310 to S350.

[0076] Step S310: Under the current resonance detection period, determine whether the accumulated value of the voltage oscillation count on the power input side of the air conditioner outdoor unit has accumulated to a value greater than or equal to the set oscillation count threshold.

[0077] Step S320: In the current resonance detection cycle, if it is determined that the cumulative value of the voltage oscillation count on the power input side of the air conditioner outdoor unit has accumulated to a value greater than or equal to the set oscillation count threshold, then it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state in the current resonance detection cycle.

[0078] Step S330: In the current resonance detection cycle, if it is determined that the cumulative value of the voltage oscillation count on the power input side of the air conditioner outdoor unit has not accumulated to a value greater than or equal to the set oscillation count threshold, then it is determined whether the current resonance detection cycle has ended, or whether to enter the next resonance detection cycle.

[0079] Step S340: In the current resonance detection cycle, if it is determined that the cumulative value of the voltage oscillation count on the power input side of the air conditioner outdoor unit has not accumulated to a value greater than or equal to the set oscillation count threshold, and if it is determined that the current resonance detection cycle has ended or that the next resonance detection cycle has begun, then it is determined that the power input side of the air conditioner outdoor unit is not in a voltage resonance state in the current resonance detection cycle, and the cumulative value of the voltage oscillation count on the power input side of the air conditioner outdoor unit is cleared to zero.

[0080] Step S350: In the current resonance detection cycle, if it is determined that the cumulative value of the voltage oscillation count on the power input side of the air conditioner outdoor unit has not accumulated to a value greater than or equal to the set oscillation count threshold, and if it is determined that the current resonance detection cycle has not ended and the next resonance detection cycle has not been entered, then return to continue to determine whether the voltage sampling signal difference on the power input side of the air conditioner outdoor unit in two adjacent sampling cycles is greater than the set resonance voltage detection threshold in the current resonance detection cycle.

[0081] Specifically, such as Figure 14 As shown, the voltage resonance detection process further includes: in step 24, after accumulating N = N + 1, determining whether the accumulated value of the number of oscillations N within a certain detection period reaches a threshold value N that is greater than or equal to the number of oscillations. th If so, the power input side of the inverter air conditioner outdoor unit enters a resonant state, that is, when the cumulative value of the oscillation number N within a certain detection period reaches a value greater than or equal to the oscillation number threshold N. th If the AC voltage is in a resonant state, then the AC voltage is considered to be in a resonant state; otherwise, proceed to step 25.

[0082] Step 25: If the difference between the current voltage sample value u1(i) and the voltage sample value u1(i-1) of the previous cycle, u1(i)-u1(i-1), is less than or equal to the resonant voltage detection threshold ΔV th If a new resonance detection cycle has begun, the system will determine whether it has entered a new cycle. If so, the power input side of the inverter air conditioner outdoor unit will exit the resonance state, and the accumulated value of the oscillation count N will be cleared to zero. Otherwise, the process will end. The accumulated value of the oscillation count N will be cleared to zero each time a new detection cycle begins.

[0083] Among them, Figure 12 In the example shown, theoretical calculations show that, with an AC voltage RMS of 300V and a frequency of 100Hz, the maximum difference between two adjacent AC voltage samples does not exceed 14V. Therefore, the resonant voltage detection threshold ΔV is... th Only a voltage greater than 14V with a certain margin is required; the threshold for the number of oscillations is N. th The detection sensitivity can be adjusted according to the actual situation.

[0084] In step S130, if it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, then the compensation duty cycle of the current loop of the PFC circuit is determined based on the voltage sampling signal of the power input side of the air conditioner outdoor unit, the voltage low-pass filter signal of the power input side of the air conditioner outdoor unit, and the maximum resonance voltage detection value of the power input side of the air conditioner outdoor unit. For example, the compensation duty cycle d2.

[0085] In some implementations, in step S130, when it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, the specific process of determining the compensation duty cycle of the current loop of the PFC circuit based on the voltage sampling signal of the power input side of the air conditioner outdoor unit, the voltage low-pass filter signal of the power input side of the air conditioner outdoor unit, and the maximum resonance voltage detection value of the power input side of the air conditioner outdoor unit is described in the following exemplary description.

[0086] The following is combined with Figure 4 The flowchart shown is a schematic diagram of an embodiment of the method of the present invention for determining the compensation duty cycle of the current loop of the PFC circuit. It further illustrates the specific process of determining the compensation duty cycle of the current loop of the PFC circuit in step S130, including steps S410 to S460.

[0087] Step S410: If it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, the difference between the voltage sampling signal of the power input side of the air conditioner outdoor unit and the voltage low-pass filtered signal of the power input side of the air conditioner outdoor unit is determined and recorded as the voltage signal difference of the power input side of the air conditioner outdoor unit.

[0088] Step S420: If it is determined that the power input side of the air conditioner outdoor unit is in a state of voltage resonance, the resonance signal component is extracted from the voltage signal difference of the power input side of the air conditioner outdoor unit as a compensation signal to suppress the voltage resonance of the power input side of the air conditioner outdoor unit, denoted as the compensation signal of the power input side of the air conditioner outdoor unit. Specifically, as... Figure 10 As shown, the method for detecting and suppressing voltage resonance in the outdoor unit of a variable frequency air conditioner, after step 11, further includes: step 12, when voltage resonance is detected on the power input side of the outdoor unit of the variable frequency air conditioner, firstly extracting the voltage resonance compensation signal, and then executing step 13. Specifically, in step 12, the extraction and compensation method of the compensation signal can be found in the following exemplary description.

[0089] When the power input side of the inverter air conditioner outdoor unit is detected ( Figure 9 When voltage resonance occurs between the L and N terminals, a voltage signal u is introduced. comp As a compensation signal for voltage resonance suppression. Wherein:

[0090] u comp =ui -u iLPF .

[0091] Among them, u i It is a voltage sampling signal, specifically Figure 9 The voltage across capacitor C3; u iLPF Voltage sampling signal u i The voltage low-pass filtered signal after low-pass filtering; u comp This is a compensation signal for voltage resonance suppression.

[0092] Step S430: When it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, the maximum hysteresis comparison accumulation value is determined according to the compensation signal of the power input side of the air conditioner outdoor unit, and the hysteresis parameter of the PFC circuit controller in digital control is determined, such as the hysteresis parameter n in the main chip digital control.

[0093] In some implementations, the specific process of determining the maximum hysteresis comparison accumulation value and the hysteresis parameter of the PFC circuit controller in digital control based on the compensation signal of the power input side of the air conditioner outdoor unit after determining that the power input side of the air conditioner outdoor unit is in a voltage resonance state in step S430 is described in the following exemplary description.

[0094] The following is combined with Figure 5 The flowchart shown is a schematic diagram of an embodiment of the method of the present invention for determining the set maximum hysteresis comparison accumulation value and the hysteresis parameter of the PFC circuit controller in digital control based on the compensation signal. It further illustrates the specific process of determining the set maximum hysteresis comparison accumulation value and the hysteresis parameter of the PFC circuit controller in digital control based on the compensation signal in step S430, including steps S510 to S560.

[0095] Step S510: If it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, determine whether the compensation signal of the power input side of the air conditioner outdoor unit is greater than the set positive threshold of hysteresis comparison voltage.

[0096] Step S520: If it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, and if it is determined that the compensation signal of the power input side of the air conditioner outdoor unit is greater than the set positive threshold of hysteresis comparison voltage, then the count value of the compensation signal of the power input side of the air conditioner outdoor unit being greater than the set positive threshold of hysteresis comparison voltage is accumulated to obtain the accumulated value of the count value of the compensation signal of the power input side of the air conditioner outdoor unit being greater than the set positive threshold of hysteresis comparison voltage, which is recorded as the hysteresis comparison accumulated value of the power input side of the air conditioner outdoor unit.

[0097] Step S530: If it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, and if it is determined that the compensation signal of the power input side of the air conditioner outdoor unit is not greater than the set positive threshold of hysteresis comparison voltage, then if the accumulated value of hysteresis comparison on the power input side of the air conditioner outdoor unit is not 0, determine whether the compensation signal of the power input side of the air conditioner outdoor unit is less than the negative value of the set positive threshold of hysteresis comparison voltage.

[0098] Step S540: If it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, and if it is determined that the compensation signal of the power input side of the air conditioner outdoor unit is not greater than the set positive threshold of hysteresis comparison voltage and the accumulated value of hysteresis comparison on the power input side of the air conditioner outdoor unit is not 0, and if it is determined that the compensation signal of the power input side of the air conditioner outdoor unit is not less than the negative value of the set positive threshold of hysteresis comparison voltage, then the accumulated value of hysteresis comparison on the power input side of the air conditioner outdoor unit continues to be accumulated.

[0099] Step S550: If it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, and if it is determined that the compensation signal of the power input side of the air conditioner outdoor unit is not greater than the set positive threshold of hysteresis comparison voltage and the accumulated value of hysteresis comparison on the power input side of the air conditioner outdoor unit is not 0, if it is determined that the compensation signal of the power input side of the air conditioner outdoor unit is less than the negative value of the set positive threshold of hysteresis comparison voltage, then the set maximum accumulated value of hysteresis comparison is equal to the accumulated value of hysteresis comparison on the power input side of the air conditioner outdoor unit, and then the accumulated value of hysteresis comparison on the power input side of the air conditioner outdoor unit is cleared to zero.

[0100] Step S560: If it is determined that the power input side of the air conditioner outdoor unit is in a state of voltage resonance, the resonant frequency at which voltage resonance occurs on the power input side of the air conditioner outdoor unit is determined based on the set maximum hysteresis comparison accumulation value and the set sampling period, such as the resonant frequency f. o Let be the resonant frequency of the power input side of the outdoor unit of the air conditioner; then, based on the set sampling period and the resonant frequency of the power input side of the outdoor unit of the air conditioner, determine the hysteresis parameter of the controller of the PFC circuit in digital control.

[0101] Specifically, such as Figure 10 As shown, the method for detecting and suppressing voltage resonance in the outdoor unit of a variable frequency air conditioner further includes, after step 12, the process of determining the resonant frequency and determining the hysteresis parameter n in the digital control of the main chip of the PFC circuit, as illustrated in the following exemplary description.

[0102] Figure 15 This is a schematic diagram of the resonance compensation curve. (Example) Figure 15As shown, theoretically, the optimal compensation method is to compensate for a positive duty cycle at the rising edge of the resonant voltage, with the absolute value of the compensation being the largest at the point of maximum slope; and to compensate for a negative duty cycle at the falling edge of the resonant voltage, with the absolute value of the compensation being the largest at the point of maximum slope. Since the voltage sampling port has a hardware filtering circuit, and the signal transmission and processing in the main chip have a delay, the compensation signal inherently has a hysteresis phase. Figure 15 The curve shown in Figure b is the compensation signal u. comp The curve shown in Figure c is the compensation signal after phase shifting.

[0103] from Figure 15 As shown in Figure b, the compensation curve crosses back and forth across the horizontal axis. The voltage resonant frequency can be calculated by detecting the frequency at which the compensation curve crosses zero. Figure 16 This is a schematic diagram of the resonant frequency detection process. To avoid false detections caused by sampling interference, a hysteresis comparison is introduced, such as... Figure 16 As shown. Figure 16 As shown, the resonant frequency detection process includes:

[0104] Step 31: Determine whether the compensation signal u is greater than the voltage resonance suppression requirement. comp Greater than the positive threshold voltage U of the hysteresis comparator T If yes, proceed to step 32; otherwise, proceed to step 33.

[0105] Step 32: When the compensation signal u for voltage resonance suppression... comp Greater than the positive threshold voltage U of the hysteresis comparator T At that time, the compensation signal u for voltage resonance suppression comp Greater than the positive threshold voltage U of the hysteresis comparator T The count value k is accumulated in each algorithm cycle, that is, let k = k + 1.

[0106] Step 33: When the compensation signal u for voltage resonance suppression... comp Not greater than the positive threshold voltage U of the hysteresis comparator T The compensation signal u for count value k≠0 and voltage resonance suppression. comp Not less than the negative threshold of the hysteresis comparator voltage -U T At that time, the count value k is accumulated in each algorithm cycle, that is, let k = k + 1.

[0107] When the compensation signal u for voltage resonance suppression comp Not greater than the positive threshold voltage U of the hysteresis comparator T The compensation signal u for count value k≠0 and voltage resonance suppression. comp Less than the negative threshold of the hysteresis comparator voltage -U T When the count value k is passed to the consecutive maximum count value k, the value of the count value k is passed to the consecutive maximum count value k. mSimultaneously, the count value k is reset to zero. Given that the PFC algorithm interrupt execution cycle is ΔT, the resonant frequency f... o for:

[0108]

[0109] Given the resonant frequency f o Compensation signal u for voltage resonance suppression comp The phase θ is discretized in the continuous time domain, and the hysteresis parameter n in the digital control of the main chip can be obtained:

[0110]

[0111] Step S440: After determining that the power input side of the air conditioner outdoor unit is in a voltage resonance state, based on the set maximum hysteresis comparison accumulation value and the maximum resonant voltage detection value of the power input side of the air conditioner outdoor unit, the hysteresis parameter of the PFC circuit controller in digital control is adjusted to obtain the adjustment value of the hysteresis parameter of the PFC circuit controller in digital control, which is used as the phase adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit. Specifically, as... Figure 10 As shown, the method for detecting and suppressing voltage resonance in the outdoor unit of a variable frequency air conditioner further includes: step 13, after extracting the voltage resonance compensation signal, adaptively adjusting the compensation phase of the voltage resonance compensation signal, and then executing step 14. And / or,

[0112] In some embodiments, in step S440, when it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, the hysteresis parameter of the PFC circuit controller in digital control is adjusted according to the set maximum hysteresis comparison accumulation value and the maximum resonance voltage detection value of the power input side of the air conditioner outdoor unit, so as to obtain the adjustment value of the hysteresis parameter of the PFC circuit controller in digital control, which is used as the phase adjustment value of the compensation signal of the power input side of the air conditioner outdoor unit. For the specific process, please refer to the following exemplary description.

[0113] The following is combined with Figure 6 The flowchart shown is a schematic diagram of an embodiment of the method of the present invention for determining the phase adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit. It further illustrates the specific process of determining the phase adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit in step S440, including steps S610 to S650.

[0114] Step S610: If it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, for the maximum resonance voltage detection value of the power input side of the air conditioner outdoor unit sampled in two adjacent sampling cycles, determine the difference between the maximum resonance voltage detection value of the power input side of the air conditioner outdoor unit sampled in the current sampling cycle and the maximum resonance voltage detection value of the power input side of the air conditioner outdoor unit sampled in the previous sampling cycle, and record it as the difference of the maximum resonance voltage detection value of the power input side of the air conditioner outdoor unit.

[0115] Step S620: If it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, determine whether the difference between the maximum resonant voltage detection values ​​on the power input side of the air conditioner outdoor unit and the set phase adjustment sensitivity. The set phase adjustment sensitivity may be the compensation signal u for voltage resonance suppression. comp The adjustment sensitivity ΔV1 of the phase θ.

[0116] Step S630: If it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, and if the difference in the maximum resonant voltage detection value of the power input side of the air conditioner outdoor unit is greater than or equal to the set phase adjustment sensitivity, then it is determined whether the phase adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is negative. If yes, then according to the set beat value, the hysteresis parameter of the PFC circuit controller in digital control is increased, and the phase adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is made positive. Otherwise, according to the set beat value, the hysteresis parameter of the PFC circuit controller in digital control is decreased, and the phase adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is made negative.

[0117] Step S640: If it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, and if it is determined that the difference in the maximum resonant voltage detection value of the power input side of the air conditioner outdoor unit is less than the set phase adjustment sensitivity, then if the difference in the maximum resonant voltage detection value of the power input side of the air conditioner outdoor unit is less than or equal to the negative value of the set phase adjustment sensitivity, determine whether the phase adjustment direction of the compensation signal of the power input side of the air conditioner outdoor unit is negative: if yes, then according to the set cycle value, decrease the hysteresis parameter of the PFC circuit controller in digital control, and make the phase adjustment direction of the compensation signal of the power input side of the air conditioner outdoor unit negative; otherwise, according to the set cycle value, increase the hysteresis parameter of the PFC circuit controller in digital control, and make the phase adjustment direction of the compensation signal of the power input side of the air conditioner outdoor unit positive. The set cycle value is, for example, 1.

[0118] Step S650: After determining that the power input side of the air conditioner outdoor unit is in a voltage resonance state, after increasing or / or decreasing the hysteresis parameter of the PFC circuit controller in digital control, determine whether the hysteresis parameter of the PFC circuit controller in digital control is 0. If yes, set the hysteresis parameter of the PFC circuit controller in digital control to 0; otherwise, set the hysteresis parameter of the PFC circuit controller in digital control to a set coefficient multiple of the maximum hysteresis comparison accumulation value, thus obtaining the adjustment value of the hysteresis parameter of the PFC circuit controller in digital control, which serves as the phase adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit. The set coefficient is, for example, 2.

[0119] Specifically, such as Figure 10 As shown, the method for detecting and suppressing voltage resonance in the outdoor unit of a variable frequency air conditioner further includes: in step 13, the specific process of adaptive phase adjustment of the compensation signal is described in the following exemplary description.

[0120] Figure 17 This is a schematic diagram of the phase compensation adaptive adjustment process. Figure 17 In the definition, the compensation signal u for voltage resonance suppression is defined. comp The adjustment sensitivity ΔV1 of the phase θ, and the adjustment direction d r1 (d r1 =0 indicates that the phase is adjusted in the negative direction, d r1 =1 indicates that the phase is adjusted in the positive direction. For example... Figure 17 As shown, the phase compensation adaptive adjustment process includes:

[0121] Step 41: When a voltage resonance state is detected, update the current cycle's maximum resonant voltage detection value ΔV in each detection cycle. max (m) and the maximum resonant voltage detection value ΔV from the previous detection cycle max (m-1), then proceed to step 42. During the detection of voltage resonance, the rate of change is calculated by subtracting two adjacent voltage sampling values. In each detection cycle, a preset intermediate variable is compared with this rate of change, and the maximum value between the preset intermediate variable and the rate of change is reassigned to the intermediate variable. At the end of each detection cycle, the intermediate variable is the maximum resonant voltage detection value. After entering a new detection cycle, this value is cleared to zero and the above operation is repeated.

[0122] Step 42: Determine whether the current cycle's maximum resonant voltage detection value ΔV is met. max (m) - Maximum resonant voltage detected in the previous detection cycle ΔV max (m-1)≥compensation signal u for voltage resonance suppressioncomp The adjustment sensitivity ΔV1 of phase θ: If yes, proceed to step 43; otherwise, proceed to step 44.

[0123] Step 43, when ΔV max (m)-ΔV max When (m-1)≥ΔV1, determine whether the compensation signal u for voltage resonance suppression is satisfied. comp The adjustment direction of phase θ d r1 =0: If the compensation signal u for voltage resonance suppression is 0 comp The adjustment direction of phase θ d r1 If the value is 0, then the hysteresis parameter n in the main chip's digital control is n+1, and the compensation signal u for updating voltage resonance suppression is updated. comp The adjustment direction of phase θ d r1 =1, then proceed to step 45; if the compensation signal u for voltage resonance suppression is... comp The adjustment direction of phase θ d r1 =1, then the hysteresis parameter n = n-1 in the main chip digital control, and the compensation signal u for updating voltage resonance suppression. comp The adjustment direction of phase θ d r1 =0, then proceed to step 45. Where n is the number of delay cycles.

[0124] Step 44, when ΔV max (m)-ΔV max When (m-1)≤-ΔV1, determine whether the compensation signal u for voltage resonance suppression is satisfied. comp The adjustment direction of phase θ d r1 =0: If the compensation signal u for voltage resonance suppression is 0 comp The adjustment direction of phase θ d r1 If the value is 0, then the hysteresis parameter n in the main chip's digital control is n-1, and the compensation signal u for updating voltage resonance suppression is updated. comp The adjustment direction of phase θ d r1 =0; if the compensation signal u for voltage resonance suppression is 0; comp The adjustment direction of phase θ d r1 =1, then the hysteresis parameter n = n+1 in the main chip digital control, and update the compensation signal u for voltage resonance suppression. comp The adjustment direction of phase θ d r1 =1.

[0125] Step 45: Determine if the lag parameter n in the main chip's digital control is less than 0: If yes, set the lag parameter n in the main chip's digital control to 0; otherwise, if n > 2k m Let n = 2k m Since the range of n is [0, 2k]... mIf, after calculation, n < 0, then let n = 0; if, after calculation, n > 2k m Let n = 2k m This step ensures that the phase of the compensation signal is near its real-time optimal value.

[0126] Step S450: If it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, the amplitude gain adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit is determined based on the detected maximum resonant voltage value of the power input side. Specifically, as follows... Figure 10 As shown, the voltage resonance detection and suppression method for the outdoor unit of a variable frequency air conditioner further includes: step 14, after extracting the voltage resonance compensation signal and adaptively adjusting the compensation phase of the voltage resonance compensation signal, adaptively adjusting the amplitude gain of the voltage resonance compensation signal, and then executing step 15.

[0127] In some implementations, the specific process of determining the amplitude gain adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit based on the maximum resonant voltage detection value on the power input side of the air conditioner outdoor unit in step S450 after determining that the power input side of the air conditioner outdoor unit is in a voltage resonance state is described in the following exemplary description.

[0128] The following is combined with Figure 7 The flowchart shown is a schematic diagram of an embodiment of the method of the present invention for determining the amplitude gain adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit. It further illustrates the specific process of determining the amplitude gain adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit in step S450, including steps S710 to S750.

[0129] Step S710: If it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, for the maximum resonance voltage detection value of the power input side of the air conditioner outdoor unit sampled in two adjacent sampling cycles, determine the difference between the maximum resonance voltage detection value of the power input side of the air conditioner outdoor unit sampled in the current sampling cycle and the maximum resonance voltage detection value of the power input side of the air conditioner outdoor unit sampled in the previous sampling cycle, and record it as the difference of the maximum resonance voltage detection value of the power input side of the air conditioner outdoor unit.

[0130] Step S720: If it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, determine whether the difference between the maximum resonant voltage detection values ​​on the power input side of the air conditioner outdoor unit and the set amplitude gain adjustment sensitivity. The set amplitude gain adjustment sensitivity may be the compensation signal u for voltage resonance suppression. comp Amplitude gain H c The adjustment sensitivity ΔV2.

[0131] Step S730: If it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, and if it is determined that the difference in the maximum resonant voltage detection value of the power input side of the air conditioner outdoor unit is greater than or equal to the set amplitude gain adjustment sensitivity, then it is determined whether the amplitude gain adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is negative: if yes, then the current amplitude gain of the controller of the PFC circuit is increased according to the set gain adjustment step size, and the amplitude gain adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is positive; otherwise, then the current amplitude gain of the controller of the PFC circuit is decreased according to the set gain adjustment step size, and the amplitude gain adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is negative.

[0132] Step S740: If it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, and if it is determined that the difference in the maximum resonant voltage detection value of the power input side of the air conditioner outdoor unit is less than the set amplitude gain adjustment sensitivity, then if the difference in the maximum resonant voltage detection value of the power input side of the air conditioner outdoor unit is less than or equal to the negative value of the set amplitude gain adjustment sensitivity, determine whether the amplitude gain adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is negative: if yes, then decrease the current amplitude gain of the controller of the PFC circuit according to the set gain adjustment step size, and make the amplitude gain adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit negative; otherwise, increase the current amplitude gain of the controller of the PFC circuit according to the set gain adjustment step size, and make the amplitude gain adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit positive.

[0133] Step S750: If it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, after increasing the current amplitude gain of the PFC circuit controller and / or decreasing the current amplitude gain of the PFC circuit controller, it is determined whether the current amplitude gain of the PFC circuit controller is 0: if so, the current amplitude gain of the PFC circuit controller is set to 0; otherwise, if the current amplitude gain of the PFC circuit controller is greater than the set maximum amplitude gain, the current amplitude gain of the PFC circuit controller is set to the set maximum amplitude gain, so as to obtain the adjustment value of the current amplitude gain of the PFC circuit controller, which is used as the amplitude gain adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit.

[0134] Specifically, such as Figure 10 As shown, the method for detecting and suppressing voltage resonance in the outdoor unit of a variable frequency air conditioner further includes: in step 14, the specific process of adaptively adjusting the amplitude gain of the compensation signal is described in the following exemplary description.

[0135] Figure 18 A schematic diagram of the adaptive adjustment process for compensating for amplitude gain. Figure 18 In the definition, the compensation signal u for voltage resonance suppression is defined. comp Amplitude gain H c The adjustment sensitivity ΔV2, adjustment direction d r2 (d r2 =0 indicates that the phase is adjusted in the negative direction, d r2 =1 indicates phase adjustment in the positive direction, gain adjustment step size ΔH, maximum gain H cmax .like Figure 18 As shown, the adaptive adjustment process for compensated amplitude gain includes:

[0136] Step 51: For each resonance detection cycle, update the maximum resonance voltage detection value ΔV from the previous cycle. max (m-1)=ΔV max (m), update the current cycle maximum resonant voltage detection value ΔV max (m)=ΔV max Then proceed to step 52.

[0137] Step 52: Determine whether ΔV is satisfied. max Current cycle maximum resonant voltage detection value (m) - Previous cycle maximum resonant voltage detection value ΔV max (m-1)≥compensation signal u for voltage resonance suppression comp Amplitude gain H c Adjust the sensitivity ΔV2: If yes, proceed to step 53; otherwise, proceed to step 54.

[0138] Step 53, when ΔV max (m)-ΔV max When (m-1)≥ΔV2, then determine whether the compensation signal u for voltage resonance suppression is satisfied. comp Amplitude gain H c Adjustment direction d r2 =0: If d r2 =0, then the compensation signal u for voltage resonance suppression comp Amplitude gain H c =H c + Gain adjustment step size ΔH, update adjustment direction d r2 =1, then proceed to step 55; if d r2 =1, then H c =H c -ΔH, update the adjustment direction d r2 =0, then proceed to step 55.

[0139] Step 54, when ΔV max (m)-ΔV maxWhen (m-1)≤-ΔV2, then determine whether d is satisfied. r2 =0: If d r2 =0, then H c =H c -ΔH, update the adjustment direction d r2 =0, then proceed to step 55; if d r2 =1, then H c =H c +ΔH, update the adjustment direction d r2 =1, then proceed to step 55.

[0140] Step 55, due to H c The value range is [0, H]. cmax If H is calculated c If H < 0, then let H c =0; if H = 0 after calculation c >H cmax Then let H c =H cmax This step ensures that the amplitude gain of the compensation signal is near its real-time optimal value.

[0141] Step S460: If it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, the compensation signal of the air conditioner outdoor unit power input side is phase-adjusted using the phase adjustment value of the compensation signal of the air conditioner outdoor unit power input side, and / or amplitude-gain adjusted using the amplitude-gain adjustment value of the compensation signal of the air conditioner outdoor unit power input side, to obtain the compensation duty cycle of the current loop of the PFC circuit. Specifically, as shown... Figure 10 As shown, the method for detecting and suppressing voltage resonance in the outdoor unit of a variable frequency air conditioner further includes: step 15, after extracting the voltage resonance compensation signal, adaptively adjusting the compensation phase of the voltage resonance compensation signal, and adaptively adjusting the amplitude gain of the voltage resonance compensation signal, finally introducing the adaptively adjusted signal into the compensation stage of the current loop to achieve the suppression of voltage resonance on the power input side of the outdoor unit of the variable frequency air conditioner.

[0142] In some implementations, in step S460, after determining that the power input side of the air conditioner outdoor unit is in a voltage resonance state, the compensation signal of the power input side of the air conditioner outdoor unit is phase-adjusted by the phase adjustment value of the compensation signal of the power input side of the air conditioner outdoor unit, and / or amplitude-gain adjusted by the amplitude-gain adjustment value of the compensation signal of the power input side of the air conditioner outdoor unit, to obtain the compensation duty cycle of the current loop of the PFC circuit, including any of the following compensation scenarios:

[0143] The first compensation scenario: If it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, the compensation signal from the power input side of the air conditioner outdoor unit is phase-adjusted by the fixed phase of the PFC circuit controller, and then amplitude-gain-adjusted by the amplitude-gain-adjustment value of the compensation signal from the power input side of the air conditioner outdoor unit, thus obtaining the compensation duty cycle of the current loop of the PFC circuit; or...

[0144] The second compensation scenario: If it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, the compensation signal from the power input side is phase-adjusted by the phase adjustment value of the compensation signal from the power input side, and then amplitude-gain adjusted by the fixed amplitude gain of the PFC circuit controller to obtain the compensation duty cycle of the PFC circuit's current loop; or...

[0145] The third compensation scenario: When it is determined that the power input side of the air conditioner outdoor unit is in a state of voltage resonance, the compensation signal of the air conditioner outdoor unit power input side is phase-adjusted by its phase adjustment value, and then amplitude-gain-adjusted by its amplitude gain adjustment value to obtain the compensation duty cycle of the current loop of the PFC circuit. The phase adjustment value of the compensation signal of the air conditioner outdoor unit power input side is determined within a first set time period; the amplitude gain adjustment value of the compensation signal of the air conditioner outdoor unit power input side is determined within a second set time period.

[0146] During the compensation process, the compensation signal u for voltage resonance suppression needs to be continuously and dynamically adjusted. comp Phase θ and amplitude gain H c To achieve the best compensation effect, define the compensation signal u for voltage resonance suppression. comp Amplitude gain H c The initial value is H c0 (This can be adjusted based on the debugging results), the compensation signal u for voltage resonance suppression. comp The initial value of the phase θ is θ0 (generally, 0 is sufficient). The compensation signal u for voltage resonance suppression... comp Amplitude gain H c The range of values ​​must ensure that the range of the total duty cycle d always includes [0,1] when the compensation duty cycle d2 takes any value within its range; for example, if the range of the original duty cycle d1 is [-1,2], then the compensation signal u for voltage resonance suppression... comp Amplitude gain H c The value range of d2 must be ensured to be [-1, 1], so that the total duty cycle d always includes [0, 1]. The compensation signal u for voltage resonance suppression. compIf the phase θ ranges from [0, 2π], then the hysteresis parameter n in the main chip's digital control ranges from [0, 2π]. m ].

[0147] Specifically, such as Figure 10 As shown, the voltage resonance detection and suppression method for the outdoor unit of a variable frequency air conditioner further includes: in step 15, the combination of adaptive adjustment mode and signal compensation mode, and the comparison of the effects before and after compensation, as illustrated in the following exemplary description.

[0148] The adaptive adjustment method for compensation phase and the adaptive adjustment method for compensation gain can be used simultaneously, or only one of them can be used. When both methods are used simultaneously, they should be executed in a time-sharing manner. That is, adaptive adjustment for compensation phase is executed in a certain time period, and adaptive adjustment for compensation gain is executed in another certain time period. For example, in one period, adaptive adjustment for compensation phase is executed first with a fixed gain, and then adaptive adjustment for compensation gain is executed with a fixed phase, so that the adaptive adjustment parameters reach their respective local optimal solutions, thereby improving the overall compensation effect. In addition, either the adaptive adjustment method for compensation phase or the adaptive adjustment method for compensation gain can use fixed compensation parameters (i.e., no dynamic adjustment). All combinations of compensation phase, compensation gain, and dynamic adjustment parameters with fixed parameters are within the scope of protection of the present invention.

[0149] In step S140, the compensation duty cycle of the current loop of the PFC circuit is added to the control of the current loop of the PFC circuit to suppress the voltage resonance on the power input side of the air conditioner outdoor unit.

[0150] Figure 19 To introduce the current loop control block diagram for the compensation stage. The compensation signal, after adaptive adjustment of the compensation phase and adaptive adjustment of the compensation gain, is then... Figure 19 The method shown is introduced into the current loop feedforward stage, which can directly intervene in the current loop duty cycle output, thereby achieving rapid and effective suppression of voltage resonance. For example... Figure 19 As shown, the output current I of the PFC circuit L (That is, the current in inductor L2) passes through the proportionality coefficient K iL After scaling, the current feedback value is obtained. Reference current I ref The error current I is obtained by subtracting the feedback current value from the first comparator. c =Reference current I ref - Current feedback value. Error current I c via transfer function G ic After processing (e.g., using a PID algorithm), the original duty cycle d1 is obtained. The compensation signal u for voltage resonance suppression is then obtained. comp Through Z -nAfter the module adjusts the phase and delays, it is then compensated by voltage resonance suppression signal u. comp Amplitude gain H c After adjustment, the compensated duty cycle d2 is obtained. The original duty cycle d1 and the compensated duty cycle d2 are subtracted by another comparator to obtain the total duty cycle d = original duty cycle d1 - compensated duty cycle d2. The total duty cycle is then transferred to the current via the duty cycle transfer function G. id After processing, the output current I of the PFC circuit is obtained. L .

[0151] This invention proposes a voltage resonance detection and suppression scheme for an inverter air conditioner outdoor unit. It determines whether the power input side of the inverter air conditioner is in a voltage resonance state by periodically detecting the rate of change of the rising edge of the AC voltage on the power input side. When the maximum number of periods with the rising edge change of the AC voltage exceeding a preset value is greater than an upper limit, the power input side of the inverter air conditioner is considered to be in a voltage resonance state. When the power input side of the inverter air conditioner is in a voltage resonance state, the resonance signal component is extracted by subtracting the original sampled signal from the low-pass filtered signal and used as a compensation signal. The compensation signal is then corrected through phase adaptive adjustment and amplitude gain adaptive adjustment, and the corrected signal is introduced into the current loop feedforward control stage, thereby suppressing the voltage resonance on the power input side of the inverter air conditioner outdoor unit. In this way, without increasing any hardware costs, when voltage resonance occurs on the power input side of the inverter air conditioner's outdoor unit, its resonance amplitude can be suppressed to a small, controllable range without reducing the power factor or increasing the current harmonic content. This avoids problems such as excessively high DC bus voltage after uncontrolled rectification of the indoor unit due to excessively high peak resonant voltage on the power input side of the inverter air conditioner's outdoor unit, which could lead to the indoor unit resetting under excessively high voltage. This improves the reliability of air conditioner operation and enhances the user experience.

[0152] Figure 20 This is a schematic diagram of the measured voltage resonance waveform. Figure 21 A schematic diagram of the actual test waveform after compensation is introduced. Figure 20 The figure shows the expanded waveform at the peak of the voltage resonance test without compensation. The peak resonant voltage can reach 228V. Figure 21 The waveform of the voltage resonance test after compensation is shown. The peak resonant voltage can be controlled within 25V. By comparison, it can be found that the improvement effect after introducing voltage resonance suppression is significant, and the peak voltage resonance value is significantly attenuated.

[0153] The threshold values ​​mentioned above will vary depending on the specific motherboard components. For a given motherboard, the threshold selection range is as follows: Resonant voltage detection threshold ΔV th Range: 10-30V; Oscillation number threshold N th Range: 3-15 times; Hysteresis comparison voltage positive threshold UT The value must be less than the resonant voltage detection threshold ΔV th .

[0154] In the scheme of this invention, the voltage resonance detection method is as follows: the rising edge change rate of the input voltage signal is directly detected. When the change rate exceeds a preset value and the number of times it exceeds the preset value within a certain detection period reaches a preset number, it is determined that the input side is in voltage resonance. The voltage resonance suppression method is as follows: by subtracting the actual input voltage signal from the low-pass filtered voltage signal, the resonant voltage signal is extracted as a compensation signal. Then, through adaptive adjustment of the compensation phase and adaptive adjustment of the compensation gain, the compensation signal is fed forward to the current loop control, thereby achieving the purpose of suppressing voltage resonance.

[0155] Some solutions estimate the instantaneous value of the capacitor voltage containing the resonant component by using the collected grid-side voltage and the calculated voltage drop across the parasitic resistance in the grid-side filter inductor. The estimated capacitor voltage is then used as a feedback variable to suppress resonance in the inverter using active damping control. However, the parasitic resistance in the grid-side filter inductor changes, and this change in resistance value can lead to deviations in the estimation results, resulting in a decrease or even failure of the resonance suppression effect.

[0156] Other schemes determine resonance based on the frequency of harmonics in the AC system of the flexible DC converter station, and determine resonance suppression strategies based on the resonance frequency. Different d-axis and q-axis voltage reference values ​​are obtained through resonance suppression strategies corresponding to different resonance frequencies to suppress resonance in different frequency bands. However, the voltage resonance detection process is not described in detail. The method of suppressing resonance is to directly transmit the filtered voltage, after being processed by a filter, to the voltage feedforward link in the inner loop current control of the flexible DC converter valve.

[0157] The present invention directly detects the rate of change of the rising edge of the input voltage signal on the power input side of the inverter air conditioner outdoor unit. When the rate of change exceeds a preset value and exceeds the preset value a preset number of times within a certain detection period, it is determined that the input side is in voltage resonance. By subtracting the actual input voltage signal from the low-pass filtered voltage signal, the resonant voltage signal is extracted as a compensation signal. Then, through adaptive adjustment of the compensation phase and adaptive adjustment of the compensation gain, the compensation signal is fed forward to the current loop control, thereby achieving the purpose of suppressing voltage resonance.

[0158] In this invention, voltage resonance is determined by periodically detecting the rate of change of the rising edge of the AC voltage on the power input side of the inverter air conditioner outdoor unit. Compared to related solutions, the computational load is significantly smaller, and the computational requirements of the main chip are extremely low, making it highly suitable for low-cost controller applications. Furthermore, this invention proposes dynamically adjusting the phase and amplitude of the compensation signal to achieve optimal real-time compensation. Figure 19As can be seen, the compensation channel of the present invention is located on the duty cycle determination side of the current loop. Compared with the approach of introducing the compensation amount into the current loop setpoint in related documents, the response of the compensation signal of the present invention to the current loop output is not affected by the hysteresis caused by the bandwidth limitation of the current loop itself. The voltage resonance suppression is more direct and the control real-time performance is stronger.

[0159] The technical solution of this embodiment addresses the AC power input side and PFC circuit of an air conditioner (such as an inverter air conditioner). The AC power input terminals (such as N and L terminals) sequentially pass through a first capacitor module (such as capacitor C1), a first inductor module (such as inductor L1), a second capacitor module (such as capacitor C2), an uncontrolled rectifier module (such as a rectifier bridge DB1 composed of diodes), and a third capacitor module (such as capacitor C3), before being output to the bus capacitor module (such as capacitor C4) after passing through the PFC circuit. The PFC circuit includes a second inductor module (such as inductor L2), a diode module (such as diode D1), and a switching transistor module (such as switching transistor G1). A sampling resistor module (such as sampling resistor RS1) is connected between the end of the third capacitor module furthest from the second inductor module and the emitter of the switching transistor module. During the operation of the air conditioner (such as an inverter air conditioner) outdoor unit, the voltage across the third capacitor module is sampled at a set time interval ΔT as the detection period to obtain the voltage. The voltage sampling signal is sampled and low-pass filtered to obtain a voltage low-pass filtered signal. When the number of times the difference between the voltage sampling signal of the current cycle and the voltage sampling signal of the previous cycle in two adjacent cycles is greater than or equal to the set resonant voltage detection threshold is greater than or equal to the set oscillation number threshold, it is considered that the power input side of the outdoor unit of the air conditioner (such as an inverter air conditioner) is in a voltage resonance state. At this time, the resonant signal component is extracted from the difference between the voltage sampling signal and the voltage low-pass filtered signal as a compensation signal for voltage resonance suppression. After phase adjustment and / or gain adjustment of the compensation signal for voltage resonance suppression, the compensation duty cycle is obtained and introduced into the current loop control of the PFC circuit. Thus, when voltage resonance occurs on the power input side of the inverter air conditioner outdoor unit, its resonance amplitude can be suppressed within a small controllable range without reducing the power factor or increasing the current harmonic content, thereby improving the reliability of the inverter air conditioner operation and the user experience.

[0160] According to embodiments of the present invention, a power supply control device for an air conditioner outdoor unit corresponding to a power supply control method for an air conditioner outdoor unit is also provided. See also Figure 8 The diagram shows a structural schematic of an embodiment of the device of the present invention. In the power supply circuit of the outdoor unit of the air conditioner, the AC power from the power input side of the outdoor unit passes sequentially through a first filter unit, a rectifier unit, a second filter unit, and a PFC circuit before being output to the DC bus; the first filter unit may consist of an X capacitor, etc. Figure 9 The capacitor C1 and common-mode inductor shown are as follows: Figure 9The inductor L1 and capacitor X shown are as follows: Figure 9 The π-type filter formed by capacitor C2 shown has a second filtering unit as follows: Figure 9 The capacitor C3 shown has a DC bus as shown. Figure 9 The busbar connected to capacitor C4 as shown; in the embodiment of the present invention, as... Figure 8 As shown, the power supply control device for the outdoor unit of the air conditioner includes: an acquisition unit 102 and a control unit 104.

[0161] The acquisition unit 102 is configured to acquire the voltage across the second filter unit during the operation of the outdoor unit of the air conditioner at a set sampling period, such as a set time interval ΔT, to obtain the voltage sampling signal of the power input side of the outdoor unit of the air conditioner. For example, the voltage across capacitor C3 can accurately reflect the voltage across capacitor X (…). Figure 9 Voltage u across capacitors C1 and C2 i After filtering the voltage sampling signal from the power input side of the air conditioner outdoor unit within a set frequency range, a low-pass filtered voltage signal from the power input side of the air conditioner outdoor unit is obtained. For example, the voltage sampling signal u... i After performing a 1kHz low-pass filter, the smoothed resonant voltage low-pass filtered signal u is obtained. iLPF ; and if it is determined that the power input side of the air conditioner outdoor unit is in a state of voltage resonance, obtain the maximum resonant voltage detection value of the power input side of the air conditioner outdoor unit, such as obtaining the maximum resonant voltage detection value ΔV. max The specific functions and processing of the acquisition unit 102 are described in step S110.

[0162] Specifically, during the operation of the outdoor unit of a variable frequency air conditioner, a voltage sampling circuit (such as a sampling circuit composed of voltage divider resistors) is used to... Figure 9 The voltage across capacitor C3 is sampled. When the PFC circuit is in operation, the voltage across capacitor C3 accurately reflects the voltage across capacitor X. Figure 9 The voltage across capacitors C1 and C2 is denoted as u. i Since the resonant frequency is generally greater than 1kHz, the voltage sampling signal u... i Perform a 1kHz low-pass filter (the filter bandwidth can be adjusted according to the actual circuit conditions) to obtain the smoothed resonant voltage low-pass filtered signal u. iLPF .

[0163] The control unit 104 is configured to determine whether the power input side of the air conditioner outdoor unit is in a voltage resonance state based on the voltage sampling signal of the power input side. The specific functions and processing of this control unit 104 are described in step S120. Specifically, Figure 10This is a schematic flowchart illustrating an embodiment of a method for detecting and suppressing voltage resonance in the outdoor unit of a variable frequency air conditioner. Figure 10 As shown, the method for detecting and suppressing voltage resonance in the outdoor unit of a variable frequency air conditioner includes: Step 11: During the operation of the outdoor unit, the voltage resonance state on the power input side of the outdoor unit is detected to determine whether the power input side is in a voltage resonance state; if so, step 12 is executed to extract the voltage resonance compensation signal; otherwise, the process ends. Specifically, in step 11, the voltage resonance detection method and the basis for determining its detection parameters can be found in the following exemplary description.

[0164] Figure 11 This is a schematic diagram showing the relationship between voltage sampling time and voltage. From Figure 11 It can be seen that during normal operation (without voltage resonance), the largest difference between two adjacent voltage samples (i.e., the largest voltage slope) occurs at the voltage zero-crossing point. Let the effective value of the AC voltage be U, the frequency be f, the detection time interval be ΔT, and the maximum difference between adjacent voltage samples be Um, then:

[0165]

[0166] Figure 12 A table for calculating resonance detection parameters is provided. Taking a PFC algorithm interrupt execution cycle ΔT = 50µs as an example, the power supply range for inverter air conditioners is generally 130-265V, 50 / 60Hz. The maximum difference between adjacent voltage samples under different power supply voltages and frequencies is theoretically calculated using the above formula, and the results are as follows: Figure 12 As shown. From Figure 12 Theoretical calculations show that, under a power supply with an effective AC voltage of 300V and a frequency of 100Hz, the maximum difference between two adjacent AC voltage samples does not exceed 14V. Actual sampling is affected by filtering devices and zero-crossing clamping, so this value will be even lower.

[0167] Figure 13 This is a schematic diagram of the voltage sampling signal change curve during the PFC startup process. When the power input side of the inverter air conditioner outdoor unit ( Figure 9 When voltage resonance occurs between the L and N terminals (in the circuit), the difference between two adjacent AC voltage samples can be much greater than 14V. Considering the voltage sampling signal waveform during the initial PFC activation phase, as shown below... Figure 13 As shown, there may be cases where the voltage slope is too large. To avoid false detection, only the voltage sample value during the rising edge stage is judged.

[0168] In some embodiments, the control unit 104 determines whether the power input side of the air conditioner outdoor unit is in a voltage resonance state based on the voltage sampling signal of the power input side of the air conditioner outdoor unit, including:

[0169] The control unit 104 is further configured to, according to a set resonance detection cycle, determine the difference between the voltage sampling signal of the air conditioner outdoor unit power input side obtained in the current sampling cycle and the voltage sampling signal of the air conditioner outdoor unit power input side obtained in the previous sampling cycle, based on the voltage sampling signals of the air conditioner outdoor unit power input side obtained in two adjacent sampling cycles, and record this difference as the voltage sampling signal difference of the air conditioner outdoor unit power input side in two adjacent cycles; wherein, the set resonance detection cycle is greater than the set sampling cycle. The specific functions and processing of this control unit 104 are further described in step S210.

[0170] The control unit 104 is further configured to determine, in the current resonance detection cycle, whether the voltage sampling signal difference between two adjacent sampling cycles on the power input side of the air conditioner outdoor unit is greater than a set resonance voltage detection threshold. The specific functions and processing of this control unit 104 are further described in step S220.

[0171] The control unit 104 is further configured to, during the current resonance detection cycle, determine that the AC voltage on the power input side of the air conditioner outdoor unit oscillates if the difference between the voltage sampling signals of two adjacent sampling cycles is greater than a set resonance voltage detection threshold. The control unit then accumulates the number of oscillations of the AC voltage on the power input side of the air conditioner outdoor unit to obtain an accumulated value of the voltage oscillation count. The specific functions and processing of this control unit 104 are further described in step S230.

[0172] The control unit 104 is further configured to determine, during the current resonance detection cycle, whether the power input side of the air conditioner outdoor unit is in a voltage resonance state based on the accumulated value of the number of voltage oscillations on the power input side of the air conditioner outdoor unit. The specific functions and processing of this control unit 104 are further described in step S240.

[0173] Specifically, Figure 14 This is a schematic diagram of the voltage resonance detection process. Figure 14 In the definition, the resonance detection parameter is: the resonance voltage detection threshold ΔV. th oscillation threshold N th .like Figure 14 As shown, the voltage resonance detection process includes:

[0174] Step 21: Update the voltage sampling signal u1(i-1) = u1(i) of the previous cycle, and then execute step 22.

[0175] Step 22: Update the voltage sampling signal u1(i) = u1 for the current cycle, and then execute step 23.

[0176] Step 23: In each PFC algorithm cycle (e.g., ΔT), calculate the difference u1(i) - u1(i-1) between the current voltage sample value u1(i) and the voltage sample value u1(i-1) of the previous cycle, and determine whether the difference u1(i) - u1(i-1) between the current voltage sample value u1(i) and the voltage sample value u1(i-1) of the previous cycle is greater than the resonant voltage detection threshold ΔV. th If the condition is met, proceed to step 24; otherwise, proceed to step 25.

[0177] Step 24: If the difference between the current voltage sample value u1(i) and the voltage sample value u1(i-1) of the previous cycle, u1(i)-u1(i-1), is greater than the resonant voltage detection threshold ΔV th The number of oscillations N in the AC voltage is accumulated, i.e., let N = N + 1; then it is determined whether the accumulated value of the number of oscillations N within a certain detection period reaches a value greater than or equal to the oscillation number threshold N. th .

[0178] In some embodiments, the control unit 104, during the current resonance detection cycle, determines whether the power input side of the air conditioner outdoor unit is in a voltage resonance state based on the accumulated value of the voltage oscillation count on the power input side of the air conditioner outdoor unit, including:

[0179] The control unit 104 is further configured to determine, during the current resonance detection cycle, whether the accumulated value of the voltage oscillation count on the power input side of the air conditioner outdoor unit has accumulated to a value greater than or equal to a set oscillation count threshold. The specific functions and processing of this control unit 104 are further described in step S310.

[0180] The control unit 104 is further configured to, during the current resonance detection cycle, determine that the power input side of the air conditioner outdoor unit is in a voltage resonance state if the accumulated value of the voltage oscillation count on the power input side of the air conditioner outdoor unit has accumulated to a value greater than or equal to a set oscillation count threshold. The specific functions and processing of this control unit 104 are further described in step S320.

[0181] The control unit 104 is further configured to, during the current resonance detection cycle, determine whether the current resonance detection cycle has ended or whether to enter the next resonance detection cycle if the accumulated value of the voltage oscillation count on the power input side of the air conditioner outdoor unit has not accumulated to a value greater than or equal to a set oscillation count threshold. The specific functions and processing of this control unit 104 are further described in step S330.

[0182] The control unit 104 is further configured to, during the current resonance detection cycle, if it is determined that the accumulated value of the voltage oscillation count on the power input side of the air conditioner outdoor unit has not accumulated to a value greater than or equal to a set oscillation count threshold, and if it is determined that the current resonance detection cycle has ended or that the next resonance detection cycle has begun, then it determines that the power input side of the air conditioner outdoor unit is not in a voltage resonance state during the current resonance detection cycle, and resets the accumulated value of the voltage oscillation count on the power input side of the air conditioner outdoor unit to zero. The specific functions and processing of this control unit 104 are further described in step S340.

[0183] The control unit 104 is further configured to, during the current resonance detection cycle, if it is determined that the accumulated value of the voltage oscillation count on the power input side of the air conditioner outdoor unit has not accumulated to a value greater than or equal to a set oscillation count threshold, and if it is determined that the current resonance detection cycle has not ended and the next resonance detection cycle has not yet begun, then return to continue determining, during the current resonance detection cycle, whether the difference between the voltage sampling signals on the power input side of the air conditioner outdoor unit in two adjacent sampling cycles is greater than a set resonance voltage detection threshold. The specific functions and processing of this control unit 104 are further described in step S350.

[0184] Specifically, such as Figure 14 As shown, the voltage resonance detection process further includes: in step 24, after accumulating N = N + 1, determining whether the accumulated value of the number of oscillations N within a certain detection period reaches a threshold value N that is greater than or equal to the number of oscillations. th If so, the power input side of the inverter air conditioner outdoor unit enters a resonant state, that is, when the cumulative value of the oscillation number N within a certain detection period reaches a value greater than or equal to the oscillation number threshold N. th If the AC voltage is in a resonant state, then the AC voltage is considered to be in a resonant state; otherwise, proceed to step 25.

[0185] Step 25: If the difference between the current voltage sample value u1(i) and the voltage sample value u1(i-1) of the previous cycle, u1(i)-u1(i-1), is less than or equal to the resonant voltage detection threshold ΔV th If a new resonance detection cycle has begun, the system will determine whether it has entered a new cycle. If so, the power input side of the inverter air conditioner outdoor unit will exit the resonance state, and the accumulated value of the oscillation count N will be cleared to zero. Otherwise, the process will end. The accumulated value of the oscillation count N will be cleared to zero each time a new detection cycle begins.

[0186] Among them, Figure 12 In the example shown, theoretical calculations show that, with an AC voltage RMS of 300V and a frequency of 100Hz, the maximum difference between two adjacent AC voltage samples does not exceed 14V. Therefore, the resonant voltage detection threshold ΔV is... th Only a voltage greater than 14V with a certain margin is required; the threshold for the number of oscillations is N. thThe detection sensitivity can be adjusted according to the actual situation.

[0187] The control unit 104 is further configured to, if it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, determine the compensation duty cycle of the current loop of the PFC circuit, such as the compensation duty cycle d2, based on the voltage sampling signal of the power input side of the air conditioner outdoor unit, the voltage low-pass filter signal of the power input side of the air conditioner outdoor unit, and the maximum resonant voltage detection value of the power input side of the air conditioner outdoor unit. The specific functions and processing of this control unit 104 are further described in step S130.

[0188] In some embodiments, the control unit 104, upon determining that the power input side of the air conditioner outdoor unit is in a voltage resonance state, determines the compensation duty cycle of the current loop of the PFC circuit based on the voltage sampling signal of the power input side of the air conditioner outdoor unit, the voltage low-pass filter signal of the power input side of the air conditioner outdoor unit, and the maximum resonant voltage detection value of the power input side of the air conditioner outdoor unit, including:

[0189] The control unit 104 is further configured to, when it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, determine the difference between the voltage sampling signal of the power input side of the air conditioner outdoor unit and the voltage low-pass filtered signal of the power input side of the air conditioner outdoor unit, and record it as the voltage signal difference of the power input side of the air conditioner outdoor unit. The specific functions and processing of this control unit 104 are further described in step S410.

[0190] The control unit 104 is further configured to, when it is determined that the power input side of the air conditioner outdoor unit is in a state of voltage resonance, extract the resonance signal component from the voltage signal difference of the power input side of the air conditioner outdoor unit, and use it as a compensation signal to suppress the voltage resonance of the power input side of the air conditioner outdoor unit, denoted as the compensation signal of the power input side of the air conditioner outdoor unit. The specific functions and processing of this control unit 104 are further described in step S420. Specifically, as... Figure 10 As shown, the method for detecting and suppressing voltage resonance in the outdoor unit of a variable frequency air conditioner, after step 11, further includes: step 12, when voltage resonance is detected on the power input side of the outdoor unit of the variable frequency air conditioner, firstly extracting the voltage resonance compensation signal, and then executing step 13. Specifically, in step 12, the extraction and compensation method of the compensation signal can be found in the following exemplary description.

[0191] When the power input side of the inverter air conditioner outdoor unit is detected ( Figure 9 When voltage resonance occurs between the L and N terminals, a voltage signal u is introduced. comp As a compensation signal for voltage resonance suppression. Wherein:

[0192] u comp=u i -u iLPF .

[0193] Among them, u i It is a voltage sampling signal, specifically Figure 9 The voltage across capacitor C3; u iLPF Voltage sampling signal u i The voltage low-pass filtered signal after low-pass filtering; u comp This is a compensation signal for voltage resonance suppression.

[0194] The control unit 104 is further configured to, when it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, determine a set maximum hysteresis comparison accumulation value based on the compensation signal of the power input side of the air conditioner outdoor unit, and determine the hysteresis parameter of the PFC circuit controller in digital control, such as determining the hysteresis parameter n in the main chip digital control. The specific functions and processing of this control unit 104 are further described in step S430.

[0195] In some embodiments, the control unit 104, upon determining that the power input side of the air conditioner outdoor unit is in a voltage resonance state, determines a set maximum hysteresis comparison accumulation value based on the compensation signal of the power input side of the air conditioner outdoor unit, and determines the hysteresis parameters of the PFC circuit controller in digital control, including:

[0196] The control unit 104 is further configured to, when it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, determine whether the compensation signal of the power input side of the air conditioner outdoor unit is greater than a set positive threshold for hysteresis comparison voltage. The specific functions and processing of this control unit 104 are further described in step S510.

[0197] The control unit 104 is further configured to, when it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, and if it is determined that the compensation signal of the power input side of the air conditioner outdoor unit is greater than a set positive hysteresis comparison voltage threshold, then accumulate the count value of the compensation signal of the power input side of the air conditioner outdoor unit being greater than the set positive hysteresis comparison voltage threshold, to obtain the accumulated value of the count value of the compensation signal of the power input side of the air conditioner outdoor unit being greater than the set positive hysteresis comparison voltage threshold, and record it as the accumulated hysteresis comparison value of the power input side of the air conditioner outdoor unit. The specific functions and processing of this control unit 104 are further described in step S520.

[0198] The control unit 104 is further configured to, when it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, and if it is determined that the compensation signal on the power input side of the air conditioner outdoor unit is not greater than a set positive hysteresis comparison voltage threshold, then, if the accumulated hysteresis comparison value on the power input side of the air conditioner outdoor unit is not zero, determine whether the compensation signal on the power input side of the air conditioner outdoor unit is less than a negative value of the set positive hysteresis comparison voltage threshold. The specific functions and processing of this control unit 104 are further described in step S530.

[0199] The control unit 104 is further configured to, when it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, and when it is determined that the compensation signal on the power input side of the air conditioner outdoor unit is not greater than a set positive hysteresis comparison voltage threshold and the accumulated hysteresis comparison value on the power input side of the air conditioner outdoor unit is not zero, if it is determined that the compensation signal on the power input side of the air conditioner outdoor unit is not less than the negative value of the set positive hysteresis comparison voltage threshold, then continue to accumulate the accumulated hysteresis comparison value on the power input side of the air conditioner outdoor unit. The specific functions and processing of this control unit 104 are further described in step S540.

[0200] The control unit 104 is further configured to, when determining that the power input side of the air conditioner outdoor unit is in a voltage resonance state, and when determining that the compensation signal on the power input side of the air conditioner outdoor unit is not greater than a set positive hysteresis comparison voltage threshold and the accumulated hysteresis comparison value on the power input side of the air conditioner outdoor unit is not zero, if determining that the compensation signal on the power input side of the air conditioner outdoor unit is less than a negative value of the set positive hysteresis comparison voltage threshold, then set the set maximum accumulated hysteresis comparison value equal to the accumulated hysteresis comparison value on the power input side of the air conditioner outdoor unit, and then clear the accumulated hysteresis comparison value on the power input side of the air conditioner outdoor unit to zero. The specific functions and processing of this control unit 104 are further described in step S550.

[0201] The control unit 104 is further configured to, upon determining that the power input side of the air conditioner outdoor unit is in a state of voltage resonance, determine the resonant frequency at which voltage resonance occurs on the power input side of the air conditioner outdoor unit, such as the resonant frequency f, based on a set maximum hysteresis comparison accumulation value and a set sampling period. o The resonant frequency of the power input side of the outdoor unit of the air conditioner is denoted as . Then, based on the set sampling period and the resonant frequency of the power input side of the outdoor unit of the air conditioner, the hysteresis parameter of the PFC circuit controller in digital control is determined. The specific functions and processing of this control unit 104 are further described in step S560.

[0202] Specifically, such as Figure 10As shown, the method for detecting and suppressing voltage resonance in the outdoor unit of a variable frequency air conditioner further includes, after step 12, the process of determining the resonant frequency and determining the hysteresis parameter n in the digital control of the main chip of the PFC circuit, as illustrated in the following exemplary description.

[0203] Figure 15 This is a schematic diagram of the resonance compensation curve. (Example) Figure 15 As shown, theoretically, the optimal compensation method is to compensate for a positive duty cycle at the rising edge of the resonant voltage, with the absolute value of the compensation being the largest at the point of maximum slope; and to compensate for a negative duty cycle at the falling edge of the resonant voltage, with the absolute value of the compensation being the largest at the point of maximum slope. Since the voltage sampling port has a hardware filtering circuit, and the signal transmission and processing in the main chip have a delay, the compensation signal inherently has a hysteresis phase. Figure 15 The curve shown in Figure b is the compensation signal u. comp The curve shown in Figure c is the compensation signal after phase shifting.

[0204] from Figure 15 As shown in Figure b, the compensation curve crosses back and forth across the horizontal axis. The voltage resonant frequency can be calculated by detecting the frequency at which the compensation curve crosses zero. Figure 16 This is a schematic diagram of the resonant frequency detection process. To avoid false detections caused by sampling interference, a hysteresis comparison is introduced, such as... Figure 16 As shown. Figure 16 As shown, the resonant frequency detection process includes:

[0205] Step 31: Determine whether the compensation signal u is greater than the voltage resonance suppression requirement. comp Greater than the positive threshold voltage U of the hysteresis comparator T If yes, proceed to step 32; otherwise, proceed to step 33.

[0206] Step 32: When the compensation signal u for voltage resonance suppression... comp Greater than the positive threshold voltage U of the hysteresis comparator T At that time, the compensation signal u for voltage resonance suppression comp Greater than the positive threshold voltage U of the hysteresis comparator T The count value k is accumulated in each algorithm cycle, that is, let k = k + 1.

[0207] Step 33: When the compensation signal u for voltage resonance suppression... comp Not greater than the positive threshold voltage U of the hysteresis comparator T The compensation signal u for count value k≠0 and voltage resonance suppression. comp Not less than the negative threshold of the hysteresis comparator voltage -U T At that time, the count value k is accumulated in each algorithm cycle, that is, let k = k + 1.

[0208] When the compensation signal u for voltage resonance suppressioncomp Not greater than the positive threshold voltage U of the hysteresis comparator T The compensation signal u for count value k≠0 and voltage resonance suppression. comp Less than the negative threshold of the hysteresis comparator voltage -U T When the count value k is passed to the consecutive maximum count value k, the value of the count value k is passed to the consecutive maximum count value k. m Simultaneously, the count value k is reset to zero. Given that the PFC algorithm interrupt execution cycle is ΔT, the resonant frequency f... o for:

[0209]

[0210] Given the resonant frequency f o Compensation signal u for voltage resonance suppression comp The phase θ is discretized in the continuous time domain, and the hysteresis parameter n in the digital control of the main chip can be obtained:

[0211]

[0212] The control unit 104 is further configured to, upon determining that the power input side of the air conditioner outdoor unit is in a voltage resonance state, adjust the hysteresis parameter of the PFC circuit controller in digital control based on a set maximum hysteresis comparison accumulation value and the maximum resonance voltage detection value of the power input side of the air conditioner outdoor unit, thereby obtaining the adjustment value of the hysteresis parameter of the PFC circuit controller in digital control, which serves as the phase adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit. The specific functions and processing of this control unit 104 are further described in step S440. Specifically, as... Figure 10 As shown, the method for detecting and suppressing voltage resonance in the outdoor unit of a variable frequency air conditioner further includes: step 13, after extracting the voltage resonance compensation signal, adaptively adjusting the compensation phase of the voltage resonance compensation signal, and then executing step 14. And / or,

[0213] In some embodiments, the control unit 104, upon determining that the power input side of the air conditioner outdoor unit is in a voltage resonance state, adjusts the hysteresis parameter of the PFC circuit controller in digital control based on a set maximum hysteresis comparison accumulation value and the maximum resonance voltage detection value of the power input side of the air conditioner outdoor unit, to obtain an adjustment value for the hysteresis parameter of the PFC circuit controller in digital control, which serves as the phase adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit, including:

[0214] The control unit 104 is further configured to, when it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, determine the difference between the maximum resonant voltage detected in the current sampling period and the maximum resonant voltage detected in the previous sampling period, based on the maximum resonant voltage detected in two adjacent sampling periods, and record this difference as the maximum resonant voltage detection difference of the air conditioner outdoor unit power input side. The specific functions and processing of this control unit 104 are further described in step S610.

[0215] The control unit 104 is further configured to, when it is determined that the power input side of the air conditioner outdoor unit is in a state of voltage resonance, determine whether the difference between the maximum resonant voltage detection values ​​of the power input side of the air conditioner outdoor unit is greater than or equal to a set phase adjustment sensitivity. The specific functions and processing of this control unit 104 are further described in step S620. The set phase adjustment sensitivity includes, for example, the compensation signal u for voltage resonance suppression. comp The adjustment sensitivity ΔV1 of the phase θ.

[0216] The control unit 104 is further configured to, when determining that the power input side of the air conditioner outdoor unit is in a voltage resonance state, if the difference in the maximum resonant voltage detection value of the power input side of the air conditioner outdoor unit is greater than or equal to a set phase adjustment sensitivity, determine whether the phase adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is negative: if yes, then according to a set cycle value, increase the hysteresis parameter of the PFC circuit controller in digital control, and make the phase adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit positive; otherwise, according to a set cycle value, decrease the hysteresis parameter of the PFC circuit controller in digital control, and make the phase adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit negative. The specific functions and processing of this control unit 104 are further described in step S630.

[0217] The control unit 104 is further configured to, when determining that the power input side of the air conditioner outdoor unit is in a voltage resonance state, if the difference in the maximum resonant voltage detection value of the power input side of the air conditioner outdoor unit is less than a set phase adjustment sensitivity, then, if the difference in the maximum resonant voltage detection value of the power input side of the air conditioner outdoor unit is less than or equal to the negative value of the set phase adjustment sensitivity, determine whether the phase adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is negative: if yes, then according to a set cycle value, decrease the hysteresis parameter of the PFC circuit controller in digital control, and make the phase adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit negative; otherwise, according to a set cycle value, increase the hysteresis parameter of the PFC circuit controller in digital control, and make the phase adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit positive. The specific functions and processing of this control unit 104 are further described in step S640. The set cycle value is as shown in step S640.

[0218] The control unit 104 is further configured to, upon determining that the power input side of the air conditioner outdoor unit is in a voltage resonance state, after increasing or / or decreasing the hysteresis parameter of the PFC circuit controller in digital control, determine whether the hysteresis parameter of the PFC circuit controller in digital control is 0: if so, set the hysteresis parameter of the PFC circuit controller in digital control to 0; otherwise, set the hysteresis parameter of the PFC circuit controller in digital control to a set coefficient multiple of the maximum hysteresis comparison accumulation value, thereby obtaining an adjustment value for the hysteresis parameter of the PFC circuit controller in digital control, which serves as the phase adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit. The specific functions and processing of this control unit 104 are further described in step S650. The set coefficient is, for example, 2.

[0219] Specifically, such as Figure 10 As shown, the method for detecting and suppressing voltage resonance in the outdoor unit of a variable frequency air conditioner further includes: in step 13, the specific process of adaptive phase adjustment of the compensation signal is described in the following exemplary description.

[0220] Figure 17 This is a schematic diagram of the phase compensation adaptive adjustment process. Figure 17 In the definition, the compensation signal u for voltage resonance suppression is defined. comp The adjustment sensitivity ΔV1 of the phase θ, and the adjustment direction d r1 (d r1 =0 indicates that the phase is adjusted in the negative direction, d r1 =1 indicates that the phase is adjusted in the positive direction. For example... Figure 17As shown, the phase compensation adaptive adjustment process includes:

[0221] Step 41: When a voltage resonance state is detected, update the current cycle's maximum resonant voltage detection value ΔV in each detection cycle. max (m) and the maximum resonant voltage detection value ΔV from the previous detection cycle max (m-1), then proceed to step 42.

[0222] Step 42: Determine whether the current cycle's maximum resonant voltage detection value ΔV is met. max (m) - Maximum resonant voltage detected in the previous detection cycle ΔV max (m-1)≥compensation signal u for voltage resonance suppression comp The adjustment sensitivity ΔV1 of phase θ: If yes, proceed to step 43; otherwise, proceed to step 44.

[0223] Step 43, when ΔV max (m)-ΔV max When (m-1)≥ΔV1, determine whether the compensation signal u for voltage resonance suppression is satisfied. comp The adjustment direction of phase θ d r1 =0: If the compensation signal u for voltage resonance suppression is 0 comp The adjustment direction of phase θ d r1 If the value is 0, then the hysteresis parameter n in the main chip's digital control is n+1, and the compensation signal u for updating voltage resonance suppression is updated. comp The adjustment direction of phase θ d r1 =1, then proceed to step 45; if the compensation signal u for voltage resonance suppression is... comp The adjustment direction of phase θ d r1 =1, then the hysteresis parameter n = n-1 in the main chip digital control, and the compensation signal u for updating voltage resonance suppression. comp The adjustment direction of phase θ d r1 =0, then proceed to step 45. Where n is the number of delay cycles.

[0224] Step 44, when ΔV max (m)-ΔV max When (m-1)≤-ΔV1, determine whether the compensation signal u for voltage resonance suppression is satisfied. comp The adjustment direction of phase θ d r1 =0: If the compensation signal u for voltage resonance suppression is 0 comp The adjustment direction of phase θ d r1 If the value is 0, then the hysteresis parameter n in the main chip's digital control is n-1, and the compensation signal u for updating voltage resonance suppression is updated. comp The adjustment direction of phase θ d r1=0; if the compensation signal u for voltage resonance suppression is 0; comp The adjustment direction of phase θ d r1 =1, then the hysteresis parameter n = n+1 in the main chip digital control, and update the compensation signal u for voltage resonance suppression. comp The adjustment direction of phase θ d r1 =1.

[0225] Step 45: Determine if the lag parameter n in the main chip's digital control is less than 0: If yes, set the lag parameter n in the main chip's digital control to 0; otherwise, if n > 2k m Let n = 2k m Since the range of n is [0, 2k]... m If, after calculation, n < 0, then let n = 0; if, after calculation, n > 2k m Let n = 2k m This step ensures that the phase of the compensation signal is near its real-time optimal value.

[0226] The control unit 104 is further configured to, when it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, determine the amplitude gain adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit based on the detected maximum resonant voltage value of the power input side. The specific functions and processing of this control unit 104 are further described in step S450. Specifically, as... Figure 10 As shown, the voltage resonance detection and suppression method for the outdoor unit of a variable frequency air conditioner further includes: step 14, after extracting the voltage resonance compensation signal and adaptively adjusting the compensation phase of the voltage resonance compensation signal, adaptively adjusting the amplitude gain of the voltage resonance compensation signal, and then executing step 15.

[0227] In some embodiments, the control unit 104, upon determining that the power input side of the air conditioner outdoor unit is in a voltage resonance state, determines the amplitude gain adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit based on the detected maximum resonant voltage value of the power input side, including:

[0228] Specifically, the control unit 104 is further configured to, when it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, determine the difference between the maximum resonant voltage detected in the current sampling period and the maximum resonant voltage detected in the previous sampling period, based on the maximum resonant voltage detected in two adjacent sampling periods, and record this difference as the maximum resonant voltage detection difference of the air conditioner outdoor unit power input side. The specific functions and processing of this control unit 104 are further described in step S710.

[0229] The control unit 104 is further configured to, when it is determined that the power input side of the air conditioner outdoor unit is in a state of voltage resonance, determine whether the difference between the maximum resonant voltage detection values ​​of the power input side of the air conditioner outdoor unit is greater than or equal to a set amplitude gain adjustment sensitivity. The specific functions and processing of this control unit 104 are further described in step S720. The set amplitude gain adjustment sensitivity includes, for example, the compensation signal u for voltage resonance suppression. comp Amplitude gain H c The adjustment sensitivity ΔV2.

[0230] The control unit 104 is further configured to, when determining that the power input side of the air conditioner outdoor unit is in a voltage resonance state, if the difference in the maximum resonant voltage detection value of the power input side of the air conditioner outdoor unit is greater than or equal to a set amplitude gain adjustment sensitivity, determine whether the amplitude gain adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is negative: if yes, increase the current amplitude gain of the controller of the PFC circuit according to a set gain adjustment step size, and make the amplitude gain adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit positive; otherwise, decrease the current amplitude gain of the controller of the PFC circuit according to a set gain adjustment step size, and make the amplitude gain adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit negative. The specific functions and processing of this control unit 104 are further described in step S730.

[0231] The control unit 104 is further configured to, when determining that the power input side of the air conditioner outdoor unit is in a voltage resonance state, if the difference in the maximum resonant voltage detection value of the power input side of the air conditioner outdoor unit is less than a set amplitude gain adjustment sensitivity, then, if the difference in the maximum resonant voltage detection value of the power input side of the air conditioner outdoor unit is less than or equal to the negative value of the set amplitude gain adjustment sensitivity, determine whether the amplitude gain adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is negative: if yes, then decrease the current amplitude gain of the controller of the PFC circuit according to a set gain adjustment step size, and make the amplitude gain adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit negative; otherwise, then increase the current amplitude gain of the controller of the PFC circuit according to a set gain adjustment step size, and make the amplitude gain adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit positive. The specific functions and processing of this control unit 104 are also described in step S740.

[0232] The control unit 104 is further configured to, when determining that the power input side of the air conditioner outdoor unit is in a voltage resonance state, after increasing and / or decreasing the current amplitude gain of the PFC circuit controller, determine whether the current amplitude gain of the PFC circuit controller is 0: if so, set the current amplitude gain of the PFC circuit controller to 0; otherwise, if the current amplitude gain of the PFC circuit controller is greater than the set maximum amplitude gain, set the current amplitude gain of the PFC circuit controller to the set maximum amplitude gain, thereby obtaining an adjustment value for the current amplitude gain of the PFC circuit controller, which serves as the amplitude gain adjustment value for the compensation signal on the power input side of the air conditioner outdoor unit. The specific functions and processing of this control unit 104 are further described in step S750.

[0233] Specifically, such as Figure 10 As shown, the method for detecting and suppressing voltage resonance in the outdoor unit of a variable frequency air conditioner further includes: in step 14, the specific process of adaptively adjusting the amplitude gain of the compensation signal is described in the following exemplary description.

[0234] Figure 18 A schematic diagram of the adaptive adjustment process for compensating for amplitude gain. Figure 18 In the definition, the compensation signal u for voltage resonance suppression is defined. comp Amplitude gain H c The adjustment sensitivity ΔV2, adjustment direction d r2 (d r2 =0 indicates that the phase is adjusted in the negative direction, d r2 =1 indicates phase adjustment in the positive direction, gain adjustment step size ΔH, maximum gain H cmax .like Figure 18 As shown, the adaptive adjustment process for compensated amplitude gain includes:

[0235] Step 51: For each resonance detection cycle, update the maximum resonance voltage detection value ΔV from the previous cycle. max (m-1)=ΔV max (m), update the current cycle maximum resonant voltage detection value ΔV max (m)=ΔV max Then proceed to step 52.

[0236] Step 52: Determine whether ΔV is satisfied. max Current cycle maximum resonant voltage detection value (m) - Previous cycle maximum resonant voltage detection value ΔV max (m-1)≥compensation signal u for voltage resonance suppression comp Amplitude gain H c Adjust the sensitivity ΔV2: If yes, proceed to step 53; otherwise, proceed to step 54.

[0237] Step 53, when ΔV max (m)-ΔV max When (m-1)≥ΔV2, then determine whether the compensation signal u for voltage resonance suppression is satisfied. comp Amplitude gain H c Adjustment direction d r2 =0: If d r2 =0, then the compensation signal u for voltage resonance suppression comp Amplitude gain H c =H c + Gain adjustment step size ΔH, update adjustment direction d r2 =1, then proceed to step 55; if d r2 =1, then H c =H c -ΔH, update the adjustment direction d r2 =0, then proceed to step 55.

[0238] Step 54, when ΔV max (m)-ΔV max When (m-1)≤-ΔV2, then determine whether d is satisfied. r2 =0: If d r2 =0, then H c =H c -ΔH, update the adjustment direction d r2 =0, then proceed to step 55; if d r2 =1, then H c =H c +ΔH, update the adjustment direction d r2 =1, then proceed to step 55.

[0239] Step 55, due to H c The value range is [0, H]. cmax If H is calculated c If H < 0, then let H c =0; if H = 0 after calculation c >H cmax Then let H c =H cmax This step ensures that the amplitude gain of the compensation signal is near its real-time optimal value.

[0240] The control unit 104 is further configured to, when it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, adjust the phase of the compensation signal of the power input side of the air conditioner outdoor unit after phase adjustment, and / or adjust the amplitude gain after amplitude gain adjustment, to obtain the compensation duty cycle of the current loop of the PFC circuit. The specific function and processing of this control unit 104 are further described in step S460. Specifically, as... Figure 10 As shown, the method for detecting and suppressing voltage resonance in the outdoor unit of a variable frequency air conditioner further includes: step 15, after extracting the voltage resonance compensation signal, adaptively adjusting the compensation phase of the voltage resonance compensation signal, and adaptively adjusting the amplitude gain of the voltage resonance compensation signal, finally introducing the adaptively adjusted signal into the compensation stage of the current loop to achieve the suppression of voltage resonance on the power input side of the outdoor unit of the variable frequency air conditioner.

[0241] In some embodiments, when the control unit 104 determines that the power input side of the air conditioner outdoor unit is in a voltage resonance state, it adjusts the phase of the compensation signal of the power input side of the air conditioner outdoor unit by adjusting the phase value of the compensation signal of the power input side of the air conditioner outdoor unit, and / or adjusts the amplitude gain by adjusting the amplitude gain value of the compensation signal of the power input side of the air conditioner outdoor unit, to obtain the compensation duty cycle of the current loop of the PFC circuit, including any of the following compensation scenarios:

[0242] The first compensation scenario: Specifically, the control unit 104 is further configured to, when determining that the power input side of the air conditioner outdoor unit is in a voltage resonance state, adjust the phase of the compensation signal on the power input side of the air conditioner outdoor unit after it has been phase-adjusted by the fixed phase of the controller of the PFC circuit, and then adjust the amplitude gain of the compensation signal on the power input side of the air conditioner outdoor unit after it has been amplitude-gain adjusted by the amplitude gain adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit, to obtain the compensation duty cycle of the current loop of the PFC circuit. Alternatively,

[0243] The second compensation scenario: Specifically, the control unit 104 is further configured to, when determining that the power input side of the air conditioner outdoor unit is in a voltage resonance state, adjust the phase of the compensation signal on the power input side of the air conditioner outdoor unit after phase adjustment of the compensation signal on the power input side of the air conditioner outdoor unit, and then adjust the amplitude gain of the PFC circuit controller after fixed amplitude gain adjustment, to obtain the compensation duty cycle of the current loop of the PFC circuit. Alternatively,

[0244] The third compensation scenario: Specifically, the control unit 104 is further configured to, when it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, adjust the phase of the compensation signal of the power input side of the air conditioner outdoor unit by adjusting the phase value of the compensation signal of the power input side of the air conditioner outdoor unit, and then adjust the amplitude gain by adjusting the amplitude gain value of the compensation signal of the power input side of the air conditioner outdoor unit to obtain the compensation duty cycle of the current loop of the PFC circuit; wherein, the phase adjustment value of the compensation signal of the power input side of the air conditioner outdoor unit is determined within a first set time period; and the amplitude gain adjustment value of the compensation signal of the power input side of the air conditioner outdoor unit is determined within a second set time period.

[0245] During the compensation process, the compensation signal u for voltage resonance suppression needs to be continuously and dynamically adjusted. comp Phase θ and amplitude gain H c To achieve the best compensation effect, define the compensation signal u for voltage resonance suppression. comp Amplitude gain H c The initial value is H c0 (This can be adjusted based on the debugging results), the compensation signal u for voltage resonance suppression. comp The initial value of the phase θ is θ0 (generally, 0 is sufficient). The compensation signal u for voltage resonance suppression... comp Amplitude gain H c The range of values ​​must ensure that the range of the total duty cycle d always includes [0,1] when the compensation duty cycle d2 takes any value within its range; for example, if the range of the original duty cycle d1 is [-1,2], then the compensation signal u for voltage resonance suppression... comp Amplitude gain H c The value range of d2 must be ensured to be [-1, 1], so that the total duty cycle d always includes [0, 1]. The compensation signal u for voltage resonance suppression. comp If the phase θ ranges from [0, 2π], then the hysteresis parameter n in the main chip's digital control ranges from [0, 2π]. m ].

[0246] Specifically, such as Figure 10 As shown, the voltage resonance detection and suppression method for the outdoor unit of a variable frequency air conditioner further includes: in step 15, the combination of adaptive adjustment mode and signal compensation mode, and the comparison of the effects before and after compensation, as illustrated in the following exemplary description.

[0247] The adaptive adjustment method for compensation phase and the adaptive adjustment method for compensation gain can be used simultaneously, or only one of them can be used. When both methods are used simultaneously, they should be executed in a time-sharing manner. That is, adaptive adjustment for compensation phase is executed in a certain time period, and adaptive adjustment for compensation gain is executed in another certain time period. For example, in one period, adaptive adjustment for compensation phase is executed first with a fixed gain, and then adaptive adjustment for compensation gain is executed with a fixed phase, so that the adaptive adjustment parameters reach their respective local optimal solutions, thereby improving the overall compensation effect. In addition, either the adaptive adjustment method for compensation phase or the adaptive adjustment method for compensation gain can use fixed compensation parameters (i.e., no dynamic adjustment). All combinations of compensation phase, compensation gain, and dynamic adjustment parameters with fixed parameters are within the scope of protection of the present invention.

[0248] The control unit 104 is further configured to incorporate the compensation duty cycle of the current loop of the PFC circuit into the control of the current loop of the PFC circuit, so as to suppress voltage resonance on the power input side of the outdoor unit of the air conditioner. The specific functions and processing of this control unit 104 are further described in step S140.

[0249] Figure 19 To introduce the current loop control block diagram for the compensation stage. The compensation signal, after adaptive adjustment of the compensation phase and adaptive adjustment of the compensation gain, is then... Figure 19 The method shown is introduced into the current loop feedforward stage, which can directly intervene in the current loop duty cycle output, thereby achieving rapid and effective suppression of voltage resonance. For example... Figure 19 As shown, the output current I of the PFC circuit L (That is, the current in inductor L2) passes through the proportionality coefficient K iL After scaling, the current feedback value is obtained. Reference current I ref The error current I is obtained by subtracting the feedback current value from the first comparator. c =Reference current I ref - Current feedback value. Error current I c via transfer function G ic After processing (e.g., using a PID algorithm), the original duty cycle d1 is obtained. The compensation signal u for voltage resonance suppression is then obtained. comp Through Z -n After the module adjusts the phase and delays, it is then compensated by voltage resonance suppression signal u. comp Amplitude gain H c After adjustment, the compensated duty cycle d2 is obtained. The original duty cycle d1 and the compensated duty cycle d2 are subtracted by another comparator to obtain the total duty cycle d = original duty cycle d1 - compensated duty cycle d2. The total duty cycle is then transferred to the current via the duty cycle transfer function G. idAfter processing, the output current I of the PFC circuit is obtained. L .

[0250] This invention proposes a voltage resonance detection and suppression scheme for an inverter air conditioner outdoor unit. It determines whether the power input side of the inverter air conditioner is in a voltage resonance state by periodically detecting the rate of change of the rising edge of the AC voltage on the power input side. When the maximum number of periods with the rising edge change of the AC voltage exceeding a preset value is greater than an upper limit, the power input side of the inverter air conditioner is considered to be in a voltage resonance state. When the power input side of the inverter air conditioner is in a voltage resonance state, the resonance signal component is extracted by subtracting the original sampled signal from the low-pass filtered signal and used as a compensation signal. The compensation signal is then corrected through phase adaptive adjustment and amplitude gain adaptive adjustment, and the corrected signal is introduced into the current loop feedforward control stage, thereby suppressing the voltage resonance on the power input side of the inverter air conditioner outdoor unit. In this way, without increasing any hardware costs, when voltage resonance occurs on the power input side of the inverter air conditioner's outdoor unit, its resonance amplitude can be suppressed to a small, controllable range without reducing the power factor or increasing the current harmonic content. This avoids problems such as excessively high DC bus voltage after uncontrolled rectification of the indoor unit due to excessively high peak resonant voltage on the power input side of the inverter air conditioner's outdoor unit, which could lead to the indoor unit resetting under excessively high voltage. This improves the reliability of air conditioner operation and enhances the user experience.

[0251] Figure 20 This is a schematic diagram of the measured voltage resonance waveform. Figure 21 A schematic diagram of the actual test waveform after compensation is introduced. Figure 20 The figure shows the expanded waveform at the peak of the voltage resonance test without compensation. The peak resonant voltage can reach 228V. Figure 21 The waveform of the voltage resonance test after compensation is shown. The peak resonant voltage can be controlled within 25V. By comparison, it can be found that the improvement effect after introducing voltage resonance suppression is significant, and the peak voltage resonance value is significantly attenuated.

[0252] The threshold values ​​mentioned above will vary depending on the specific motherboard components. For a given motherboard, the threshold selection range is as follows: Resonant voltage detection threshold ΔV th Range: 10-30V; Oscillation number threshold N th Range: 3-15 times; Hysteresis comparison voltage positive threshold U T The value must be less than the resonant voltage detection threshold ΔV th .

[0253] In the scheme of this invention, the voltage resonance detection method is as follows: the rising edge change rate of the input voltage signal is directly detected. When the change rate exceeds a preset value and the number of times it exceeds the preset value within a certain detection period reaches a preset number, it is determined that the input side is in voltage resonance. The voltage resonance suppression method is as follows: by subtracting the actual input voltage signal from the low-pass filtered voltage signal, the resonant voltage signal is extracted as a compensation signal. Then, through adaptive adjustment of the compensation phase and adaptive adjustment of the compensation gain, the compensation signal is fed forward to the current loop control, thereby achieving the purpose of suppressing voltage resonance.

[0254] The present invention directly detects the rate of change of the rising edge of the input voltage signal on the power input side of the inverter air conditioner outdoor unit. When the rate of change exceeds a preset value and exceeds the preset value a preset number of times within a certain detection period, it is determined that the input side is in voltage resonance. By subtracting the actual input voltage signal from the low-pass filtered voltage signal, the resonant voltage signal is extracted as a compensation signal. Then, through adaptive adjustment of the compensation phase and adaptive adjustment of the compensation gain, the compensation signal is fed forward to the current loop control, thereby achieving the purpose of suppressing voltage resonance.

[0255] In this invention, voltage resonance is determined by periodically detecting the rate of change of the rising edge of the AC voltage on the power input side of the inverter air conditioner outdoor unit. Compared to related solutions, the computational load is significantly smaller, and the computational requirements of the main chip are extremely low, making it highly suitable for low-cost controller applications. Furthermore, this invention proposes dynamically adjusting the phase and amplitude of the compensation signal to achieve optimal real-time compensation. Figure 19 As can be seen, the compensation channel of the present invention is located on the duty cycle determination side of the current loop. Compared with the approach of introducing the compensation amount into the current loop setpoint in related documents, the response of the compensation signal of the present invention to the current loop output is not affected by the hysteresis caused by the bandwidth limitation of the current loop itself. The voltage resonance suppression is more direct and the control real-time performance is stronger.

[0256] Since the processing and functions implemented by the device in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned methods, any details not covered in the description of this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0257] The technical solution of this invention addresses the power input side and PFC circuit of an air conditioner (such as an inverter air conditioner). The AC power input terminals (such as N and L terminals) sequentially pass through a first capacitor module (such as capacitor C1), a first inductor module (such as inductor L1), a second capacitor module (such as capacitor C2), an uncontrolled rectifier module (such as a rectifier bridge DB1 composed of diodes), and a third capacitor module (such as capacitor C3), before being output to the bus capacitor module (such as capacitor C4) after passing through the PFC circuit. The PFC circuit includes a second inductor module (such as inductor L2), a diode module (such as diode D1), and a switching transistor module (such as switching transistor G1). A sampling resistor module (such as sampling resistor RS1) is connected between the end of the third capacitor module furthest from the second inductor module and the emitter of the switching transistor module. During the operation of the air conditioner (such as an inverter air conditioner) outdoor unit, a detection period of ΔT is used to sample... The voltage across the third capacitor module is used to obtain a voltage sampling signal, which is then low-pass filtered to obtain a low-pass filtered signal. When the difference between the voltage sampling signal of the current cycle and the voltage sampling signal of the previous cycle in two adjacent cycles is greater than or equal to the set resonant voltage detection threshold, the power input side of the outdoor unit of the air conditioner (such as an inverter air conditioner) is considered to be in a voltage resonance state. At this time, the resonant signal component is extracted from the difference between the voltage sampling signal and the low-pass filtered signal as a compensation signal for voltage resonance suppression. After phase adjustment and / or gain adjustment of the compensation signal for voltage resonance suppression, a compensation duty cycle is obtained, which is introduced into the current loop control of the PFC circuit. The compensation signal is fed forward to the current loop control through adaptive adjustment of the compensation phase and adaptive adjustment of the compensation gain, thereby achieving the purpose of suppressing voltage resonance.

[0258] According to an embodiment of the present invention, an air conditioner corresponding to a power supply control device for an outdoor unit is also provided. This air conditioner may include the power supply control device for the outdoor unit described above.

[0259] Since the processing and functions implemented by the air conditioner in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned device, any details not covered in the description of this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0260] The technical solution of this invention addresses the power input side and PFC circuit of an air conditioner (e.g., inverter air conditioner). The AC power input terminals (e.g., N and L terminals) sequentially pass through a first capacitor module (e.g., capacitor C1), a first inductor module (e.g., inductor L1), a second capacitor module (e.g., capacitor C2), an uncontrolled rectifier module (e.g., a rectifier bridge DB1 composed of diodes), and a third capacitor module (e.g., capacitor C3), before being output to the bus capacitor module (e.g., capacitor C4) after passing through the PFC circuit. The PFC circuit includes a second inductor module (e.g., inductor L2), a diode module (e.g., diode D1), and a switching transistor module (e.g., switching transistor G1). A sampling resistor module (e.g., sampling resistor RS1) is connected between the end of the third capacitor module furthest from the second inductor module and the emitter of the switching transistor module. During the operation of the outdoor unit of the air conditioner (e.g., inverter air conditioner), a set time interval ΔT is used to... During the detection cycle, the voltage across the third capacitor module is sampled to obtain a voltage sampling signal. This voltage sampling signal is then low-pass filtered to obtain a low-pass filtered voltage signal. When the number of times the difference between the voltage sampling signal of the current cycle and the voltage sampling signal of the previous cycle exceeds the set resonant voltage detection threshold is greater than or equal to the set oscillation frequency threshold, the power input side of the outdoor unit of the air conditioner (such as an inverter air conditioner) is considered to be in a voltage resonance state. At this time, the resonant signal component is extracted from the difference between the voltage sampling signal and the low-pass filtered voltage signal as a compensation signal for voltage resonance suppression. After phase adjustment and / or gain adjustment of the compensation signal for voltage resonance suppression, the compensation duty cycle is obtained and introduced into the current loop control of the PFC circuit. The phase and amplitude of the compensation signal are dynamically adjusted according to the compensation effect to achieve the best real-time compensation effect.

[0261] According to an embodiment of the present invention, a storage medium corresponding to a power supply control method for an air conditioner outdoor unit is also provided. The storage medium includes a stored program, wherein, when the program is executed, the device where the storage medium is located controls the execution of the power supply control method for the air conditioner outdoor unit described above.

[0262] Since the processing and functions implemented by the storage medium in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned methods, any details not covered in this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0263] Using the technical solution of this invention, for the power input side of the outdoor unit of an air conditioner (such as an inverter air conditioner) and the PFC circuit, the AC power input terminals (such as N terminals and L terminals) sequentially pass through a first capacitor module (such as capacitor C1), a first inductor module (such as inductor L1), a second capacitor module (such as capacitor C2), an uncontrolled rectifier module (such as a rectifier bridge DB1 composed of diodes), and a third capacitor module (such as capacitor C3), and then through the PFC circuit to the bus capacitor module (such as capacitor C4); the PFC circuit includes a second inductor module (such as inductor L2), a diode module (such as diode D1), and a switching transistor module (such as switching transistor G1). A sampling resistor module (such as sampling resistor RS1) is connected between the end of the third capacitor module away from the second inductor module and the emitter of the switching transistor module; during the operation of the outdoor unit of the air conditioner (such as an inverter air conditioner), the third capacitor module is sampled at a set time interval ΔT as the detection period. The voltage across the capacitor module is used to obtain a voltage sampling signal, which is then low-pass filtered to obtain a low-pass filtered signal. When the difference between the voltage sampling signal of the current cycle and the voltage sampling signal of the previous cycle in two adjacent cycles is greater than or equal to the set resonant voltage detection threshold, the power input side of the outdoor unit of the air conditioner (such as an inverter air conditioner) is considered to be in a voltage resonance state. At this time, the resonant signal component is extracted from the difference between the voltage sampling signal and the low-pass filtered signal as a compensation signal for voltage resonance suppression. After phase adjustment and / or gain adjustment of the compensation signal for voltage resonance suppression, the compensation duty cycle is obtained and introduced into the current loop control of the PFC circuit. The response of the compensation signal to the current loop output is not affected by the hysteresis caused by the bandwidth limitation of the current loop itself, making voltage resonance suppression more direct and control more real-time.

[0264] In summary, it is readily understood by those skilled in the art that, without conflict, the aforementioned advantageous methods can be freely combined and superimposed.

[0265] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A power supply control method of an air conditioner outdoor unit, characterized by, In the power supply circuit of the outdoor unit of the air conditioner, the AC power from the power input side of the outdoor unit passes sequentially through a first filter unit, a rectifier unit, a second filter unit, and a PFC circuit before being output to the DC bus; the power supply control method for the outdoor unit includes: During the operation of the outdoor unit of the air conditioner, the voltage across the second filter unit is acquired according to a set sampling period to obtain the voltage sampling signal of the power input side of the outdoor unit of the air conditioner; after filtering the voltage sampling signal of the power input side of the outdoor unit of the air conditioner within a set frequency range, a low-pass filtered voltage signal of the power input side of the outdoor unit of the air conditioner is obtained; and when it is determined that the power input side of the outdoor unit of the air conditioner is in a voltage resonance state, the maximum resonance voltage detection value of the power input side of the outdoor unit of the air conditioner is acquired. Based on the voltage sampling signal of the power input side of the air conditioner outdoor unit, determine whether the power input side of the air conditioner outdoor unit is in a voltage resonance state; If it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, then the compensation duty cycle of the current loop of the PFC circuit is determined based on the voltage sampling signal of the power input side of the air conditioner outdoor unit, the voltage low-pass filter signal of the power input side of the air conditioner outdoor unit, and the maximum resonance voltage detection value of the power input side of the air conditioner outdoor unit. The compensation duty cycle of the current loop of the PFC circuit is added to the control of the current loop of the PFC circuit to suppress the voltage resonance on the power input side of the air conditioner outdoor unit.

2. The power supply control method of the outdoor unit of an air conditioner according to claim 1, characterized by, Based on the voltage sampling signal of the power input side of the air conditioner outdoor unit, determine whether the power input side of the air conditioner outdoor unit is in a voltage resonance state, including: According to the set resonance detection period, under the current resonance detection period, for the voltage sampling signals of the power input side of the air conditioner outdoor unit sampled in two adjacent sampling periods, the difference between the voltage sampling signal of the power input side of the air conditioner outdoor unit sampled in the current sampling period and the voltage sampling signal of the power input side of the air conditioner outdoor unit sampled in the previous sampling period is determined and recorded as the voltage sampling signal difference of the power input side of the air conditioner outdoor unit in two adjacent periods; wherein, the set resonance detection period is greater than the set sampling period; Determine whether the voltage sampling signal difference on the power input side of the air conditioner outdoor unit in two adjacent sampling periods is greater than the set resonant voltage detection threshold; If it is determined that the voltage sampling signal difference between the power input side of the air conditioner outdoor unit in two adjacent sampling periods is greater than the set resonant voltage detection threshold, then it is determined that the AC voltage on the power input side of the air conditioner outdoor unit is oscillating. The number of times the AC voltage on the power input side of the air conditioner outdoor unit oscillates is accumulated to obtain the accumulated value of the voltage oscillation count on the power input side of the air conditioner outdoor unit. Based on the cumulative value of the number of voltage oscillations on the power input side of the air conditioner outdoor unit, it is determined whether the power input side of the air conditioner outdoor unit is in a voltage resonance state.

3. The power supply control method of the outdoor unit of an air conditioner according to claim 2, characterized by, Based on the cumulative value of the number of voltage oscillations on the power input side of the air conditioner outdoor unit, determine whether the power input side of the air conditioner outdoor unit is in a voltage resonance state, including: Determine whether the accumulated value of the voltage oscillation count on the power input side of the air conditioner outdoor unit has accumulated to a value greater than or equal to the set oscillation count threshold; If it is determined that the cumulative value of the voltage oscillation count on the power input side of the air conditioner outdoor unit has accumulated to a value greater than or equal to the set oscillation count threshold, then it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state under the current resonance detection cycle. If it is determined that the cumulative value of the voltage oscillation count on the power input side of the air conditioner outdoor unit has not accumulated to a value greater than or equal to the set oscillation count threshold, then it is determined whether to enter the next resonance detection cycle. If it is determined that the next resonance detection cycle has been entered, it is determined that the power input side of the air conditioner outdoor unit is not in a voltage resonance state under the current resonance detection cycle, and the cumulative value of the voltage oscillation count of the power input side of the air conditioner outdoor unit is cleared to zero. If it is determined that the next resonance detection cycle has not been entered, the process returns to continue determining whether the voltage sampling signal difference between the power input side of the air conditioner outdoor unit in two adjacent sampling cycles is greater than the set resonance voltage detection threshold.

4. The power supply control method of the outdoor unit of the air conditioner according to claim 1, characterized by, Based on the voltage sampling signal from the power input side of the air conditioner outdoor unit, the low-pass filtered voltage signal from the power input side of the air conditioner outdoor unit, and the detected maximum resonant voltage value from the power input side of the air conditioner outdoor unit, the compensation duty cycle of the current loop of the PFC circuit is determined, including: The difference between the voltage sampling signal at the power input side of the air conditioner outdoor unit and the voltage low-pass filtered signal at the power input side of the air conditioner outdoor unit is determined and denoted as the voltage signal difference at the power input side of the air conditioner outdoor unit. The resonant signal component is extracted from the voltage signal difference on the power input side of the air conditioner outdoor unit and used as a compensation signal to suppress the voltage resonance on the power input side of the air conditioner outdoor unit. This compensation signal is denoted as the compensation signal on the power input side of the air conditioner outdoor unit. Based on the compensation signal from the power input side of the outdoor unit of the air conditioner, the maximum hysteresis comparison accumulation value is determined, and the hysteresis parameters of the PFC circuit controller in digital control are determined. Based on the set maximum hysteresis comparison accumulation value and the maximum resonant voltage detection value on the power input side of the air conditioner outdoor unit, the hysteresis parameter of the PFC circuit controller in digital control is adjusted to obtain the adjustment value of the hysteresis parameter of the PFC circuit controller in digital control, which is used as the phase adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit; and / or, Based on the maximum resonant voltage detection value of the power input side of the air conditioner outdoor unit, determine the amplitude gain adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit; The compensation signal from the power input side of the air conditioner outdoor unit is phase-adjusted by the phase adjustment value of the compensation signal from the power input side of the air conditioner outdoor unit, and / or amplitude-gain adjusted by the amplitude-gain adjustment value of the compensation signal from the power input side of the air conditioner outdoor unit, to obtain the compensation duty cycle of the current loop of the PFC circuit.

5. The power supply control method of the outdoor unit of an air conditioner according to claim 4, characterized by, Based on the compensation signal from the power input side of the air conditioner outdoor unit, the set maximum hysteresis comparison accumulation value is determined, and the hysteresis parameters of the PFC circuit controller in digital control are determined, including: Determine whether the compensation signal on the power input side of the outdoor unit of the air conditioner is greater than the set positive threshold of the hysteresis comparison voltage; If it is determined that the compensation signal on the power input side of the air conditioner outdoor unit is greater than the set positive threshold of hysteresis comparison voltage, then the count value of the compensation signal on the power input side of the air conditioner outdoor unit being greater than the set positive threshold of hysteresis comparison voltage is accumulated to obtain the accumulated value of the count value of the compensation signal on the power input side of the air conditioner outdoor unit being greater than the set positive threshold of hysteresis comparison voltage, which is recorded as the hysteresis comparison accumulated value on the power input side of the air conditioner outdoor unit. If it is determined that the compensation signal on the power input side of the air conditioner outdoor unit is not greater than the set positive threshold of hysteresis comparison voltage, then if the accumulated value of hysteresis comparison on the power input side of the air conditioner outdoor unit is not 0, it is determined whether the compensation signal on the power input side of the air conditioner outdoor unit is less than the negative value of the set positive threshold of hysteresis comparison voltage. If it is determined that the compensation signal on the power input side of the air conditioner outdoor unit is not less than the negative value of the set positive threshold of the hysteresis comparison voltage, then the hysteresis comparison accumulation value on the power input side of the air conditioner outdoor unit continues to be accumulated. If it is determined that the compensation signal on the power input side of the outdoor unit of the air conditioner is less than the negative value of the set positive threshold of the hysteresis comparison voltage, then the set maximum hysteresis comparison accumulation value is made equal to the hysteresis comparison accumulation value on the power input side of the outdoor unit of the air conditioner, and then the hysteresis comparison accumulation value on the power input side of the outdoor unit of the air conditioner is cleared to zero. Based on the set maximum hysteresis comparison accumulation value and the set sampling period, the resonant frequency at which voltage resonance occurs on the power input side of the air conditioner outdoor unit is determined and denoted as the resonant frequency of the power input side of the air conditioner outdoor unit; then, based on the set sampling period and the resonant frequency of the power input side of the air conditioner outdoor unit, the hysteresis parameters of the PFC circuit controller in digital control are determined.

6. The power supply control method of the outdoor unit of an air conditioner according to claim 4 or 5, characterized by, Based on the set maximum hysteresis comparison accumulation value and the maximum resonant voltage detection value on the power input side of the air conditioner outdoor unit, the hysteresis parameter of the PFC circuit controller in digital control is adjusted to obtain the adjustment value of the hysteresis parameter of the PFC circuit controller in digital control, which serves as the phase adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit, including: For the maximum resonant voltage detection value of the power input side of the air conditioner outdoor unit sampled in two adjacent sampling periods, the difference between the maximum resonant voltage detection value of the power input side of the air conditioner outdoor unit sampled in the current sampling period and the maximum resonant voltage detection value of the power input side of the air conditioner outdoor unit sampled in the previous sampling period is determined and recorded as the difference of the maximum resonant voltage detection value of the power input side of the air conditioner outdoor unit. Determine whether the difference in the maximum resonant voltage detected on the power input side of the air conditioner outdoor unit is greater than or equal to the set phase adjustment sensitivity; If the difference in the maximum resonant voltage detected on the power input side of the air conditioner outdoor unit is greater than or equal to the set phase adjustment sensitivity, then it is determined whether the phase adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is negative. If yes, then according to the set beat value, the hysteresis parameter of the PFC circuit controller in digital control is increased, and the phase adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is made positive. Otherwise, according to the set beat value, the hysteresis parameter of the PFC circuit controller in digital control is decreased, and the phase adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is made negative. If the difference in the maximum resonant voltage detected on the power input side of the air conditioner outdoor unit is determined to be less than the set phase adjustment sensitivity, then if the difference in the maximum resonant voltage detected on the power input side of the air conditioner outdoor unit is less than or equal to the negative value of the set phase adjustment sensitivity, it is determined whether the phase adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is negative: if yes, then according to the set beat value, the hysteresis parameter of the PFC circuit controller in digital control is reduced, and the phase adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is made negative; otherwise, according to the set beat value, the hysteresis parameter of the PFC circuit controller in digital control is increased, and the phase adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is made positive. Determine whether the hysteresis parameter of the PFC circuit controller in digital control is 0: if so, set the hysteresis parameter of the PFC circuit controller in digital control to 0; otherwise, set the hysteresis parameter of the PFC circuit controller in digital control to a set coefficient multiple of the set maximum hysteresis comparison accumulation value, so as to obtain the adjustment value of the hysteresis parameter of the PFC circuit controller in digital control, which is used as the phase adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit.

7. The power supply control method of the outdoor unit of the air conditioner according to claim 4, characterized by, Based on the detected maximum resonant voltage value at the power input side of the air conditioner outdoor unit, the amplitude gain adjustment value of the compensation signal at the power input side of the air conditioner outdoor unit is determined, including: For the maximum resonant voltage detection value of the power input side of the air conditioner outdoor unit sampled in two adjacent sampling periods, the difference between the maximum resonant voltage detection value of the power input side of the air conditioner outdoor unit sampled in the current sampling period and the maximum resonant voltage detection value of the power input side of the air conditioner outdoor unit sampled in the previous sampling period is determined and recorded as the difference of the maximum resonant voltage detection value of the power input side of the air conditioner outdoor unit. Determine whether the difference in the maximum resonant voltage detected on the power input side of the air conditioner outdoor unit is greater than or equal to the set amplitude gain adjustment sensitivity; If the difference in the maximum resonant voltage detected on the power input side of the air conditioner outdoor unit is greater than or equal to the set amplitude gain adjustment sensitivity, then it is determined whether the amplitude gain adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is negative: if yes, then the current amplitude gain of the PFC circuit controller is increased according to the set gain adjustment step size, and the amplitude gain adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is positive; otherwise, then the current amplitude gain of the PFC circuit controller is decreased according to the set gain adjustment step size, and the amplitude gain adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is negative. If the difference in the maximum resonant voltage detected on the power input side of the air conditioner outdoor unit is determined to be less than the set amplitude gain adjustment sensitivity, then if the difference in the maximum resonant voltage detected on the power input side of the air conditioner outdoor unit is less than or equal to the negative value of the set amplitude gain adjustment sensitivity, it is determined whether the amplitude gain adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is negative: if yes, then the current amplitude gain of the controller of the PFC circuit is reduced according to the set gain adjustment step size, and the amplitude gain adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is negative; otherwise, then the current amplitude gain of the controller of the PFC circuit is increased according to the set gain adjustment step size, and the amplitude gain adjustment direction of the compensation signal on the power input side of the air conditioner outdoor unit is positive. Determine whether the current amplitude gain of the PFC circuit controller is 0: if so, set the current amplitude gain of the PFC circuit controller to 0; otherwise, if the current amplitude gain of the PFC circuit controller is greater than the set maximum amplitude gain, set the current amplitude gain of the PFC circuit controller to the set maximum amplitude gain, so as to obtain the adjustment value of the current amplitude gain of the PFC circuit controller, which is used as the amplitude gain adjustment value of the compensation signal on the power input side of the air conditioner outdoor unit.

8. The power supply control method of the air conditioning outdoor unit according to any one of claims 4 to 7, characterized by, The compensation signal from the power input side of the air conditioner outdoor unit is phase-adjusted using the phase adjustment value of the compensation signal from the power input side of the air conditioner outdoor unit, and / or amplitude-gain adjusted using the amplitude-gain adjustment value of the compensation signal from the power input side of the air conditioner outdoor unit, to obtain the compensation duty cycle of the current loop of the PFC circuit, including: The compensation signal from the power input side of the air conditioner outdoor unit is phase-adjusted by the fixed phase of the PFC circuit controller, and then amplitude-gain-adjusted by the amplitude-gain-adjustment value of the compensation signal from the power input side of the air conditioner outdoor unit, thus obtaining the compensation duty cycle of the current loop of the PFC circuit; or, The compensation signal from the power input side of the air conditioner outdoor unit is phase-adjusted by the phase adjustment value of the compensation signal from the power input side of the air conditioner outdoor unit, and then amplitude-gain adjusted by the fixed amplitude gain of the PFC circuit controller to obtain the compensation duty cycle of the current loop of the PFC circuit; or, The compensation signal from the power input side of the air conditioner outdoor unit is phase-adjusted by its phase adjustment value, and then amplitude-gain-adjusted by its amplitude gain adjustment value to obtain the compensation duty cycle of the current loop of the PFC circuit. The phase adjustment value of the compensation signal from the power input side of the air conditioner outdoor unit is determined within a first set time period, and the amplitude gain adjustment value is determined within a second set time period.

9. A power supply control device for an air conditioner outdoor unit, characterized in that, In the power supply circuit of the outdoor unit of the air conditioner, the AC power from the power input side of the outdoor unit passes sequentially through a first filter unit, a rectifier unit, a second filter unit, and a PFC circuit before being output to the DC bus; the power supply control device of the outdoor unit includes: The acquisition unit is configured to acquire the voltage across the second filtering unit at a set sampling period during the operation of the outdoor unit of the air conditioner, thereby obtaining a voltage sampling signal on the power input side of the outdoor unit of the air conditioner; to perform filtering processing on the voltage sampling signal on the power input side of the outdoor unit of the air conditioner within a set frequency range, thereby obtaining a low-pass filtered voltage signal on the power input side of the outdoor unit of the air conditioner; and, if it is determined that the power input side of the outdoor unit of the air conditioner is in a voltage resonance state, to acquire the maximum resonant voltage detection value on the power input side of the outdoor unit of the air conditioner. The control unit is configured to determine whether the power input side of the air conditioner outdoor unit is in a voltage resonance state based on the voltage sampling signal of the power input side of the air conditioner outdoor unit; The control unit is further configured to, if it is determined that the power input side of the air conditioner outdoor unit is in a voltage resonance state, determine the compensation duty cycle of the current loop of the PFC circuit based on the voltage sampling signal of the power input side of the air conditioner outdoor unit, the voltage low-pass filter signal of the power input side of the air conditioner outdoor unit, and the maximum resonance voltage detection value of the power input side of the air conditioner outdoor unit; The control unit is further configured to incorporate the compensation duty cycle of the current loop of the PFC circuit into the control of the current loop of the PFC circuit, so as to suppress voltage resonance on the power input side of the air conditioner outdoor unit.

10. An air conditioner, characterized in that, include: The power supply control device for the outdoor unit of an air conditioner as described in claim 9.

11. A storage medium, characterized in that, The storage medium includes a stored program, wherein, when the program is executed, it controls the device containing the storage medium to perform the power supply control method for the outdoor unit of an air conditioner as described in any one of claims 1 to 8.

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