Methods and devices for adjusting PFC circuit parameters in air conditioner controllers and air conditioners

Abstract

A method, apparatus, and air conditioner for adjusting PFC circuit parameters in an air conditioner controller are provided. The method includes: S1: Real-time detection of whether the AC input voltage of the air conditioner oscillates; S2: When AC input voltage oscillation occurs, adaptively adjusting the P parameter in the PFC circuit parameters until the smoothness Q of the AC input voltage is less than a preset threshold. The smoothness Q of the AC input voltage is defined as the ratio of the absolute values ​​of the differences K between two consecutive sampled AC voltage peak values ​​within a predetermined time period to the maximum value of the AC voltage peak value. According to the present invention, when the input voltage oscillates, it can accurately and quickly identify whether the input power supply voltage has oscillated, adaptively adjust the operating parameters, ensure reliable operation of the air conditioning system, and reduce the cost of the filter circuit.

Description

Technical Field

[0001] This invention relates to the field of intelligent control, and more specifically to a method, apparatus, and air conditioner for adjusting PFC circuit parameters in an air conditioner controller. Background Technology

[0002] As air conditioners become increasingly common, their operating environments are becoming more complex, and their power supplies are also diverse, including inverters, generators, mains power, and other power equipment. For air conditioner applications, the quality of the power supply has a significant impact on the reliability of the air conditioner's operation. In particular, the presence of parasitic inductance or transformers in the air conditioner's power input lines can easily cause input voltage oscillations.

[0003] With the development of power electronics technology, the pollution of the power grid caused by current harmonics and reactive power generated by various electronic devices and household appliances is attracting increasing attention. To suppress power grid harmonics, air conditioner controllers are generally equipped with PFC (Power Factor Correction) circuits. PFC control methods are typically based on average current control. The working principle of PFC is as follows: the product of the detected output voltage signal after AC power is rectified by a rectifier bridge and the output signal of a voltage error amplifier generates a reference signal. This reference signal is compared and amplified by the inductor current sampling signal through a current error amplifier, and then compared with a sawtooth wave to output a pulse width modulation (PWM) signal to the switching transistor. This control process involves a voltage loop (PID algorithm: Proportional Integral Derivative) and a current loop (PI algorithm: Proportional Integral). In the PID algorithm, P represents amplification, I represents integration, and D represents differentiation. The PID algorithm is used to more accurately and promptly reflect the changes in the input. P, PI, PID, and other control algorithms can be used according to the output requirements of the actual control system.

[0004] When the oscillating voltage generated on the power supply input line is introduced into the control loop of the air conditioner's PFC circuit, it creates positive feedback in the control loop, causing the input voltage oscillation to become increasingly severe. This affects the air conditioner's performance and reliability. Therefore, existing technology requires a solution for adjusting the parameters in the FPC circuit.

[0005] The information disclosed in the background section above is only used to further understand the background of the present invention, and therefore may include information known to those skilled in the art that does not constitute prior art. Summary of the Invention

[0006] This invention provides a method, device, and air conditioner for adjusting PFC circuit parameters in an air conditioner controller. The PFC parameter adjustment scheme provided by this invention can accurately and quickly identify whether the input power supply voltage has oscillated when the input voltage oscillates, and can adaptively adjust the operating parameters, thereby avoiding the problem of increasingly severe input voltage oscillations, improving the reliability of the air conditioning system, and reducing the cost of the filter circuit topology.

[0007] The first aspect of the present invention provides a method for adjusting PFC circuit parameters in an air conditioner controller, comprising: S1: real-time detection of whether the AC input voltage of the air conditioner oscillates; S2: when AC input voltage oscillation occurs, adaptively adjusting the P parameter in the PFC circuit parameters until the smoothness Q of the AC input voltage is less than a preset threshold, wherein the smoothness Q of the AC input voltage is defined as the ratio of the absolute value of the difference K between two consecutive sampling peak values ​​of AC voltage within a predetermined time period to the maximum value of the AC voltage peak value.

[0008] According to one embodiment of the present invention, the preset threshold is related to the number of cycles, frequency, and high-voltage filtering parameters of the air conditioner AC power supply.

[0009] According to one embodiment of the present invention, in step S2, adaptively adjusting the P parameter in the PFC parameters includes: decreasing the value of the P parameter once every first predetermined time until a set minimum P parameter is reached.

[0010] According to an embodiment of the present invention, wherein step S1, real-time detection of whether the AC input voltage of the air conditioner oscillates includes: S11: Real-time acquisition of the peak value of the current sampled AC input voltage of the air conditioner and calculation of the absolute value K of the difference between the peak value and the adjacent previously sampled AC voltage peak value; S12: Calculation of the smoothness Q of the AC voltage; S13: Setting a counter, if the value of Q is greater than the preset threshold, incrementing the counter by 1, and repeating steps S11 and S12; S14: If the value of Q is less than the preset threshold, resetting the counter to zero; S15: When the value of the counter is greater than a preset value, determining that the AC input voltage oscillates.

[0011] According to an embodiment of the present invention, the method further includes: S3: when the value of Q is less than a preset threshold and continues for a second predetermined time, the value of the P parameter is increased once every predetermined third predetermined time until the initial preset value of the P parameter is restored.

[0012] A second aspect of the present invention provides a PFC circuit parameter adjustment device in an air conditioner controller, comprising: a detection unit for real-time detection of whether the AC input voltage of the air conditioner oscillates; and an adjustment unit for adaptively adjusting the P parameter in the PFC circuit parameters when AC input voltage oscillation occurs, until the smoothness Q of the AC input voltage is less than a preset threshold, wherein the smoothness Q of the AC input voltage is defined as: the ratio of the sum of the K values ​​of all sampling points within a predetermined time period to the maximum value of the AC voltage peak.

[0013] According to one embodiment of the present invention, the adjustment unit is further configured to: decrease the value of parameter P once every first predetermined time until a set minimum value of parameter P is reached.

[0014] According to an embodiment of the present invention, the detection unit is further configured to: acquire the peak value of the current sampled AC input voltage of the air conditioner in real time and calculate the absolute value K of the difference between the peak value of the AC voltage and the adjacent previously sampled peak value; calculate the smoothness Q of the AC voltage; set a counter, and if the value of Q is greater than the preset threshold, increment the counter by 1 and repeat the calculation of the Q value; if the value of Q is less than the preset threshold, reset the counter to zero; when the value of the counter is greater than a preset value, determine that the AC input voltage has oscillated.

[0015] According to an embodiment of the present invention, the adjustment unit is further configured to: when the value of Q is less than a preset threshold and continues for a second predetermined time, increase the value of the P parameter once every predetermined third predetermined time until the initial preset value of the P parameter is restored.

[0016] A third aspect of the present invention provides an air conditioner that employs the above-described PFC circuit parameter adjustment device method, or the above-described PFC circuit parameter adjustment device.

[0017] According to the solution of the present invention, when the input voltage oscillates, it can accurately and quickly identify whether the input power supply voltage has oscillated, and can adaptively adjust the operating parameters to ensure the reliable operation of the air conditioning system, while reducing the cost of the filter circuit. Attached Figure Description

[0018] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is an exemplary flowchart of the cargo initial placement posture model construction method according to the present invention.

[0020] Figure 2 This is a flowchart of a PFC circuit parameter adjustment method in an air conditioner controller according to an exemplary embodiment of the present invention.

[0021] Figure 3 This is a test data graph of the smoothness value Q according to an exemplary embodiment of the present invention.

[0022] Figure 4 This is a block diagram of a PFC circuit parameter adjustment device in an air conditioner controller according to an exemplary embodiment of the present invention. Specific Implementation

[0023] As used herein, the terms "first," "second," etc., can be used to describe elements in exemplary embodiments of the present invention. These terms are used only to distinguish one element from another, and the inherent features or order of the corresponding elements are not limited by the term. Unless otherwise defined, all terms used herein (including technical or scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in common dictionaries are to be interpreted as having the same meaning as in the context of the relevant technical field, and not as having an ideal or overly formal meaning, unless explicitly defined as having such a meaning in this invention.

[0024] Those skilled in the art will understand that the apparatus and methods of the present invention described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments, and the scope of the invention is defined only by the claims. Features illustrated or described in conjunction with an exemplary embodiment may be combined with features of other embodiments. Such modifications and variations are included within the scope of the invention.

[0025] In the following description, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, detailed descriptions of known functions or configurations are omitted to avoid unnecessarily obscuring the key technical aspects of the invention. Furthermore, throughout the description, the same reference numerals always refer to the same circuits, modules, or units, and for the sake of brevity, repeated descriptions of the same circuits, modules, or units are omitted.

[0026] Furthermore, it should be understood that one or more of the following methods or aspects can be performed by at least one control unit or controller. The terms "control unit," "controller," "control module," or "main control module" can refer to a hardware device including a memory and a processor. The memory or computer-readable storage medium is configured to store program instructions, and the processor is specifically configured to execute the program instructions to perform one or more processes, which will be further described below. Moreover, it should be understood that, as those skilled in the art will recognize, the following methods can be performed by including a processor in conjunction with one or more other components.

[0027] This invention utilizes the existing AC voltage sampling circuit of the air conditioner controller to collect and detect in real time whether the AC voltage input to the air conditioner has oscillated. If it is determined that the input power supply voltage has oscillated, the control parameters of the air conditioner are adaptively adjusted, especially the P parameter in the FPC circuit of the air conditioner controller.

[0028] Figure 1 This is a flowchart illustrating an exemplary method for constructing a cargo initial placement posture model according to the present invention. Figure 1 As shown,

[0029] At step S1, it is detected in real time whether the AC input voltage of the air conditioner is oscillating;

[0030] In step S2, when AC input voltage oscillation occurs, the P parameter in the PFC circuit parameters is adaptively adjusted until the smoothness Q of the AC input voltage is less than a preset threshold.

[0031] At step S3, when the value of Q is less than a preset threshold and continues for a second predetermined time, the value of the P parameter is increased once every third predetermined time until the initial preset value of the P parameter is restored.

[0032] According to one or more embodiments of the present invention, the smoothness Q of the AC input voltage is defined as: the ratio of the sum of the K values ​​at all sampling points within a predetermined time period to the maximum value of the AC voltage peak. The preset threshold is related to the number of cycles, frequency, and high-voltage filtering parameters of the air conditioner's AC power supply.

[0033] Figure 2 This is a flowchart of a PFC circuit parameter adjustment method in an air conditioner controller according to an exemplary embodiment of the present invention.

[0034] Specifically, at S11, the peak value of the current sampled AC input voltage of the air conditioner is collected in real time, and the absolute value K of the difference between the peak value of the AC voltage and the previous sampled AC voltage is calculated.

[0035] At S12, calculate the smoothness Q of the AC voltage;

[0036] At S13, a counter is set. If the value of Q is greater than the preset threshold, the counter is incremented by 1, and steps S11 and S12 are repeated.

[0037] At S14, if the value of Q is less than the preset threshold, the counter is reset to zero;

[0038] At S15, when the value of the counter is greater than a preset value, it is determined that the AC input voltage is oscillating.

[0039] According to one or more embodiments of the present invention, specifically, firstly, the air conditioning unit starts up and operates according to preset parameters; secondly, it detects in real time whether voltage oscillation occurs in the AC input voltage, including the following process:

[0040] (1) Real-time acquisition of the peak value of the current AC input voltage of the air conditioning unit and calculation of the absolute value K of the difference between the peak value of the AC voltage sampled in the previous sampling, Kn = abs(Vn - Vn-1). Vn represents the peak value of the current AC input voltage of the air conditioning unit; Vn-1 represents the peak value of the AC voltage sampled in the previous sampling; Kn represents the absolute value of the difference between the peak value of the nth sampling voltage and the peak value of the (n-1)th sampling voltage.

[0041] (2) Calculate the sum of K values ​​over a period of time. A period of time is generally designed as M power supply cycles. Based on the AC voltage sampling period, one power supply cycle can be divided into N sampling points. M power supply cycles will have a total of M*N points. Therefore, K... sum =K1+K2+K3+...+K MN Ksum is the sum of the absolute values ​​of the differences between two adjacent voltage peaks over M power supply cycles. For example, for different input power supply frequencies of 50Hz and 60Hz, M*N is optimally 3000, which can be determined based on the sampling period. For example, with a sampling period of 0.05ms, a total of 2000 samples are collected, taking 100ms, meaning the sum of K values ​​over 100ms is calculated. For example, 100ms equals 5 power supply cycles for a 50Hz power supply and 6 power supply cycles for a 60Hz power supply.

[0042] (3) The smoothness value is defined as the sum of the absolute values ​​of the differences between the peak values ​​of two consecutive AC voltage samples within a certain period, divided by the peak value of the AC voltage. The peak value of the AC voltage is the maximum value of the peak AC voltage within a sampling period. For example, if the maximum AC input voltage within a certain period is U, then U... Max =1.414*U is the maximum peak AC voltage during this period. Smoothness value Q = K sum / U Max Peak value. UMax peak value is the maximum value of the AC voltage after sampling and low-pass filtering constructed by a software algorithm.

[0043] (4) Compare the smoothness value Q with the preset threshold. The preset threshold needs to be analyzed from a large amount of experimental data verification results. It is related to the number of power supply cycles, frequency and high voltage filtering parameters. Specifically, when the power supply does not experience voltage oscillation, the smoothness value is not significantly affected by the number of power supply cycles, frequency and high voltage filtering parameters.

[0044] Figure 3 This is a test data graph of the smoothness value Q according to an exemplary embodiment of the present invention.

[0045] like Figure 3 As shown, some test data of the smoothness value Q are listed. According to the logic of the control method described above according to the present invention, a test program is written in the system and burned into the DSP chip of the outdoor unit controller. The air conditioning unit is tested and run with power supply from the mains power grid, EFT equipment power supply, harmonic power supply equipment, and frequency converter power supply equipment. The correspondence between the smoothness value Q and the peak value of AC input voltage oscillation under each power supply equipment is obtained. Then, the preset threshold is determined according to the magnitude of the peak value of AC input voltage oscillation.

[0046] from Figure 3 The test data shows that when PFC is not enabled, the Q value is very small, approximately equal to 1. Under the same hardware, power supply equipment, and power frequency conditions, if the input voltage oscillates, a larger Q value corresponds to a larger AC voltage peak value. Under the same hardware and power supply equipment, when the AC voltage oscillation peak value is the same, the Q value of the 60Hz power supply is greater than that of the 50Hz power supply. The larger the number of sampling points, the larger the Q value. Under the same power supply equipment and power frequency, when the AC voltage oscillation peak value is the same, the Q value of the controller with poor filtering is greater than that of the controller with good filtering. For example, according to experimental data, a Q value of 28 is preferred, which can ensure that the voltage peak value is below 450V when the AC input power supply voltage oscillates, ensuring the reliability of the entire controller.

[0047] According to one or more embodiments of the present invention, if the smoothness value Q is greater than a preset threshold, the counter is incremented by one; and the above steps (1)-(4) are repeated; if the smoothness value Q is less than the preset threshold, the counter is cleared.

[0048] (5) When the counter value is greater than the preset value, it is determined that the AC input voltage has oscillated; otherwise, it continues to determine whether the counter value is greater than the preset value. The preset value is related to the sampling period and the program call time base, and can be determined according to the actual situation, preferably 10000. The above invention logic can be implemented by program programming. The program statement is called according to a certain time base, such as once every 1ms, then 10000 times is 10 seconds. According to the previous example, the Q value is refreshed once every 100ms, that is, if the Q value is greater than the preset Q threshold for 10 consecutive times, then the adaptive P parameter adjustment will start.

[0049] According to one or more embodiments of the present invention, the P parameter is adaptively adjusted, and the P parameter of the current loop in the PFC control loop is adjusted stepwise. Preferably, P is adjusted towards a smaller value until the smoothness value Q is less than a preset threshold. For example, when the Q value is greater than the preset Q threshold, the P parameter in the PI algorithm of the current loop is decreased stepwise every 10 seconds until the set minimum P parameter is reached; for example, when the Q value is less than the preset Q threshold for 20 minutes, the P parameter value is increased stepwise until the initial P parameter value is restored. The step size can be determined according to actual needs, and is generally 0.2. The maximum value of the P parameter is generally set to 0.9, and the minimum is 0.2. The adjustment interval can be determined according to actual needs. Wherein, the larger the voltage oscillation peak value, the larger the Q value; when the Q value is greater than the preset Q threshold, decreasing the P parameter can effectively reduce the voltage oscillation peak value, and the Q value will also decrease accordingly. During the adjustment of the P parameter, if the Q value is still greater than the preset Q threshold, P is decreased stepwise until it is reduced to the preset minimum P value. According to experimental verification data, the control objective of this invention can generally be achieved by decreasing the P parameter by 1 or 2 steps.

[0050] Figure 4 This is a block diagram of a PFC circuit parameter adjustment device in an air conditioner controller according to an exemplary embodiment of the present invention.

[0051] like Figure 4 As shown, the PFC circuit parameter adjustment device includes: a detection unit for real-time detection of whether the AC input voltage of the air conditioner oscillates; and an adjustment unit for adaptively adjusting the P parameter in the PFC circuit parameters when AC input voltage oscillation occurs, until the smoothness Q of the AC input voltage is less than a preset threshold, wherein the smoothness Q of the AC input voltage is defined as the ratio of the sum of the K values ​​of all sampling points within a predetermined time period to the maximum value of the AC voltage peak.

[0052] According to one or more embodiments of the present invention, the adjustment unit is further configured to: decrease the value of parameter P once every first predetermined time interval until a set minimum value of parameter P is reached. The detection unit is further configured to: acquire the peak value of the current sampled AC input voltage of the air conditioner in real time and calculate the absolute value K of the difference between the peak value of the AC voltage and the adjacent previously sampled peak value; calculate the smoothness Q of the AC voltage; set a counter, and if the value of Q is greater than the preset threshold, increment the counter by 1 and repeat the calculation of the Q value; if the value of Q is less than the preset threshold, reset the counter to zero; when the value of the counter is greater than a preset value, determine that the AC input voltage has oscillated. The adjustment unit is further configured to: when the value of Q is less than the preset threshold and continues for a second predetermined time interval, increase the value of parameter P once every third predetermined time interval until the initial preset value of parameter P is restored.

[0053] According to one or more embodiments of the present invention, an air conditioner is also provided, which employs the above-described PFC circuit parameter adjustment device method, or the above-described PFC circuit parameter adjustment device.

[0054] According to one or more embodiments of the present invention, the control logic in the method of the present invention can implement the processing of the process as described above in the method of the present invention using encoded instructions (e.g., computer and / or machine-readable instructions) stored on a non-transitory computer and / or machine-readable medium (e.g., hard disk drive, flash memory, read-only memory, optical disk, digital multifunction disk, cache, random access memory and / or any other storage device or storage disk), storing information for any time period (e.g., extended time period, permanent, transient instance, temporary cache and / or information cache) in the non-transitory computer and / or machine-readable medium. As used herein, the term "non-transitory computer-readable medium" is explicitly defined to include any type of computer-readable storage device and / or storage disk, and excludes propagation signals and transmission media.

[0055] According to one or more embodiments of the present invention, the method of the present invention can be implemented using control circuitry (control logic, main control system, or control module), which may include one or more processors and may internally include a non-transitory computer-readable medium. Specifically, the main control system or control module may include a microcontroller (MCU). The processor used to implement the processing of the method of the present invention may be, such as, but not limited to, one or more single-core or multi-core processors. The processor(s) may include any combination of general-purpose processors and special-purpose processors (e.g., graphics processors, application processors, etc.). The processor may be coupled thereto and / or may include memory / storage devices and may be configured to execute instructions stored in the memory / storage devices to implement various applications and / or operating systems running on the controller in the present invention.

[0056] The accompanying drawings and detailed description of the invention, cited above as examples, serve to explain the invention but do not limit its meaning or scope as described in the claims. Therefore, those skilled in the art can readily make modifications from the above description. Furthermore, those skilled in the art can remove some of the components described herein without degrading performance, or add other components to improve performance. Additionally, those skilled in the art can change the order of steps in the method described herein depending on the process or equipment environment. Therefore, the scope of the invention should not be determined by the embodiments described above, but rather by the claims and their equivalents.

[0057] Although the invention has been described in conjunction with embodiments now considered to be achievable, it should be understood that the invention is not limited to the disclosed embodiments, but rather is intended to cover various modifications and equivalent configurations included within the spirit and scope of the appended claims.

Claims

1. A method for adjusting PFC circuit parameters in an air conditioner controller, comprising: S1: Real-time detection of whether the AC input voltage of the air conditioner is oscillating; S2: When AC input voltage oscillation occurs, the P parameter in the PFC circuit parameters is adaptively adjusted until the smoothness Q of the AC input voltage is less than a preset threshold. The smoothness Q of the AC input voltage is defined as the ratio of the sum of the absolute values ​​of the differences K between two consecutive AC voltage peak values ​​within a predetermined time period to the maximum value of the AC voltage peak value. In step S1, the real-time detection of whether the AC input voltage of the air conditioner is experiencing voltage oscillation includes: S11: Real-time acquisition of the peak value of the current sampled AC input voltage of the air conditioner and calculation of the absolute value K of the difference between the peak value of the AC voltage and the adjacent previous sampled peak value; S12: Calculate the smoothness Q of the AC voltage; S13: Set a counter. If the value of Q is greater than the preset threshold, increment the counter by 1 and repeat steps S11 and S12. S14: If the value of Q is less than the preset threshold, the counter is reset to zero; S15: When the value of the counter is greater than the preset value, it is determined that the AC input voltage is oscillating.

2. The method according to claim 1, wherein the preset threshold is related to the number of cycles, frequency, and high-voltage filtering parameters of the air conditioner's AC power supply.

3. The method according to claim 1, wherein in step S2, the adaptive adjustment of the P parameter in the PFC circuit parameters comprises: Every first predetermined time interval, the value of parameter P decreases once until it reaches the set minimum threshold of parameter P.

4. The method according to claim 1, further comprising: S3: When the value of Q is less than the preset threshold and continues for a second predetermined time, the value of the P parameter is increased once every third predetermined time until the initial preset value of the P parameter is restored.

5. A PFC circuit parameter adjustment device in an air conditioner controller, comprising: Detection unit: Used to detect in real time whether the AC input voltage of the air conditioner is oscillating; Adjustment unit: Used to adaptively adjust the P parameter in the PFC circuit parameters when AC input voltage oscillation occurs, until the smoothness Q of the AC input voltage is less than a preset threshold. The smoothness Q of the AC input voltage is defined as the ratio of the sum of the K values ​​at all sampling points within a predetermined time period to the maximum value of the AC voltage peak. The detection unit is further configured to: acquire the peak value of the current sampled AC input voltage of the air conditioner in real time and calculate the absolute value K of the difference between the peak value of the AC voltage and the adjacent previous sampled peak value; calculate the smoothness Q of the AC voltage; set a counter, and if the value of Q is greater than the preset threshold, increment the counter by 1 and repeat the calculation of the Q value. If the value of Q is less than the preset threshold, the counter is reset to zero; when the value of the counter is greater than the preset value, it is determined that the AC input voltage is oscillating.

6. The device according to claim 5, wherein the preset threshold is related to the number of cycles, frequency, and high-voltage filtering parameters of the air conditioner AC power supply.

7. The apparatus according to claim 5, wherein the adjustment unit is further configured to: decrease the value of parameter P once every first predetermined time interval until a set minimum value of parameter P is reached.

8. The apparatus according to claim 5, wherein the adjustment unit is further configured to: when the value of Q is less than a preset threshold and continues for a second predetermined time, increase the value of the P parameter once every predetermined third predetermined time until the initial preset value of the P parameter is restored.

9. An air conditioner that employs the method according to any one of claims 1-4, or includes the apparatus according to any one of claims 5-8.

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