Three-Phase Bridgeless Power Factor Corrected AC-DC Converter

Abstract

The invention relates to an alternating current-direct current conversion technology and discloses a three-phase bridgeless power factor correction (PFC) alternating current-direct current converter. The technical scheme of the invention is as follows: the alternating current-direct current converter comprises an A-phase converter, a B-phase converter, a C-phase converter and a control system for the A-phase converter, the B-phase converter and the C-phase converter, wherein the A-phase converter, the B-phase converter and the C-phase converter are bridgeless double boost power factor correction converters with same structure; the alternating current input ends of the A-phase converter, the B-phase converter and the C-phase converter are respectively connected with an A-phase line, an A-phase central line, a B-phase line, a B-phase central line and a C-phase phase line and a C-phase central line; and the direct current output positive ends and the direct current output negative ends of the converters are respectively connected to form the direct current output end of the three-phase bridgeless PFC alternating current-direct current converter so as to connect a load to provide direct current to the load. Due to the circuit design disclosed by the invention, not only can mutual interference and influence among three single-phase converters be reduced, but also the redundancy characteristics of the converters are realized; if one phase goes wrong, the other two phases still can supply power to the load so that the robustness of the system is greatly enhanced, and thereby the converter is very suitable for three-phase high-power applications.

Description

technical field [0001] The invention relates to an AC-DC conversion technology, in particular to a three-phase bridgeless power factor correction (PFC) AC-DC converter. Background technique [0002] In medium and high power (above several kilowatts) applications, due to the limitation of the maximum input power of single-phase AC, the input of electrical equipment mostly adopts three-phase voltage. However, most of the traditional DC power equipment is directly used for the load after uncontrolled rectification and filtering, resulting in intermittent input current, high current total harmonic distortion (THD), and low power factor, which seriously affects the quality of power supply and not only increases the loss of the power grid , and can also cause damage to some equipment. In order to achieve high power factor (PF) and low harmonic distortion, power factor correction (PFC) technology based on power electronics technology is widely used in AC-DC (AC-DC) power conversio...

AI Technical Summary

Problems solved by technology

Among them, the single-switch three-phase bridgeless power factor correction AC-DC converter, the current works in discontinuous mode, the current harmonic distortion on the input side is large, and a large electromagnetic compatibility (EMI) filter is required; the three-switch three-phase Bridgeless power factor correction AC-DC converter, three switching tubes must be bidirectional switches; six-switch three-phase bridgeless power factor correction AC-DC converter can achieve complete control, but there are problems such as high cost and complicated control

Moreover, in the prior art three-phase bridgeless power factor correction AC-DC converter, the working state of each phase switch and inductor current is jointly participated and restricted by other two-phase circuits, and it is very difficult or even impossible to independently control any one phase Achieved

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