Additional-voltage-free zero voltage switch bridge-free power factor corrector and modulation method

Abstract

The invention provides an additional-voltage-free zero voltage switch bridge-free power factor corrector and a modulation method. The corrector comprises a power factor corrector direct current side load, a direct current side capacitor, an alternating current filtering capacitor, a bridge arm formed by two full control main switches with antiparallel diodes and a bridge arm formed by connecting two diodes in series. An antiparallel diode auxiliary switch is connected between bridge arm side direct current buses formed by directly connecting the direct current side capacitor and the diodes. Capacitors are arranged at two ends of the main switches and the auxiliary switch in parallel, capacitors are connected at two ends of the diodes on the bridge arm in parallel, and resonant branches formed by connecting resonant inductors and clamping capacitors are in bridge joint with two ends of the auxiliary switch. The main switches adopt the sine wave pulse width modulation method, and demodulation signals of the auxiliary switch are synchronous with those of the main switches. The corrector is simple in structure, and the direct current output can serve as a direct current power supply in use. The corrector is small in switch consumption, high in circuit efficiency and favorable for improving working efficiency and further improves power accuracy.

Description

technical field [0001] The invention relates to a bridgeless power factor corrector, in particular to a circuit topology and modulation method of a bridgeless power factor corrector with no additional voltage stress and a zero-voltage switch bridgeless power factor corrector. Background technique [0002] The current general single-phase power factor corrector, its circuit is as follows figure 1 shown, it consists of four diodes D 1 ~D 4 The bridge arm of the single-phase full bridge is connected to the input filter inductance L between the midpoint of the bridge arm and the AC power grid. This single-phase power factor corrector can be used as a communication power supply, etc., but there are many diodes in the loop channel of this circuit, and the conduction loss is relatively large. In order to reduce the conduction loss of the diode, a bridgeless power factor corrector is proposed, and its circuit is as follows figure 2 As shown, it consists of two fully controlled ...

AI Technical Summary

Problems solved by technology

However, the circuit works in a hard switching state, there is a problem of reverse recovery of the diode, and the switching loss of the device is large, which limits the improvement of the operating frequency, reduces the circuit efficiency and has a large electromagnetic interference

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