Low additional voltage zero voltage switching energy storage bridge inverter and modulation method

Abstract

The invention discloses a low-additional-voltage zero-voltage switch energy storage bridge type inverter and a modulation method. The low-additional-voltage zero-voltage switch energy storage bridge type inverter comprises a direct-current side storage battery, a direct-current capacitor, an alternating-current filter inductor and a single-phase bridge arm, wherein the single phase bridge arm is formed by four full-control master switches with anti-parallel diodes, a series branch of an auxiliary switch with an anti-parallel diode and a clamping capacitor is connected between the direct-current side storage battery and a direct-current bus of the single-phase bridge arm, two ends of the branch are connected with resonance inductors, and two ends of the master switches and the auxiliary switch are in parallel connection with the capacitor. The low-additional-voltage zero-voltage switch energy storage bridge type inverter can independently run with load or runs in a grid-connection mode and is simple in structure, power can flow bidirectionally to charge and discharge the storage battery, the master switch uses a sine wave pulse width modulation method, and modulation signals of the master switches are synchronous with the auxiliary switch. In one switching period, the auxiliary switch only works once to enable all master switches to achieve zero-voltage switching. Reverse recovery current of the anti-parallel diodes of the master switches can be restrained so as to be small in switching loss, high in circuit efficiency and favorable for improving efficiency to improve power density.

Description

technical field [0001] The invention relates to a battery energy storage inverter, in particular to a circuit topology and modulation method of a zero-voltage switching battery energy storage bridge inverter with bidirectional flow of energy and low additional voltage stress. Background technique [0002] A single-phase battery energy storage inverter with the function of grid-connected power generation and independent operation with load, its circuit is as follows figure 1 As shown, it consists of four fully controlled main switches with anti-parallel diodes (S 1 ~S 4 ) constitutes a single-phase bridge arm, connected to the output filter inductance (L) between the midpoint of the bridge arm and the AC grid or AC load. This single-phase battery energy storage inverter can realize the function of grid-connected power generation, and can also run independently with load, but the circuit works in a hard switching state, and there is a problem of reverse recovery of the diode...

AI Technical Summary

Problems solved by technology

This single-phase battery energy storage inverter can realize the function of grid-connected power generation, and can also run independently with load, but the circuit works in a hard switching state, and there is a problem of reverse recovery of the diode, and the switching loss of the device is large, which limits the operating frequency. The improvement of the circuit efficiency reduces the circuit efficiency and there is a large electromagnetic interference

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