A power electronic transformer with arc suppression coil and its control method

Abstract

The invention relates to a power electronic transformer with an arc suppression coil and a control method thereof. The power electronic transformer includes a medium voltage stage, an isolation stage and a low voltage stage. The medium-voltage stage adopts a series H-bridge structure. Each phase bridge arm is composed of N H-bridge converters connected in series. The three-phase bridge arms are connected to the medium-voltage AC power grid after a star connection. Grounded through a reactor; the isolation stage is composed of 3N dual active full-bridge converters, each dual active full-bridge converter is composed of two H-bridge converters and a two-port high-frequency transformer, each dual active One end of the full-bridge converter is connected to an H-bridge converter of the medium-voltage stage, and the other end is connected to the public low-voltage DC bus; the low-voltage stage uses a three-phase two-level converter, the DC port is connected to the public low-voltage DC bus, and the AC port Connect to low voltage AC grid. The medium-voltage stage of the power electronic transformer is grounded through a reactor, and has the function of automatic arc suppression under the single-phase ground fault state of the medium-voltage side power grid.

Description

technical field [0001] The invention belongs to the field of power electronic transformers, in particular to a power electronic transformer with arc suppression coils. Background technique [0002] The power frequency power transformer is an important component in the power system, which has the functions of voltage level conversion and electrical isolation. However, with the intelligentization of the power system and the access of distributed power generation, the function of traditional power frequency power transformers has become increasingly difficult to meet the demand. In addition to realizing the voltage level conversion and electrical isolation functions of traditional power frequency power transformers, power electronic transformers can also provide many additional functions, including voltage and current closed-loop adjustment, communication, automatic protection, etc., which can meet the diverse functions of future power systems Demand, is expected to replace th...

AI Technical Summary

Problems solved by technology

However, in the currently published literature on power electronic transformers, the connection of arc suppression coils has not been considered in terms of topology and control.

Images