Boost power factor correction (PFC) controller

Abstract

The present invention relates to a power factor correction (PFC) controller. In one embodiment, a boost PFC controller configured in an AC / DC converter can include: (i) a conductive signal generator configured to receive a first sampling signal, and to generate a conductive signal according to the first sampling signal and a first control signal; (ii) a shutdown signal generator configured to compare a second control signal against a third control signal, and to generate a shutdown signal when the second control signal reaches a level of the third control signal; and (iii) a logic controller coupled to the conductive signal generator and the shutdown signal generator to control a switching state of a power switch in AC / DC converter.

Description

Technical field [0001] The present invention relates to the field of power factor correction, and more specifically, to a boost PFC controller. Background technique [0002] In order to reduce the harmonic pollution caused by power electronic devices to the power grid, a power factor correction (PFC) circuit is usually added to its input side. Currently, active power factor correction circuits are often used to convert the input current of power electronic devices to the input voltage The sine wave of the same phase can improve the power factor of the power electronic device, thereby reducing the harmonic pollution of the power grid. At present, the active PFC circuit often adopts the boost PFC circuit topology. In high-power applications, the continuous conduction mode (CCM) boost PFC circuit is more attractive, the following reference figure 1 Describes a typical CCM boost PFC circuit. [0003] reference figure 1 , Shown is a block diagram of a typical CCM boost PFC circuit, whi...

AI Technical Summary

Problems solved by technology

In the PWM controller of this traditional CCM step-up PFC circuit, an oscillator needs to be built in to generate a sawtooth wave signal with a fixed clock frequency, so as to ensure that the power switch tube Q M The operating frequency is constant; in addition, in this CCM step-up PFC circuit, it is essential to detect the input voltage Vg waveform, which is used to generate the reference signal Vr, so the number of pins of the PWM controller is large, Therefore, the traditional CCM boost PFC circuit design is costly and difficult

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