Part active power factor correction circuit controlled by input voltage threshold value

Abstract

The invention discloses a part active power factor correction circuit controlled by an input voltage threshold value. The part active power factor correction circuit comprises a boost circuit controlled by two loops, a voltage error amplifier, a multiplier, a current error amplifier, an input voltage sampling signal threshold value judging module, a PWM waveform generating module and an IC driven by PWM. On the basis of the boost circuit controlled by two loops, an input voltage sampling signal of the boost circuit is judged through the input voltage sampling signal sampling threshold value judging module, the IC driven by PWM is controlled to output a proper chopping signal or stop the copping signal, the boost circuit is subjected to chopping or chopping is stopped, and therefore part active power factor correction can be achieved, the number of electronic devices of the whole circuit under a high power factor value and low total current harmonic distortion is reduced, the area of the circuit can be reduced, and expenditure of the whole circuit is reduced.

Description

technical field [0001] The invention relates to the technical field of partial active power factor correction, in particular to a partial active power factor correction circuit controlled by an input voltage threshold. Background technique [0002] At present, most implementations of partial active power factor correction include a zero-crossing detection circuit hardware. When the detected input AC voltage changes from positive to negative, or from negative to positive, the zero-crossing detection circuit will generate a The zero-crossing flag signal is sent to the power factor correction PFC (Power Factor Correction, power factor correction) analog chip or digital PFC chip, and the power factor correction PFC analog chip or digital PFC chip determines at what time each half-wave sine cycle Stop PWM (Pulse Width Modulation, pulse width modulation) chopping, when to resume PWM chopping. In this implementation, the zero-crossing detection circuit is indispensable, which make...

AI Technical Summary

Problems solved by technology

In this implementation, the zero-crossing detection circuit is indispensable, which makes the number of electronic devices in the entire circuit larger, the circuit area is larger, and the overhead of the circuit is increased.

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