Bidirectional hybrid direct-current circuit breaker based on capacitor commutation, and direct-current power transmission system

Abstract

The invention discloses a bidirectional hybrid direct-current circuit breaker based on capacitor commutation, and a direct-current power transmission system. The direct-current circuit breaker comprises an ultra-fast mechanical switch unit, a load change-over switch unit, a capacitor current conversion unit and an energy absorption unit, wherein the ultra-fast mechanical switch unit is connected in series with the load change-over switch unit, the capacitor current conversion unit is connected in parallel with the ultra-fast mechanical switch unit and the load change-over switch unit which areconnected in series, the energy absorption unit is connected in parallel with the capacitor current conversion unit, the capacitor current conversion unit is used for providing a low-voltage branch for the ultra-fast mechanical switch unit and the load change-over switch unit to ensure normal switching-on and switching-off of the ultra-fast mechanical switch unit and the load change-over switch unit when a short-circuit fault occurs in the system, and cutting off fault current by utilizing a self-switching-off function, and the energy absorption unit is used for absorbing energy stored by aninductive element in a power system after the fault current is cut off after the on-off fault. The bidirectional hybrid direct-current circuit breaker based on capacitor commutation provided by the invention can realize on-off of fault current and energy absorption limitation of a lightning arrester.

Description

technical field [0001] The invention belongs to the technical field of direct current circuit breakers, and more specifically relates to a bidirectional hybrid direct current circuit breaker and a direct current transmission system based on capacitive commutation. Background technique [0002] In recent years, the total amount of new energy power generation has increased rapidly, and the application of flexible DC transmission can effectively improve the utilization efficiency of renewable energy power generation and reduce the economic losses caused by abandoning wind and light. Components are widely used all over the world. [0003] With the continuous expansion of the DC grid scale and the increasingly complex structure of the DC grid, many key issues need to be solved urgently, one of which is the DC short-circuit fault. Therefore, it is very necessary to develop a DC circuit breaker that can quickly cut off the fault current, isolate the fault point, and ensure the nor...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the defects of the prior art, the purpose of the present invention is to provide a bidirectional hybrid DC circuit breaker based on capacitive commutation, which aims to solve the technical problems of the difficulty in breaking the fault current of the DC circuit breaker and the large energy absorption of the arrester in the prior art

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