Staggered power factor correction circuit based on FAN9672

Abstract

The invention discloses an FAN9672-based staggered power factor correction circuit, which comprises a 220VAC commercial power input rectification filter circuit, two paths of staggered PFC switch circuits, an FAN9672 chip and a peripheral circuit thereof, the 220VAC commercial power is input and filtered and then is converted into a DC voltage signal through a rectifier bridge, the FAN9672 chip is configured with the peripheral circuit to realize input voltage, current sampling and two paths of staggered PFC control, and the FAN9672 chip is connected with the FAN9672 chip. Output voltage sampling is carried out, PFC adjustment is carried out through an internal program of the FAN9672 chip, voltage sag and short-time interruption slow-down protection and under-voltage protection are supported, and 380VDC output is achieved. Based on an FAN9672 chip, the alternating two-path continuous conduction mode power factor correction function is achieved through simple peripheral circuit design, and the power factor reaches 0.99 or above; according to the design, software configuration is not needed, the PFC function can be achieved only through a hardware circuit, meanwhile, two-way current monitoring and voltage monitoring are achieved, protection response is fast, and a post-stage circuit can be protected to the maximum extent.

Description

Technical Field

[0001] The present invention relates to the field of power electronic equipment, and in particular to an interleaved power factor correction circuit based on FAN9672. Background Art

[0002] In modern power supply systems, traditional rectifier circuits cause input current waveform distortion, generate a large number of harmonics, reduce power factor and increase the burden on the power grid. Power factor correction (PFC) technology adjusts the input current waveform to synchronize it with the voltage waveform, thereby improving energy efficiency and reducing harmonic pollution. Traditional PFC solutions are usually implemented using discrete components, which have problems such as complex design, limited performance and high cost. Discrete components not only increase circuit complexity and design difficulty, but also affect PFC accuracy and stability due to parameter matching and temperature drift issues. At the same time, the large number of components also increases costs. How to design a circuit with low cost, simple structure and good performance is an urgent problem to be solved. Summary of the invention

[0003] Purpose of the invention: The purpose of the present invention is to provide an interleaved power factor correction circuit based on FAN9672.

[0004] Technical solution: The interleaved power factor correction circuit based on FAN9672 described in the present invention includes a 220VAC mains input rectification and filtering circuit, a two-way interleaved PFC switching circuit, a FAN9672 chip and its peripheral circuits. The 220VAC mains input is filtered and converted into a DC voltage signal through a rectifier bridge, which is input into the FAN9672 chip through two-way interleaved PFC switching circuits. The FAN9672 chip is configured with peripheral circuits to realize input voltage and current sampling, two-way interleaved PFC control, and output voltage sampling. The internal program of the FAN9672 chip generates an error signal by comparing the collected input voltage and current signals with a reference value, adjusts the PWM duty cycle through a multiplier and a current control loop, controls the switch tube, makes the input current and voltage in phase, close to a sine wave, realizes PFC regulation, and supports voltage sag and short-time interruption mitigation protection and undervoltage protection to realize 380VDC output.

[0005] Furthermore, the 220VAC mains power input is converted into a DC voltage and current signal through a rectifier bridge after passing through a fuse and a filter circuit.

[0006] Furthermore, the DC voltage and current signals are provided to the FAN9672 chip for PFC control after voltage division and current limiting by resistors.

[0007] Furthermore, the two-way interleaved PFC switch circuits are controlled by outputting control signals PFC_O1 and PFC_O2 via the FAN9672 chip.

[0008] Furthermore, the two-way interleaved PFC switch circuit feeds back two current signals to the FAN9672 chip through CS1 and CS2 to perform current monitoring and PFC regulation.

[0009] Furthermore, the peripheral circuit configuration of the FAN9672 chip includes a PFC-BIBO signal, an FC_IAC signal, a PFC_FB signal, FC_O1 and PFC_O2 output signals, and two differential current signals CS1 and CS2.

[0010] Furthermore, the PFC-BIBO signal is used for voltage sag and short-time interruption mitigation protection.

[0011] Furthermore, the FC_IAC signal is used to monitor the input current and perform regulation.

[0012] Furthermore, the FC_O1 and PFC_O2 output signals control two switches.

[0013] Furthermore, the peripheral circuit of the FAN9672 chip cooperates with other signals to perform PFC regulation.

[0014] Beneficial effect: Compared with the prior art, the present invention has the following significant advantages: the present invention is based on the FAN9672 chip, and realizes the alternating two-way continuous conduction mode power factor correction function through a simple peripheral circuit design, and the power factor reaches above 0.99; the design does not require software configuration, and the PFC function can be realized only through the hardware circuit. At the same time, it has dual-way current monitoring, voltage monitoring, and fast protection response, which can protect the subsequent circuit to the greatest extent; the overall circuit design is simple and low-cost, and can be effectively applied to various scenarios such as inverters and high-power AC / DC power supplies. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a principle block diagram of the present invention;

[0016] Figure 2 This is the 220VAC mains input circuit diagram;

[0017] Figure 3 It is a circuit diagram of two-way interleaved PFC switches;

[0018] Figure 4 The circuit diagram for the peripheral circuit configuration of FAN9672. DETAILED DESCRIPTION

[0019] The technical solution of the present invention is further described below in conjunction with the accompanying drawings.

[0020] The principle block diagram of the interleaved power factor correction circuit based on FAN9672 described in the present invention is as follows Figure 1As shown in the figure, the mains 220VAC input is filtered and converted into a DC voltage signal through a rectifier bridge. Through simple peripheral circuit configuration, the FAN9672 chip can realize input voltage and current sampling, two-way interleaved PFC control, and output voltage sampling. The internal program performs PFC regulation, supports voltage sag and short-time interruption mitigation protection, undervoltage protection and other functions, and realizes 380VDC output.

[0021] like Figure 2 As shown in the figure, 220VAC mains power input is converted into DC through a fuse and filter circuit through a rectifier bridge. The voltage and current signals are divided by resistors and limited by current to be provided to the FAN9672 chip for PFC control.

[0022] like Figure 3 As shown, the two-way PFC switch circuit performs switch control through the output control signals PFC O1 and PFC O2 of the FAN9672 chip, and CS1 and CS2 feed back two-way current signals to the FAN9672 chip for current monitoring and PFC regulation.

[0023] like Figure 4 As shown in the figure, the peripheral circuit configuration of the FAN9672 chip, the PFC-BIBO signal is used for voltage sag and short-time interruption mitigation protection; FC_IAC is used to monitor the input current and perform regulation; the PFC_FB signal is the DC output voltage feedback; FC_O1 and PFC_O2 output control two switches; CS1 and CS2 two-way differential current signal monitoring, and cooperate with other signals to perform PFC regulation.

[0024] Through the cooperation of the above circuits, the PFC function can be realized. The hardware circuit configuration is simple, no software configuration is required, and the operation is stable and reliable.

[0025] The present invention realizes the alternating two-way continuous conduction mode (CCM) power factor correction (PFC) function only by hardware circuit design based on FAN9672 chip, and has simple structure, small size and low cost. While realizing high power factor, it is equipped with current and voltage monitoring, undervoltage protection and other functions, and has better EMI performance. The present invention can be used in the fields of frequency converter, high-power AC / DC power supply, etc., and has a wide range of application scenarios.

Claims

1. An interleaved power factor correction circuit based on FAN9672, characterized in that: It includes a 220VAC mains input rectification and filtering circuit, a two-way interleaved PFC switching circuit, a FAN9672 chip and its peripheral circuits. The 220VAC mains input is filtered and converted into a DC voltage signal through a rectifier bridge, which is input into the FAN9672 chip through two-way interleaved PFC switching circuits. The FAN9672 chip is configured with peripheral circuits to realize input voltage and current sampling, two-way interleaved PFC control, and output voltage sampling. The internal program of the FAN9672 chip generates an error signal by comparing the collected input voltage and current signals with a reference value, adjusts the PWM duty cycle through a multiplier and a current control loop, controls the switch tube, makes the input current and voltage in phase and close to a sine wave, realizes PFC regulation, and supports voltage sag and short-time interruption mitigation protection and undervoltage protection to realize 380VDC output.

2. The interleaved power factor correction circuit based on FAN9672 according to claim 1, characterized in that: The 220VAC mains power input is converted into a DC voltage and current signal through a rectifier bridge after passing through a fuse and a filter circuit.

3. The interleaved power factor correction circuit based on FAN9672 according to claim 2, characterized in that: The DC voltage and current signals are provided to the FAN9672 chip for PFC control after voltage division and current limiting by resistors.

4. The interleaved power factor correction circuit based on FAN9672 according to claim 1, characterized in that: The two-way interleaved PFC switch circuits are controlled by outputting control signals PFC_O1 and PFC_O2 via the FAN9672 chip.

5. The interleaved power factor correction circuit based on FAN9672 according to claim 1, characterized in that: The two-way interleaved PFC switch circuit feeds back two current signals to the FAN9672 chip through CS1 and CS2 for current monitoring and PFC regulation.

6. The interleaved power factor correction circuit based on FAN9672 according to claim 1, characterized in that: The peripheral circuit configuration of the FAN9672 chip includes a PFC-BIBO signal, an FC_IAC signal, a PFC_FB signal, FC_O1 and PFC_O2 output signals, and two differential current signals CS1 and CS2.

7. The interleaved power factor correction circuit based on FAN9672 according to claim 6, characterized in that: The PFC-BIBO signal is used for voltage sag and short interruption mitigation protection.

8. The interleaved power factor correction circuit based on FAN9672 according to claim 6, characterized in that: The FC_IAC signal is used to monitor the input current and perform regulation.

9. The interleaved power factor correction circuit based on FAN9672 according to claim 6, characterized in that: The FC_O1 and PFC_O2 output signals control two switches.

10. The interleaved power factor correction circuit based on FAN9672 according to claim 1, characterized in that: The peripheral circuit of the FAN9672 chip cooperates with other signals to perform PFC regulation.

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