Three-phase four-wire zero-voltage switch rectifier circuit with balancing bridge arm, and modulation method for three-phase four-wire zero-voltage switch rectifier circuit

Abstract

The invention discloses a three-phase four-wire zero-voltage switch rectifier circuit with a balancing bridge arm, and a modulation method for the three-phase four-wire zero-voltage switch rectifier circuit. The circuit comprises a DC side load of the rectifier circuit, a DC side series capacitor, an AC side filter inductor, a balancing bridge arm inductor, and four groups of bridge arms which are composed of two full-control main switches with anti-parallel diodes. An auxiliary switch comprising an anti-parallel diode, and a resonant branch circuit composed of the clamping capacitor and a resonant inductor are connected between a DC side bus capacitor and a bus of the four groups of bridge arms. Two ends of the main switch and the auxiliary switch are in parallel connection with capacitors. According to the invention, the circuit achieves the synchronization of the pulse signals of the auxiliary switch and the main switch, can achieve the zero-voltage connection of all switches in each switching period, effectively inhibits the reverse recovery current of the anti-parallel diode of the main switch, is small in switching loss, is high in circuit efficiency, facilitates the improvement of the switching frequency, and improves the system power density.

Description

technical field [0001] The invention relates to the technical field of rectifiers, in particular to a three-phase four-wire zero-voltage switch rectifier circuit with a balanced bridge arm and a modulation method thereof. Background technique [0002] A traditional two-level three-phase four-wire PWM rectifier with balanced legs consists of six fully controlled main switches (S 1 ~S 6 ) composed of three-phase bridge arm, three input filter inductors (L a , L b , L c ), two DC bus capacitors (C 1 , C 2 ), the fully controlled main switch (S 8 , S 9 ) composed of the first balanced bridge arm and the balanced inductance L across the midpoint of the balanced bridge arm and the midpoint of the bus capacitance bal , connected to the neutral point of the positive and negative bus capacitors and the neutral point of the power grid. The circuit works in a hard switching state, there is a diode reverse recovery phenomenon, and the switching loss of the converter device is l...

AI Technical Summary

Problems solved by technology

The circuit works in a hard switching state, there is a diode reverse recovery phenomenon, and the switching loss of the converter device is large, which limits the improvement of the operating frequency, resulting in the need to use a larger filter and reducing the circuit efficiency

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