In-phase power supply system based on three-phase AC/DC type power electronic transformer

Abstract

The invention provides an in-phase power supply system based on a three-phase AC / DC type power electronic transformer, which comprises a traction transformer TT, a three-phase compensation transformer MT, the three-phase AC / DC type power electronic transformer and a coordination control unit CC, wherein a primary side of the traction transformer TT is connected with two phases in a three-phase power grid, one end of the secondary side of the traction transformer TT is connected with a traction bus, a primary side of the three-phase compensation transformer MT is connected with the three-phase power grid, and a secondary side of the three-phase compensation transformer MT is connected with the input end of the three-phase AC / DC type power electronic transformer; and the primary side of the traction transformer TT is provided with a current transformer CT, the three-phase power grid is internally provided with voltage transformers PT1 and PT2, and the voltage transformers PT1 and PT2 are respectively connected in parallel between two different phases of the three-phase power grid. By arranging the three-phase compensation transformer MT and the three-phase AC / DC type power electronic transformer, a new in-phase power supply compensation scheme can be formed, the power electronic transformer technology is applied to the in-phase power supply system, and different voltage grades can be adapted by reasonably configuring the number of module units.

Description

technical field [0001] The invention relates to the technical field of electrified railways and urban rails, in particular to a three-phase AC / DC power electronic transformer-based in-phase power supply system. Background technique [0002] The electrified railway in my country generally adopts single-phase power frequency AC system. In order to make the single-phase traction load as balanced as possible in the three-phase power system, the electrified railway often adopts the scheme of alternating phase sequence and split-phase partition power supply. The adjacent power supply intervals at the phase separation partition form a phase separation insulator, which is called electrical phase separation or phase separation. During the transient electrical process of the train passing through the electric phase separation, a large operating overvoltage or overcurrent is likely to occur, causing accidents such as burning of the traction network and on-board equipment, affecting the...

AI Technical Summary

Problems solved by technology

However, this topology and compensation scheme need to take into account the IGBT module voltage level and price factors, the secondary voltage of the three-phase compensation transformer must be low enough, and the flexibility is relatively limited

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