Single-phase half-bridge five-level inverter and application circuit thereof

Abstract

The invention provides a single-phase half-bridge five-level inverter and an application circuit thereof. The single-phase half-bridge five-level inverter comprises eight switching tubes and eight diodes, and does not comprise clamping diodes and flying capacitors in the prior art. In the prior art, the clamping diodes in the five-level inverter cannot be omitted because the diodes not only provide passages for current and prevent short circuit of capacitors. In the five-level inverter provided by the invention, passages are provided for current by utilizing diodes which are reversely connected with the eight switching tubes in parallel, so that the short circuit of the capacitors is prevented. Therefore, the inverter has fewer semiconductor devices, lower loss, higher efficiency, small volume and low cost. In the prior art, the flying capacitors are used for generating multiple levels, however, the capacitors have higher cost; and in the embodiment of the invention, the multiple levels are generated without using the capacitors, thus the inverter has low cost.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a single-phase half-bridge five-level inverter and an application circuit thereof. Background technique [0002] In medium-voltage and large-capacity applications, multi-level inverters are widely used. The current five-level inverters are mainly diode-clamped and flying capacitor structures. To be introduced below. [0003] see Figure 1a , which is a topology diagram of a diode-clamped five-level inverter provided in the prior art. [0004] Figure 1a Shown is the topology of a half-bridge five-level inverter. Diodes are used for voltage clamping for each switching tube. For example, the first diode DB1 is used to clamp the potential of the lower end of the switching tube T1 to the lower end of the first capacitor C1; the second diode DB2 is used to clamp the potential of the lower end of the switching tube T5 to the lower end of the first capacitor C1. The other ...

AI Technical Summary

Problems solved by technology

[0008] figure 2 The capacitors in the topology shown can play the role of voltage equalization, but the disadvantage is that the number of capacitors used is large

[0009] To sum up, the two five-level inverter topologies in the prior art both use more semiconductor devices, resulting in larger volume, more losses, and lower efficiency

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