Interphase power loop-based star chain STATCOM and control method

Abstract

The invention discloses an interphase power loop-based star chain STATCOM and a control method thereof. The system comprises three phases of chain converters; one ends of the three phases of chain converters are connected by adopting a star mode and the other ends are connected with ABC three phases of an AC power grid through inductors; an LC series resonant circuit is arranged between adjacent chain units of the three phases of chain converters; and the two ends of the LC series resonant circuit are connected with inductance sides of the three phases of chain converters. Through enabling high-frequency AC components outputted by half-bridge converters / full-bridge converters of the three phases of chain units to perform energy transfer, the unbalanced reactive power compensation capability of the star chain STATCOM is improved; and as an interphase power channel is added between phases of the star chain STATCOM, the power density of the device is enhanced.

Description

technical field [0001] The invention relates to power electronics technology, in particular to a star chain STATCOM based on an interphase power loop and a control method thereof. Background technique [0002] Chained STATCOM has been widely used in the field of power quality management of medium and high voltage distribution networks. It has the characteristics of modularization and easy expansion, and can be directly integrated into medium and high voltage power grids without transformers. The traditional chained STATCOM topology can be divided into star structure and delta structure. Under the same voltage level, the star structure can use fewer units, thereby greatly reducing the complexity of the system. [0003] Invention patent CN201220674796.5 discloses a star-connected chained STATCOM device with unbalanced current compensation function. It uses a power frequency transformer to provide a zero-sequence current loop to realize energy exchange between phases, thereby a...

AI Technical Summary

Problems solved by technology

[0003] Invention patent CN201220674796.5 discloses a star-connected chained STATCOM device with unbalanced current compensation function. It uses a power frequency transformer to provide a zero-sequence current loop to realize energy exchange between phases, thereby achieving any unbalanced compensation. However, the structure The industrial frequency transformer is very bulky and does not use the power density of the device to increase

[0004] Invention patents CN201510196420.6 and CN201310101371.4 disclose the method of using zero-sequence voltage injection to realize a small amount of energy exchange between phases, but due to the constraints of hardware topology, the software method can only perform a small amount of unbalanced reactive power compensation, unbalanced reactive power limited ability to compensate

Images