TOPOLOGICAL STRUCTURE FOR TRANSFORMERLESS FOUR-QUADRANT HIGH VOLTAGE FREQUENCY CONVERTER

摘要

A topological structure for a transformerless high voltage frequency converter, comprising a high voltage charging circuit, an inductor (L1, L2), a rectifier circuit and an inverter circuit. A high voltage power network is directly connected to the high voltage frequency converter rectifier circuit via the high voltage charging circuit and a coupled or uncoupled inductor (L1). The rectifier circuit is a controllable rectification system consisting of a plurality of rectification units. After rectification, the direct current voltage supplies power to the inverter circuit. The output terminal of the inverter circuit is connected to the coupled or uncoupled inductor (L2). The rectifier circuit and the inverter circuit consist of power units in series. The topological structure allows the four-quadrant high voltage frequency converter to be controlled at variable-frequency speeds and also allows four-quadrant operation of a motor without a transformer, thereby reducing the volume of the high voltage frequency converter and lowering costs.