A New Topology of Combined DC Circuit Breaker

Abstract

The invention discloses a novel combined DC circuit breaker topology, which adopts only one main breaker switch, one malfunctioning auxiliary switch, one transfer switch TS0 connected in series with the main breaker switch, two groups of diodes in different directions, and a transfer switch TS1 corresponding to m lines on each DC bus bar, wherein, the main breaker switch TS0 is connected with themain breaker switch TS0, and the main breaker switch TS1 is connected with the main breaker switch TS0-TSm. The transfer switch TS0 is connected in parallel with the failed auxiliary switch in serieswith the main disconnect switch, one end of the main disconnect switch is connected with the DC bus bar, the other end is connected with the diode group in the direction of the inflow line through thetransfer switch TS0, and is also connected with the diode group in the direction of the outflow line through the failed auxiliary switch. The transfer switch TS1-TSm is respectively connected to thebus bar and the corresponding line 1-Line m. When the system is in normal operation, the voltage on both ends of the switches of each part of the novel combined DC circuit breaker is zero, which can effectively reduce the breakdown probability of the device, improve the operation reliability of the system as a whole, adopt fewer main devices, and have better economy.

Description

technical field [0001] The invention relates to the field of flexible direct current transmission systems, in particular to a novel combined direct current circuit breaker topology with a reclosing function and a fast mechanical switch failure protection function. Background technique [0002] In recent years, the adjustment of my country's energy structure has promoted the development of new energy generation technologies based on wind power. At the same time, in order to improve the ability of the grid to absorb unstable new energy, the flexible DC transmission technology based on voltage source converter (voltage source converter, VSC) has also received extensive attention. [0003] In the flexible DC transmission system, the traditional VSC converter station does not have the ability to clear the DC side fault, which is a hot research topic. There are two solutions to this problem by using self-clearing sub-modules or using DC circuit breakers in transforming converter ...

AI Technical Summary

Problems solved by technology

However, when this combined circuit breaker is in normal operation, the device continues to withstand high voltage for a long time, and there is a main break grounding process when any line fault operates, and it does not have the failure protection function for the fast mechanical switch, so further improvement is still needed

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