A series coupled inductance high voltage DC circuit breaker and its control method

Abstract

The invention relates to a series coupling inductance high-voltage direct current breaker and a control method thereof. The breaker comprises a change-over switch, a switching circuit and an energy consumption device which are connected in series. The change-over switch adopts a mechanical switch, the switching circuit adopts a coupling circuit, and the energy consumption device adopts a lightning arrester. The high-voltage direct current breaker is connected with a control circuit, when a failure happens, the mechanical switch detects failure current, and transfers the failure current to the coupling circuit. The failure current charges a capacitor in the coupling circuit, flows over current change of a conductance L1, generates change current which is opposite to the failure current in direction and flows through a conductance L2. The failure current and the change current are overlaid, and the overlaid current makes a zero crossing point on a main circuit of the mechanical switch to cut off the mechanical switch. Voltage on two ends of the capacitor reaches operation voltage of the lighting arrester so that the lightning arrester acts and energy is released from the lightning arrester. The series coupling inductance high-voltage direct current breaker can meet requirements of quick cutting off of the failure current, can realize non-arc cutting-off of the mechanical switch, and the control method is simple and easy to operate, and complete in function.

Description

technical field [0001] The invention relates to a power system circuit breaker, in particular to a high-voltage direct-current circuit breaker with coupled inductance in series and a control method thereof. Background technique [0002] High-voltage DC circuit breakers have broad application prospects in IGBT-based multi-terminal flexible DC transmission and DC grid systems. The traditional AC circuit breaker mainly uses the two current zero points of the AC current in each cycle to extinguish the arc, thereby breaking the current, but there is no natural zero point in the DC system, so it is difficult for the high voltage DC circuit breaker to break the current It is how to extinguish the arc quickly. A DC circuit breaker is generally composed of three parts: a transfer switch, a transfer circuit and an energy consumer, such as figure 1 shown. Its main breaking principle is: when opening, the current is first transferred from the transfer switch to the conversion circuit...

AI Technical Summary

Problems solved by technology

[0003] However, the existing DC circuit breaker adopts the arc negative resistance characteristic of the circuit breaker and the auxiliary branch capacitor inductance to resonate, so as to create a zero-crossing point on the mechanical switch to realize breaking, and the existing DC circuit breaker has a resonant branch and arc. Auxiliary branch capacitance and inductance are prone to resonance

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