Power electronic transformer with arc elimination coil and control method of power electronic transformer

Abstract

The invention relates to a power electronic transformer with an arc elimination coil and a control method of the power electronic transformer. The power electronic transformer comprises an intermediate-voltage stage, an isolation stage and a low-voltage stage, wherein the intermediate-voltage stage employs a series H-bridge structure, each phase bridge arm is formed by connecting N H-bridge converters in series, three phase bridge arms are connected in a star shape and then are connected with an intermediate-voltage AC power grid, neutral points of the three phase bridge arms are connected with ground via a reactor, the isolation stage comprises 3N dual-active full-bridge converters, each dual-active full-bridge converter comprises two H-bridge converters and a two-port high-frequency transformers, one end of each dual-active full-bridge converter is connected with one of the H-bridge converts of the intermediate-voltage stage, the other end of each dual-active full-bridge converter isconnected with a public low-voltage DC bus, the low-voltage stage employs a three-phase two-level converter, a DC port is connected with the public low-voltage DC bus, and an AC port s connected witha low-voltage AC power grid. The intermediate-voltage stage of the power electronic transformer is connected with the ground via the reactor, and the power electronic transformer has an automatic arcelimination function in a state of a single-phase grounding fault of a power grid at an intermediate-voltage side.

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.

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