Compressor start / stop control methods, devices, air conditioning equipment and storage media

Abstract

This application relates to a compressor start-stop control method, device, air conditioning equipment, and storage medium. The method includes: upon receiving a compressor stop command, determining in real time whether the compressor's stop rotation state is reversed based on the electrical signal timing of the permanent magnet synchronous motor inside the compressor. If it is reversed, the permanent magnet synchronous motor is controlled to generate electricity according to the braking mode. Since the high and low pressure difference in the system drives the pump body and drives the built-in rotor to rotate in the opposite direction after the compressor stops, the rotor is dragged in reverse by the external force of the pressure difference. The permanent magnet synchronous motor passively becomes a generator. At this time, actively controlling the permanent magnet synchronous motor to enter the controllable power generation mode can generate electromagnetic resistance torque opposite to the reverse direction, which can offset the thrust of the pressure difference and prevent the rotor from continuing to reverse. This solves the problem that existing compressor stop anti-reverse methods cannot detect and prevent reverse in real time, resulting in a high risk of mechanical damage.

Description

Technical Field

[0001] This application relates to the field of compressor start-stop control, and more particularly to a compressor start-stop control method, device, air conditioning equipment, and storage medium. Background Technology

[0002] In air conditioning, refrigeration, and heat pump systems that use reciprocating, scroll, or screw compressors, the compressor, as a core power component, directly affects the performance and lifespan of the entire system. During normal operation, the compressor drives a rotor or piston to rotate forward via a motor, compressing and circulating the refrigerant. However, after the compressor stops, a significant pressure difference remains between the high-pressure and low-pressure sides of the system. If the compressor is not fully unloaded, high-pressure gas may push the rotor in reverse through the compression chamber, causing the compressor to reverse. Compressor reversal typically occurs under the following conditions: sudden power outages or emergency shutdowns, frequent start-stop control, failure or absence of a one-way valve, and voltage fluctuations during startup. Compressor reversal can lead to a series of serious problems: mechanical damage, motor damage, decreased system efficiency, increased noise and vibration, and control system misjudgments.

[0003] However, existing compressor shutdown anti-reverse measures are passive protection methods such as delayed start or one-way valves. These methods have a delayed response, resulting in a high risk of mechanical damage. Summary of the Invention

[0004] This application provides a compressor start-stop control method, device, air conditioning equipment, and storage medium to solve the problem that existing compressor shutdown anti-reverse control methods cannot detect and prevent reverse reversal in real time, resulting in a high risk of mechanical damage.

[0005] In a first aspect, this application provides a compressor start-stop control method, the method comprising: Upon receiving a compressor shutdown command, acquire the electrical signal timing of the permanent magnet synchronous motor inside the compressor; The shutdown and operation status of the compressor is determined based on the timing of the electrical signals. When the compressor is in reverse rotation while it is stopped, the permanent magnet synchronous motor is controlled to generate electricity in braking mode to prevent the compressor from continuing to reverse.

[0006] Optionally, determining the compressor's shutdown / rotation state based on the electrical signal timing includes: The shutdown and rotation state of the compressor is determined based on the Hall state timing and / or back electromotive force phase timing in the electrical signal timing sequence.

[0007] Optionally, the shutdown and operation state of the compressor is determined based on the Hall state timing and back electromotive force phase timing in the electrical signal timing sequence, including: If the shutdown rotation state determined according to the Hall state timing is different from the shutdown rotation state determined according to the back electromotive force phase timing, the shutdown rotation state determined according to the Hall state timing shall be taken as the shutdown rotation state of the compressor.

[0008] Optionally, when the compressor's stop rotation state is in reverse, the permanent magnet synchronous motor is controlled to generate electricity according to the braking mode to prevent the compressor from continuing to reverse, including: When the compressor is in reverse rotation during shutdown, the target braking current and / or target braking torque are determined according to the braking mode. The permanent magnet synchronous motor is controlled according to the target braking current and / or the target braking torque to prevent the compressor from continuing to reverse.

[0009] Optionally, when the compressor's stop rotation state is in reverse, determining the target braking current according to the braking mode includes: When the compressor is in reverse rotation while it is stopped, the reference braking current is determined based on the product of a preset proportional coefficient and the compressor's rated current. When the reverse rotation speed of the compressor is less than the preset speed, the reference braking current is used as the target braking current; When the reverse rotation speed of the compressor is greater than or equal to the preset speed, the sum of the reverse rotation coefficient and the reference braking current is used as the target braking current, wherein the reverse rotation coefficient is the product of the speed proportional coefficient and the reverse rotation speed of the compressor.

[0010] Optionally, when the compressor's stop rotation state is in reverse, determining the target braking torque according to the braking mode includes: When the compressor is in reverse rotation while it is stopped, the power angle between the back electromotive force vector and the voltage vector of the permanent magnet synchronous motor is obtained. The target braking torque is determined based on the back electromotive force vector, the voltage vector, the power angle, and the motor parameters of the permanent magnet synchronous motor.

[0011] Optionally, when the compressor's stop rotation state is in reverse, after controlling the permanent magnet synchronous motor to generate electricity according to the braking mode, the method further includes: Upon receiving a compressor start command, the pressure difference between the compressor's inlet pressure and outlet pressure is obtained. When the compressor is in a stopped state and the pressure difference is less than the preset pressure difference, the compressor is controlled to start in a delayed soft start mode. When the compressor is in reverse rotation while it is stopped, the permanent magnet synchronous motor is controlled to generate electricity in braking mode until the compressor is in non-reverse rotation state. Then, the compressor is controlled to start in delayed soft start mode.

[0012] Secondly, this application provides a compressor start-stop control device, the device comprising: The acquisition module is used to acquire the electrical signal timing of the permanent magnet synchronous motor inside the compressor when a compressor stop command is received; The reverse detection module is used to determine the shutdown and rotation state of the compressor based on the timing of the electrical signals. The control module is used to control the permanent magnet synchronous motor to generate electricity in a braking mode when the compressor is in a reverse rotation state after stopping, so as to prevent the compressor from continuing to reverse.

[0013] Thirdly, this application provides an air conditioning device, which includes a compressor and a variable frequency drive assembly. The compressor is equipped with a permanent magnet synchronous motor, and the variable frequency drive assembly includes a drive circuit, a sampling circuit, and a compressor start-stop control device as described above.

[0014] Fourthly, this application also provides a computer storage medium storing computer-executable instructions for executing the above-described compressor start-stop control method.

[0015] Compared with the prior art, the above-mentioned technical solution provided in this application has the following advantages: When the compressor shutdown command is received, the method provided in this application determines in real time whether the compressor shutdown rotation state is reversed according to the electrical signal timing of the permanent magnet synchronous motor in the compressor. If it is reversed, the permanent magnet synchronous motor is controlled to generate electricity according to the braking mode. Since the system high and low pressure difference drives the pump body and drives the built-in rotor to rotate in the opposite direction after the compressor stops, the rotor is dragged in reverse by the external force of the pressure difference. The permanent magnet synchronous motor passively becomes a generator. At this time, the permanent magnet synchronous motor is actively controlled to enter the controllable power generation mode, which can generate electromagnetic resistance torque opposite to the reverse direction, offset the thrust of the pressure difference, and prevent the rotor from continuing to reverse. This solves the problem that the existing compressor shutdown anti-reverse method cannot detect and prevent reverse in real time, resulting in a high risk of mechanical damage. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0019] Figure 1 An application environment diagram of a compressor start-stop control method provided in this application embodiment; Figure 2 A flowchart illustrating a compressor start-stop control method provided in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of a DC braking module with three current sampling provided in an embodiment of this application; Figure 4 This is a schematic diagram of the structure of a DC braking module with dual current sampling provided in an embodiment of this application; Figure 5 A schematic diagram of the dq-axis mapping of the back electromotive force vector provided in an embodiment of this application; Figure 6 A detailed flowchart illustrating another compressor start-stop control method provided in this application embodiment; Figure 7 A timing effect diagram of a compressor start-stop control method provided in an embodiment of this application; Figure 8 A structural block diagram of a compressor start-stop control device provided in an embodiment of this application; Figure 9 This is a schematic diagram of the internal structure of an air conditioning device provided in an embodiment of this application. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] The following disclosure provides numerous different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0022] Figure 1 This is a diagram illustrating the application environment of a compressor start-stop control method in one embodiment. (Refer to...) Figure 1 This compressor start-stop control method is applied to air conditioning equipment, which includes a compressor and a variable frequency drive assembly. The compressor contains a permanent magnet synchronous motor, and the variable frequency drive assembly includes a drive circuit, a sampling circuit, and a compressor start-stop control device. The drive circuit includes a DC braking module, an IGBT drive circuit, and a three-phase inverter bridge. The sampling circuit includes a voltage sampling circuit, a current sampling circuit, a Hall sensor, and a pressure sensor. The pressure sensor is used to detect the compressor's inlet pressure and outlet pressure, respectively. The compressor start-stop control device is implemented using a microcontroller unit (MCU).

[0023] In one embodiment, Figure 2 This is a flowchart illustrating a compressor start-stop control method in one embodiment, with reference to... Figure 2 A compressor start-stop control method is provided. This embodiment mainly applies this method to the above-mentioned... Figure 1 Taking the compressor start-stop control device as an example, the compressor start-stop control method specifically includes the following steps: Step S210: Upon receiving a compressor stop command, acquire the electrical signal timing of the permanent magnet synchronous motor inside the compressor.

[0024] Specifically, the compressor stop command is used to shut down the compressor. The electrical signal timing of the permanent magnet synchronous motor inside the compressor includes Hall state timing and / or back electromotive force phase timing. The Hall state timing includes Hall level signals collected multiple times in succession. The Hall level signals are signals transmitted by the Hall sensors. The compressor motor stator has three Hall sensors built in, which are installed at 120° electrical angles evenly offset along the circumference. They are used to sense the N / S magnetic poles of the rotor permanent magnet. That is, the Hall level signals are used to indicate the rotor magnetic poles sweeping past different Hall sensors. The order in which the different Hall sensors are swept can be used to determine whether the compressor is rotating in the forward or reverse direction.

[0025] The back electromotive force (EMF) phase sequence includes back EMF vectors acquired multiple times consecutively. After the compressor stops, the refrigerant pressure difference drives the rotor to rotate, and the permanent magnet cuts the three-phase stator windings, generating three-phase symmetrical sinusoidal back EMFs e_U, e_V, and e_W. The rotor rotation direction directly determines the lead / lag sequence, zero-crossing direction, and positive / negative sequence of the three-phase waveforms. Forward / reverse rotation can be determined by sampling the waveform phase at high frequency.

[0026] Step S220: Determine the shutdown and rotation state of the compressor based on the electrical signal timing.

[0027] Specifically, based on the analysis results of electrical signal timing, the compressor's shutdown and rotation status can be determined in real time. The shutdown and rotation status is divided into forward rotation, reverse rotation, and stop rotation.

[0028] In step S230, when the compressor is in reverse rotation while in shutdown mode, the permanent magnet synchronous motor is controlled to generate electricity in braking mode to prevent the compressor from continuing to reverse.

[0029] Specifically, if the compressor is in reverse rotation when it is stopped, the permanent magnet synchronous motor is controlled to generate electricity according to the braking mode. After the compressor stops, the high and low pressure difference in the system drives the pump body and drives the built-in rotor to rotate in the opposite direction. At this time, the rotor is dragged in reverse by the external force of the pressure difference, and the permanent magnet synchronous motor passively becomes a generator. At this time, the permanent magnet synchronous motor is actively controlled to enter the controllable power generation mode, which can generate electromagnetic resistance torque opposite to the reverse direction, offset the thrust of the pressure difference, and prevent the rotor from continuing to reverse. This solves the problem that the existing compressor shutdown anti-reverse method cannot detect and prevent reverse rotation in real time, resulting in a high risk of mechanical damage.

[0030] In one embodiment, determining the compressor's shutdown / rotation state based on the electrical signal timing includes: The shutdown and rotation state of the compressor is determined based on the Hall state timing and / or back electromotive force phase timing in the electrical signal timing sequence.

[0031] Specifically, when the rotor's N pole is aligned with the Hall sensor, it outputs a high level (1); when the rotor's N pole is aligned with the Hall sensor, it outputs a low level (0). For every 60° electrical angle the rotor rotates, one Hall level signal flips once. One 360° electrical angle rotation generates six unique Hall level signals (Hall states). The remaining combinations (all 0 / all 1) represent invalid fault states. The six valid Hall states are encoded in binary (…). , , The sequence is: 1(100), 3(110), 2(010), 6(011), 4(001), 5(101). When the compressor is rotating forward, the rotor magnetic pole sweeps the Hall state in the following order: Hall state cycle switching sequence is 1-3-2-6-4-5-1. Each state transition strictly follows the above sequence in the forward direction. The adjacent state is the next one in the sequence. This Hall state cycle switching sequence is taken as the forward rotation sequence.

[0032] When the compressor reverses, the rotor magnetic poles sweep across the Hall effect sensors in the following sequence: The rotor magnetic poles sweep across the Hall state in a cyclical switching sequence of 1-5-4-6-2-3-1. Adjacent states are reversed along the forward sequence, and this cyclical switching sequence of the Hall state is used as the reverse sequence.

[0033] The compressor's rotation is determined by matching the Hall state switching sequence during compressor reversal with the Hall state switching sequence continuously acquired at different times in the Hall state timing sequence. If the Hall state switching sequence satisfies the reversal sequence for n consecutive times (e.g., 3 times) in the Hall state timing sequence, the compressor is determined to be in reverse rotation. Conversely, if the Hall state switching sequence satisfies the forward rotation sequence, the compressor is determined to be in forward rotation. If the Hall state switching sequence does not satisfy either the forward or reverse rotation sequence, the compressor is determined to be in a stopped state.

[0034] Reference Figure 7 When the compressor rotates forward, the rotor rotates counterclockwise. At this time, the U-phase back electromotive force vector leads the V-phase back electromotive force vector by 120°, and the V-phase back electromotive force vector leads the W-phase back electromotive force vector by 120°. When rotating forward, the phase progression order of the three back electromotive forces is U-V-W. The zero-crossing time sequence of the waveforms is U-phase, V-phase, W-phase, that is, the U-phase crosses the zero point first, and when the U-phase crosses the zero point, it is from the positive potential downwards through the zero point into the negative potential.

[0035] When the compressor reverses, the rotor rotates clockwise. At this time, the U-phase back electromotive force vector leads the W-phase back electromotive force vector by 120°, and the W-phase back electromotive force vector leads the V-phase back electromotive force vector by 120°. That is, the U-phase back electromotive force vector lags behind the V-phase back electromotive force vector by 120°. When reversing, the phase progression order of the three back electromotive forces is U-W-V, and the zero-crossing time sequence of the waveforms is U-phase, W-phase, V-phase. When the U-phase crosses the zero point, it moves from negative potential upwards through the zero point to positive potential. The rotor direction is reversed, and the phase progression order of the three back electromotive forces is completely reversed.

[0036] Therefore, the shutdown rotation state can be determined based on the phase progression order between the three back EMF vectors in the back EMF phase sequence and the crossing direction of the back EMF vector when it crosses zero. If the phase progression order between the three back EMF vectors satisfies the phase progression order of the three back EMFs during reverse rotation, and the crossing direction of the back EMF vector when it crosses zero is from negative potential upwards through zero to positive potential, then the shutdown rotation state is determined to be reverse rotation. Conversely, if the phase progression order between the three back EMF vectors satisfies the phase progression order of the three back EMFs during forward rotation, and the crossing direction of the back EMF vector when it crosses zero is from positive potential downwards through zero to negative potential, then the shutdown rotation state is determined to be forward rotation.

[0037] The compressor's shutdown / rotation state can be determined solely based on Hall state timing or back EMF phase sequence, or by combining both. Combining both timing sequences allows for cross-verification of the detection results, eliminating potential signal misjudgment issues that might arise with a single detection method in environments with strong electromagnetic interference. When the compressor rotor speed is extremely low, the back EMF amplitude decreases synchronously with the speed, and the weak back EMF signal is easily drowned out by electromagnetic noise generated by the driver's switching action. Relying solely on the back EMF phase sequence can easily lead to incorrect results due to zero-crossing detection deviations. However, at this time, the Hall state signal, being a digital level signal, has strong anti-interference capabilities and can still stably output an accurate state switching sequence. The Hall state timing can be used to correct deviations in back EMF detection. Furthermore, when the Hall sensor... When temperature drift or installation position deviation causes misalignment of the output level transition edge, relying solely on the Hall state timing may result in state matching errors. In this case, a stable back EMF phase relationship can calibrate the Hall state judgment result. The two detection methods complement each other, which can improve the accuracy of judging the compressor's shutdown rotation state. Accurate rotation state judgment results can be output throughout the entire speed range when the rotor slowly coasts after the compressor stops, providing a precise state basis for rotor position pre-positioning before subsequent startup. This avoids problems such as startup reversal and excessive startup current jitter caused by incorrect judgment of the shutdown rotation state, thus improving the smoothness and reliability of compressor startup.

[0038] In one embodiment, determining the compressor's shutdown / rotation state based on the Hall state timing and back electromotive force phase timing in the electrical signal timing sequence includes: If the shutdown rotation state determined according to the Hall state timing is different from the shutdown rotation state determined according to the back electromotive force phase timing, the shutdown rotation state determined according to the Hall state timing shall be taken as the shutdown rotation state of the compressor.

[0039] Specifically, when determining the compressor's shutdown state by simultaneously combining the Hall state timing sequence and the back EMF phase timing sequence, if the shutdown state determined by the Hall state timing sequence is the same as the shutdown state determined by the back EMF phase timing sequence, then the shutdown state determined by both is taken as the compressor's shutdown state. If the shutdown state determined by the Hall state timing sequence is different from the shutdown state determined by the back EMF phase timing sequence, then the shutdown state determined by the Hall state timing sequence takes precedence; that is, the judgment based on the Hall state timing sequence has a higher priority than the judgment based on the back EMF phase timing sequence.

[0040] This priority setting rule can significantly improve the robustness and accuracy of compressor shutdown and rotation status judgment. Because the Hall sensor itself is a position detection device, the output Hall state timing directly reflects the change in the magnetic pole position of the compressor rotor. In scenarios where the compressor shutdown speed is low, the Hall signal has a higher signal-to-noise ratio and is less affected by residual voltage in the compressor stator winding and external electromagnetic interference. Unlike the back EMF signal, the signal amplitude will not attenuate below the noise floor due to the low shutdown speed, resulting in phase misjudgment. At the same time, the scheme of dual timing cross-verification combined with priority judgment retains the advantage of redundant judgment to improve reliability of the two detection methods, while avoiding the problem of state locking misjudgment when the two judgment results conflict. It can provide accurate rotor initial position information for subsequent compressor startup, effectively reducing the probability of startup failure and startup reversal, improving the stability of the compressor operation startup phase, and adapting to the startup control requirements of variable frequency compressors under various shutdown conditions.

[0041] In one embodiment, when the compressor's stop rotation state is in reverse, controlling the permanent magnet synchronous motor to generate electricity according to the braking mode to prevent the compressor from continuing to reverse includes: When the compressor is in reverse rotation during shutdown, the target braking current and / or target braking torque are determined according to the braking mode. The permanent magnet synchronous motor is controlled according to the target braking current and / or the target braking torque to prevent the compressor from continuing to reverse.

[0042] Specifically, when the compressor is in reverse rotation during shutdown, a target braking current and / or target braking torque are determined according to the braking mode. The target braking current is applied to the motor windings of the permanent magnet synchronous motor to generate a constant magnetic field, thereby forming an electromagnetic braking torque that forces the rotor to quickly stop reversing. The target braking current is a direct current (DC) current. Applying DC braking technology to the compressor's reverse rotation protection achieves a shift from passive waiting to active intervention, thus shortening the shutdown time. Compared to the traditional passive waiting for the compressor to naturally stop reversing, this solution can significantly shorten the reverse rotation shutdown time and reduce the risk of poor oil return and abnormal bearing wear caused by prolonged compressor reversal.

[0043] The target braking torque is used to make the permanent magnet synchronous motor output a braking torque, that is, to make the permanent magnet synchronous motor operate in a generating state, so as to generate an electromagnetic resistance torque opposite to the reverse direction, to counteract the thrust of the pressure difference and prevent the rotor from continuing to reverse. By adjusting the magnitude of the target braking torque in real time to match the system pressure difference thrust, it is possible to avoid the inability to stop the reverse due to insufficient braking torque, or the motor current surge and mechanical structure vibration caused by excessive braking torque. It is suitable for scenarios of high and low pressure difference changes after shutdown under different refrigeration conditions.

[0044] The compressor's reverse rotation can be intervened using either the target braking current or the target braking torque, or both can be used simultaneously. When the two braking parameters are used in combination, the rapid response characteristics of DC braking and the stable voltage regulation characteristics of torque braking can be utilized. In the initial stage of reverse rotation, DC braking is used to quickly establish braking torque, while torque braking is used to maintain stable reverse resistance. This improves the braking response speed and avoids the problems of overheating of the windings due to prolonged operation of DC braking and poor braking effect at low speeds in a single scheme. This increases the success rate of compressor reverse rotation protection, while the temperature rise of the permanent magnet synchronous motor windings can be controlled within a safe range, without causing additional damage to the motor's insulation performance.

[0045] In one embodiment, when the compressor's stop rotation state is in reverse, determining the target braking current according to the braking mode includes: When the compressor is in reverse rotation while it is stopped, the reference braking current is determined based on the product of a preset proportional coefficient and the compressor's rated current. When the reverse rotation speed of the compressor is less than the preset speed, the reference braking current is used as the target braking current; When the reverse rotation speed of the compressor is greater than or equal to the preset speed, the sum of the reverse rotation coefficient and the reference braking current is used as the target braking current, wherein the reverse rotation coefficient is the product of the speed proportional coefficient and the reverse rotation speed of the compressor.

[0046] Specifically, the preset ratio coefficient is: The compressor's rated current is The reference braking current is In this embodiment, let Assuming the compressor's rated current is 240A, then If the preset proportional coefficient is too small, the reference braking current will be too small and the braking force will be insufficient, and the rotor will not be able to stop quickly. If the preset proportional coefficient is too large, the reference braking current will be too large, causing the winding copper loss to rise sharply, and the short-term braking heat will exceed the standard. The compressor reversal is a short-term transient braking (maximum 0.5s). 10% of the compressor's rated current takes into account both the braking effect and the temperature rise safety.

[0047] The reverse rotation speed of the compressor is also the rotor's reverse rotation electrical angular velocity. The higher the reverse speed, the greater the reverse rotational energy, and the greater the braking current required. Therefore, if the compressor's reverse rotation speed is less than the preset speed, it means that a large braking current is not needed, and the reference braking current can be used as the target braking current, i.e., the target braking current. If the compressor's reverse rotation speed is greater than or equal to the preset speed, it indicates that a larger braking current is required, meaning the reference braking current is insufficient to stop the rotor. Therefore, the sum of the reverse rotation coefficient and the reference braking current is used as the target braking current. ,in The inversion coefficient, This is the speed proportional coefficient, which is the factory-calibrated value of the motor. The higher the power, the larger the value of this coefficient.

[0048] for Figure 3 The DC braking module with three current sampling shown applies a target braking current to any two of the three phases U, V, and W, forming a DC braking current of approximately 10% of the compressor's rated current, thus stopping the rotor from reversing. Figure 4 The DC braking module shown in the diagram uses dual-current sampling to supply the target braking current to the two-phase circuit being sampled. Figure 4 (U and V phases) to form a DC braking current of about 10% of the compressor's rated current. During braking, the back electromotive force and / or Hall state are continuously monitored to continuously detect the compressor's shutdown and rotation status.

[0049] This method of dynamically adjusting the target braking current based on the reverse rotation speed can achieve matching between the braking torque and the kinetic energy of the reverse rotor. When high-speed reverse rotation occurs, the additional braking current can provide a larger electromagnetic braking torque, accelerating the energy dissipation process of the high-energy rotor, thereby compressing the total duration of rotor reverse rotation and avoiding problems such as lubricating oil backflow and abnormal wear of bearing seals caused by prolonged compressor reverse rotation. Simultaneously, for low-speed reverse rotation scenarios, no extra braking current is added, ensuring the braking effect while keeping the winding braking temperature rise within a safe threshold range, preventing localized overheating and insulation aging. This solution requires no additional hardware detection and braking modules; parameter calculations can be achieved using only existing current sensors and Hall effect sensors, without increasing the hardware cost of the compressor drive system. Furthermore, the algorithm logic is simple, with low computational load, and does not consume excessive computing resources of the main control chip. It is compatible with the computing power of mainstream variable frequency compressor drive chips and is compatible with the shutdown braking control scenarios of various commercial and residential compressor products, including fixed-frequency and variable-frequency models.

[0050] In one embodiment, when the compressor's stop rotation state is in reverse, determining the target braking torque according to the braking mode includes: When the compressor is in reverse rotation while it is stopped, the power angle between the back electromotive force vector and the voltage vector of the permanent magnet synchronous motor is obtained. The target braking torque is determined based on the back electromotive force vector, the voltage vector, the power angle, and the motor parameters of the permanent magnet synchronous motor.

[0051] Specifically, when the compressor is rotating in the forward direction, the voltage vector of the permanent magnet synchronous motor... Leading back electromotive force vector The angle of work between two vectors Greater than zero; when the compressor reverses, the back electromotive force vector Leading voltage vector At this point, the work angle between the two vectors Less than zero.

[0052] The formula for calculating the target braking torque is: ,in, , Indicates the d-axis inductive reactance. Electric angular velocity, The number of pole pairs is the motor parameter, which includes the number of pole pairs, electrical angular velocity, and d-axis reactance of the permanent magnet synchronous motor.

[0053] When the compressor is running in the forward direction, , , At this time, the permanent magnet synchronous motor is in electric drive mode; when the compressor reverses, , , At this time, the permanent magnet synchronous motor is in the generator braking state.

[0054] For example, refer to Figure 5 Back electromotive force vector , The rotor permanent magnet flux linkage, during reverse rotation, generates a back electromotive force vector by cutting the stator windings. Fixed along the positive +q axis, rotor permanent magnet flux Along the positive d-axis, , These are the direct-axis and quadrature-axis components of the stator current after decomposition. Along the negative d-axis, Along the negative q-axis, Voltage vector Hysteresis back electromotive force vector The included angle.

[0055] That is, after detecting compressor reversal, the d / q components of the inverter's three-phase output current are adjusted ( This causes the stator current vector to deflect, creating a negative power angle. The motor enters a controllable power generation phase, and the negative torque generated continuously brakes the reverse rotor, converting the mechanical energy of the reverse inertia into electrical energy fed back to the DC bus. Compared to simple DC resistance braking, this method generates less heat and has a higher energy utilization rate. It is not limited by speed; even at extremely low speeds with slight reversal, a stable power generation braking effect can be established solely through current phase control, without relying on a back EMF amplitude greater than the bus voltage. Combined with parallel DC electromagnetic braking, it quickly stops the reverse rotor, resolving the problem of pressure differential backflow damaging compressor bearings and valves.

[0056] In one embodiment, when the compressor's stop rotation state is in reverse, after controlling the permanent magnet synchronous motor to generate electricity according to the braking mode, the method further includes: Upon receiving a compressor start command, the pressure difference between the compressor's inlet pressure and outlet pressure is obtained. When the compressor is in a stopped state and the pressure difference is less than the preset pressure difference, the compressor is controlled to start in a delayed soft start mode. When the compressor is in reverse rotation while it is stopped, the permanent magnet synchronous motor is controlled to generate electricity in braking mode until the compressor is in non-reverse rotation state. Then, the compressor is controlled to start in delayed soft start mode.

[0057] Specifically, refer to Figure 6After operating in braking mode, the system enters the safe start preparation stage. If a compressor start command is received, the system reads the pressure detection data of the high-pressure side pressure sensor and the low-pressure side pressure sensor, that is, obtains the compressor's inlet pressure and outlet pressure, thereby determining the pressure difference between the compressor's inlet pressure and outlet pressure, and then determines the compressor's safe start mode based on the compressor's stop and start state and the pressure difference.

[0058] Reference Figure 6 and Figure 7 If the compressor is in a stopped state and the pressure difference is less than the preset pressure difference (e.g., 0.25 MPa), the compressor will be controlled to start in a delayed soft-start mode. This mode controls the compressor to start after a preset delay using a soft-start strategy (e.g., gradual V / F curve increase or vector control low-frequency torque compensation) to prevent current surges. Compared to traditional direct-start schemes, this control method reduces peak starting current, effectively avoids demagnetization of the permanent magnet synchronous motor due to excessive current surges, reduces load impact on the driver power switching devices and power grid, extends the service life of core components, and lowers the system failure rate.

[0059] If the compressor is in reverse rotation when it is stopped, the permanent magnet synchronous motor continues to generate electricity in braking mode until the compressor is in non-reverse rotation when it is stopped. Then, the compressor is controlled to start in delayed soft-start mode to ensure that it has stopped after braking. A safe start is only performed after confirming that the compressor is not participating in rotation. This step-by-step braking and restart control scheme avoids the reverse torque cancellation problem caused by direct start-up in reverse rotation, improves starting torque output efficiency, reduces mechanical vibration amplitude during startup, reduces mechanical wear on the internal transmission structure of the compressor, extends the overall service life of the compressor, and avoids problems such as start-up failure and system fault shutdown caused by reverse load start-up, thus improving the operational stability of the entire refrigeration / heat pump system.

[0060] Figure 2 and Figure 6 This is a flowchart illustrating a compressor start-stop control method in one embodiment. It should be understood that, although... Figure 2 and Figure 6 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figure 2 and Figure 6At least some of the steps in the process may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0061] In one embodiment, such as Figure 8 As shown, a compressor start / stop control device is provided, comprising: The acquisition module 310 is used to acquire the electrical signal timing of the permanent magnet synchronous motor inside the compressor when a compressor stop command is received; The reverse detection module 320 is used to determine the stop-rotation state of the compressor based on the timing of the electrical signals. The control module 330 is used to control the permanent magnet synchronous motor to generate electricity in a braking mode when the compressor is in a reverse rotation state after stopping, so as to prevent the compressor from continuing to reverse.

[0062] In one embodiment, the inversion detection module 320 is further configured to: The shutdown and rotation state of the compressor is determined based on the Hall state timing and / or back electromotive force phase timing in the electrical signal timing sequence.

[0063] In one embodiment, the inversion detection module 320 is further configured to: If the shutdown rotation state determined according to the Hall state timing is different from the shutdown rotation state determined according to the back electromotive force phase timing, the shutdown rotation state determined according to the Hall state timing shall be taken as the shutdown rotation state of the compressor.

[0064] In one embodiment, the control module 330 is further configured to: When the compressor is in reverse rotation during shutdown, the target braking current and / or target braking torque are determined according to the braking mode. The permanent magnet synchronous motor is controlled according to the target braking current and / or the target braking torque to prevent the compressor from continuing to reverse.

[0065] In one embodiment, the control module 330 is further configured to: When the compressor is in reverse rotation while it is stopped, the reference braking current is determined based on the product of a preset proportional coefficient and the compressor's rated current. When the reverse rotation speed of the compressor is less than the preset speed, the reference braking current is used as the target braking current; When the reverse rotation speed of the compressor is greater than or equal to the preset speed, the sum of the reverse rotation coefficient and the reference braking current is used as the target braking current, wherein the reverse rotation coefficient is the product of the speed proportional coefficient and the reverse rotation speed of the compressor.

[0066] In one embodiment, the control module 330 is further configured to: When the compressor is in reverse rotation while it is stopped, the power angle between the back electromotive force vector and the voltage vector of the permanent magnet synchronous motor is obtained. The target braking torque is determined based on the back electromotive force vector, the voltage vector, the power angle, and the motor parameters of the permanent magnet synchronous motor.

[0067] In one embodiment, the control module 330 is further configured to: Upon receiving a compressor start command, the pressure difference between the compressor's inlet pressure and outlet pressure is obtained. When the compressor is in a stopped state and the pressure difference is less than the preset pressure difference, the compressor is controlled to start in a delayed soft start mode. When the compressor is in reverse rotation while it is stopped, the permanent magnet synchronous motor is controlled to generate electricity in braking mode until the compressor is in non-reverse rotation state. Then, the compressor is controlled to start in delayed soft start mode.

[0068] It should be noted that the examples and application scenarios implemented by the above modules and corresponding steps are the same, but are not limited to the content disclosed in the above embodiments. It should also be noted that the above modules, as part of a device, can operate in environments such as... Figure 1 The hardware environment shown can be implemented either through software or through hardware.

[0069] like Figure 9 As shown, this application embodiment provides an air conditioning device, including a processor 711, a communication interface 712, a memory 713, and a communication bus 714. The processor 711, the communication interface 712, and the memory 713 communicate with each other through the communication bus 714. The memory 713 is used to store computer programs. When the processor 711 executes the program stored in the memory 713, it implements the compressor start-stop control method provided in any of the aforementioned method embodiments.

[0070] The memory and processor in the aforementioned electronic devices communicate with each other via a communication bus and a communication interface. The communication bus can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. This communication bus can be divided into an address bus, a data bus, a control bus, etc.

[0071] The memory may include random access memory (RAM) or non-volatile memory, such as at least one disk storage device. Optionally, the memory may also be at least one storage device located remotely from the aforementioned processor.

[0072] The processors mentioned above can be general-purpose processors, including central processing units (CPUs), network processors (NPs), etc.; they can also be digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0073] Those skilled in the art will understand that Figure 9 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the air conditioning equipment to which the present application is applied. Specific air conditioning equipment may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0074] According to another aspect of the embodiments of this application, a computer program product or computer program is also provided, which includes computer instructions stored in a computer-readable storage medium. A processor of an air conditioning device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the air conditioning device to perform the steps of any of the above embodiments.

[0075] In one embodiment, the compressor start-stop control device provided in this application can be implemented as a computer program, and the computer program can be implemented as follows: Figure 9 The air conditioning unit shown is running. The air conditioning unit's memory can store the various program modules that make up the compressor start-stop control device, for example, Figure 8 The acquisition module 310, the reversal detection module 320, and the control module 330 are shown. The computer program composed of these various program modules causes the processor to execute the compressor start-stop control methods of the various embodiments of this application described in this specification.

[0076] Figure 9 The air conditioning equipment shown can be used as follows Figure 8 The acquisition module 310 in the compressor start / stop control device shown acquires the electrical signal timing of the permanent magnet synchronous motor inside the compressor upon receiving a compressor stop command. The air conditioning equipment can determine the compressor's stop-rotation state based on the electrical signal timing through the reverse detection module 320. If the compressor's stop-rotation state is reversed, the air conditioning equipment can control the permanent magnet synchronous motor to generate electricity in a braking mode through the control module 330 to prevent the compressor from continuing to reverse.

[0077] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the compressor start-stop control method as provided in any of the foregoing method embodiments.

[0078] Optionally, in embodiments of this application, the computer-readable medium is configured to store program code for the processor to perform the following steps: Upon receiving a compressor shutdown command, acquire the electrical signal timing of the permanent magnet synchronous motor inside the compressor; The shutdown and operation status of the compressor is determined based on the timing of the electrical signals. When the compressor is in reverse rotation while it is stopped, the permanent magnet synchronous motor is controlled to generate electricity in braking mode to prevent the compressor from continuing to reverse.

[0079] Optionally, specific examples in this embodiment can refer to the examples described in the above embodiments, and will not be repeated here.

[0080] It is understood that the embodiments described herein can be implemented in hardware, software, firmware, middleware, microcode, or a combination thereof. For hardware implementation, the processing unit can be implemented in one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), general-purpose processors, controllers, microcontrollers, microprocessors, other electronic units for performing the functions described herein, or combinations thereof.

[0081] For software implementation, the techniques described herein can be implemented by units that perform the functions described herein. The software code can be stored in memory and executed by a processor. The memory can be implemented in the processor or external to the processor.

[0082] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0083] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0084] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0085] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0086] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0087] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented using software plus a general-purpose hardware platform, or of course, using hardware. Based on this understanding, the above technical solutions, in essence or the parts that contribute to the related technology, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as a USB flash drive, mobile hard drive, ROM, RAM, magnetic disk, or optical disk, or other media capable of storing program code, including several instructions to cause an air conditioning device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0088] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also mean including the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that alternatives or substitutions may be used.

[0089] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A compressor start-stop control method, characterized in that, The method includes: Upon receiving a compressor shutdown command, acquire the electrical signal timing of the permanent magnet synchronous motor inside the compressor; The shutdown and operation status of the compressor is determined based on the timing of the electrical signals. When the compressor is in a reverse rotation state while it is in a shutdown state, the permanent magnet synchronous motor is controlled to generate electricity according to the braking mode to prevent the compressor from continuing to reverse. This includes: when the compressor is in a reverse rotation state while it is in a shutdown state, determining a target braking current and / or a target braking torque according to the braking mode; and controlling the permanent magnet synchronous motor according to the target braking current and / or the target braking torque to prevent the compressor from continuing to reverse.

2. The method according to claim 1, characterized in that, Determining the compressor's shutdown / rotation state based on the electrical signal timing includes: The shutdown and rotation state of the compressor is determined based on the Hall state timing and / or back electromotive force phase timing in the electrical signal timing sequence.

3. The method according to claim 1, characterized in that, The shutdown and operation state of the compressor is determined based on the Hall state timing and back electromotive force phase timing in the electrical signal timing sequence, including: If the shutdown rotation state determined according to the Hall state timing is different from the shutdown rotation state determined according to the back electromotive force phase timing, the shutdown rotation state determined according to the Hall state timing shall be taken as the shutdown rotation state of the compressor.

4. The method according to claim 1, characterized in that, When the compressor is in reverse rotation after being stopped, the target braking current is determined according to the braking mode, including: When the compressor is in reverse rotation while it is stopped, the reference braking current is determined based on the product of a preset proportional coefficient and the compressor's rated current. When the reverse rotation speed of the compressor is less than the preset speed, the reference braking current is used as the target braking current; When the reverse rotation speed of the compressor is greater than or equal to the preset speed, the sum of the reverse rotation coefficient and the reference braking current is used as the target braking current, wherein the reverse rotation coefficient is the product of the speed proportional coefficient and the reverse rotation speed of the compressor.

5. The method according to claim 1, characterized in that, When the compressor is in reverse rotation after being stopped, the target braking torque is determined according to the braking mode, including: When the compressor is in reverse rotation while it is stopped, the power angle between the back electromotive force vector and the voltage vector of the permanent magnet synchronous motor is obtained. The target braking torque is determined based on the back electromotive force vector, the voltage vector, the power angle, and the motor parameters of the permanent magnet synchronous motor.

6. The method according to claim 1, characterized in that, When the compressor is in reverse rotation after being stopped, and the permanent magnet synchronous motor is controlled to generate electricity according to the braking mode, the method further includes: Upon receiving a compressor start command, the pressure difference between the compressor's inlet pressure and outlet pressure is obtained. When the compressor is in a stopped state and the pressure difference is less than the preset pressure difference, the compressor is controlled to start in a delayed soft start mode. When the compressor is in reverse rotation while it is stopped, the permanent magnet synchronous motor is controlled to generate electricity in braking mode until the compressor is in non-reverse rotation state. Then, the compressor is controlled to start in delayed soft start mode.

7. A compressor start / stop control device, characterized in that, The device includes: The acquisition module is used to acquire the electrical signal timing of the permanent magnet synchronous motor inside the compressor when a compressor stop command is received; The reverse detection module is used to determine the shutdown and rotation state of the compressor based on the timing of the electrical signals. A control module is configured to control the permanent magnet synchronous motor to generate electricity according to a braking mode when the compressor's stop-rotation state is in reverse rotation, so as to prevent the compressor from continuing to reverse rotation. This includes: determining a target braking current and / or a target braking torque according to a braking mode when the compressor's stop-rotation state is in reverse rotation; and controlling the permanent magnet synchronous motor according to the target braking current and / or the target braking torque to prevent the compressor from continuing to reverse rotation.

8. An air conditioning device, characterized in that, The air conditioning equipment includes a compressor and a variable frequency drive assembly. The compressor is equipped with a permanent magnet synchronous motor. The variable frequency drive assembly includes a drive circuit, a sampling circuit, and a compressor start-stop control device as described in claim 7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method of any one of claims 1 to 6.

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