WO2020232993A1

WO2020232993A1 - Power factor correction circuit and air conditioner

Info

Publication number: WO2020232993A1
Application number: PCT/CN2019/117014
Authority: WO
Inventors: 鲍殿生
Original assignee: 广东美的制冷设备有限公司
Priority date: 2019-05-17
Filing date: 2019-11-11
Publication date: 2020-11-26
Also published as: JP7374226B2; JP2022533665A

Abstract

A power factor correction circuit and an air conditioner. The power factor correction circuit comprises: a power factor correction module (10) used for receiving a power supply signal, the power factor correction module (10) comprising a switch tube, the switch tube being configured to control the power supply signal to supply power to a load; drive modules (202, 204) connected to a drive input end of the switch tube and used for outputting a switch signal to the switch tube; a control module (30) connected to the drive modules (202, 204) and used for controlling the drive modules (202, 204) to enable an output switch signal or disable an output switch signal; a current transformer (40) provided at an input side of the power factor correction module (10) to collect a sampling signal; and a drive protection module (50) connected to the current transformer (40) and the control module (30) and used for outputting a protection signal to the control module (30). By means of the technical solution, whether an abnormality occurs in a rectifier can be detected more directly, and when it is determined that an abnormality occurs, corresponding abnormal components can be determined in different working conditions.

Description

Power factor correction circuit and air conditioner

This application requires that it be submitted to the Chinese Patent Office on May 17, 2019, the application number is "201910413439.X", the title of the invention is "Power Factor Correction Circuit and Air Conditioner", and the application to the Chinese Patent Office on May 17, 2019 The priority of the Chinese patent application with the number "201920713087.5" and the invention title "Power factor correction circuit and air conditioner", the entire content of which is incorporated into this application by reference.

Technical field

This application relates to the technical field of air conditioners, and specifically to a power factor correction circuit and an air conditioner.

Background technique

In related technologies, the power factor correction circuit (Power Factor Correction, or PFC circuit) uses high-power MOS switching technology as the main power device to replace IGBT devices, and uses the characteristics of low on-resistance of MOS to replace the characteristics of constant on-voltage drop of IGBTs. The power consumption is reduced under medium and small power, so as to reduce the power consumption of the air conditioner.

Four switch tubes are used to form a power factor correction module, and two half-bridge drive chips are used to drive. One of the drive chips has a protection function and is combined with a sampling resistor for overcurrent detection. If a large current is detected, the four switches are triggered to close The driver output is used for over-current protection, but the scheme has the following defects:

As shown in Figure 1, the existing protection scheme can only detect when the upper and lower Q1 and Q3 are abnormal, or the upper and lower Q2 and Q4 are abnormal. In practical applications, the upper and lower switch tubes can be built-in due to the drive module itself. Interlocking protection circuit, the upper and lower bridge arms are difficult to appear directly, so the probability of failure corresponding to this protection scheme is very low, and the practicability is relatively poor.

Summary of the invention

This application aims to solve at least one of the technical problems existing in the prior art or related technologies.

To this end, an object of the present application is to provide a power factor correction circuit.

Another object of the application is to provide an air conditioner.

In order to achieve the above objective, according to an embodiment of the first aspect of the present application, a power factor correction circuit is provided, which includes a power factor correction module that receives a power supply signal, the power factor correction module includes a switch tube, and the switch tube Is configured to control the power supply signal to supply power to the load; a drive module, connected to the drive input end of the switch tube, for outputting a switch signal to the switch tube; a control module, connected to the drive module, for controlling The drive module turns on the output of the switch signal or turns off the output of the switch signal; a current transformer is arranged on the input side of the power factor correction module to collect sampling signals; the drive protection module is connected with the current transformer and The control module is connected to detect that the sampling signal is greater than or equal to a first safety threshold, and output a protection signal to the control module, where the protection signal is used to trigger the control module to turn off the output of the drive module.

In this technical solution, a current transformer is set at the AC input end of the power factor correction module. Based on the set position, the current transformer collects the input current or output current of the power factor correction module, and converts the current into a voltage signal for output drive On the protection module, the drive protection module detects whether there is an over-current phenomenon, so that when an over-current phenomenon is detected, it controls to stop outputting the switching signal to the power factor correction module. On the one hand, because the current transformer is not in contact with the measured The electrical contact of the circuit does not consume the power of the power supply under test, so it does not affect the high-efficiency and low-power control of the frequency conversion equipment. On the other hand, because the current transformer directly collects the input current of the power factor correction module, the power factor correction module When performing different functional operations, the corresponding different current flow paths can be detected by the current transformer for circuit abnormality, so it can be more directly detected whether the rectifier is abnormal, and when the abnormality is determined, it can be used under different working conditions. Determining the corresponding abnormal components has smaller limitations and more pertinence and practicability compared to the prior art that uses a driving chip with protection function combined with a sampling resistor for overcurrent detection.

Wherein, the first safety threshold is the safety voltage at the input side of the detection power factor correction module, preferably the safety voltage upper limit value.

Among them, those skilled in the art can understand that a current transformer is an instrument that converts a large current on the primary side into a small current on the secondary side based on the principle of electromagnetic induction for measurement. The current transformer is used in power frequency large current measurement occasions. In order to realize the function of current conversion and electrical isolation, based on the principle of electromagnetic induction, the output voltage is proportional to the rate of change of the AC side current, so it can accurately detect whether there is overcurrent on the AC side, and collect the current signal through the reactor through the current transformer. It is converted into a corresponding voltage signal and sent to the drive protection module to determine whether an overcurrent phenomenon occurs based on the voltage signal collected by the current transformer.

In the above technical solution, it further includes: a sampling resistor, which is arranged at the negative output terminal of the power factor correction module and connected to the drive protection module. The drive protection module detects a voltage drop on the sampling resistor. When the second safety threshold is exceeded, the control module outputs the protection signal.

Furthermore, a current transformer is connected in series on the AC side of the power factor correction module to be responsible for detecting the current on the AC side, and then the voltage signal output by the sensor is used as the input signal to drive the protection module, combined with the power factor correction module A sampling resistor connected in series with the negative output terminal. The voltage detected by the sampling resistor is also input to the drive protection module. When either of the two input voltages exceeds the preset voltage of the current detection and drive protection module, the current detection and drive protection will be triggered. The module protects and shuts down the power factor correction module, so that the detection function of overcurrent phenomenon can be realized on both the input and output sides.

The second safety threshold is the safety voltage on the output side of the detection power factor correction module, preferably the safety voltage upper limit value.

In any one of the above technical solutions, further comprising: a first reactor and a second reactor, the first reactor is arranged on the live line of the AC power source, and the second reactor is arranged on the neutral line of the AC power source On; zero-crossing detection module, set between the live wire end and the neutral wire end of the AC power supply, and connected to the control module, the zero-crossing detection module is used to collect the live wire end and the zero wire end The control module is also used to determine the phase state of the AC power supply according to the zero-crossing detection signal output by the zero-crossing detection module, so as to output to the drive module according to the phase state The corresponding switch control signal, wherein the AC power supply is used to output the power supply signal, and the current transformer is arranged between the live terminal of the AC power supply and the first reactor, or is arranged in the AC Between the neutral end of the power supply and the second reactor.

In this technical solution, by arranging the first reactor and the second reactor, compared with a single reactor circuit, on the one hand, the effect of superimposing two reactors can be realized, and on the other hand, it can replace the large size that is difficult to assemble The reactor is installed in the power factor correction circuit to reduce the difficulty of installation.

Further, by arranging the first reactor and the second reactor connected in parallel between the AC input end of the power factor correction module and the AC power supply, when the AC power supply performs AC output, the first reactor and the second reactor connected in parallel are The converter can convert the electrical energy supplied from the AC power supply into magnetic energy for energy storage, and can realize the boosting of the PFC circuit and the improvement of the power factor by releasing the energy.

In addition, by setting a zero-crossing detection module between the live line and the neutral line, the zero-crossing detection module can determine the real-time phase of the AC power supply, so as to drive different switching devices in the power factor correction module to perform switching operations according to different phase states. The rectification function or the power factor correction (PFC) function is realized respectively, so that the DC power supply of the load is realized based on the rectification function, or through PFC control, the AC side voltage and the AC side current are in phase.

In addition, there are many reasons for the over-current phenomenon, for example, the circuit is disturbed and the control module crashes and resets, or the first reactor and the second reactor connected in parallel have a short circuit abnormality.

In any of the above technical solutions, the current transformer is arranged between the live terminal of the AC power source and the first reactor, or the current transformer is arranged between the neutral terminal and the neutral terminal of the AC power source. Between the second reactor; the drive protection module is also used to: if the voltage signal is detected to be greater than the first safety threshold, output the protection signal to the control module to turn off the drive module Output.

In any one of the above technical solutions, the power factor correction module is formed by a first switching tube, a second switching tube, a third switching tube, and a fourth switching tube. The first switching tube, the second switching tube The third switching tube, the third switching tube and the fourth switching tube all have their own freewheeling diodes. The drain of the first switching tube is connected in series with the drain of the second switching tube, and the connection point is determined as The positive output terminal of the power factor correction module connects the source of the third switching tube and the source of the fourth switching tube in series, and connects the connection point in series with the sampling resistor and then grounds, and connects the first switch The source of the tube is connected in series with the drain of the third switching tube, and the connection point is connected to the live terminal, the source of the second switching tube is connected in series with the drain of the fourth switching tube, and Connect the connection point to the neutral terminal.

The power factor correction module is formed by a first switch tube, a second switch tube, a third switch tube, and a fourth switch tube. The first switch tube and the second switch tube are arranged on the upper part of the power factor correction module. The fourth switch tube and the second switch tube are arranged at the lower part of the power factor correction module, the first switch tube and the third switch tube are arranged at the left part of the power factor correction module, and the second switch tube and the fourth switch tube are arranged at the bottom of the power factor correction module. On the right, the first switching tube, the second switching tube, the third switching tube, and the fourth switching tube are all equipped with freewheeling diodes to connect the drain of the first switching tube to the The drain of the second switching tube is connected in series, and the connection point is determined as the positive output terminal of the power factor correction module, the source of the third switching tube is connected in series with the source of the fourth switching tube, and the connection point is Connected in series with the sampling resistor and grounded, connect the source of the first switch in series with the drain of the third switch, connect the connection point to the live terminal, and connect the The source is connected in series with the drain of the fourth switch tube, and the connection point is connected to the neutral terminal.

Specifically, the first switching tube, the second switching tube, the third switching tube, and the fourth switching tube may all be MOSFETs (Metal-Oxide-Semiconductor Field-Effect TransIstor, metal oxide semiconductor field effect transistor, that is, MOS tube), For example, super junction MOSFET, or SiC-MOSFET.

The working mode of the MOS tube realizes the switch by controlling the on-off between the source and the drain by the gate, and the gate power is greater than the source power when it is turned on.

In this technical solution, by setting a power factor correction module composed of four switch tubes, combined with the control instructions output by the control module, the control circuit performs rectification operation or power factor correction operation respectively. When used as a component of the motor drive system, Boost the voltage by alternately performing "power factor improvement actions" and "synchronous rectification actions" to achieve the purpose of increasing the allowable limit of the motor speed, and during the work process, by adding a current transformer to the circuit to detect operation When the abnormal current is detected, the power factor correction module is controlled to stop working and re-run after the abnormality is eliminated, so as to ensure the safety of the motor driving process.

In this technical solution, by setting a current transformer at the AC input end of the power factor correction module, no matter whether the rectification operation or the power factor correction operation is performed, current flows through the current transformer, so that when it is detected that there is current flowing through the current When a transformer is used, the device will output the corresponding voltage. According to the current value that the four switch tubes of the power factor correction module can withstand, the voltage value that needs to be protected is set in the overcurrent detection unit built in the drive protection module or the current transformer , The first switching tube is connected in series with the second switching tube between the live wire and the neutral line, and the third switching tube is connected in series with the fourth switching tube between the live wire and the neutral line. When the first switching tube-the second switching tube or the third When the switch tube-the fourth switch tube has abnormal overcurrent, the current will output the corresponding voltage through the current transformer and trigger the drive protection module, and then turn off the switch signal of the drive module, so as to protect the overcurrent to the switch tube. When the current signal is released, the drive protection module will release the control of the overcurrent drive module to resume normal operation, so that timely and effective detection of faults with relatively high probability can be achieved during the rectification operation or the power factor correction process. In order to achieve the purpose of improving the safety of the entire PFC circuit.

Specifically, after interconnecting the source of the third switching tube with the source of the fourth switching tube, the connection point is connected to one end of the sampling resistor, and the other end of the sampling resistor is grounded. By collecting the voltage signals at both ends of the sampling resistor, The voltage signal is transmitted to the drive protection module, so that after detecting that the voltage drop across the sampling resistor exceeds the second safety threshold, the control module is triggered to turn off the output of the drive module.

For power factor correction circuits equipped with current transformers and sampling resistors, the voltage can be sampled based on the current transformers and/or sampling resistors in different current flow paths, and the detection results of the sampling voltages can be used to determine whether there is a short circuit. Therefore, the detection requirements of different combined flow paths of the first switching tube, the second switching tube, the third switching tube and the fourth switching tube in the power factor correction module can be met.

In any of the above technical solutions, the driving module includes a first driving module for driving the first switching tube and the third switching tube, and a driving module for driving the second switching tube and the first switching tube. The second drive module with four switch tubes, wherein, if the drive protection module detects that the voltage signal is greater than the first safety threshold and/or the voltage drop is greater than the second safety threshold, the control module is triggered to turn off the The drive output of the first drive module and the second drive module.

In this technical solution, the driving module includes a first driving module and a second driving module to realize the half-bridge driving of the H-bridge organizer.

Specifically, the first switching tube and the third switching tube are driven by the first driving module, the second switching tube and the fourth switching tube are driven by the second driving module, and the voltage signal output by the current transformer and the voltage sampling signal of the sampling resistor are both Connected to the drive protection module, when the drive protection module detects that the voltage output by the current transformer and the voltage sampling signal on the sampling resistor exceed the preset value, it will forcibly shut down the first drive module and the second drive module, thereby protecting the four switch tubes .

Among them, the current transformer is mainly used to detect when the current passes through the first switching tube and the second switching tube in turn, or when the current passes through the third switching tube and the fourth switching tube in turn, when a short circuit is abnormal. Detection when the current passes through the first switch tube and the third switch tube in turn, or when the current passes through the second switch tube and the fourth switch tube in turn, when a short circuit is abnormal.

Among them, those skilled in the art can understand that the priority of the protection signal generated based on the current transformer trigger is the same as that of the protection signal generated based on the sampling resistor trigger. Any abnormality in any way will trigger the drive protection module, and the cause of overcurrent may be The circuit is subject to electromagnetic or surge interference, causing the control module to crash and reset, or the reactor has a short circuit abnormality, etc.

In any of the above technical solutions, it further includes: a bus capacitor, one end of the bus capacitor is connected to the positive output terminal, the other end of the bus capacitor is grounded, and the driving module outputs the switching signal through the AC The power supply charges the bus capacitance or discharges the bus capacitance, the driving module does not output the switching signal, and the bus capacitance is discharged.

In any of the above technical solutions, the control module is further configured to: if the input voltage of the AC power supply is in a positive half cycle, control the output of the drive module to make the first switch tube and the fourth The switching signal of the switch tube is turned on, and the corresponding freewheeling diode is bypassed; the control module is also used for: if the input voltage of the AC power supply is in the negative half cycle, control the drive module to output for causing the first The second switching tube and the third switching tube conduct the switching signal, and bypass the corresponding freewheeling diode to achieve synchronous rectification.

Among them, there is a freewheeling diode inside the first switching tube. The freewheeling diode is part of the PN junction existing between the source and drain of the first switching tube. The saturation voltage of the first switching tube (in the on state) The voltage between the drain and the source) is lower than the forward voltage drop of the freewheeling diode. As a result, compared with the current flowing in the parasitic diode, the voltage drop in the current flowing in the source and drain of the first switch tube is reduced, and the conduction loss can even be reduced. It is easy to understand that the current flowing in the first switching tube in the on state makes the conduction loss smaller than the current flowing in the freewheeling diode in the first switching tube in the off state. In addition, for other The second switching tube, the third switching tube, and the fourth switching tube are also applicable.

In this technical solution, the low-power synchronous rectification can be realized by using the principle of low conduction voltage drop of the MOS tube and turning on the corresponding MOS tube according to the phase state of the alternating current.

Specifically, the control module outputs a corresponding control signal according to the current alternating current phase detected by the zero-crossing detection module, and drives the corresponding switch tube to work.

In the related art, when performing synchronous rectification, during the positive half cycle of the AC power supply, the current passes through the current transformer and the reactor, and then rectifies the system through the freewheeling diodes of the first switch tube and the fourth switch tube. The voltage drop of the flow diode is large, causing energy waste.

In this technical solution, at this time, the control module judges according to the zero-crossing detection module that at the beginning of the positive half cycle of the AC power supply, the current passes through the current transformer and the reactor, and the output switching signal drives the first switching tube and the fourth switching tube to conduct. The current flowing through the first switching tube and the freewheeling diode on the fourth switching tube of the sampling resistor flows through the MOS tube, and the low conduction characteristic of the MOS tube is used to bypass the freewheeling diode, thereby reducing conduction loss. Similarly, in the negative half cycle of the AC power supply, the control module controls to turn on the second switching tube and the third switching tube, so that the four MOS tubes realize the synchronous rectification function. In the synchronous rectification process, through the current transformer and the sampling resistor The current detection is to detect whether there is an overcurrent phenomenon.

In any of the above technical solutions, the control module 30 is further configured to: if the input voltage of the AC power supply is in a positive half cycle, control the third switching tube according to the zero-crossing detection signal and the switching signal Q3 and the fourth switching tube Q4 are switched on and off, and the third switching tube Q3 and the fourth switching tube Q4 are turned on to charge the reactor L1 and turn off the third switching tube Q3 and The fourth switching tube Q4, the first switching tube Q1 are turned on, and the reactor L1 supplies power to the load; the control module 30 is also used to: if the input voltage of the AC power supply is in the negative half cycle, perform The zero-crossing detection signal and the switching signal control the opening and closing of the third switching tube Q3 and the fourth switching tube Q4, and the third switching tube Q3 and the fourth switching tube Q4 are turned on to connect The reactor L1 is charged, the third switching tube Q3 and the fourth switching tube Q4 are turned off, the second switching tube Q2 is driven to be turned on, and the reactor L1 supplies power to the load to achieve power factor Correction.

In this technical solution, when the circuit is used for PFC operation, when the input is in the positive half cycle of the AC power supply, the control module drives the third switch tube and the fourth switch tube to conduct according to the zero-crossing detection signal to conduct the reactor During the charging process, the current on the current transformer is detected to determine whether there is a short circuit. When the third switch tube and the fourth switch tube are turned off, the control module drives the first switch tube to open, and the electric energy stored in the reactor will be The first switching tube is released to the subsequent circuit to supply power to the bus capacitor and load (such as a motor). When the input is in the negative half cycle of the AC power supply, the control module drives the third switching tube and the fourth switching tube according to the zero-crossing detection signal Turn on to charge the reactor. When the third switch tube and the fourth switch tube are turned off, the control module drives the second switch tube to turn on. The electric energy stored in the reactor will be released to the subsequent circuit through the second switch tube. The bus capacitor and the load (such as a motor) supply power. By releasing the energy accumulated in the reactor to the bus capacitor, the DC voltage of the bus capacitor is boosted, so that the short-circuit current can be passed, reducing the distortion of the current waveform, and making the current waveform close Sine wave can improve the power factor of the PFC circuit. Furthermore, by calculating the pulse width of the third switching tube or the first switching tube according to the bus voltage of the load, the duration of the short-circuit current in the PFC circuit can be reasonably adjusted according to the pulse change Reasonable control of the number of times each switch is turned on/off can reduce the conduction loss of the switching unit, reduce switching loss, and improve efficiency.

In any one of the above technical solutions, it further includes: a load drive module, which is provided between the positive output terminal and the negative output terminal, and is configured to receive the DC output of the power factor correction module to supply power to the load; The DC bus voltage detection module is connected to the DC output terminal of the power factor correction module and is arranged in parallel with the load driving module for detecting the DC bus voltage.

In this technical solution, in the application scenario where the load is a motor, the load drive module is used to invert a regulated DC into a three-phase AC output to achieve power supply to the motor. Combined with the setting of the DC bus voltage detection module, The detection of the DC output bus voltage of the factor correction module and the detection of the input voltage control the switching state of each switch tube in the power factor correction module and the pulse width when each switch tube is turned on.

In any of the above technical solutions, the control module is also connected to the load drive module for outputting an inverter control signal to the load drive module.

According to an embodiment of the second aspect of the present application, there is provided an air conditioner including: the power factor correction circuit as described in the technical solution of the first aspect of the present application.

Specifically, the power factor correction circuit is applied to the motor drive system of the compressor, by detecting whether an overcurrent phenomenon occurs in the circuit, so as to prevent the motor from rotating too fast when the overcurrent occurs, causing the compressor to demagnetize.

The additional aspects and advantages of this application will be given in the following description, and some will become obvious from the following description, or be understood through the practice of this application.

Description of the drawings

The above and/or additional aspects and advantages of the present application will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, in which:

Figure 1 shows a schematic diagram of a power factor correction circuit in the related art;

Fig. 2 shows a schematic diagram of a power factor correction circuit according to an embodiment of the present application.

Detailed ways

In order to be able to understand the above objectives, features and advantages of the application more clearly, the application will be further described in detail below in conjunction with the accompanying drawings and specific implementations. It should be noted that the embodiments of the application and the features in the embodiments can be combined with each other if there is no conflict.

In the following description, many specific details are set forth in order to fully understand this application. However, this application can also be implemented in other ways different from those described here. Therefore, the scope of protection of this application is not covered by the specific details disclosed below. Limitations of the embodiment.

Example one

As shown in FIG. 2, the power factor correction circuit according to an embodiment of the present application is suitable for air conditioners and includes: a power factor correction module 10 for receiving a power supply signal, the power factor correction module 10 includes a switch tube, and the switch The tube is configured to control the power supply signal to supply power to the load; the drive module is connected to the drive input end of the switch tube for outputting switching signals to the switch tube; the control module 30 is connected to the drive module for To control the drive module to turn on the output of the switch signal or turn off the output of the switch signal; a current transformer 40 is arranged on the input side of the power factor correction module to collect sampling signals; the drive protection module 50 is connected to the The current transformer is connected to the control module, and is used to detect that the sampling signal is greater than or equal to a first safety threshold, and output a protection signal to the control module, and the protection signal is used to trigger the control module to turn off the drive The output of the module.

In this embodiment, a current transformer 40 is provided at the AC input end of the power factor correction module 10. The current transformer 40 collects the input current or output current of the power factor correction module 10 based on the set position, and converts the current into The voltage signal output drives the protection module 50, so that the drive protection module 50 detects whether an over-current phenomenon occurs, so that when an over-current phenomenon is detected, the control stops outputting the switching signal to the power factor correction module 10. On the one hand, because The current transformer 40 does not make electrical contact with the circuit under test, and can not consume the power of the power supply under test, so it does not affect the high-efficiency and low-power control of the frequency conversion equipment. On the other hand, because the current transformer 40 directly collects the power factor correction module 10 The input terminal current is connected to the live and neutral terminal N of the AC power supply, so it can be more directly detected whether the rectifier is abnormal, and when the abnormality is determined, the corresponding abnormality can be determined under different working conditions Compared with the prior art that uses a driver chip with protection function combined with a sampling resistor Rs for overcurrent detection, the component has smaller limitations and is more targeted and practical.

Among them, those skilled in the art can understand that the current transformer 40 is an instrument that converts a large current on the primary side into a small current on the secondary side according to the principle of electromagnetic induction, and the current transformer 40 is applied to the measurement of power frequency large current. In order to realize the function of current conversion and electrical isolation, based on the principle of electromagnetic induction, the output voltage is proportional to the rate of change of the AC side current, so it can accurately detect whether there is an overcurrent phenomenon on the AC side, and the current transformer 40 collects the flow through the reactor. The current signal is converted into a corresponding voltage signal and sent to the drive protection module 50 to determine whether an overcurrent phenomenon occurs based on the voltage signal collected by the current transformer 40.

Example two

As shown in FIG. 2, in the above-mentioned embodiment, it further includes a sampling resistor Rs, which is arranged at the negative output terminal of the power factor correction module 10 and connected to the drive protection module 50. The drive protection module 50 is Detecting that the voltage drop on the sampling resistor Rs exceeds a second safety threshold, the control module 30 outputs the protection signal.

In this embodiment, a current transformer 40 is connected in series on the AC side of the power factor correction module 10 to detect the current on the AC side, and then the voltage signal output by the sensor is used as the input signal to drive the protection module 50, combined with A sampling resistor Rs is connected in series to the negative output terminal of the power factor correction module 10. The voltage detected by the sampling resistor Rs is also input to the drive protection module 50. When either of the two input voltages exceeds the preset value of the current detection and drive protection module 50 When the voltage is applied, the protection of the current detection and driving protection module 50 is triggered and the power factor correction module 10 is turned off.

As shown in FIG. 2, in any of the above embodiments, it further includes: a first reactor L1 and a second reactor L2, the first reactor L1 is arranged on the live wire of the AC power source, the second reactor The reactor L2 is arranged on the neutral line of the AC power source; the zero-crossing detection module 60 is arranged between the live wire terminal L and the neutral wire terminal N of the AC power source and is connected to the control module 30. The zero detection module 60 is used to collect the zero-crossing detection signal between the live terminal L and the neutral terminal N; the control module 30 is also used to: according to the zero-crossing detection signal output by the zero-crossing detection module 60 Determine the phase state of the AC power source to output a corresponding switch control signal to the drive module according to the phase state, wherein the current transformer 40 is arranged at the live terminal L of the AC power source and the first Between the reactor L1, or between the neutral terminal N of the AC power supply and the second reactor L2.

In this embodiment, by arranging two parallel-connected first reactor L1 and second reactor L2, compared to a single reactor circuit, on the one hand, the effect of superimposing two reactors can be realized, on the other hand, Instead of large-size reactors that are difficult to assemble, they are installed in the power factor correction circuit to reduce the difficulty of installation.

Further, by arranging the first reactor L1 and the second reactor L2 in parallel between the AC input end of the power factor correction module 10 and the AC power source, when the AC power source performs AC output, the parallel first reactor L1 The second reactor L2 can convert the electrical energy supplied from the AC power supply into magnetic energy for energy storage, and can release the energy to achieve the boosting of the PFC circuit and the improvement of the power factor.

In addition, by setting the zero-crossing detection module 60 between the live wire and the neutral wire, the zero-crossing detection module 60 can determine the real-time phase of the AC power supply, so as to drive different switching devices in the power factor correction module 10 to perform switching according to different phase states. Operate to realize the rectification function or the power factor correction (PFC) function respectively, thereby realizing the DC power supply on the load side based on the rectification function, or through PFC control, so that the AC side voltage and the AC side current are in phase.

In addition, there are many reasons for the overcurrent phenomenon, for example, the control module 30 crashes and resets when the circuit is interfered, or the first reactor L1 and the second reactor L2 are short-circuited abnormally, and so on.

Example three

As shown in FIG. 2, in any of the above embodiments, the power factor correction module 10 is formed by a first switching tube Q1, a second switching tube Q2, a third switching tube Q3, and a fourth switching tube Q4. A switch tube Q1 and a second switch tube Q2 are arranged on the upper part of the power factor correction module 10, the third switch tube Q3 and the fourth switch tube Q4 are arranged on the lower part of the power factor correction module 10, the first switch tube Q1 and the third switch The tube Q3 is arranged at the left part of the power factor correction module 10, the second switching tube Q2 and the fourth switching tube Q4 are arranged at the right part of the power factor correction module 10, the first switching tube Q1, the second switching tube Q2 , The third switching tube Q3 and the fourth switching tube Q4 both have their own freewheeling diodes. The drain of the first switching tube Q1 and the drain of the second switching tube Q2 are connected in series and connected The point is determined as the positive output terminal of the power factor correction module 10, the source of the third switching tube Q3 and the source of the fourth switching tube Q4 are connected in series, and the connection point is connected in series with the sampling resistor Rs before being grounded , Connect the source of the first switching tube Q1 and the drain of the third switching tube Q3 in series, and connect the connection point to the live terminal L, and connect the source of the second switching tube Q2 to the The drain of the fourth switch tube Q4 is connected in series, and the connection point is connected to the neutral terminal N.

Specifically, the first switching tube Q1, the second switching tube Q2, the third switching tube Q3, and the fourth switching tube Q4 can all be MOSFT (Mta-Oxid-Smicoductor Fid-ffct TrasIstor, metal oxide semiconductor field effect transistors, namely MOS tube), such as super junction MOSFT or SiC-MOSFT.

In this embodiment, by setting the power factor correction module 10 composed of four switch tubes, combined with the control instructions output by the control module 30, the control circuit performs the rectification operation or the power factor correction operation respectively, as a component of the motor drive system When the voltage is increased by alternately performing “power factor improvement actions” and “synchronous rectification actions” to achieve the purpose of increasing the allowable limit of the motor speed, and in the working process, by adding a current transformer 40 in the circuit In order to detect the operating current, and in the case of detecting an abnormal current, the power factor correction module 10 is controlled to stop working and re-run after the abnormality is eliminated, so as to ensure the safety of the motor driving process.

In any of the above embodiments, the driving module includes a first driving module 202 for driving the first switching tube Q1 and the third switching tube Q3, and a first driving module 202 for driving the second switching tube Q2 And the second drive module 204 of the fourth switch tube Q4, wherein, if the drive protection module 50 detects that the voltage signal is greater than the first safety threshold and/or the voltage drop is greater than the second safety threshold, then The control module 30 is triggered to turn off the driving output of the first driving module 202 and the second driving module 204.

In this embodiment, the driving module includes a first driving module 202 and a second driving module 204 to realize the half-bridge driving of the H-bridge organizer.

Specifically, the first switching tube Q1 and the third switching tube Q3 are driven by the first driving module 202, the second switching tube Q2 and the fourth switching tube Q4 are driven by the second driving module 204, and the voltage signal output by the current transformer 40 and The voltage sampling signals of the sampling resistor Rs are all connected to the drive protection module 50. When the drive protection module 50 detects that the voltage output by the current transformer 40 and the voltage sampling signal on the sampling resistor Rs exceed the preset value, the first drive module will be forcibly shut down 202 and the second driving module 204 to protect the four switch tubes.

In any one of the above embodiments, it further includes: a bus capacitor E, one end of the bus capacitor is connected to the positive output terminal, the other end of the bus capacitor is grounded, and the driving module outputs the switching signal through the When the AC power supply charges the bus capacitor or discharges the bus capacitor, the drive module does not output the switching signal, and the bus capacitor discharges.

Example four

As shown in FIG. 2, in any of the above embodiments, the current transformer 40 is provided between the live terminal L of the AC power source and the first reactor L1, or the current transformer 40 is provided Between the neutral terminal N of the AC power supply and the second reactor L2.

In this embodiment, by providing a current transformer 40 at the AC input end of the power factor correction module 10, no matter whether the rectification operation or the power factor correction operation is being performed, current flows through the current transformer 40, so that when a current is detected When flowing through the current transformer 40, the device will output the corresponding voltage, according to the current value that the four switch tubes of the power factor correction module 10 can withstand, in the overcurrent detection unit built in the drive protection module 50 or the current transformer 40 Set the voltage value to be protected. The first switching tube Q1 and the second switching tube Q2 are connected in series between the live wire and the neutral line, and the third switching tube Q3 and the fourth switching tube Q4 are connected in series between the live wire and the neutral line. When an abnormal overcurrent occurs in a switching tube Q1-a second switching tube Q2 or a third switching tube Q3-a fourth switching tube Q4, the current will output the corresponding voltage through the current transformer 40 and trigger the drive protection module 50 to turn off the drive The switching signal of the module, so as to protect the overcurrent to the switch tube, when the overcurrent signal is released, the drive protection module 50 will release the control of the overcurrent drive module to restore normal operation, so that the power factor or power factor During the calibration process, timely and effective detection of faults with relatively high probability can be realized, so as to achieve the purpose of improving the safety of the entire PFC circuit.

As shown in Figure 2, after interconnecting the source of the third switching tube Q3 and the source of the fourth switching tube Q4, the connection point is connected to one end of the sampling resistor Rs, and the other end of the sampling resistor Rs is grounded. The voltage signal at both ends of the sampling resistor Rs is sampled, and the voltage signal is transmitted to the drive protection module 50, so that after detecting that the voltage drop across the sampling resistor Rs exceeds the second safety threshold, the control module 30 is triggered to turn off the output of the drive module.

For the power factor correction circuit of the current transformer 40 and the sampling resistor Rs, the voltage can be sampled based on the current transformer 40 and/or the sampling resistor Rs in different current flow paths, and whether there is a voltage is determined according to the detection result of the sampled voltage The short-circuit phenomenon can therefore meet the detection requirements of different combined flow paths of the first switching tube Q1, the second switching tube Q2, the third switching tube Q3, and the fourth switching tube Q4 in the power factor correction module 10.

The first switching tube Q1 and the third switching tube Q3 are driven by the first driving module 202, the second switching tube Q2 and the fourth switching tube Q4 are driven by the second driving module 204, the voltage signal output by the current transformer 40 and the sampling resistor Rs The voltage sampling signals of are connected to the drive protection module 50. When the drive protection module 50 detects that the voltage output by the current transformer 40 and the voltage sampling signal on the sampling resistor Rs exceed the preset value, the first drive module 202 and the first drive module 202 will be forcibly shut down. The second drive module 204 protects the four switch tubes.

Among them, the current transformer 40 is mainly used to detect when the current passes through the first switching tube Q1 and the second switching tube Q2 in sequence, or when the current passes through the third switching tube Q3 and the fourth switching tube Q4 in sequence when a short circuit abnormality occurs, and sampling The resistance Rs is mainly used to detect when the current passes through the first switching tube Q1 and the third switching tube Q3 in sequence, or when the current passes through the second switching tube Q2 and the fourth switching tube Q4 in sequence, when a short circuit abnormality occurs.

Among them, those skilled in the art can understand that the protection signal generated based on the triggering of the current transformer 40 has the same priority as the protection signal generated based on the triggering of the sampling resistor Rs. Any abnormality in any way will trigger the drive protection module 50, and overcurrent The reason may be that the circuit is subject to electromagnetic or surge interference, which causes the control module 30 to crash and reset, or the reactor has a short circuit abnormality, etc.

Example five

In any of the above embodiments, the control module 30 is further configured to: if the input voltage of the AC power supply is in a positive half cycle, control the output of the drive module to make the first switch Q1 and the The fourth switching tube Q4 turns on the switching signal and bypasses the corresponding freewheeling diode; the control module 30 is also used to: if the input voltage of the AC power supply is in the negative half cycle, control the drive module to output The switching signal that causes the second switching tube Q2 and the third switching tube Q3 to conduct, and the corresponding freewheeling diode is bypassed to realize synchronous rectification.

Among them, there is a freewheeling diode inside the first switching tube Q1. The freewheeling diode is a part of the P junction that exists between the source and drain of the first switching tube Q1. The saturation voltage of the first switching tube Q1 (connected to The voltage between the drain and the source in the on state is lower than the forward voltage drop of the freewheeling diode. Therefore, compared with the current flowing in the parasitic diode, the voltage drop of the current flowing in the source and drain of the first switching tube Q1 is reduced, and the conduction loss can even be reduced. It is easy to understand that the current flowing in the first switching tube Q1 in the on state makes the conduction loss smaller than the current flowing in the freewheeling diode in the first switching tube Q1 in the off state. In addition, for Other second switching tubes Q2, third switching tubes Q3, and fourth switching tubes Q4 are also applicable.

In this embodiment, the low-power synchronous rectification can be realized by using the principle of the low conduction voltage drop of the MOS transistor and turning on the corresponding MOS transistor according to the phase state of the alternating current.

Specifically, the control module 30 outputs a corresponding control signal according to the current alternating current phase detected by the zero-crossing detection module 60, and drives the corresponding switch tube to work.

In the related art, when performing synchronous rectification, during the positive half cycle of the AC power supply, the current passes through the current transformer 40 and the reactor, and then the freewheeling diodes of the first switching tube Q1 and the fourth switching tube Q4 are rectified to supply power to the system. Due to the large voltage drop of the freewheeling diode, energy wasted.

In this embodiment, at this time, the control module 30 judges according to the zero-crossing detection module 60 that at the beginning of the positive half cycle of the AC power supply, the current flows through the current transformer 40 and the reactor, and the output switching signal drives the first switching tube Q1 and the fourth switch The tube Q4 is turned on, so that the current flowing through the first switching tube Q1, the sampling resistor Rs and the freewheeling diode on the fourth switching tube Q4 flows through the MOS tube. The low conduction characteristic of the MOS tube is used to bypass the freewheeling diode, thereby Reduce conduction loss. Similarly, in the negative half cycle of the AC power supply, the control module 30 controls to turn on the second switching tube Q2 and the third switching tube Q3, so that the four MOS tubes realize the synchronous rectification function. During the synchronous rectification process, the current transformer 40 With the current detection on the sampling resistor Rs, it detects whether there is an overcurrent phenomenon.

Example Six

In any of the above embodiments, the control module 30 is further configured to: if the input voltage of the AC power supply is in a positive half cycle, drive the third switch Q3 and the The fourth switching tube Q4 is turned on to charge the reactor. If the third switching tube Q3 and the fourth switching tube Q4 are turned off, the first switching tube Q1 is driven to turn on, and the reactor The stored electric energy is released through the first switch tube Q1 to supply power to the load; the control module 30 is also used to: if the input voltage of the AC power supply is in the negative half cycle, drive the third switch according to the zero-crossing detection signal The tube Q3 and the fourth switching tube Q4 are turned on to charge the reactor. If the third switching tube Q3 and the fourth switching tube Q4 are turned off, the first switching tube Q1 is driven to turn on , The electric energy stored in the reactor is released to supply power to the load through the first switching tube Q1, so as to realize power factor correction.

In this embodiment, when the circuit is used for PFC operation, when the input is in the positive half cycle of the AC power supply, the control module 30 drives the third switching tube Q3 and the fourth switching tube Q4 to be turned on according to the zero-crossing detection signal. The reactor is charged. When the third switching tube Q3 and the fourth switching tube Q4 are turned off, the control module 30 drives the first switching tube Q1 to turn on, and the electric energy stored in the reactor will be released to the subsequent circuit through the first switching tube Q1. Supply power to the bus capacitor E and the load (such as a motor). When the input is in the negative half cycle of the AC power supply, the control module 30 drives the third switching tube Q3 and the fourth switching tube Q4 to conduct according to the zero-crossing detection signal to conduct the reactor When the third switching tube Q3 and the fourth switching tube Q4 are turned off, the control module 30 drives the second switching tube Q2 to turn on, and the electric energy stored in the reactor will be released to the subsequent circuit through the second switching tube Q2 to provide the bus capacitor E is supplying power to the load (such as a motor). By releasing the energy accumulated in the reactor to the bus capacitor E, the DC voltage of the bus capacitor E is boosted, so that the short-circuit current can be passed, reducing the distortion of the current waveform and making the current waveform Close to a sine wave, which can improve the power factor of the PFC circuit. Furthermore, by calculating the pulse width of the third switching tube Q3 or the first switching tube Q1 according to the bus voltage of the load, the duration of the short-circuit current in the PFC circuit can be reasonably adjusted. Reasonably controlling the turn-on/turn-off times of each switch according to the number of pulse changes can reduce the turn-on loss of the switching unit, reduce switching loss, and improve efficiency.

As shown in FIG. 2, in any one of the above embodiments, it further includes: a load driving module 70, which is provided between the positive output terminal and the negative output terminal, and is configured to receive the power factor correction module 10 DC output to supply power to the load; a DC bus voltage detection module (not shown in the figure), connected to the DC output terminal of the power factor correction module 10, and set in parallel with the load driving module 70 for detecting DC bus voltage.

In this embodiment, in an application scenario where the load is a motor, the load drive module 70 is used to invert a regulated DC into a three-phase AC output to achieve power supply to the motor. Combined with the setting of the DC bus voltage detection module, The detection of the bus voltage of the DC output of the power factor correction module 10 and the detection of the input voltage control the switching state of each switching tube in the power factor correction module 10 and the pulse width when each switching tube is turned on.

In any of the above embodiments, the control module 30 is further connected to the load driving module 70 for outputting an inverter control signal to the load driving module 70.

An air conditioner according to an embodiment of the present application includes: the power factor correction circuit described in any one of the above embodiments.

Compared with the prior art, the embodiments disclosed in the technical solution of this application have at least the following beneficial effects:

(1) Since the current transformer directly collects the input current of the power factor correction module, the different current flow paths corresponding to the power factor correction module when performing different functional operations can be detected by the current transformer for circuit abnormality. Directly detect whether the rectifier is abnormal, and when the abnormality is determined, the corresponding abnormal component can be determined under different working conditions. Compared with the prior art, the driver chip with protection function combined with the sampling resistor for overcurrent detection The program has smaller limitations and is more targeted and practical.

(2) A current transformer is connected in series on the AC side of the power factor correction module to detect the current on the AC side, and then the voltage signal output by the sensor is used as the input signal to drive the protection module, combined with the power factor correction module A sampling resistor connected in series with the negative output terminal. The voltage detected by the sampling resistor is also input to the drive protection module. When either of the two input voltages exceeds the preset voltage of the current detection and drive protection module, the current detection and drive protection will be triggered. The module protects and shuts down the power factor correction module, so that the detection function of overcurrent phenomenon can be realized on both the input and output sides.

(3) For the power factor correction circuit of the current transformer and the sampling resistor, the voltage can be sampled based on the current transformer and/or the sampling resistor in different current flow paths, and the detection result of the sampling voltage can be used to determine whether there is a short circuit Therefore, it can meet the detection requirements of different combined flow paths of the first switching tube, the second switching tube, the third switching tube, and the fourth switching tube in the power factor correction module.

The technical solution of the present application is described in detail above in conjunction with the drawings. A current transformer is connected in series on the AC side of the power factor correction module to detect the current on the AC side, and then the voltage signal output by the sensor is used as the driving protection module. The input signal is combined with a sampling resistor connected in series with the negative output terminal of the power factor correction module. The voltage detected by the sampling resistor is also input to the drive protection module. When either of the two input voltages exceeds the preset voltage of the current detection and drive protection module At the same time, it will trigger the protection of the current detection and drive protection module and turn off the power factor correction module.

Those skilled in the art should understand that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, this application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

This application is described with reference to flowcharts and/or block diagrams of methods, equipment (systems), and computer program products according to the embodiments of this application. It should be understood that each process and/or block in the flowchart and/or block diagram, and the combination of processes and/or blocks in the flowchart and/or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing equipment to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing equipment are generated It is a device that realizes the functions specified in one process or multiple processes in the flowchart and/or one block or multiple blocks in the block diagram.

These computer program instructions can also be stored in a computer-readable memory that can guide a computer or other programmable data processing equipment to work in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture including the instruction device. The device implements the functions specified in one process or multiple processes in the flowchart and/or one block or multiple blocks in the block diagram.

These computer program instructions can also be loaded on a computer or other programmable data processing equipment, so that a series of operation steps are executed on the computer or other programmable equipment to produce computer-implemented processing, so as to execute on the computer or other programmable equipment. The instructions provide steps for implementing functions specified in a flow or multiple flows in the flowchart and/or a block or multiple blocks in the block diagram.

It should be noted that in the claims, any reference signs located between parentheses should not be constructed as limitations on the claims. The word "comprising" does not exclude the presence of parts or steps not listed in the claims. The word "a" or "an" preceding a component does not exclude the presence of multiple such components. This application can be realized by means of hardware including several different components and by means of a suitably programmed computer. In the module claims that list several devices, several of these devices can be embodied in the same hardware item. The use of the words first, second, and third, etc. do not indicate any order. These words can be interpreted as names.

Although the preferred embodiments of the present application have been described, those skilled in the art can make additional changes and modifications to these embodiments once they learn the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

Obviously, those skilled in the art can make various changes and modifications to the application without departing from the scope of the claims of the application and its equivalent technologies, and the application also intends to include these changes and modifications.

Claims

A power factor correction circuit, which includes:

A power factor correction module that receives a power supply signal, the power factor correction module includes a switch tube configured to control the power supply signal to supply power to the load;

The drive module is connected to the drive input end of the switch tube and is used to output a switch signal to the switch tube;

The control module is connected to the drive module and is used to control the drive module to turn on the output of the switch signal or turn off the output of the switch signal;

A current transformer is arranged on the input side of the power factor correction module to collect sampling signals;

The drive protection module is connected to the current transformer and the control module, and is used to detect that the sampling signal is greater than or equal to a first safety threshold, and output a protection signal to the control module. The protection signal is used to trigger the The control module turns off the output of the drive module.
The power factor correction circuit according to claim 1, further comprising:

The sampling resistor is set at the negative output terminal of the power factor correction module and connected to the drive protection module. When the drive protection module detects that the voltage drop on the sampling resistor exceeds a second safety threshold, the control The module outputs the protection signal.
The power factor correction circuit according to claim 2, further comprising:

A first reactor and a second reactor, the first reactor is arranged on the live wire of the AC power source, and the second reactor is arranged on the neutral wire of the AC power source;

The zero-crossing detection module is arranged between the live terminal and the neutral terminal of the AC power supply and is connected to the control module, and the zero-crossing detection module is used to collect between the live terminal and the neutral terminal The zero-crossing detection signal;

The control module is further configured to determine the phase state of the AC power source according to the zero-cross detection signal output by the zero-cross detection module, so as to output a corresponding switch control signal to the drive module according to the phase state,

Wherein, the AC power supply is used to output the power supply signal, and the current transformer is arranged between the live terminal of the AC power source and the first reactor, or is arranged between the neutral terminal of the AC power source and the first reactor. Between the second reactor.
The power factor correction circuit according to claim 3, wherein:

The power factor correction module is formed by a first switching tube, a second switching tube, a third switching tube, and a fourth switching tube. The first switching tube, the second switching tube, the third switching tube and the The fourth switching tube is equipped with a freewheeling diode, the drain of the first switching tube is connected in series with the drain of the second switching tube, and the connection point is determined as the positive output of the power factor correction module Terminal, connect the source of the third switching tube in series with the source of the fourth switching tube, connect the connection point in series with the sampling resistor and then ground, connect the source of the first switching tube with the third The drains of the switching tubes are connected in series, and the connection point is connected to the live terminal, the source of the second switching tube is connected in series with the drain of the fourth switching tube, and the connection point is connected to the neutral line end.
The power factor correction circuit according to claim 4, wherein:

The driving module includes a first driving module for driving the first switching tube and the third switching tube, and a second driving module for driving the second switching tube and the fourth switching tube,

Wherein, if the drive protection module detects that the sampling signal is greater than the first safety threshold and/or the pressure drop is greater than the second safety threshold, the control module is triggered to turn off the first drive module and the second safety threshold. Two drive output of the drive module.
The power factor correction circuit according to claim 4, wherein:

The control module is further configured to: if the input voltage of the AC power supply is in a positive half cycle, control the driving module to output a switching signal for conducting the first switching tube and the fourth switching tube, and Bypass the corresponding freewheeling diode;

The control module is further configured to: if the input voltage of the AC power supply is in the negative half cycle, control the driving module to output a switching signal for conducting the second switching tube and the third switching tube, and Bypass the corresponding freewheeling diode to realize synchronous rectification.
The power factor correction circuit according to claim 4, wherein:

The control module is further configured to: if the input voltage of the AC power supply is in a positive half cycle, control the opening and closing of the third switching tube and the fourth switching tube according to the zero-crossing detection signal and the switching signal, The third switching tube and the fourth switching tube are turned on to charge the reactor, the third switching tube and the fourth switching tube are turned off, and the first switching tube is turned on, The reactor supplies power to the load;

The control module is further configured to: if the input voltage of the AC power supply is in the negative half cycle, control the opening and closing of the third switching tube and the fourth switching tube according to the zero-crossing detection signal and the switching signal, The third switching tube and the fourth switching tube are turned on to charge the reactor, turning off the third switching tube and the fourth switching tube, and driving the second switching tube to be turned on , The reactor supplies power to the load to realize power factor correction.
The power factor correction circuit according to any one of claims 4 to 7, further comprising:

A bus capacitor, one end of the bus capacitor is connected to the positive output terminal, the other end of the bus capacitor is grounded, the driving module outputs the switching signal, and the bus capacitor is charged through the AC power supply, or the bus When the capacitor is discharged, the driving module does not output the switching signal, and the bus capacitor is discharged.
The power factor correction circuit according to any one of claims 4 to 7, further comprising:

A load drive module, arranged between the positive output terminal and the negative output terminal, and used to receive the DC output of the power factor correction module to supply power to the load;

The control module is also connected to the load drive module for outputting an inverter control signal to the load drive module.
An air conditioner, comprising: the power factor correction circuit according to any one of claims 1 to 9.