Power factor correction circuit adaptive control method and system

Abstract

The invention provides a power factor correction circuit adaptive control method and system, and the method comprises the steps: collecting an input voltage signal of a power factor correction circuit, obtaining a voltage control signal of the power factor correction circuit, and collecting a current sampling signal of the power factor correction circuit; the duty ratio of a switch driving signal is calculated based on the current sampling signal, the input voltage signal and the voltage control signal, the current sampling signal and the duty ratio are in a reverse growth relation, the input voltage signal and the duty ratio are in a reverse growth relation, and the current sampling signal and the input voltage signal are in a reverse growth relation. The voltage control signal and the duty ratio are in a homodromous growth relationship; and controlling the on-off of a switching device of the power factor correction circuit according to the duty ratio of the switching driving signal. According to the invention, the switch driving signal of the power factor correction circuit is adaptively adjusted based on the load change and the input voltage change, and the stable operation of the driven equipment is ensured.

Description

Technical Field

[0001] The present application relates to the technical field of power factor correction circuit control, and in particular to a power factor correction circuit adaptive control method and system. Background Art

[0002] The input voltage range of the welding power supply of welding equipment is wide. The input voltage of commonly used low-voltage AC welding equipment includes single-phase 220V and three-phase 380V. Single-phase 220V voltage is suitable for use in places such as homes and construction sites, while three-phase 380V voltage is suitable for factories, large-scale construction and other occasions that require high-power electricity. In foreign industrial applications, the input power grid may even be as high as 600V. The diversity of input voltage increases the complexity of input voltage detection and judgment. In practical applications, it is necessary to accurately detect the phase, amplitude and frequency of the input voltage, and select the appropriate control strategy based on the detection results.

[0003] In addition, the load of the welding power supply of the welding equipment changes greatly during operation. From tiny welding points to large-scale workpieces, the load resistance changes in a wide range. This feature brings challenges to the design of its control system. In the case of sudden load changes, if the transfer function under a specific load condition is used as the design basis, the stability and dynamic characteristics of the control system may not be guaranteed.

[0004] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0005] In response to the problems in the prior art, the purpose of the present application is to provide a power factor correction circuit adaptive control method and system, which adaptively adjusts the switch drive signal of the power factor correction circuit based on load changes and input voltage changes to ensure the stable operation of the driven equipment.

[0006] The present application provides a method for adaptively controlling a power factor correction circuit, including:

[0007] Collecting an input voltage signal of a power factor correction circuit, obtaining a voltage control signal of the power factor correction circuit, and collecting a current sampling signal of the power factor correction circuit;

[0008] Calculating the duty cycle of the switch drive signal based on the current sampling signal, the input voltage signal and the voltage control signal, wherein the current sampling signal and the duty cycle are in an inverse growth relationship, the input voltage signal and the duty cycle are in an inverse growth relationship, and the voltage control signal and the duty cycle are in a symmetric growth relationship;

[0009] The on and off of the switch device of the power factor correction circuit is controlled according to the duty cycle of the switch drive signal.

[0010] In some embodiments, obtaining a voltage control signal of a power factor correction circuit includes the following steps:

[0011] Collecting the output voltage signal of the power factor correction circuit;

[0012] A voltage control signal is obtained based on a preset voltage control algorithm according to the output voltage signal and a preset reference voltage.

[0013] In some embodiments, the power factor correction circuit includes a rectifier module, an inductor module, a switch device, and an output module;

[0014] Wherein, collecting the input voltage signal of the power factor correction circuit includes collecting the input voltage signal of the rectifier module;

[0015] Collecting the output voltage signal of the power factor correction circuit, including collecting the output voltage signal of the output module;

[0016] The current sampling signal of the power factor correction circuit is collected, including the current sampling signal of the inductor module.

[0017] In some embodiments, the preset voltage control algorithm is a proportional-integral control algorithm, in which the difference between the output voltage signal and the preset reference voltage is taken as the error.

[0018] In some embodiments, calculating the duty cycle of the switch driving signal based on the current sampling signal, the input voltage signal and the voltage control signal includes:

[0019] Based on the current sampling signal, the input voltage signal and the voltage control signal, a duty cycle calculation function of a single-cycle control is used to calculate the duty cycle of the switch driving signal.

[0020] In some embodiments, calculating the duty cycle of the switch driving signal based on the current sampling signal, the input voltage signal and the voltage control signal includes:

[0021] Based on the function D = f 1 (I L R s ,K in V in ,V m ) calculates the duty cycle of the switch drive signal; where D is the duty cycle of the switch drive signal, I L is the current sampling signal, R s is the resistance of the current sampling resistor, K in is the input voltage sampling feedforward coefficient, V in is the input voltage signal, V mis the voltage control signal, function f 1 Satisfaction: I L R s K has an inverse growth relationship with D. in V in It has an inverse growth relationship with D, V m It has the same growth relationship with D.

[0022] In some embodiments, before calculating the duty cycle of the switch drive signal based on the current sampling signal, the input voltage signal and the voltage control signal, the following steps are also included:

[0023] Determine the input voltage peak value based on the collected input voltage signal;

[0024] An input voltage sampling feed-forward coefficient is calculated based on an input voltage peak value, wherein the input voltage peak value and the input voltage sampling feed-forward coefficient are in a same-direction growth relationship.

[0025] In some embodiments, calculating the input voltage sampling feed-forward coefficient based on the input voltage peak value includes:

[0026] Based on the function K in =f 2 (R s P min ,V inPeak ) calculates the input voltage sampling feedforward coefficient; where P min is the preset minimum stable power value, V inPeak is the input voltage peak value, function f 2 Satisfaction: R s P min With k in is an inverse growth relationship, V inPeak With k in It is a growth relationship in the same direction.

[0027] In some embodiments, the power factor correction circuit includes a first switching device and a second switching device, the duty cycles of the first switching device and the second switching device are the same, and the switch drive signal of the first switching device and the switch drive signal of the second switching device are staggered by half a cycle.

[0028] The embodiment of the present application also provides a power factor correction circuit adaptive control system, which is applied to a power factor correction circuit adaptive control method, and the system includes:

[0029] A signal acquisition module, used to acquire an input voltage signal of a power factor correction circuit, obtain a voltage control signal of the power factor correction circuit, and acquire a current sampling signal of the power factor correction circuit;

[0030] A duty cycle calculation module, used to calculate the duty cycle of the switch drive signal based on the current sampling signal, the input voltage signal and the voltage control signal, wherein the current sampling signal and the duty cycle are in an inverse growth relationship, the input voltage signal and the duty cycle are in an inverse growth relationship, and the voltage control signal and the duty cycle are in a symmetric growth relationship;

[0031] The circuit control module is used to control the on and off of the switch device of the power factor correction circuit according to the duty cycle of the switch drive signal.

[0032] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application.

[0033] The power factor correction circuit adaptive control method and system provided in this application have the following advantages:

[0034] By adopting the present application, the duty cycle of the switch drive signal of the power factor correction circuit is calculated based on the current sampling signal, the input voltage signal and the voltage control signal, the load changes and the changes in the input power at the power supply end are monitored in real time, the switch drive signal of the power factor correction circuit is adjusted in real time following the load changes and the input voltage changes, and the control strategy is dynamically adjusted, thereby achieving precise control of the switch on and off time of the power factor correction circuit, ensuring that the driven equipment can obtain stable and efficient power output under various working conditions.

[0035] This application can significantly improve the power factor of the power supply system through the power factor correction circuit, reduce the reactive power consumption at the power supply end, and effectively reduce the harmonic content of the input current, reduce the harmonic pollution to the power supply end, and ensure the safe and stable operation of the driven equipment. This application has high anti-interference ability and adaptability, can cope with complex power supply end environments and variable load requirements, and provide strong guarantees for the stable operation of the driven equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings herein are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present invention, and together with the specification are used to explain the principles of the present invention. Obviously, the accompanying drawings described below are only some embodiments of the present invention, and for those of ordinary skill in the art, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0037] Figure 1 is a flow chart of a power factor correction circuit adaptive control method according to an embodiment of the present application;

[0038] Figure 2 is a circuit diagram of a three-phase power factor correction circuit according to an embodiment of the present application;

[0039] Figure 3is a circuit diagram of a single-phase power factor correction circuit according to an embodiment of the present application;

[0040] Figure 4 This is a flow chart of collecting signals according to an embodiment of the present application;

[0041] Figure 5 is a schematic diagram of a digital single-cycle control implementation method of an embodiment of the present application;

[0042] Figure 6 is a current loop control block diagram of an embodiment of the present application;

[0043] Figure 7 is a flow chart of a power factor correction circuit control process according to an embodiment of the present application;

[0044] Figure 8 It is a structural block diagram of a power factor correction circuit adaptive control system according to an embodiment of the present application. DETAILED DESCRIPTION

[0045] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present application will be comprehensive and complete and the concepts of the example embodiments will be fully conveyed to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their repeated descriptions will be omitted. "Or" and "or" in the specification may both mean "and" or "or". Although "first" or "second" etc. are used in this specification to represent certain features, they are only used to represent the function and are not used as a limitation on the number and importance of specific features.

[0046] In order to solve the technical problems in the prior art, the present application aims to provide an adaptive control method for a power factor correction circuit arranged between a power supply end and an output end of a load (driven device). The driven device is, for example, a welding device, but is not limited thereto. The driven device may be other electrical equipment that requires electric drive. The power factor correction circuit is arranged in the housing of the driven device and is used to control the output voltage signal of the driven device. The power factor correction circuit (Power Factor Correction) is used to improve the power factor, improve the energy utilization efficiency of the power supply end, and reduce the harmonic pollution and reactive power at the power supply end.

[0047] like Figure 1 As shown, the embodiment of the present application provides a power factor correction circuit adaptive control method, including:

[0048] S100: collecting an input voltage signal of a power factor correction circuit, acquiring a voltage control signal of the power factor correction circuit, and collecting a current sampling signal of the power factor correction circuit;

[0049] Here, the input voltage signal, the voltage control signal and the current sampling signal refer to the specific input voltage value, the voltage control value and the current sampling value respectively;

[0050] The input voltage signal is a voltage signal input from a power supply end to an input end of the power factor correction circuit, where the power supply end is, for example, a power grid or other power supply equipment;

[0051] The voltage control signal is a voltage control signal generated according to a preset reference voltage of a target, and is used to control the output voltage of the power factor correction circuit;

[0052] S200: Calculating a duty cycle of a switch drive signal based on a current sampling signal, an input voltage signal, and a voltage control signal, wherein the current sampling signal and the duty cycle are in an inverse growth relationship, the input voltage signal and the duty cycle are in an inverse growth relationship, and the voltage control signal and the duty cycle are in a symmetric growth relationship;

[0053] The switch drive signal is a PWM (Pulse Width Modulation) signal used to control the on and off of the switch of the power factor correction circuit;

[0054] The inverse growth relationship between the current sampling signal and the duty cycle means that, when other parameters remain unchanged, the larger the current sampling signal, the smaller the duty cycle, so as to reduce the current in the power factor correction circuit to adapt to the change of the load, so that the output voltage is adapted to the load and the stability of the output voltage is maintained; the inverse growth relationship between the input voltage signal and the duty cycle means that, when other parameters remain unchanged, the larger the input voltage signal, the smaller the duty cycle, so as to adapt to the change of the input voltage and maintain the stability of the output voltage; the same growth relationship between the voltage control signal and the duty cycle means that, when other parameters remain unchanged, the larger the voltage control signal, the larger the duty cycle, so that the output voltage is quickly adjusted to the preset reference voltage;

[0055] S300: Controlling the on and off of a switch device of a power factor correction circuit according to the duty cycle of a switch driving signal.

[0056] By adopting the adaptive control method of the power factor correction circuit of the present application, the duty cycle of the switch drive signal of the power factor correction circuit is calculated based on the current sampling signal, the input voltage signal and the voltage control signal, the load changes and the changes of the input power at the power supply end are monitored in real time, and the switch drive signal of the power factor correction circuit is adjusted in real time according to the load changes and the input voltage changes, and the control strategy is dynamically adjusted, so as to achieve precise control of the switch on and off time of the power factor correction circuit, and ensure that the driven equipment can obtain stable and efficient power output under various working conditions.

[0057] This application can significantly improve the power factor of the power supply system through the power factor correction circuit, reduce the reactive power consumption of the power supply end, and effectively reduce the harmonic content of the input current, reduce the harmonic pollution to the power supply end, and ensure the safe and stable operation of the power supply end. This application has high anti-interference ability and adaptability, can cope with complex power supply end environments and variable load requirements, and provide strong guarantees for the stable operation of the power supply end.

[0058] The algorithm logic of the adaptive control method can be implemented by a controller disposed inside the driven device. When the present application is applied to welding equipment, it can well cope with application scenarios with large load changes and high dynamic characteristics requirements during welding, and improve the adaptability and stability of welding equipment under different working conditions.

[0059] The power factor correction circuit adaptive control method of the present application has good adaptability to both single-phase and three-phase power grids. Figure 2 is a circuit diagram of a three-phase power factor correction circuit according to an embodiment of the present application. Figure 3 1 is a circuit diagram of a single-phase power factor correction circuit of an embodiment of the present application. Here, the power factor correction circuit includes two switches: a first switch device Q1 and a second switch device Q2. It is understandable that in other embodiments, the power factor correction circuit may also be a circuit structure including only one switch, which also falls within the scope of protection of the present application.

[0060] like Figure 2 and Figure 3As shown, the power factor correction circuit includes a rectifier module, an inductor module, a switch device and an output module. In the three-phase power factor correction circuit, the rectifier module includes diodes D1-D6, and in the single-phase power factor correction circuit, the rectifier module includes diodes D1-D4. The inductor module includes an inductor L1 and an inductor L2, and the inductor L1 and the inductor L2 are Boost boost inductors. The power factor correction circuit is also provided with a current sampling resistor CS, and the current sampling signal collected by the resistor CS is the inductor current signal of the inductor L1 and the inductor L2. The first switch device Q1 and the second switch device Q2 are IGBTs (Insulated Gate Bipolar Transistors). The output module includes a diode D7, a diode D8, an output capacitor C1 and an output capacitor C2. Diodes D7 and D8 are SiC diodes. The rectifier module, the boost inductor, the switch device and the output module constitute a Boost circuit. In the power factor correction circuit, the first switch device and the second switch device are connected in series and connected to the midpoint of the output module, so that the output module capacitor dynamic voltage balancing can be achieved, and the stress of the IGBT and the diode is halved. After the duty cycle of the switch drive signal is calculated in step S200, the duty cycles of the first switch device and the second switch device are the same, and the switch drive signal of the first switch device and the switch drive signal of the second switch device are staggered for half a cycle, and the inductor current ripple can be reduced by phase shifting and staggering control of the two switch drive signals.

[0061] Figure 3 FIG. 4 shows a flow chart of collecting signals of this embodiment. Figure 3 As shown, after the driven device is turned on, the internal parameters of the device are initialized. The initialized parameters include, for example, the output voltage, current sampling value, etc. The input voltage signal of the rectifier module is collected as the input voltage signal of the power factor correction module. The input voltage sampling feedforward coefficient is calculated based on the input voltage signal (which will be described in detail below). It is determined whether the soft start of the device is completed. If not, return to the step of collecting the input voltage signal. If it is completed, the output voltage signal of the output module is collected as the output voltage signal of the power factor correction module. The voltage control signal is calculated based on the output voltage signal and the preset reference voltage. Then the current sampling signal between the rectifier module and the switching device is collected as the current sampling signal of the power factor correction circuit.

[0062] In this embodiment, in step S100, obtaining the voltage control signal of the power factor correction circuit includes the following steps:

[0063] Collect the output voltage signal of the power factor correction circuit to Figure 2 and Figure 3 Take the output voltage signal of the output capacitor as an example.

[0064] According to the output voltage signal and the preset reference voltage, a voltage control signal is obtained based on a preset voltage control algorithm; in this embodiment, the preset voltage control algorithm is a proportional integral control algorithm, wherein the difference between the output voltage signal and the preset reference voltage is used as an error, and the error is reduced by a proportional integral (PI) control algorithm so that the output voltage signal is as close to the preset reference voltage as possible. The preset reference voltage is the output voltage required by the driven device. Taking the driven device as a welding device as an example, the preset reference voltage is the required welding output voltage.

[0065] In this embodiment, in step S200, the duty cycle of the switch drive signal is calculated based on the current sampling signal, the input voltage signal and the voltage control signal, including:

[0066] Based on the current sampling signal, input voltage signal and voltage control signal, the duty cycle calculation function of the single-cycle control is used to calculate the duty cycle of the switch drive signal. In the power factor correction circuit, the change of input voltage and sampling current can be tracked within one switching cycle through the single-cycle control (One-CycleControl, OCC), thereby effectively improving the power factor and realizing fast and accurate control of the power factor correction circuit.

[0067] Figure 5 Schematic diagram of a digital single cycle control implementation method of an embodiment of the present application. In this embodiment, based on a preset reference voltage V ref And the output voltage signal V o Perform PI control algorithm to obtain voltage control signal V m After that, based on the current sampling signal I L 、Input voltage signal V in and voltage control signal V m The duty cycle D of the switch drive signal is calculated. Specifically, based on the function D=f 1 (I L R s ,K in V in ,V m ) calculates the duty cycle of the switch drive signal.

[0068] Among them, R s is the resistance of the current sampling resistor, which corresponds to Figure 2 and Figure 3 The organization of the resistor CS. K in is the input voltage sampling feedforward coefficient, and its value affects the input voltage signal V in The impact on the final duty cycle. K in is a number greater than 0. The larger its value, the higher the input voltage signal V inThe greater the impact of the change on the final duty cycle. Function f 1 Satisfaction: I L R s K has an inverse growth relationship with D. in V in It has an inverse growth relationship with D, V m It has the same growth relationship with D.

[0069] For example, the function f 1 Satisfies the following formula 1:

[0070]

[0071] Here the function f 1 The implementation form is only an example, and other formulas that satisfy the correlation between various parameters can also be used as f 1 For example, to increase the input voltage signal V in The effect of the change in V on the final duty cycle can be calculated by in Change to V in 2 , or replace the voltage control signal V in Formula 1 m Change to V m 2 , or the voltage control signal V m Add a preset coefficient in front to adjust the voltage control signal V m The effect of the change on the duty cycle, etc., is obtained according to the changes in various adjustment requirements. 1 All implementation forms belong to the protection scope of this application.

[0072] In one embodiment, the input voltage sampling feed-forward coefficient K in It can be directly set to a fixed empirical value. For example, the input voltage sampling feedforward coefficient K can be directly set to in Set to 1 to increase the input voltage signal V in When considering the influence of the change of the final duty cycle, the input voltage sampling feedforward coefficient K in Set to a value greater than 1 to reduce the input voltage signal V in When considering the influence of the change of the final duty cycle, the input voltage sampling feedforward coefficient K in Set to a value less than 1.

[0073] In another embodiment, the input voltage sampling feed-forward coefficient K in It is a value that changes with the peak value of the input voltage at the power supply end. Figure 4As shown, the step S200: before calculating the duty cycle of the switch drive signal based on the current sampling signal, the input voltage signal and the voltage control signal, after collecting the input voltage signal, also includes the step of calculating the input voltage sampling feedforward coefficient.

[0074] Specifically, the input voltage sampling feedforward coefficient is calculated using the following steps:

[0075] Determine the input voltage peak value based on the collected input voltage signal;

[0076] An input voltage sampling feed-forward coefficient is calculated based on an input voltage peak value, wherein the input voltage peak value and the input voltage sampling feed-forward coefficient are in a same-direction growth relationship.

[0077] Here, the input voltage peak value and the input voltage sampling feedforward coefficient are in the same direction of growth relationship, which means that, when other parameters remain unchanged, the larger the input voltage peak value, the larger the input voltage sampling feedforward coefficient. In applications, the input voltages corresponding to different power supply terminals will be different. For example, when the driven equipment is connected to power grids with different voltages, the corresponding input voltage sampling feedforward coefficients will be different. The higher the input voltage, the more unstable the control system, so the input voltage sampling feedforward coefficient needs to be larger to improve the adaptability and stability of the output voltage to the input voltage. Therefore, the value of the input voltage sampling feedforward coefficient changes with the different input power supplies at the power supply terminal, achieving self-adaptation to different power supply terminals.

[0078] In this embodiment, the input voltage sampling feed-forward coefficient is calculated based on the input voltage peak value, including:

[0079] Based on the function K in =f 2 (R s P min ,V inPeak ) calculates the input voltage sampling feedforward coefficient; where P min is the preset minimum stable power value, V inPeak is the input voltage peak value, function f 2 Satisfaction: R s P min With K in is an inverse growth relationship, V inPeak With K in It is a growth relationship in the same direction.

[0080] The preset minimum stable power value is the minimum power required to ensure the stability of the driven device power supply, and can be set according to the rated power, and the preset minimum stable power value can be set to a*rated power, where a is a value of 5% to 25%, for example, set to 10%. If the power is less than the preset minimum stable power value, even if the current fluctuates, the fluctuating current value is very small, and the current fluctuation is acceptable, and will not have adverse effects on the driven device and the power supply end.

[0081] The input voltage peak value is the peak value determined based on the detected value of the input voltage within a period of time after the driven device is started. Since the preset minimum stable power value and the input voltage peak value are fixed after the device is started, the input voltage sampling feedforward coefficient remains stable when the power factor correction circuit is working.

[0082] For example, the function f 2 Satisfies formula 2:

[0083]

[0084] Among them, C is a fixed constant, and the value of C is determined according to the empirical value of the control system when it is working stably. The value of C is determined, for example, according to the crossover frequency of the control system current loop. The crossover frequency refers to the frequency when the open-loop amplitude-frequency characteristic curve intersects with the 0dB line (i.e., the line with an amplitude gain of 1). At this frequency point, the open-loop gain of the control system is 1. By adjusting the value of C, when the phase angle corresponding to the phase-frequency characteristic of the open-loop amplitude-frequency characteristic curve at the crossover frequency corresponds to the phase angle range of the system stability, the C value at this time is determined.

[0085] The following is an explanation of the principle by which Formula 2 can improve the stability of power supply control.

[0086] To establish a small signal model, each signal quantity in Formula 1 is split into the sum of a steady-state component and a small signal component:

[0087]

[0088] Among them, D, V m ,I L 、V in They are the duty cycle, voltage control signal, current sampling signal, and steady-state component of the input voltage signal. They are duty cycle, voltage control signal, current sampling signal, and small signal component of input voltage signal. m 、i L 、v in They are the duty cycle, voltage control signal, current sampling signal, and input voltage signal after combining the small signal component, satisfying the following formula 4:

[0089]

[0090] Substituting formula 3 into formula 4 and separating the small signal component, we get the following formula 5. This process is equivalent to differentiating both sides of formula 4:

[0091]

[0092] Based on formula 5, we can establish Figure 6 The current loop control block diagram is shown in Figure 2.

[0093] like Figure 6 As shown, the current loop open-loop transfer function is:

[0094]

[0095] Among them G cp (s) is the power stage transfer function of the Boost circuit, and its expression is:

[0096]

[0097] Substituting formula 7 into formula 6 yields:

[0098]

[0099] Where L is the inductance of the Boost inductor, R s is the current sampling coefficient, that is, the resistance value of the current sampling resistor, and s is the Laplace variable.

[0100] According to the basic formula of Boost circuit:

[0101]

[0102] Combining Formula 4, Formula 8, and Formula 9, we get:

[0103]

[0104] The open-loop transfer function T(s) is a function used to describe the transfer relationship from the controller output (control signal) to the controlled current (feedback signal);

[0105] To keep the control system stable, the current loop open-loop transfer function gain must remain constant, and Rs and L are fixed values, so the system can satisfy:

[0106]

[0107] Where C is a fixed constant to ensure the stability of the system.

[0108] Simplify and set P = V in I L Substituting in, we get:

[0109]

[0110] Since the system is most unstable when the power is minimum and the input voltage is highest, P can be taken as the preset minimum stable power value P min , take V in V inPeak , substituting into Formula 12, we can get the above Formula 2.

[0111] The above function f 2 The form of is only an example, and other formulas that satisfy the correlation between various parameters can also be used as f 2 For example, in formula 2, V inPeak 2 Add an adjustment coefficient in front, and control the influence of the change of input voltage peak value on the input voltage sampling feedforward coefficient through the size of the adjustment coefficient, or change V inPeak 2 Modified to V inPeak , or adjust P in Formula 2 min The value of, etc., various variations are within the protection scope of this application.

[0112] Figure 7 The process of controlling the on and off of the switch device according to the duty cycle in step S300 is shown. After the duty cycle of the switch drive signal is calculated by step S200, it is determined whether the protection signal of the driven device (such as the short-circuit protection signal, temperature protection signal and other fault protection signals of the driven device) is triggered. If not triggered, the PWM signal is modulated based on the duty cycle, and the two switch drive signals of the two switch devices are processed in an interlaced half-cycle, and the on and off of the two switch devices in the power factor correction circuit are controlled based on the two switch drive signals. Determine whether the shutdown signal is triggered. If so, turn off the driven device. If the shutdown signal is not triggered, return to Figure 4 The step of collecting the output voltage signal in the next cycle continues with the signal collection and duty cycle calculation. If the protection signal is triggered, the duty cycle is reset to zero and the control system enters the protection mode (such as shutting down the output, issuing an alarm, and recording faults).

[0113] like Figure 8 As shown, the embodiment of the present application also provides a power factor correction circuit adaptive control system, which is applied to a power factor correction circuit adaptive control method, and the system includes:

[0114] The signal acquisition module M100 is used to acquire the input voltage signal of the power factor correction circuit, obtain the voltage control signal of the power factor correction circuit, and acquire the current sampling signal of the power factor correction circuit;

[0115] The duty cycle calculation module M200 is used to calculate the duty cycle of the switch drive signal based on the current sampling signal, the input voltage signal and the voltage control signal, wherein the current sampling signal and the duty cycle are in an inverse growth relationship, the input voltage signal and the duty cycle are in an inverse growth relationship, and the voltage control signal and the duty cycle are in a symmetric growth relationship;

[0116] The circuit control module M300 is used to control the on and off of the switch device of the power factor correction circuit according to the duty cycle of the switch drive signal.

[0117] By adopting the power factor correction circuit adaptive control system of the present application, the duty cycle of the switch drive signal of the power factor correction circuit is calculated based on the current sampling signal, the input voltage signal and the voltage control signal, the load changes and the changes in the input power of the power supply end are monitored in real time, and the switch drive signal of the power factor correction circuit is adjusted in real time according to the load changes and the input voltage changes. The control strategy is dynamically adjusted to achieve precise control of the switch on and off time of the power factor correction circuit, ensuring that the power supply end can provide stable and efficient power output under various working conditions.

[0118] This application can significantly improve the power factor of the power supply system through the power factor correction circuit, reduce the reactive power consumption at the power supply end, and effectively reduce the harmonic content of the input current, reduce the harmonic pollution to the power supply end, and ensure the safe and stable operation of the driven equipment. This application has high anti-interference ability and adaptability, can cope with complex power supply end environments and variable load requirements, and provide strong guarantees for the stable operation of the driven equipment.

[0119] The specific functions of each module in the power factor correction circuit adaptive control system can be implemented by adopting the specific implementation methods of the corresponding steps in the above-mentioned power factor correction circuit adaptive control method, which will not be described in detail here.

[0120] The above content is a further detailed description of the present application in combination with specific preferred implementation methods, and it cannot be determined that the specific implementation of the present application is limited to these descriptions. For ordinary technicians in the technical field to which the present application belongs, several simple deductions or substitutions can be made without departing from the concept of the present application, which should be deemed to fall within the scope of protection of the present application.

Claims

1. A power factor correction circuit adaptive control method, characterized in that: include: Collecting an input voltage signal of the power factor correction circuit, acquiring a voltage control signal of the power factor correction circuit, and collecting a current sampling signal of the power factor correction circuit; Calculating a duty cycle of a switch drive signal based on the current sampling signal, the input voltage signal and the voltage control signal, wherein the current sampling signal and the duty cycle are in an inverse growth relationship, the input voltage signal and the duty cycle are in an inverse growth relationship, and the voltage control signal and the duty cycle are in a symmetric growth relationship; The on-off of the switch device of the power factor correction circuit is controlled according to the duty cycle of the switch drive signal.

2. The power factor correction circuit adaptive control method according to claim 1, characterized in that: Obtaining the voltage control signal of the power factor correction circuit comprises the following steps: Collecting an output voltage signal of the power factor correction circuit; A voltage control signal is obtained based on a preset voltage control algorithm according to the output voltage signal and a preset reference voltage.

3. The adaptive control method for a power factor correction circuit according to claim 2, characterized in that: The power factor correction circuit includes a rectifier module, an inductor module, a switch device and an output module; Wherein, collecting the input voltage signal of the power factor correction circuit includes collecting the input voltage signal of the rectifier module; Collecting the output voltage signal of the power factor correction circuit, including collecting the output voltage signal of the output module; Collecting the current sampling signal of the power factor correction circuit includes collecting the current sampling signal of the inductor module.

4. The adaptive control method for a power factor correction circuit according to claim 2, characterized in that: The preset voltage control algorithm is a proportional-integral control algorithm, wherein the difference between the output voltage signal and the preset reference voltage is taken as an error.

5. The adaptive control method for a power factor correction circuit according to claim 1, characterized in that: Calculating the duty cycle of the switch drive signal based on the current sampling signal, the input voltage signal and the voltage control signal, comprising: Based on the current sampling signal, the input voltage signal and the voltage control signal, a duty cycle calculation function of a single-cycle control is used to calculate the duty cycle of the switch drive signal.

6. The adaptive control method for a power factor correction circuit according to claim 1, characterized in that: Calculating the duty cycle of the switch drive signal based on the current sampling signal, the input voltage signal and the voltage control signal, comprising: Based on the function D = f1(I L R s ,K in V in ,V m ) calculates the duty cycle of the switch drive signal; wherein D is the duty cycle of the switch drive signal, I L is the current sampling signal, R s is the resistance of the current sampling resistor, K in is the input voltage sampling feedforward coefficient, V in is the input voltage signal, V m is the voltage control signal, and the function f1 satisfies: I L R s K has an inverse growth relationship with D. in V in It has an inverse growth relationship with D, V m It has the same growth relationship with D.

7. The adaptive control method for a power factor correction circuit according to claim 6, characterized in that: Before calculating the duty cycle of the switch drive signal based on the current sampling signal, the input voltage signal and the voltage control signal, the following steps are also included: Determining an input voltage peak value based on said collecting said input voltage signal; An input voltage sampling feed-forward coefficient is calculated based on an input voltage peak value, wherein the input voltage peak value and the input voltage sampling feed-forward coefficient are in a same-direction growth relationship.

8. The adaptive control method of a power factor correction circuit according to claim 6, characterized in that: The step of calculating the input voltage sampling feed-forward coefficient based on the input voltage peak value includes: Based on the function K in =f2(R s P min ,V inPeak ) calculates the input voltage sampling feedforward coefficient; where P min is the preset minimum stable power value, V inPeak is the input voltage peak value, function f2 satisfies: R s P min With K in is an inverse growth relationship, V inPeak With K in It is a growth relationship in the same direction.

9. The adaptive control method for a power factor correction circuit according to claim 1, characterized in that: The power factor correction circuit includes a first switching device and a second switching device, the first switching device and the second switching device have the same duty cycle, and the switch drive signal of the first switching device and the switch drive signal of the second switching device are staggered by half a cycle.

10. A power factor correction circuit adaptive control system, characterized in that: The power factor correction circuit adaptive control method applied to any one of claims 1 to 9, the system comprising: A signal acquisition module, used to acquire an input voltage signal of the power factor correction circuit, obtain a voltage control signal of the power factor correction circuit, and acquire a current sampling signal of the power factor correction circuit; a duty cycle calculation module, configured to calculate the duty cycle of the switch drive signal based on the current sampling signal, the input voltage signal and the voltage control signal, wherein the current sampling signal and the duty cycle are in an inverse growth relationship, the input voltage signal and the duty cycle are in an inverse growth relationship, and the voltage control signal and the duty cycle are in a symmetric growth relationship; A circuit control module is used to control the on and off of the switch device of the power factor correction circuit according to the duty cycle of the switch drive signal.

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