A DC Circuit Breaker Combining Oscillation Transfer and Solid State Switching

Abstract

A DC circuit breaker combining oscillation transfer and solid-state switch is composed of a main current loop, a current transfer branch, an energy absorption branch and a control system. In the case of small current breaking, the high-speed mechanical switch is controlled to open and the corresponding power electronic device is turned on, the current is transferred to the current transfer branch under the action of the arc voltage, and then the power electronic device is controlled to turn off, and the voltage at both ends of the power electronic component rises , the arrester conducts. When a high-current short-circuit fault occurs, the high-speed mechanical switch is controlled to open and the power electronic device is turned on. The pre-charging capacitor injects a reverse current into the fracture, the current at the fracture crosses zero and extinguishes the arc, the short-circuit current is transferred to the current transfer branch and charges the capacitor, and when the capacitor voltage is greater than the conduction voltage of the arrester, the arrester is turned on. The novel direct current circuit breaker has the characteristics of simple structure, small on-state loss, fast full current breaking speed and the like.

Description

technical field [0001] The invention relates to a direct current circuit breaker combining oscillation transfer and solid-state switch, especially by adding a trigger switch to the current transfer branch, and using two methods to break currents of different levels. Realize the function of quick disconnection of short-circuit faults under various current conditions of the medium-voltage DC system. 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. The operating conditions of some special power systems are complex. The traditional DC circuit breaker, due to its long breaking time and limited current limiting capacity, cannot take into account the limitations of different working conditions and other characteristics at the same time, and it is difficult ...

AI Technical Summary

Problems solved by technology

However, when the small current is broken, the injected current may reversely break down the contacts of the high-speed mechanical switch, making it difficult to extinguish the arc between the contacts of the high-speed mechanical switch when breaking, prolonging the breaking time, and adversely affecting the system

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