Converter station comprising hybrid inductance type superconducting current limiter and direct-current circuit breaker and direct-current fault processing method of converter station

Abstract

The invention provides a converter station containing a hybrid inductance type superconducting current limiter and a direct-current circuit breaker and a direct-current line fault processing method ofthe converter station. The converter station adopts a true bipolar structure, and a converter of the converter station adopts a modular multilevel converter. The DC side of the converter station is connected with other converter stations in the multi-terminal flexible DC system through a multi-circuit DC line. In the converter station, the direct-current high-voltage end of a positive converter is connected to a positive direct-current bus, the direct-current low-voltage end of a negative converter is connected to a negative direct-current bus, and the direct-current low-voltage end of the positive converter and the direct-current high-voltage end of the negative converter are connected and grounded; and the direct-current line is connected with the positive direct-current bus or the negative direct-current bus of the converter station through the hybrid inductance type superconducting current limiter and the direct-current circuit breaker in sequence. According to the invention, thecost of the superconducting fault current limiter is reduced, and the requirement on the on-off capacity of the high-voltage direct-current circuit breaker is lowered; meanwhile, the stability problempossibly caused by overlarge current limiting reactor in a normal operation state can be avoided.

Description

technical field [0001] The invention relates to the field of new energy flexible direct current transmission systems, in particular to a method for reducing the breaking requirements of a high-voltage direct current circuit breaker by limiting the fault current of a direct current system. Background technique [0002] In recent years, my country has made breakthroughs and great achievements in the field of large-capacity long-distance HVDC transmission technology and engineering applications. Since the official completion and operation of my country's first high-voltage direct current transmission project ±800kV Xiangjiaba-Shanghai DC project in 2010, the State Grid Corporation of China has completed and put into operation eleven high-voltage direct current transmission projects. Flexible DC transmission refers to high-voltage DC transmission based on voltage source converter (Voltage source converter, VSC), which has no reactive power compensation and commutation failure pr...

AI Technical Summary

Problems solved by technology

[0005] In view of the DC transmission system, especially the multi-terminal flexible DC transmission system, the DC side of the converter station is connected to other converter stations in the multi-terminal flexible DC system through a multi-circuit DC line. The current hybrid inductance superconducting current limiter and the converter station of the DC circuit breaker and its DC fault handling strategy can make full use of the inductance's ability to deeply suppress the fault current, which not only reduces the cost of the superconducting fault current limiter, but also reduces High-voltage DC circuit breaker breaking capacity requirements; at the same time, it can avoid stability problems that may be caused by excessive current-limiting reactors under normal operating conditions

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