Converter device for electrified railway ground automatic neutral section system

Abstract

The invention provides a converter device for an electrified railway ground automatic neutral section system. The topological structure of the device comprises a high voltage pre-charging unit, an MMCrectifying unit, an intermediate direct current isolation conversion unit and an MMC inverter conversion unit. The MMC rectifying unit and the MMC inverter conversion unit comprises left and right bridge arms respectively. Each bridge arm is composed of symmetrical upper and lower half bridges, and the upper and lower half bridges comprise a reactor and n power modules connected in series respectively. The intermediate direct current isolation conversion unit is composed of m direct current isolation conversion modules DCM directly connected in series on the direct current side. The device provided by the invention realizes converting for the power supply of the neutral section of the electrical sectioning of a contact network, so that a train can pass through the electrical sectioning without power off.

Description

technical field [0001] The invention relates to the field of electrified railway catenary traction power supply, and more specifically relates to a current conversion device for an electrified railway ground automatic phase separation system. Background technique [0002] my country's electrified railway traction network adopts phase-separated and segmented single-phase power frequency AC power supply. Every 30-60km, there is an isolation area of ​​about 200-900m in neutral electrical phase separation, which is called electrical separation. In addition to affecting the comfort and total running time of the catenary, and reducing the railway transportation capacity, the catenary phase separation may bring at least 80 kV operating overvoltage, which may cause damage or failure of the high-voltage equipment of the train. At the same time , Frequent and excessive phase separation can easily lead to driver fatigue. Therefore, catenary phase separation has always been a high-freque...

AI Technical Summary

Problems solved by technology

[0005] The over-phase splitting equipment based on the automatic switching of ground mechanical switches has a small amount of application in my country, but the actual application also shows the following defects: 1. Mechanical switch switching cannot accurately control the phase, and there are overvoltage and overcurrent impacts; 2. Mechanical switches The switching time is long, and there is a long non-electric dead zone in the neutral section during the commutation process; 3, there is a high overvoltage and overcurrent impact, and the control software and protection setting value of the train need to be modified; 4, the life of the mechanical switch is low , requires regular maintenance and replacement, high operating costs in the later period

[0006] In view of some defects in the automatic switching over-phase separation technology of ground mechanical switches, in recent years, relevant institutions have also carried out research on automatic switching over-phase separation technology based on ground electronic switches. This technology is characterized by the use of electronic switches instead of mechanical switches. The basic principle of over-phase separation has not changed, so there must still be an electric dead zone in the neutral section during the commutation process, which will still bring problems such as overvoltage and overcurrent shocks to the train

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