Energy-storage half-bridge type inverter of low-additional-voltage zero-voltage switch and modulating method

Abstract

The invention provides an energy-storage half-bridge type inverter of a low-additional-voltage zero-voltage switch and a modulating method. The energy-storage half-bridge type inverter comprises a direct-current side storage battery, direct-current side partial-pressure capacitors, an alternating-current side filter inductor and a single-phase bridge arm, wherein the single-phase bridge arm comprises two full-control main switches with anti-parallel diodes. A serially connected branch circuit of an auxiliary switch with an anti-parallel diode and a clamping capacitor is connected among the direct-current side partial pressure capacitors and a direct-current bus of the single-phase bridge arm, a resonance inductor is connectively crossed at two ends of the branch circuit, and two ends of the main switches and the auxiliary switch are connected with the capacitors in parallel. The energy-storage half-bridge type inverter runs with load independently or in a grid connection manner, the main switches adopt a sine wave pulse width modulation method, and modulation signals of the auxiliary switch are synchronous with those of the main switches. The auxiliary switch only acts once in each switch period so that zero-voltage conducting of all the main switches can be realized, reverse restoration current of the anti-parallel diodes of the main switches is suppressed, voltage stress of the switches is equal to the voltage of the direct-current side of the inverter, the loss of the switches is low, circuit efficiency is high, work frequency is improved and power density is improved.

Description

technical field [0001] The invention relates to a half-bridge inverter, in particular to a circuit topology and a modulation method of a zero-voltage switching battery energy storage half-bridge inverter with low additional voltage stress. Background technique [0002] A battery energy storage single-phase half-bridge inverter with the functions of grid-connected power generation and independent operation with load, its circuit is as follows figure 1 As shown, it consists of two fully controlled main switches S with antiparallel diodes 1 ~S 2 The single-phase bridge arm is connected to the output filter inductance L between the midpoint of the bridge arm and the load or the AC grid. This kind of inverter can realize independent inverter function, and can also realize grid-connected power generation operation, but 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 ...

AI Technical Summary

Problems solved by technology

This kind of inverter can realize independent inverter function, and can also realize grid-connected power generation operation, but 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 increase of the operating frequency and reduces the The circuit efficiency is improved and there is a large electromagnetic interference

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