Adjustment method of power factor correction circuit, controller and electric equipment

Abstract

The invention discloses an adjusting method of a power factor correction circuit, a controller and electric equipment. The power factor correction circuit comprises an inductor and a target switch tube. The adjusting method comprises the following steps: acquiring an output current and an output voltage of the power factor correction circuit; adjusting the target switching frequency of the driving signal according to the duty ratio of the output driving signal, the output current, the output voltage, the working characteristics of the inductor and the working characteristics of the target switching tube; the driving signal is a signal used for driving the target switching tube to be switched on and off. In the embodiment of the invention, the target switching frequency can be quickly determined, and the working efficiency of the circuit is improved.

Description

Technical Field

[0001] The present application relates to the field of electronic circuits, and in particular to an adjustment method, a controller and an electrical device of a power factor correction circuit. Background Art

[0002] The power factor correction circuit (Power Factor Correction, PFC) has several common operating modes, including continuous conduction mode (Continuous Conduction Mode, CCM), discontinuous conduction mode (Discontinuous Conduction Mode, DCM) and critical conduction mode (Critical Conduction Mode, CRM). When the power factor correction circuit switches from low load control to large load control, the discontinuous conduction mode is usually switched to the continuous conduction mode. Since the switch tube is in a low-frequency switching state in the discontinuous conduction mode, the peak current of the inductor is large. After entering the continuous conduction mode, the switching frequency of the switch tube is accelerated, resulting in increased losses of the switch tube and the inductor, and reduced circuit efficiency.

[0003] The existing discontinuous conduction mode is usually a full analog control circuit solution, and it is difficult to overcome the problem of reduced circuit efficiency when entering the continuous conduction mode. Summary of the invention

[0004] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes an adjustment method, a controller and an electrical device for a power factor correction circuit, which can quickly determine a target switching frequency and improve the working efficiency of the circuit.

[0005] An embodiment of the first aspect of the present application provides an adjustment method, wherein the power factor correction circuit includes an inductor and a target switch tube; the adjustment method includes:

[0006] Obtaining an output current and an output voltage of the power factor correction circuit;

[0007] Adjusting the target switching frequency of the drive signal according to the duty cycle of the output drive signal, the output current, the output voltage, the operating characteristics of the inductor and the operating characteristics of the target switch tube;

[0008] The driving signal is a signal used to drive the target switch tube to switch.

[0009] The adjustment method of the first aspect embodiment of the present application has at least the following beneficial effects: during the operation of the power factor correction circuit, the switching state of the switch tube is controlled by a certain drive signal. The embodiment of the present application determines the target switching frequency of the target switch tube through the duty cycle of the drive signal, the output current, the output voltage, the working characteristics of the inductor and the working characteristics of the target switch tube. That is to say, the target switching frequency takes into account the output condition of the power factor correction circuit, as well as the losses in the inductor and the target switch tube in the power factor correction circuit. Therefore, when the power factor correction circuit switches from a discontinuous conduction mode to a continuous conduction mode, the adjusted target switching frequency can reduce the inductor loss and the switch tube loss of the target switch tube based on the current output voltage and output current of the power factor correction circuit, thereby quickly adjusting the drive signal and improving the working efficiency of the power factor correction circuit.

[0010] According to some embodiments of the present application, adjusting the target switching frequency of the drive signal according to the duty cycle of the output drive signal, the output current, the output voltage, the operating characteristics of the inductor, and the operating characteristics of the target switch tube includes:

[0011] Determine the inductance loss of the inductor of the power factor correction circuit and the switching tube loss of the target switching tube according to the duty cycle of the output drive signal, the output current, the output voltage, the operating characteristics of the inductor and the operating characteristics of the target switching tube;

[0012] The target switching frequency of the driving signal is adjusted according to the inductor loss and the switch tube loss.

[0013] According to some embodiments of the present application, the loss characteristic parameters of the inductor include the magnetic field coefficient, hysteresis loss coefficient and eddy current loss coefficient of the inductor; the switch response characteristic parameters include the first time length required for the conduction process of the target switch tube and the second time length required for the shutdown process of the target switch tube.

[0014] According to some embodiments of the present application, adjusting the target switching frequency of the driving signal according to the inductor loss and the switch tube loss includes:

[0015] Determine the current total loss according to the inductor loss and the switch tube loss;

[0016] The current switching frequency of the driving signal is changed as the target switching frequency, and the target switching frequency is adjusted according to the change of the current total loss.

[0017] According to some embodiments of the present application, changing the current switching frequency of the driving signal as the target switching frequency, and adjusting the target switching frequency according to the change of the current total loss, includes:

[0018] increasing the current switching frequency of the driving signal as a target switching frequency;

[0019] When the current total loss increases, the target switching frequency is reduced, and when the current total loss decreases, the target switching frequency is increased;

[0020] The adjusted target switching frequency is used as the current switching frequency, and the current total loss is re-determined.

[0021] According to some embodiments of the present application, changing the current switching frequency of the driving signal as the target switching frequency, and adjusting the target switching frequency according to the change of the current total loss, includes:

[0022] reducing a current switching frequency of the driving signal as a target switching frequency;

[0023] When the current total loss increases, the target switching frequency is increased, and when the current total loss decreases, the target switching frequency is decreased;

[0024] The adjusted target switching frequency is used as the current switching frequency, and the current total loss is re-determined.

[0025] According to some embodiments of the present application, reducing the target switching frequency includes:

[0026] reducing the target switching frequency of the drive signal according to a first preset value, where the first preset value is a fixed value or is determined according to a variation range of the current total loss;

[0027] The step of increasing the target switching frequency includes:

[0028] The target switching frequency of the driving signal is increased according to a second preset value, where the second preset value is a fixed value or is determined according to a variation range of the current total loss.

[0029] According to some embodiments of the present application, the second preset value is a fixed value or is determined according to the variation range of the current total loss.

[0030] Before obtaining the output current and output voltage of the power factor correction circuit, the adjustment method further includes:

[0031] Monitoring the output power of the power factor correction circuit to determine that the output power of the power factor correction circuit is in a stable state;

[0032] or,

[0033] The operating power of the compressor connected to the power factor correction circuit is monitored to determine whether the operating power of the compressor is in a stable state.

[0034] According to some embodiments of the present application, adjusting the target switching frequency of the drive signal according to the duty cycle of the output drive signal, the output current, the output voltage, the operating characteristics of the inductor, and the operating characteristics of the target switch tube includes:

[0035] The target switching frequency is determined according to the current switching frequency of the drive signal, the loss characteristic parameters of the inductor, the duty cycle of the drive signal, the current switching frequency of the drive signal, the output current, the output voltage and the switching response characteristic parameters of the target switch tube.

[0036] A second aspect of the present application provides a controller, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the adjustment method as described in the first aspect when executing the computer program.

[0037] The third aspect of the present application provides an electrical device, including the controller described in the second aspect.

[0038] Other features and advantages of the present application will be described in the following description, and partly become apparent from the description, or understood by practicing the present application. The purpose and other advantages of the present application can be realized and obtained through the structures particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a circuit diagram of a power factor correction circuit provided by an embodiment of the present application;

[0040] Figure 2 is a method flow chart of an adjustment method provided by an embodiment of the present application;

[0041] Figure 3 yes Figure 2 Specific flow chart of step S200;

[0042] Figure 4 yes Figure 3 Specific flow chart of step S220;

[0043] Figure 5 yes Figure 4 Specific flow chart of step S222;

[0044] Figure 6 yes Figure 4 Another specific flow chart of step S222;

[0045] Figure 7 is a flow chart of a method for reducing a target switching frequency provided by an embodiment of the present application;

[0046] Figure 8 is a flow chart of a method for increasing a target switching frequency provided by an embodiment of the present application;

[0047] Fig. 9 is a method flow chart of an adjustment method provided by another embodiment of the present application;

[0048] Fig.10 is a method flow chart of an adjustment method provided by another embodiment of the present application;

[0049] Fig.11 yes Figure 2 Another specific flow chart of step S200 in FIG. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below in conjunction with the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. In addition, the characteristics, operations or features described in the specification can be combined in any appropriate manner to form various implementation methods. At the same time, the steps or actions in the method description can also be replaced or adjusted in order in a manner that is obvious to those skilled in the art. Therefore, the various sequences in the specification and the accompanying drawings are only for the purpose of clearly describing a certain embodiment and are not meant to be a necessary sequence, unless otherwise specified that a certain sequence must be followed.

[0051] In the description of this application, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, and "above", "below", "within", etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0052] The serial numbers of the components in this document, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in this application, unless otherwise specified, include direct and indirect connections (couplings).

[0053] The power factor correction circuit has several common operating modes, including continuous conduction mode, intermittent conduction mode and critical conduction mode, etc. The existing control methods of the power factor correction circuit basically adopt the fixed frequency control method, and some schemes use the control mode of the critical conduction mode to change the control frequency of the power factor correction circuit.

[0054] On the one hand, when the fixed frequency control method is adopted, when the power factor correction circuit switches from low load control to larger load control, the discontinuous conduction mode is usually switched to the continuous conduction mode. Since the switch tube is in a low-frequency switching state in the discontinuous conduction mode, the peak current of the inductor is large. After entering the continuous conduction mode, the switching frequency of the switch tube is accelerated, resulting in increased losses in the switch tube and the inductor, and reduced circuit efficiency.

[0055] It can be seen that when the power factor correction circuit works at a low load, the loss in the power factor correction circuit is basically the loss of the switch tube, which is not conducive to improving the efficiency of the power factor correction circuit at a light load. When the power factor correction circuit switches from low load control to large load control, the loss of the switch tube and the loss of the inductor will increase, and the circuit efficiency will decrease.

[0056] On the other hand, the existing discontinuous conduction mode is usually a full analog control circuit solution, and it is difficult to overcome the problem of reduced circuit efficiency when entering the continuous conduction mode.

[0057] Based on this, the embodiments of the present application provide an adjustment method, a controller and an electrical equipment for a power factor correction circuit. During the operation of the power factor correction circuit, the switching state of the switching tube is controlled by a certain driving signal. The embodiments of the present application determine the target switching frequency of the target switching tube through the duty cycle of the driving signal, the output current, the output voltage, the working characteristics of the inductor and the working characteristics of the target switching tube. That is to say, the target switching frequency takes into account the output condition of the power factor correction circuit, as well as the losses in the inductor and the target switching tube in the power factor correction circuit. Therefore, when the power factor correction circuit switches from a discontinuous conduction mode to a continuous conduction mode, the adjusted target switching frequency can reduce the inductor loss and the switching tube loss of the target switching tube based on the current output voltage and output current of the power factor correction circuit, thereby quickly adjusting the driving signal and improving the working efficiency of the power factor correction circuit.

[0058] The embodiments of the present application are further described below in conjunction with the accompanying drawings.

[0059] like Figure 1 As shown, Figure 1 : is a circuit diagram of a power factor correction circuit provided by an embodiment of the present application, the power factor correction circuit comprising:

[0060] In some embodiments, the power factor correction circuit includes an inductor L1 and a target switch tube, and the inductor L1 is connected to the target switch tube, wherein the power factor correction circuit also includes a first bridge arm 100 and a second bridge arm 200, the first bridge arm 100 is provided with a first switch tube Q1 and a second switch tube Q2 connected in series; the second bridge arm 200 is provided with a third switch tube Q3 and a fourth switch tube Q4 connected in series.

[0061] It should be noted that the first switch tube Q1, the second switch tube Q2, the third switch tube Q3 and the fourth switch tube Q4 in this embodiment can be PMOS tubes or NMOS tubes. This embodiment and the accompanying drawings are explained by taking the first switch tube Q1, the second switch tube Q2, the third switch tube Q3 and the fourth switch tube Q4 as NMOS tubes. For example, Figure 1 In the circuit diagram shown, the first switch tube Q1 , the second switch tube Q2 , the third switch tube Q3 and the fourth switch tube Q4 are all NMOS tubes.

[0062] In some embodiments, the power factor correction circuit is a totem pole circuit, which includes an inductor L1, a middle connection point of the first bridge arm 100 is connected to one phase of the AC voltage through the inductor L1, and a middle connection point of the second bridge arm 200 is connected to another phase of the AC voltage.

[0063] It can be understood that the first bridge arm 100 is connected in parallel with the second bridge arm 200. When the first switch tube Q1, the second switch tube Q2, the third switch tube Q3 and the fourth switch tube Q4 are all NMOS tubes, the source of the first switch tube Q1 is connected to the drain of the second switch tube Q2, the drain of the first switch tube Q1 is connected to the voltage output end, the source of the second switch tube Q2 is connected to the reference ground, the source of the third switch tube Q3 is connected to the drain of the fourth switch tube Q4, the drain of the third switch tube Q3 is connected between the first switch tube Q1 and the voltage output end, the source of the fourth switch tube Q4 is connected between the second switch tube Q2 and the reference ground, and the inductor L1 is connected between the source of the first switch tube Q1 and the drain of the second switch tube Q2.

[0064] It should be noted that the target switch tube in this embodiment is the first switch tube Q1 or the second switch tube Q2.

[0065] Based on the structural diagram of the above power factor correction circuit, various embodiments of the control method of the present application are proposed.

[0066] like Figure 2 As shown, Figure 2 It is a method flow chart of an adjustment method provided by an embodiment of the present application. The adjustment method includes but is not limited to steps S100 to S200.

[0067] Step S100, obtaining the output current and output voltage of the power factor correction circuit;

[0068] Step S200, adjusting the target switching frequency of the driving signal according to the duty cycle of the output driving signal, the output current, the output voltage, the working characteristics of the inductor and the working characteristics of the target switch tube.

[0069] It should be noted that the driving signal is a signal used to drive the target switch tube to switch.

[0070] In some embodiments, the output current and output voltage of the power factor correction circuit are obtained to obtain the working state of the power factor correction circuit during operation, and then the target switching frequency of the drive signal is adjusted according to the duty cycle of the output drive signal, the output current, the output voltage, the working characteristics of the inductor and the working characteristics of the target switch tube, so that the output condition of the power factor correction circuit and the loss of the inductor and the target switch tube can be considered at the same time, so as to reduce the energy loss of the inductor element due to the internal resistance during operation, and reduce the energy loss of the switch tube due to conduction and cutoff during the switching process, so as to improve the efficiency of the power factor correction circuit, reduce energy waste, and at the same time improve the reliability and life of the target switch tube.

[0071] It should be noted that the duty cycle of the drive signal is the ratio of the high level time of the signal in one cycle to the total cycle time. It is generally expressed as a percentage, such as 50% means that the high level time accounts for 50% of the total cycle time. Among them, the duty cycle can be obtained by changing the length of the high level time and the low level time of the drive signal. For example, if the high level time is 2 milliseconds and the low level time is 2 milliseconds, the duty cycle is 50%. The duty cycle of the drive signal can be used to control and adjust the output voltage.

[0072] It is worth noting that the working characteristics of the inductor are used to characterize the working performance of the inductor under the working state, including but not limited to the energy storage characteristics, impedance characteristics, filtering characteristics, current transient suppression characteristics, etc. of the inductor, and the working characteristics of the inductor include multiple characteristic parameters of the inductor, for example, the inductance coefficient of the inductor, the saturation current value of the inductor, the internal resistance of the inductor, etc.

[0073] Among them, the energy storage characteristic refers to the ability of the inductor to store electrical energy, that is, when current passes through the inductor, the inductor stores electrical energy in the magnetic field; the impedance characteristic refers to the inductor's certain impedance capacity to alternating current, and the impedance value of the inductor is related to the inductance, frequency and inductance of the inductor; the filtering characteristic refers to the inductor's ability to change the transmission of signals of different frequencies in the circuit through its impedance value; the current transient suppression characteristic refers to the inductor's ability to resist current transients, thereby avoiding instantaneous large changes in current.

[0074] The working characteristics of the target switch tube are used to characterize the working performance of the target switch tube in the on and off states, for example, the time required for the switch tube to switch states, the losses generated during the switching state conversion process, etc., and the working characteristics of the target switch tube include multiple characteristic parameters of the target switch tube, for example, the on-state voltage drop of the target switch tube, the off-state current of the target switch tube, the switching speed parameters of the target switch tube, the switching loss value of the target switch tube, etc.

[0075] Among them, the on-state voltage drop of the target switch tube is used to characterize the voltage drop value at both ends of the target switch tube when the target switch tube is in the on state; the cut-off current of the target switch tube is used to characterize the leakage current at both ends of the target switch tube when the target switch tube is in the off state; the switching speed parameter of the target switch tube is used to characterize the switching time of the target switch tube from on-state to off-state or from off-state to on-state.

[0076] It is understandable that different types of switch tubes have different on-state voltage drops.

[0077] like Figure 3 As shown, Figure 3 yes Figure 2 Specific flow chart of step S200, step S200 includes but is not limited to steps S210 to S220.

[0078] Step S210, determining the inductance loss of the inductor of the power factor correction circuit and the switching tube loss of the target switching tube according to the duty cycle of the output drive signal, the output current, the output voltage, the working characteristics of the inductor and the working characteristics of the target switching tube;

[0079] Step S220, adjusting the target switching frequency of the driving signal according to the inductor loss and the switch tube loss.

[0080] In some embodiments, the inductance loss of the inductor of the power factor correction circuit and the switching tube loss of the target switching tube are determined according to the duty cycle of the output drive signal, the output current, the output voltage, the operating characteristics of the inductor and the operating characteristics of the target switching tube, so that the response degree of the inductor element to the current change can be reflected through the inductance loss to realize the evaluation of the inductance transmission effect and performance, and the drive signal and the target switching frequency are adjusted according to the inductance loss and the switching tube loss to reduce the inductance loss and the switching tube loss of the target switching tube, thereby improving the efficiency and stability of the power factor correction circuit, thereby optimizing the energy conversion and transmission process, reducing energy loss and improving system performance.

[0081] In some embodiments, the inductor loss is determined based on the current switching frequency of the drive signal, the loss characteristic parameters of the inductor and the output current; the switch tube loss is determined based on the duty cycle of the drive signal, the current switching frequency of the drive signal, the output current, the output voltage and the switch response characteristic parameters of the target switch tube, so that the energy loss caused by the internal resistance of the inductor element during operation can be obtained, which is convenient for subsequent reduction of losses in the energy conversion process and improvement of the overall efficiency of the power factor correction circuit. In addition, determining the inductor loss and the switch tube loss can achieve efficient, stable and reliable operation of the power factor correction circuit, thereby improving the efficiency in the energy conversion and transmission process and extending the service life of the system.

[0082] In some embodiments, the loss characteristic parameters of the inductor include the magnetic field coefficient, hysteresis loss coefficient and eddy current loss coefficient of the inductor; the switch response characteristic parameters include the first time required for the conduction process of the target switch tube and the second time required for the shutdown process of the target switch tube, so as to achieve accurate determination of the inductance loss of the inductor of the power factor correction circuit and the switching tube loss of the target switch tube, and achieve a comprehensive analysis of the working state of the power factor correction circuit.

[0083] It should be noted that the magnetic field coefficient of the inductor is the degree of response of the magnetic induction intensity to the change of current per unit length. For the inductor in the power factor correction circuit, the magnetic field coefficient can be used to evaluate the sensitivity of the inductor element to the change of current, so as to achieve effective power factor correction; the hysteresis loss coefficient refers to the energy loss caused by the hysteresis phenomenon in the alternating magnetic field of the magnetic material. In the power factor correction circuit, the magnetic field generated by the inductor will change frequently. If the magnetic material has a large hysteresis loss coefficient, it will cause additional energy loss and heat generation, reducing the efficiency of the circuit. Therefore, when selecting the inductor in the power factor correction circuit, the hysteresis loss coefficient needs to be considered; the eddy current loss coefficient refers to the energy loss caused by the induced eddy current in the conductor in the alternating magnetic field. In the power factor correction circuit, the coil in the inductor is usually composed of metal conductors. When the current passing through these conductors changes, eddy currents will be generated. If the geometry of the conductor, the conductivity of the material, and the frequency of the alternating magnetic field are unreasonable, it will cause large eddy current losses and reduce the efficiency of the circuit. Therefore, when designing the inductor in the power factor correction circuit, it is necessary to reasonably select the conductor material and structure to reduce the eddy current loss.

[0084] It is worth noting that the first time duration is the time duration required for the conduction process of the target switch tube, wherein the conduction process is the process of the target switch tube changing from the off-state to the on-state, and the first time duration starts from the moment the off-state changes to the duration of the entire process of completely changing to the on-state; the second time duration is the time duration required for the shutdown process of the target switch tube, wherein the shutdown process is the process of the target switch tube changing from the on-state to the off-state, and the second time duration starts from the moment the on-state changes to the duration of the entire process of completely changing to the off-state.

[0085] In some embodiments, the calculation formula of the inductor loss is shown in the following formula (1):

[0086]

[0087] The calculation formula of the switch tube loss is shown in the following formula (2):

[0088] P sw =Y 0f (t on +t off ) (2)

[0089] Where X0 = τI o , τ is the magnetic field coefficient of inductance, K h is the hysteresis loss coefficient, K e is the eddy current loss coefficient, t on is the first duration, t off is the second duration, f is the current switching frequency of the drive signal, I o is the output current, D is the duty cycle of the drive signal, U o is the output voltage.

[0090] like Figure 4 As shown, Figure 4 yes Figure 3 Specific flow chart of step S220, step S220 includes but is not limited to steps S221 to S222.

[0091] Step S221, determining the current total loss according to the inductor loss and the switch tube loss;

[0092] Step S222, changing the current switching frequency of the driving signal as the target switching frequency, and adjusting the target switching frequency according to the change of the current total loss.

[0093] In some embodiments, the current switching frequency of the drive signal is fixed, and the sum of the inductor loss and the switch tube loss is calculated to determine the current total loss of the power factor correction circuit, and then the current switching frequency of the drive signal is changed as the target switching frequency, and the target switching frequency is adjusted in real time according to the change of the current total loss, so that the output of the power factor correction circuit and the loss of the inductor and the target switch tube can be considered at the same time, thereby realizing rapid adjustment of the drive signal.

[0094] like Figure 5 As shown, Figure 5 yes Figure 4 Specific flow chart of step S222 in the figure, step S222 includes but is not limited to steps S2220 to S2222.

[0095] Step S2220, increasing the current switching frequency of the driving signal as the target switching frequency;

[0096] Step S2221, when the current total loss increases, the target switching frequency is reduced, and when the current total loss decreases, the target switching frequency is increased;

[0097] Step S2222, using the adjusted target switching frequency as the current switching frequency, and re-determining the current total loss.

[0098] In some embodiments, in the process of changing the current switching frequency of the driving signal as the target switching frequency, the current switching frequency of the driving signal can be first increased as the target switching frequency. When it is determined that the current total loss increases, that is, the sum of the inductance loss and the switching tube loss increases, the target switching frequency is lowered. When it is determined that the current total loss decreases, that is, the sum of the inductance loss and the switching tube loss decreases, the target switching frequency is increased. Finally, the adjusted target switching frequency is used as the current switching frequency, the current total loss is re-determined, and steps S2220 to S2222 are repeated. The current switching frequency is continuously changed until the target switching frequency meets the preset optimal solution interval, thereby reducing the inductance loss and the switching tube loss of the target switching tube, and improving the working efficiency of the power factor correction circuit.

[0099] It is worth noting that the optimal solution interval includes multiple switching frequency values. The target switching frequency finally obtained in this embodiment needs to be within the optimal solution interval to improve the working efficiency of the power factor correction circuit.

[0100] like Figure 6 As shown, Figure 6 yes Figure 4 Another specific flow chart of step S222, step S222 includes but is not limited to steps S2223 to S2225.

[0101] Step S2223, reducing the current switching frequency of the driving signal as the target switching frequency;

[0102] Step S2224, when the current total loss increases, the target switching frequency is increased, and when the current total loss decreases, the target switching frequency is decreased;

[0103] Step S2225, taking the adjusted target switching frequency as the current switching frequency, and re-determining the current total loss.

[0104] In some embodiments, in the process of changing the current switching frequency of the driving signal as the target switching frequency, the current switching frequency of the driving signal can also be first lowered as the target switching frequency. When it is determined that the current total loss increases, that is, the sum of the inductance loss and the switching tube loss increases, the target switching frequency is increased. When it is determined that the current total loss decreases, that is, the sum of the inductance loss and the switching tube loss decreases, the target switching frequency is lowered. Finally, the adjusted target switching frequency is used as the current switching frequency, the current total loss is re-determined, and steps S2223 to S2225 are repeated. The current switching frequency is continuously changed until the target switching frequency meets the preset optimal solution interval, thereby reducing the inductance loss and the switching tube loss of the target switching tube, and improving the working efficiency of the power factor correction circuit.

[0105] like Figure 7 As shown, Figure 7It is a flow chart of a method for reducing a target switching frequency provided by an embodiment of the present application. The method includes but is not limited to step S300.

[0106] Step S300 , reducing the target switching frequency of the driving signal according to a first preset value, where the first preset value is a fixed value or is determined according to a variation range of the current total loss.

[0107] In some embodiments, in the process of reducing the target switching frequency, the target switching frequency of the driving signal is reduced according to a first preset value to avoid the switching frequency being too low after reduction and causing abnormal noise in the power factor correction circuit, wherein the first preset value is a fixed value or is determined according to the change amplitude of the current total loss.

[0108] It should be noted that when the load power of the power factor correction circuit is very low, the switching frequency will drop very low. At this time, the power factor correction circuit will produce abnormal noise. Therefore, the minimum frequency needs to be limited so that in the entire process of increasing the current switching frequency of the driving signal, the target switching frequency after the reduction is controlled to be higher than the minimum frequency, so as to avoid the influence of abnormal noise of the power factor correction circuit and improve the stability of the power factor correction circuit.

[0109] like Figure 8 As shown, Figure 8 It is a flow chart of a method for increasing the target switching frequency provided by an embodiment of the present application, and the method includes but is not limited to step S400.

[0110] Step S400: increasing the target switching frequency of the driving signal according to a second preset value, where the second preset value is a fixed value or is determined according to a variation range of the current total loss.

[0111] In some embodiments, when the target switching frequency is increased, the target switching frequency of the drive signal is increased according to a second preset value to avoid the increased switching frequency exceeding the control range of the controller, wherein the second preset value is a fixed value or is determined according to the variation range of the current total loss.

[0112] It should be noted that in the process of increasing the current switching frequency of the driving signal, when the load power is large and a magnetic core with large losses is used, the switching frequency will be increased to a very high level, exceeding the control range of the controller. Therefore, this embodiment needs to limit the maximum frequency of the switching frequency, so that in the entire process of increasing the current switching frequency of the driving signal, the target switching frequency after the increase is controlled to be less than the maximum frequency, so as to avoid exceeding the control range of the controller and improve the stability of the power factor correction circuit.

[0113] like Fig. 9 As shown, Fig. 9 It is a method flow chart of an adjustment method provided by another embodiment of the present application. The adjustment method includes but is not limited to step S500.

[0114] It should be noted that step S500 occurs before obtaining the output current and output voltage of the power factor correction circuit.

[0115] Step S500, monitoring the output power of the power factor correction circuit to determine whether the output power of the power factor correction circuit is in a stable state.

[0116] In some embodiments, before obtaining the output current and output voltage of the power factor correction circuit, it is also necessary to monitor the output power of the power factor correction circuit to determine whether the output power of the power factor correction circuit is in a stable state, thereby reducing energy loss and improving the stability and reliability of the power factor correction circuit.

[0117] It should be noted that, in this embodiment, whether the power factor correction circuit is in a stable state can be determined by observing the fluctuation range of the power factor correction circuit under normal operating conditions through the output power. For example, when the fluctuation of the output power is small and stable within a certain range, it indicates that it is in a stable state; whether the power factor correction circuit is in a stable state can also be determined by judging the stabilization time of the output power. For example, the output power of the power factor correction circuit after startup or adjustment can be observed. When the output power remains relatively stable for a period of time, it can be determined that the power factor correction circuit is in a stable state, etc. This embodiment does not impose specific restrictions.

[0118] like Fig.10 As shown, Fig.10 It is a method flow chart of an adjustment method provided by another embodiment of the present application. The adjustment method includes but is not limited to step S600.

[0119] It should be noted that step S600 occurs before obtaining the output current and output voltage of the power factor correction circuit.

[0120] Step S600, monitoring the operating power of the compressor connected to the power factor correction circuit to determine whether the operating power of the compressor is in a stable state.

[0121] In some embodiments, before obtaining the output current and output voltage of the power factor correction circuit, the operating power of the compressor connected to the power factor correction circuit can also be monitored to determine whether the operating power of the compressor is in a stable state, thereby reducing energy loss and improving the stability and reliability of the power factor correction circuit.

[0122] It should be noted that, in this embodiment, whether the power factor correction circuit is in a stable state can be determined by the operating power of the compressor, wherein whether the power factor correction circuit is in a stable state can be determined by judging the active power and apparent power of the compressor. For example, when the active power and the apparent power remain stable, it is determined that the power factor correction circuit is in a stable state; it is also possible to judge whether the power factor correction circuit is in a stable state by observing the power factor in the operating power of the compressor. For example, when the operating power of the compressor is stable in a fixed interval, it is determined that the power factor correction circuit is in a stable state, and so on. This embodiment does not impose specific restrictions.

[0123] like Fig.11 As shown, Fig.11 yes Figure 2 Another specific flow chart of step S200, step S200 includes but is not limited to step S230.

[0124] Step S230, determining the target switching frequency according to the current switching frequency of the driving signal, the loss characteristic parameters of the inductor, the duty cycle of the driving signal, the current switching frequency of the driving signal, the output current, the output voltage and the switching response characteristic parameters of the target switch tube.

[0125] In some embodiments, in addition to determining the inductance loss of the inductor of the power factor correction circuit and the switching tube loss of the target switch tube based on the duty cycle of the output drive signal, the output current, the output voltage, the operating characteristics of the inductor and the operating characteristics of the target switch tube, the target switching frequency can also be determined based on the current switching frequency of the drive signal, the loss characteristic parameters of the inductor, the duty cycle of the drive signal, the current switching frequency of the drive signal, the output current, the output voltage and the switching response characteristic parameters of the target switch tube, thereby reducing the inductance loss and the switching tube loss of the target switch tube, improving the efficiency and stability of the power factor correction circuit, optimizing the energy conversion and transmission process, reducing energy loss and improving system performance.

[0126] It should be noted that the target switching frequency of step S230 is expressed as shown in the following formula (3):

[0127]

[0128] Where X0 = τI o , τ is the magnetic field coefficient of inductance, K h is the hysteresis loss coefficient, K e is the eddy current loss coefficient, t on is the first duration, t off is the second duration, f is the current switching frequency of the drive signal, I o is the output current, D is the duty cycle of the drive signal, Uo is the output voltage.

[0129] In addition, an embodiment of the present application also provides a controller, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the aforementioned adjustment method when executing the computer program.

[0130] An embodiment of the present application also provides an electrical device, including the aforementioned controller.

[0131] It should be noted that the electrical equipment provided in this embodiment has the beneficial effects brought about by the control method of the power factor correction circuit as described above, which will not be described in detail in this embodiment.

[0132] The device embodiments described above are merely illustrative, and the units described as separate components may or may not be physically separated, that is, they may be located in one place or distributed on multiple network nodes. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0133] It will be appreciated by those skilled in the art that all or some of the steps and systems in the disclosed method above may be implemented as software, firmware, hardware and appropriate combinations thereof. Some physical components or all physical components may be implemented as software executed by a processor, such as a central processing unit, a digital signal processor or a microprocessor, or may be implemented as hardware, or may be implemented as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer-readable storage medium (or a non-transitory medium) and a communication medium (or a temporary medium). As known to those skilled in the art, the term computer-readable storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules or other data). Computer-readable storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, disk storage or other magnetic storage devices, or any other medium that may be used to store desired information and may be accessed by a computer. Furthermore, it is well known to those skilled in the art that communication media typically embodies computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

[0134] The above is a specific description of the preferred implementation of the present application, but the present application is not limited to the above-mentioned implementation mode. Technical personnel familiar with the field can also make various equivalent deformations or substitutions without violating the spirit of the present application. These equivalent deformations or substitutions are all included in the scope defined by the claims of the present application.

Claims

1. A method for adjusting a power factor correction circuit, characterized in that: The power factor correction circuit includes an inductor and a target switch tube; the adjustment method includes: Obtaining an output current and an output voltage of the power factor correction circuit; Adjusting the target switching frequency of the drive signal according to the duty cycle of the output drive signal, the output current, the output voltage, the operating characteristics of the inductor and the operating characteristics of the target switch tube; The driving signal is a signal used to drive the target switch tube to switch.

2. The adjustment method according to claim 1, characterized in that: The step of adjusting the target switching frequency of the drive signal according to the duty cycle of the output drive signal, the output current, the output voltage, the operating characteristics of the inductor, and the operating characteristics of the target switch tube comprises: Determine the inductance loss of the inductor of the power factor correction circuit and the switching tube loss of the target switching tube according to the duty cycle of the output drive signal, the output current, the output voltage, the operating characteristics of the inductor and the operating characteristics of the target switching tube; The target switching frequency of the driving signal is adjusted according to the inductor loss and the switch tube loss.

3. The adjustment method according to claim 2, characterized in that: The inductor loss is determined according to the current switching frequency of the drive signal, the loss characteristic parameter of the inductor and the output current; The switch tube loss is determined according to the duty cycle of the drive signal, the current switching frequency of the drive signal, the output current, the output voltage and the switch response characteristic parameter of the target switch tube.

4. The adjustment method according to claim 3, characterized in that: The loss characteristic parameters of the inductor include the magnetic field coefficient, hysteresis loss coefficient and eddy current loss coefficient of the inductor; the switch response characteristic parameters include the first time required for the target switch tube to turn on and the second time required for the target switch tube to turn off.

5. The adjustment method according to claim 2, characterized in that: The adjusting the target switching frequency of the driving signal according to the inductor loss and the switch tube loss includes: Determine the current total loss according to the inductor loss and the switch tube loss; The current switching frequency of the driving signal is changed as the target switching frequency, and the target switching frequency is adjusted according to the change of the current total loss.

6. The adjustment method according to claim 5, characterized in that: The changing the current switching frequency of the driving signal as the target switching frequency, and adjusting the target switching frequency according to the change of the current total loss, includes: increasing the current switching frequency of the driving signal as a target switching frequency; When the current total loss increases, the target switching frequency is reduced, and when the current total loss decreases, the target switching frequency is increased; The adjusted target switching frequency is used as the current switching frequency, and the current total loss is re-determined.

7. The adjustment method according to claim 5, characterized in that: The changing the current switching frequency of the driving signal as the target switching frequency, and adjusting the target switching frequency according to the change of the current total loss, includes: reducing a current switching frequency of the driving signal as a target switching frequency; When the current total loss increases, the target switching frequency is increased, and when the current total loss decreases, the target switching frequency is decreased; The adjusted target switching frequency is used as the current switching frequency, and the current total loss is re-determined.

8. The adjustment method according to claim 6 or 7, characterized in that: The reducing the target switching frequency comprises: reducing the target switching frequency of the drive signal according to a first preset value, where the first preset value is a fixed value or is determined according to a variation range of the current total loss; The step of increasing the target switching frequency includes: The target switching frequency of the driving signal is increased according to a second preset value, where the second preset value is a fixed value or is determined according to a variation range of the current total loss.

9. The adjustment method according to claim 1, characterized in that: Before obtaining the output current and output voltage of the power factor correction circuit, the adjustment method further includes: Monitoring the output power of the power factor correction circuit to determine that the output power of the power factor correction circuit is in a stable state; or, The operating power of the compressor connected to the power factor correction circuit is monitored to determine whether the operating power of the compressor is in a stable state.

10. The adjustment method according to claim 1, characterized in that: The step of adjusting the target switching frequency of the drive signal according to the duty cycle of the output drive signal, the output current, the output voltage, the operating characteristics of the inductor, and the operating characteristics of the target switch tube comprises: The target switching frequency is determined according to the current switching frequency of the drive signal, the loss characteristic parameters of the inductor, the duty cycle of the drive signal, the current switching frequency of the drive signal, the output current, the output voltage and the switching response characteristic parameters of the target switch tube.

11. A controller, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the adjustment method according to any one of claims 1 to 10 when executing the computer program.

12. An electrical device, characterized in that: Comprising a controller as claimed in claim 11.

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