Improved and high-performance bidirectional Z-source inverter

Abstract

Aiming at the defects of high capacitance voltage stress, large starting impact current, abnormal working state, incapability of bidirectional energy flowing and the like of a traditional Z-source inverter, the invention proposes an improved and high-performance bidirectional Z-source inverter. The improved and high-performance bidirectional Z-source inverter comprises a three-phase inverter and also comprises a Z-source network, wherein the three-phase inverter comprises a DC voltage source and a three-phase inversion bridge, the Z-source network comprises a power diode, a switch inductor anda capacitor, the improved and high-performance bidirectional Z-source inverter is characterized in that a single inductor is substituted by a switch inductance branch, an initial end of the Z-sourcenetwork is connected to a positive electrode of a power supply, a tail end of the Z-source network is connected to a positive end of the three-phase inversion bridge, and the inversion bridge and thepower supply are in common ground. Compared with the traditional Z-source inverter, the improved and high-performance bidirectional Z-source inverter has the advantages that the boost capability of the inverter can be improved, a high-gain factor is achieved, the output quality of the whole inverter is improved, the voltage stress of a Z-network capacitor is effectively reduced, so that the volumeand the weight of the inverter are reduced; and meanwhile, a full-control switch tube is reversely connected in parallel to a diode for blocking energy feedback, and the improved and high-performancebidirectional Z-source inverter has the capability of bidirectional energy flowing.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to an improved high-performance bidirectional Z-source inverter. Background technique [0002] Microgrid technology is the key to the development and utilization of renewable energy such as wind energy and solar energy. The inverter is the core interface component of the micro-grid, it is the guarantee for the efficient operation of the micro-grid, and it is the medium of energy exchange between the distributed energy source and the grid; For grid-connected power generation, it is necessary to add a DC-DC step-up link to form a two-stage grid-connected power generation system, which has a complex structure and difficult control. [0003] The Z-source inverter uses the straight-through state to achieve a single-stage boost, which is suitable for a single-stage grid-connected power generation system, but there are problems such as large start-up surge current, low boost gai...

AI Technical Summary

Problems solved by technology

The inverter is the core interface component of the micro-grid, it is the guarantee for the efficient operation of the micro-grid, and it is the medium of energy exchange between the distributed energy source and the grid; If the inverter is connected to the grid for power generation, it is necessary to add a DC-DC step-up link to form a two-stage grid-connected power generation system, which has a complex structure and difficult control

[0003] The Z-source inverter uses the straight-through state to achieve a single-stage boost, which is suitable for a single-stage grid-connected power generation system, but there are problems such as large start-up surge current, low boost gain, and bidirectional energy flow; for example, the application number is "201110166524.4". Although an improved high-performance bidirectional Z-source inverter improves the boosting capability, it does not solve the problem of bidirectional flow of energy; and a new type of Z-source grid-connected converter with the application number "201510037253.0" makes the capacitor voltage The stress is reduced, but the boost capability of the Z source impedance network is not changed

Images