Self-adaptive PFC (Power Factor Correction) control circuit, control method and system

Abstract

The invention discloses a self-adaptive PFC (Power Factor Correction) control circuit, control method and system, and the circuit comprises a rectifier bridge which is used for receiving commercial power alternating current and carrying out the rectification output of the commercial power alternating current; the detection module is used for detecting whether the mains supply alternating current is line voltage or phase voltage, and generating and sending a detection signal according to a detection result; the MCU module is electrically connected with the detection module and is used for receiving the detection signal sent by the detection module and generating and sending a control signal according to the detection signal; and the PFC boosting module is electrically connected with the rectifier bridge and the MCU module respectively, and is used for receiving the control signal sent by the MCU module and switching to a phase voltage working mode or a line voltage working mode according to the control signal, and then the PFC boosting module receives the direct current sent by the rectifier bridge, boosts the direct current and outputs the direct current.

Description

Technical Field

[0001] This invention relates to the field of charger technology, and more specifically, to an adaptive PFC control circuit, control method, and system. Background Technology

[0002] PFC stands for Power Factor Correction. The power factor refers to the relationship between effective power and total power consumption (apparent power), which is the ratio of effective power to total power consumption (apparent power). Basically, the power factor measures the degree to which electricity is used effectively; the higher the power factor value, the higher the power utilization rate.

[0003] Current PFC circuits are typically only applicable to three-phase or single-phase voltages, and their input voltage range is relatively small, which prevents chargers from being universal and results in low charger utilization. Summary of the Invention

[0004] To address the shortcomings of existing technologies, an adaptive PFC control circuit, control method, and system are provided.

[0005] To achieve the above objectives, the present invention provides an adaptive PFC control circuit, comprising a rectifier bridge for receiving AC mains power, rectifying the AC mains power into a DC signal and outputting it; a detection module for detecting whether the AC mains power is line voltage or phase voltage, generating and sending a detection signal based on the detection result; an MCU module electrically connected to the detection module for receiving the detection signal sent by the detection module, and generating and sending a control signal based on the detection signal; and a PFC boost module electrically connected to both the rectifier bridge and the MCU module for receiving the control signal sent by the MCU module, switching between phase voltage operating mode and line voltage operating mode based on the control signal, and then receiving the DC power sent by the rectifier bridge, boosting it, and outputting it.

[0006] According to one embodiment of the present invention, the PFC boost module includes an inductor L2, a MOSFET Q24, a MOSFET Q25, and a MOSFET Q2. One end of the inductor L2 is connected to the output terminal of the rectifier bridge, and the other end of the inductor L2 is connected to the drain of the MOSFET Q24 and the drain of the MOSFET Q25, respectively. The gate of the MOSFET Q24 is connected to the MCU module, and the source of the MOSFET Q24 is connected to the drain of the MOSFET Q2 and the source of the MOSFET Q25, respectively. The gate of the MOSFET Q25 is connected to the MCU module, the gate of the MOSFET Q2 is connected to the MCU module, and the source of the MOSFET Q2 is grounded.

[0007] According to one embodiment of the present invention, when the PFC boost module switches to phase voltage mode, MOSFET Q2 is normally closed, MOSFETs Q24 and Q25 are connected in parallel, and MOSFETs Q24 and Q25 operate in phase; when the PFC boost module switches to line voltage mode, MOSFETs Q24 and Q2 are connected in series and combined to form a first branch, and MOSFETs Q25 and Q2 are connected in series and combined to form a second branch, and the first branch and the second branch are connected in phase.

[0008] According to one embodiment of the present invention, an input buffer module is further included. The input buffer module includes a relay, a capacitor CY4, a control unit, a diode D1, and a capacitor C75. The relay has a first terminal to a sixth terminal. The fifth and sixth terminals of the relay are connected to the live wire of the mains power. One end of the capacitor CY4 is connected to the fifth and sixth terminals of the relay, and the other end is connected to the third and fourth terminals of the relay. The second terminal of the relay is connected to the power supply and the negative terminal of the diode D1, respectively. The positive terminal of the diode D1 is connected to the first terminal of the relay. The first terminal of the relay is also connected to the control unit, and the control unit is also connected to the MCU module. One end of the capacitor CY5 is connected to the capacitor CY4 and the third terminal of the rectifier bridge, respectively, and the other end is connected to the neutral wire of the mains power and the second terminal of the rectifier bridge, respectively.

[0009] According to one embodiment of the present invention, the detection module includes a first current limiting unit, a second current limiting unit, a first filtering unit, and a comparator U6. One end of the first current limiting unit is connected to the live wire of the mains power supply, and the other end is connected to the positive input terminal of the comparator U6. One end of the second current limiting unit is connected to the neutral wire of the mains power supply, and the other end is connected to the negative input terminal of the comparator U6. The first filtering unit is connected in parallel between the positive and negative input terminals of the comparator U6, and the output terminal of the comparator U6 is connected to the MCU module.

[0010] According to one embodiment of the present invention, the control unit includes a resistor R1, a resistor R2 and a transistor Q1. One end of the resistor R1 is connected to the MCU module and the other end is connected to the base of the transistor Q1. The resistor R2 is connected between the base and emitter of the transistor Q1. The emitter of the transistor Q1 is grounded. The collector of the transistor Q1 is connected to the first terminal of the relay and the positive terminal of the diode D1.

[0011] According to one embodiment of the present invention, the detection module further includes a first RC unit and a second RC unit. The first RC unit includes a resistor R129 and a capacitor C28. The second RC unit includes a capacitor C73 and a resistor R128. One end of the capacitor C28 is connected to the positive input terminal of the comparator U6, and the other end is connected to the output terminal of the comparator U6. The resistor R129 is connected in parallel across the two ends of the capacitor C28. One end of the resistor R128 is connected to the negative input terminal of the comparator U6, and the other end is connected to the output terminal of the comparator U6. The capacitor C73 is connected in parallel across the two ends of the resistor R128.

[0012] According to one embodiment of the present invention, the PFC boost module further includes a diode D3, the anode of which is connected to the drain of inductor L2, the drain of MOSFET Q24 and the drain of MOSFET Q25.

[0013] This invention also provides a control method for an adaptive PFC control circuit, applied to the aforementioned adaptive PFC control circuit, comprising the following steps: a detection module and a rectifier bridge respectively receive AC mains power; the detection module determines whether the AC mains power is phase voltage or line voltage; when the AC mains power is phase voltage, the detection module outputs a first detection signal; when the AC mains power is line voltage, the detection module outputs a second detection signal; the rectifier bridge rectifies the AC mains power and outputs a DC signal; the MCU module receives the first detection signal output by the detection module and sends a first control signal to the PFC boost module; the MCU module receives the first detection signal output by the detection module and sends a second control signal to the PFC boost module; the PFC boost module receives the first or second control signal sent by the MCU module; the PFC boost module receives the first control signal and switches to phase voltage mode; the PFC boost module receives the second control signal and switches to line voltage mode; the PFC boost module receives the DC signal output by the rectifier bridge and boosts the DC signal.

[0014] The present invention also provides an adaptive PFC control system, which includes the above-described adaptive PFC control circuit.

[0015] The beneficial effects of this invention lie in the fact that by employing a detection module to determine the type of input AC mains power, and using an MCU module to control the PFC boost module to switch operating modes accordingly based on the type of input AC mains power, the PFC boost module switches to phase voltage mode when the input AC mains voltage is phase voltage, and switches to line voltage mode when the input AC mains voltage is line voltage. By switching the PFC boost module to the corresponding mode under different usage scenarios, the input voltage range of the adaptive PFC control circuit is effectively widened, while the utilization rate of the PFC boost module components is improved. This allows the adaptive PFC control circuit to be applied to different charging scenarios, thereby improving the utilization rate of the charger. Attached Figure Description

[0016] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a block diagram of the adaptive PFC control circuit in the embodiment; Figure 2This is a circuit diagram of the PFC boost module in the embodiment; Figure 3 This is a schematic diagram showing the current flow direction of the inductor energy storage when the PFC boost module in the embodiment is in phase voltage mode; Figure 4 This is a schematic diagram showing the current flow direction of inductor discharge when the PFC boost module in the embodiment is in phase voltage mode; Figure 5 This is a schematic diagram showing the current flow direction of the inductor energy storage when the PFC boost module in the embodiment is in line voltage mode. Figure 6 This is another schematic diagram showing the current flow of the inductor energy storage when the PFC boost module in the embodiment is in line voltage mode; Figure 7 This is a schematic diagram showing the current flow direction of inductor discharge when the PFC boost module in the embodiment is in line voltage mode; Figure 8 This is a schematic diagram showing the connection between the input buffer module and the rectifier bridge in the embodiment. Figure 9 This is a circuit diagram of the detection module in the embodiment.

[0017] Explanation of reference numerals in the attached figures 1. Rectifier bridge; 2. Detection module; 21. First current limiting unit; 22. Second current limiting unit; 23. First filtering unit; 24. First RC unit; 25. Second RC unit; 3. MCU module; 4. PFC boost module; 41. First branch; 42. Second branch; 5. Input buffer module; 51. Relay; 52. Control unit. Detailed Implementation

[0018] The following drawings disclose several embodiments of the present invention. For clarity, many practical details will be described in the following description. However, it should be understood that these practical details are not intended to limit the invention. That is, in some embodiments of the invention, these practical details are not essential. Furthermore, for the sake of simplicity, some conventional structures and components will be shown in the drawings in a simple schematic manner.

[0019] Furthermore, in this invention, the use of terms such as "first" and "second" is for descriptive purposes only and does not specifically refer to any order or sequence, nor is it intended to limit the invention. They are merely used to distinguish components or operations described using the same technical terms, and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If a combination of technical solutions is contradictory or impossible to implement, such a combination should be considered nonexistent and not within the scope of protection claimed by this invention.

[0020] Please refer to Figure 1 , Figure 1 This is a block diagram of an adaptive PFC control circuit. This embodiment provides an adaptive PFC control circuit, which includes a rectifier bridge 1, a detection module 2, an MCU module 3, and a PFC boost module 4. The output of the rectifier bridge 1 is connected to the PFC boost module 4, the output of the detection module 2 is connected to the MCU module 3, and the MCU module 3 is connected to the PFC boost module 4. The rectifier bridge 1 receives AC mains power, rectifies it, and outputs a DC signal. The detection module 2 detects whether the input AC mains power is line voltage or phase voltage, and then generates and sends a detection signal to the MCU module 3 based on the detection result. The MCU module 3 generates a control signal based on the detection signal sent by the detection module 2 and sends the control signal to the PFC boost module 4. The PFC boost module 4 receives the control signal sent by the MCU module 3 and switches between phase voltage operating mode and line voltage operating mode according to the control signal. When the input AC mains voltage is phase voltage, the PFC boost module 4 switches to phase voltage mode, increasing the output current and effectively improving operating efficiency. When the input AC mains voltage is line voltage, the PFC boost module 4 switches to line voltage mode, improving its withstand voltage. After switching operating modes, the PFC boost module 4 receives the DC signal output from the rectifier bridge 1, boosts the DC signal, and outputs it. By determining the type of input AC mains voltage and controlling the PFC boost module 4 to switch between different operating modes, the PFC boost module 4 can meet different application scenarios, thereby achieving wide voltage input and improving its utilization rate.

[0021] Please refer to Figure 2 , Figure 2This is the circuit diagram of the PFC boost module. Specifically, the PFC boost module 4 includes inductor L2, MOSFET Q24, MOSFET Q25, and MOSFET Q2. One end of inductor L2 is connected to the output terminal of rectifier bridge 1, and the other end of inductor L2 is connected to the drain of MOSFET Q24 and the drain of MOSFET Q25. The gate of MOSFET Q24 is connected to MCU module 3, and the source of MOSFET Q24 is connected to the drain of MOSFET Q2 and the source of MOSFET Q25. The gate of MOSFET Q25 is connected to MCU module 3. The gate of MOSFET Q2 is connected to MCU module 3, and the source of MOSFET Q2 is grounded.

[0022] Please refer to Figure 3 and Figure 4 , Figure 3 This diagram illustrates the current flow direction of the inductor energy storage when the PFC boost module is in phase voltage mode. Figure 4 This diagram illustrates the current flow during inductor discharge in the PFC boost module when it is in phase voltage mode. When the PFC boost module 4 switches to phase voltage mode, the MCU module 3 controls MOSFET Q2 to be normally closed, and the MCU controls MOSFETs Q24 and Q25 to be simultaneously turned on or off, resulting in MOSFETs Q24 and Q25 being connected in parallel. In actual use, when the MCU module 3 controls MOSFETs Q24 and Q25 to be turned on simultaneously, the electrical signal output from rectifier bridge 1 is input to the PFC boost module 4. The electrical signal output from rectifier bridge 1 passes through inductor L2 and then enters MOSFETs Q24 and Q25. The signal then flows through MOSFETs Q24 and Q25 respectively before flowing to MOSFET Q2, and finally through MOSFET Q2 to ground. At this time, inductor L2 stores energy. By keeping MOSFET Q2 on, current is avoided from flowing through the diode inside MOSFET Q2 when MOSFET Q2 is turned off, which would increase the circuit loss. When MCU module 3 controls MOSFETs Q24 and Q25 to turn off simultaneously, inductor L2 releases an electrical signal. The electrical signal output from rectifier bridge 1 and the electrical signal released by inductor L2 cannot pass through MOSFETs Q24 and Q25, and are instead output to the bus, causing the bus voltage to rise. MOSFET Q2 remains on, ensuring a complete current loop and preventing current from passing through the diode inside MOSFET Q2, thus reducing losses. Furthermore, setting MOSFET Q2 to a normally closed state keeps it on, effectively reducing switching losses. Thus, when the input AC mains power is supplied, MOSFETs Q24 and Q25 operate in parallel, reducing the equivalent on-resistance and effectively improving the input current carrying capacity of PFC boost module 4, making the adaptive PFC control circuit suitable for high-current input applications.

[0023] Please refer to Figures 5-7 , Figure 5This is a schematic diagram showing the current flow direction of the inductor energy storage when the PFC boost module is in line voltage mode. Figure 6 Another schematic diagram showing the current flow of the inductor when the PFC boost module is in line voltage mode. Figure 7 This diagram illustrates the current flow during inductor discharge in the PFC boost module when it is in line voltage mode. When the PFC boost module 4 switches to line voltage mode, MOSFETs Q24 and Q25 conduct out of phase. Simultaneously, MOSFETs Q24 and Q25 share MOSFET Q2 to form a half-bridge-like structure. Specifically, MOSFETs Q24 and Q2 are connected in series to form the first branch 41, and MOSFETs Q25 and Q2 are connected in series to form the second branch 42. In actual use, the first branch 41 and the second branch 42 conduct alternately, with a dead time allowed. By connecting MOSFETs Q24 and Q2 in series, and Q25 in series with Q2, when MOSFETs Q24 and Q2 are turned on, their series connection creates a voltage divider; conversely, when MOSFETs Q25 and Q2 are turned on, their series connection also creates a voltage divider. This utilizes MOSFET Q2 to increase the overall voltage withstand capability of each series branch, effectively allowing the PFC boost module 4 to withstand higher input voltages. This eliminates the need to configure MOSFETs Q24 and Q25 with high voltage withstand specifications, effectively reducing component costs. In this example, MOSFETs Q24 and Q25 are selected with a low voltage withstand of 650V, while MOSFET Q2 is selected with a high voltage withstand of 1000V, further reducing circuit costs.

[0024] In practical use, when MOSFETs Q24 and Q2 are turned on, MOSFET Q25 is turned off. At this time, the electrical signal output from rectifier bridge 1 passes through inductor L2, then through MOSFETs Q24 and Q2 in sequence, and finally outputs to ground. In this case, inductor L2 stores energy. When MOSFETs Q25 and Q2 are turned on and MOSFET Q24 is turned off, the electrical signal output from rectifier bridge 1 passes through inductor L2, then through MOSFETs Q25 and Q2 in sequence, and finally outputs to ground. In this case, inductor L2 stores energy. When MOSFETs Q24, Q25, and Q2 are all turned off, inductor L2 releases energy. The electrical signal output from rectifier bridge 1 and the energy released from inductor L2 are output simultaneously to achieve a boost effect.

[0025] The PFC boost module 4 also includes a diode D3. The anode of diode D3 is connected to one end of inductor L2, the drain of MOSFET Q24, and the drain of MOSFET Q25, respectively. The cathode of diode D3 serves as the output terminal of the PFC boost module 4. Diode D3 is used for rectification. When inductor L2 releases energy, the electrical signal input to the PFC boost module 4 and the energy released by inductor L2 are rectified by diode D3 and output to the PFC boost module 4.

[0026] Please refer to Figure 8 , Figure 8 This is a schematic diagram showing the connection between the input buffer module and the rectifier bridge. Furthermore, the adaptive PFC control circuit also includes an input buffer module 5. The input buffer module 5 includes a relay 51, a capacitor CY4, a control unit 52, a diode D1, and a capacitor C75. The relay 51 has a first terminal, a second terminal, a third terminal, a fourth terminal, a fifth terminal, and a sixth terminal. The fifth and sixth terminals of the relay 51 are connected to the live wire L. One end of the capacitor CY4 is connected to the fifth and sixth terminals of the relay 51, and the other end of the capacitor CY4 is connected to the third and fourth terminals of the relay 51. The second terminal of the relay 51 is connected to the power supply and the negative terminal of the diode D1, while the positive terminal of the diode D1 is connected to the first terminal of the relay 51. The first terminal of the relay 51 is also connected to the control unit 52, which is connected to the MCU module 3. One end of the capacitor CY5 is connected to the capacitor CY4 and the third terminal of the rectifier bridge 1, and the other end is connected to the neutral wire N and the second terminal of the rectifier bridge 1. The diode D1 is used to prevent reverse current flow.

[0027] During the initial power-on phase, MCU module 3 controls control unit 52 to conduct, causing relay 51 to close. At this time, capacitor CY4 is connected to the circuit. AC mains power passes through capacitor CY4 and is then input to capacitor CY5, before returning to the neutral line N. Capacitors CY4 and CY5 form a voltage divider network, dividing the input AC mains power to prevent impact on subsequent circuits. The AC mains power passes through input buffer module 5 and is output to rectifier bridge 1. Rectifier bridge 1 rectifies the input signal and outputs it to PFC boost module 4. PFC boost module 4 switches between line voltage mode and phase voltage mode according to the control of MCU module 3, receives the signal output from rectifier bridge 1, and then boosts the signal. Once PFC boost module 4 is operating stably, MCU module 3 controls control unit 52 to close, causing relay 51 to open. At this time, capacitor CY4 is disconnected from the circuit to reduce losses.

[0028] Furthermore, the control unit 52 includes resistors R1 and R2 and transistor Q1. One end of resistor R1 is connected to MCU module 3, and the other end is connected to the base of transistor Q1. One end of resistor R2 is connected to both resistor R1 and the emitter of transistor Q1. The emitter of transistor Q1 is grounded, and the collector of transistor Q1 is connected to the anode of diode and the first terminal of relay 51.

[0029] Specifically, resistor R1 is used for current limiting, and resistor R2 is the pull-down resistor for transistor Q1. When MCU module 3 sends a high-level signal to control unit 52, transistor Q1 conducts, causing relay 51 to close; when MCU module 3 sends a low-level signal to control unit 52, transistor Q1 does not conduct, preventing relay 51 from closing. Thus, MCU module 3 changes the closed and open state of relay 51 by controlling the on / off state of transistor Q1.

[0030] Please refer to Figure 9 , Figure 9 This is the circuit diagram of the detection module. Detection module 2 includes a first current limiting unit 21, a second current limiting unit 22, a first filtering unit 23, and a comparator U6. One end of the first current limiting unit 21 is connected to the live wire L, and the other end is connected to the positive input terminal of the comparator U6. One end of the second current limiting unit 22 is connected to the neutral wire N, and the other end is connected to the negative input terminal of the comparator U6. The first filtering unit 23 is connected between the positive and negative input terminals of the comparator U6, and the output terminal of the comparator U6 is connected to the MCU module 3.

[0031] In this example, the first current limiting unit 21 includes a resistor R132, the second current limiting unit 22 includes a resistor R137, and the first filter unit 23 includes a capacitor C69. The first current limiting unit 21 and the second current limiting unit 22 are used to limit the current and prevent the comparator U6 from being damaged by excessive input current. The first filter unit 23 is used to filter the current input to the comparator U6, making the current smoother.

[0032] Furthermore, the detection module 2 also includes a first RC unit 24 and a second RC unit 25. The first RC unit 24 includes a resistor R129 and a capacitor C28, and the second RC unit 25 includes a capacitor C73 and a resistor R128. When connected, one end of capacitor C28 is connected to the positive input terminal of comparator U6, and the other end is connected to the output terminal of comparator U6. Resistor R129 is connected in parallel across capacitor C28. One end of capacitor C73 is connected to the negative input terminal of comparator U6, and the other end is connected to the output terminal of comparator U6. Resistor R129 is connected in parallel across capacitor C28. By placing the first RC unit 24 between the positive input terminal and the output terminal of comparator U6, high-frequency noise of the input electrical signal is eliminated; by placing the second RC unit 25 between the negative input terminal and the output terminal of comparator U6, a negative feedback loop is formed.

[0033] In this example, detection module 2 also includes resistor R134 and capacitor C72. One end of resistor R134 is connected to the output of comparator U6, and the other end is connected to MCU module 3. One end of capacitor C72 is connected to both resistor R134 and MCU module 3, and the other end is connected to the second RC unit 25 and ground. Resistor R134 is used for current limiting, and capacitor C72 is used for filtering.

[0034] In practical use, a preset reference value is incorporated into comparator U6. In this example, the preset reference value is 320V. AC mains power is input to comparator U6, which compares the input AC mains power with the preset reference value. When the AC mains voltage is less than the preset reference value, comparator U6 outputs a low-level detection signal. MCU module 3 receives this low-level detection signal and determines that the input AC mains voltage is the phase voltage. When the AC mains voltage is greater than the preset reference value, comparator U6 outputs a high-level detection signal. MCU module 3 receives this high-level detection signal and determines that the input AC mains voltage is the line voltage.

[0035] Example 2 This embodiment provides a control method for an adaptive PFC control circuit, which includes the following steps: S1, detection module 2 and rectifier bridge 1 respectively receive AC mains power and determine whether the input AC mains power is phase voltage or line voltage; when detection module 2 determines that the input AC mains power is phase voltage, detection module 2 outputs a first detection signal; when detection module 2 determines that the input AC mains power is line voltage, detection module 2 outputs a second detection signal; at the same time, rectifier bridge 1 receives AC mains power, rectifies the AC mains power into DC power signal, and outputs the DC power signal; S2, MCU module 3 receives the first detection signal and sends the first control signal to PFC boost module 4; MCU module 3 receives the second detection signal and sends the second control signal to PFC boost module 4; S3, PFC boost module 4 receives the first control signal and switches to phase voltage mode; PFC boost module 4 receives the second control signal and switches to line voltage mode. After switching modes, PFC boost module 4 receives the DC signal output by rectifier bridge 1, boosts the DC signal and outputs it to power the connected electrical equipment.

[0036] In another embodiment, the present invention also provides an adaptive PFC control system, including the above-described adaptive PFC control circuit.

[0037] In summary, by using detection module 2 to determine the type of input AC mains power, and then using MCU module 3 to control PFC boost module 4 to switch operating modes accordingly based on the type of input AC mains power, PFC boost module 4 switches to phase voltage mode when the input AC mains voltage is phase voltage, and switches to line voltage mode when the input AC mains voltage is line voltage. By switching PFC boost module 4 to the corresponding mode under different usage scenarios, the input voltage range of the adaptive PFC control circuit is effectively widened, while the utilization rate of the components in PFC boost module 4 is improved. This allows the adaptive PFC control circuit to be applied to different charging scenarios, improving the utilization rate of the charger.

[0038] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should be included within the scope of the claims of the present invention.

Claims

1. An adaptive PFC control circuit, characterized in that, include: The rectifier bridge (1) is used to receive AC mains power and rectify the AC mains power into DC signal and output it. The detection module (2) is used to detect whether the AC mains voltage is line voltage or phase voltage, and generates and sends a detection signal based on the detection result; The MCU module (3) is electrically connected to the detection module (2), and is used to receive the detection signal sent by the detection module (2), and generate and send control signals according to the detection signal; The PFC boost module (4) is electrically connected to the rectifier bridge (1) and the MCU module (3) respectively. It is used to receive the control signal sent by the MCU module (3) and switch to phase voltage working mode or line voltage working mode according to the control signal. Then the PFC boost module (4) receives the DC signal sent by the rectifier bridge, boosts it and outputs it.

2. The adaptive PFC control circuit according to claim 1, characterized in that, The PFC boost module (4) includes an inductor L2, a MOSFET Q24, a MOSFET Q25, and a MOSFET Q2. One end of the inductor L2 is connected to the output terminal of the rectifier bridge, and the other end of the inductor L2 is connected to the drain of the MOSFET Q24 and the drain of the MOSFET Q25. The gate of the MOSFET Q24 is connected to the MCU module (3), and the source of the MOSFET Q24 is connected to the drain of the MOSFET Q2 and the source of the MOSFET Q25. The gate of the MOSFET Q25 is connected to the MCU module (3), and the gate of the MOSFET Q2 is connected to the MCU module (3). The source of the MOSFET Q2 is grounded.

3. The adaptive PFC control circuit according to claim 2, characterized in that, When the PFC boost module (4) switches to phase voltage mode, the MOS transistor Q2 is normally closed, the MOS transistors Q24 and Q25 are connected in parallel, and the MOS transistors Q24 and Q25 operate in phase; when the PFC boost module (4) switches to line voltage mode, the MOS transistors Q24 and Q2 are connected in series and combined to form the first branch (41), and the MOS transistors Q25 and Q2 are connected in series and combined to form the second branch (42). The first branch (41) and the second branch (42) are connected in phase.

4. The adaptive PFC control circuit according to claim 1, characterized in that, It also includes an input buffer module (5), which includes a relay (51), a capacitor CY4, a control unit (52), a diode D1 and a capacitor C75. The relay (51) has a first terminal to a sixth terminal. The fifth and sixth terminals of the relay (51) are connected to the live wire of the mains power. One end of the capacitor CY4 is connected to the fifth and sixth terminals of the relay (51), and the other end is connected to the third and fourth terminals of the relay (51). The second terminal of the relay (51) is connected to the power supply and the negative terminal of the diode D1. The positive terminal of the diode D1 is connected to the first terminal of the relay (51). The first terminal of the relay (51) is also connected to the control unit (52), and the control unit (52) is also connected to the MCU module (3). One end of the capacitor CY5 is connected to the capacitor CY4 and the third terminal of the rectifier bridge (1), and the other end is connected to the neutral wire of the mains power and the second terminal of the rectifier bridge (1).

5. The adaptive PFC control circuit according to claim 1, characterized in that, The detection module (2) includes a first current limiting unit (21), a second current limiting unit (22), a first filtering unit (23), and a comparator U6. One end of the first current limiting unit (21) is connected to the live wire of the mains power, and the other end is connected to the positive input terminal of the comparator U6. One end of the second current limiting unit (22) is connected to the neutral wire of the mains power, and the other end is connected to the negative input terminal of the comparator U6. The first filtering unit (23) is connected in parallel between the positive input terminal and the negative input terminal of the comparator U6. The output terminal of the comparator U6 is connected to the MCU module.

6. The adaptive PFC control circuit according to claim 1, characterized in that, The control unit (52) includes resistors R1 and R2 and transistor Q1. One end of resistor R1 is connected to the MCU module (3), and the other end is connected to the base of transistor Q1. Resistor R2 is connected between the base and emitter of transistor Q1. The emitter of transistor Q1 is grounded. The collector of transistor Q1 is connected to the first terminal of relay (51) and the positive terminal of diode D1, respectively.

7. The adaptive PFC control circuit according to claim 1, characterized in that, The detection module (2) further includes a first RC unit (24) and a second RC unit (25). The first RC unit (24) includes a resistor R129 and a capacitor C28. The second RC unit (25) includes a capacitor C73 and a resistor R128. One end of the capacitor C28 is connected to the positive input terminal of the comparator U6, and the other end is connected to the output terminal of the comparator U6. The resistor R129 is connected in parallel across the two ends of the capacitor C28. One end of the resistor R128 is connected to the negative input terminal of the comparator U6, and the other end is connected to the output terminal of the comparator U6. The capacitor C73 is connected in parallel across the two ends of the resistor R128.

8. The adaptive PFC control circuit according to claim 3, characterized in that, The PFC boost module (4) also includes a diode D3, the positive terminal of which is connected to the inductor L2, the drain of the MOS transistor Q24 and the drain of the MOS transistor Q25.

9. A control method for an adaptive PFC control circuit, characterized in that, The adaptive PFC control circuit according to any one of claims 1-8 includes the following steps: The detection module (2) and the rectifier bridge (1) respectively receive AC mains power. The detection module determines whether the AC mains power is a phase voltage or a line voltage. When the AC mains power is determined to be a phase voltage, the detection module (2) outputs a first detection signal. When the AC mains power is determined to be a line voltage, the detection module (2) outputs a second detection signal. The rectifier bridge (1) rectifies the AC mains power and outputs a DC signal. The MCU module (3) receives the first detection signal output by the detection module (2) and sends a first control signal to the PFC boost module (4); the MCU module (3) receives the first detection signal output by the detection module (2) and sends a second control signal to the PFC boost module (4). The PFC boost module (4) receives a first control signal or a second control signal sent by the MCU module (3). The PFC boost module (4) receives the first control signal and switches to phase voltage mode. The PFC boost module (4) receives the second control signal and switches to line voltage mode. The PFC boost module (4) receives the DC signal output by the rectifier bridge and boosts the DC signal.

10. An adaptive PFC control system, characterized in that, Includes the adaptive PFC control circuit as described in any one of claims 1-8.

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