Single-stage isolation type three-phase PFC converter

Abstract

The invention discloses a single-stage isolation type three-phase PFC converter which comprises an input end circuit and an output end circuit, wherein the input end circuit consists of an A-phase input circuit, a B-phase input circuit, a C-phase input circuit, an upper bus capacitor (C1) and a lower bus capacitor (C2); the output end circuit comprises an A-phase output circuit, a B-phase output circuit, a C-phase output circuit and an output capacitor (Co). By only adopting a single-stage circuit, the single-stage isolation type three-phase PFC converter realizes electrical isolation of conversion from alternating current to direct current; due to cooperative control, inputting of a unity power factor of the alternating current end and outputting of constant pressure, constant current and constant power are realized. Compared with a conventional two-stage structure, the circuit contains a small number of circuit devices, is simple in structure, efficient and reliable, and can substantially reduce the volume and the cost of a system; a control system is simple and high in dynamic performance; the single-stage isolation type three-phase PFC converter is applicable to a high voltage direct current UPS server power supply and an AC-DC isolation switching occasion for electric automobile direct current charging.

Description

technical field [0001] The invention relates to a single-stage isolated three-phase PFC converter. Background technique [0002] In a traditional UPS system, the grid input is connected to the storage battery through an AC-DC rectifier, and then output through an inverter and a static switch. Such a system has disadvantages such as low reliability, difficulty in maintenance and expansion, high risk, and low conversion efficiency. The high-voltage DC power supply solution has gradually become the mainstream of the system, which is the isolated AC-DC conversion. In recent years, the DC charging module power supply system for electric vehicles has developed rapidly. This system also uses isolated AC-DC converters. Therefore, isolated AC input and DC output rectifiers have become a hot research topic in the industry. At present, most rectifiers are composed of a two-stage system. The front stage is a PFC circuit, which realizes unit power factor power input and regulates the b...

AI Technical Summary

Problems solved by technology

[0003] The two-stage circuit structure is complex and costly

On the one hand, the large number of components increases the cost of the system and reduces the reliability of the system. On the other hand, there are two sets of control algorithms to control the cascade operation of the circuit, which is complex and difficult to meet the dynamic performance of the system.

Images