Three-channel interlaced PFC circuit for frequency converter and channel management method

Abstract

The invention discloses a three-channel interlaced PFC circuit for a frequency converter and a channel management method. The PFC circuit is composed of a rectifier circuit, a PFC first branch circuit, a PFC second branch circuit and a PFC third branch circuit. The first branch circuit consists of a first inductor, a first diode and a first switching tube; the second branch circuit includes a second inductor, a second diode and a second switching tube; and the third branch circuit includes a third inductor, a third diode and a third switching tube. A first terminal of the first inductor, a first terminal of the second inductor, and a first terminal of the third inductor are connected to one point; a second terminal of the first inductor and a first terminal of the first diode are connected; a second terminal of the first inductor and a first terminal of the first switching tube are connected; and a second terminal of the first switching tube and a first terminal of a first sampling resistor are connected. According to the invention, flexible control of power changing is realized; the load transient response of the PFC converter is improved; the output and input current ripples are substantially reduced; and the service life of the capacitor is prolonged.

Description

technical field [0001] The invention belongs to the technical field of electronic circuits and frequency converters of asynchronous motors, and more specifically relates to a three-channel interleaved PFC circuit for frequency converters and a channel management method. Background technique [0002] With the popularization of frequency conversion technology, more and more PFC circuits are applied to power supply circuits. Existing PFC circuits include single-channel PFC circuits and interleaved PFC circuits. Such as figure 1 As shown, the existing single-channel PFC circuit is designed for a certain power level, and the current waveform is distorted when overloaded, and the power factor is low, and it cannot guarantee a high power factor in the full power range. [0003] The ripple current of the interleaved PFC circuit is smaller, so the output voltage is more stable, and the operating frequency is increased, so that the inductance components in the circuit can be reduced,...

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Problems solved by technology

[0005] Aiming at the defects of the prior art, the object of the present invention is to provide a three-channel interleaved PFC circuit for frequency converters, aiming at solving the problems of current distortion when the interleaved PFC is overloaded and the inability to ensure high power factor in the full power range in the prior art. question

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