Novel transformer-free three-bridge-arm series active voltage quality regulator and control method

Abstract

A topological structure of the novel transformerless three-bridge-arm series active voltage quality regulator mainly comprises a main circuit and a bypass, the main circuit comprises a left bridge arm, a middle bridge arm, a right bridge arm, an inductor L1, a direct-current bus capacitor and a passive filter, and the left bridge arm, the middle bridge arm and the inductor L1 form a parallel rectification part of the main circuit; and the middle bridge arm, the right bridge arm and the passive filter form a series inversion part of the main circuit. In the topological structure, a boost circuit can be formed between the bridge arms, and the bus voltage is maintained at a high value when the voltage drop is deep and the compensation voltage is inversed, so that compared with the existing transformerless series active voltage quality control device, the transformerless series active voltage quality control device has higher efficiency and smaller volume under the condition of the same compensation capability.

Description

technical field [0001] The invention relates to the field of electric energy quality management, in particular to a novel transformerless three-bridge arm series active voltage quality regulator and a control method. Background technique [0002] The transformerless series active voltage quality regulator is mostly used in low power applications, and its volume is generally required to be small, that is, the power density must be high, and the cost must also be considered. At the same time, how to improve the compensation ability of the active voltage quality regulator is also a permanent direction of efforts. For the existing DySC topology, back-to-back H-bridge and PB-AVQR topology, it is collectively referred to as the half-bridge transformerless topology. Its performance is limited by the characteristics of the half-bridge system, and its output ripple is large. Larger filter parameters are required, and the DC bus is relatively high, requiring high-voltage IGBT tubes a...

AI Technical Summary

Problems solved by technology

For the existing DySC topology, back-to-back H-bridge and PB-AVQR topology, it is collectively referred to as the half-bridge transformerless topology. Its performance is limited by the characteristics of the half-bridge system, and its output ripple is large. Larger filter parameters are required, while the DC bus is relatively high, high withstand voltage IGBT tubes are required, and more DC side capacitors are required; the higher bus voltage leads to an increase in the safety distance of the entire system, so Will increase the size of the device and reduce the power density of the system

Three half-bridge IGBTs form a three-arm topology. Due to the large number of IGBT tubes, there is a problem of high cost.

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