Direct-current circuit breaker based on combination of current limiting and oscillation transfer and control method thereof

Abstract

The invention discloses a direct-current circuit breaker based on combination of current limiting and oscillation transfer and a control method thereof. The direct-current circuit breaker comprises a main current loop, a current transfer branch and an energy absorption branch which are connected in parallel. The main current loop comprises a high-speed mechanical switch and one or more liquid metal units which are connected in series; the current transfer branch comprises an inductor, a capacitor and a thyristor which are connected in series; the energy absorption branch comprises a lightning arrester; and under the impact of a short-circuit current, the liquid metal units arc through a magnetostrictive effect, and the liquid metal units are connected in series so that an arc voltage reaches the voltage level of a system power supply, and a fault current is limited. The circuit breaker has the function of quickly breaking short-circuit faults, the breaking energy is small, and the stability of the system can be improved.

Description

technical field [0001] The invention belongs to the technical field of DC circuit breakers, in particular to a DC circuit breaker based on the combination of current limiting and oscillation transfer and a control method thereof. Background technique [0002] With the continuous advancement of urban construction, the development of high power supply density, large capacity, and high reliability DC power distribution system has become an urgent need for the development of large and medium-sized cities. In some special power systems, the peak value of short-circuit current is generally high, and the current rises rapidly, up to dozens or even hundreds of kiloamperes. Traditional DC circuit breakers are difficult to adapt to the high voltage and high current development needs of DC systems due to their own limitations such as long breaking time and limited current limiting capacity. [0003] Compared with the traditional AC system, the short-circuit fault of the DC system has ...

AI Technical Summary

Problems solved by technology

Most of the currently widely used hybrid circuit breakers create artificial zero-crossing points by injecting a current opposite to the short-circuit current, so as to achieve the purpose of DC segmentation; but when the short-circuit current is too large, the injected current cannot offset the short-circuit current of the system, resulting in a It is difficult to extinguish the arc between the contacts of the high-speed mechanical switch when it is off, which prolongs the breaking time and has an adverse effect on the system

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