Research and design of a layout structure suitable for active loop used in DC circuit breaker based on artificial current zero technology
Multi-terminal HVDC system has gradually become a focus of DC transmission development because of superior economic efficiency and flexibility. It can effectively solve the breaking problems of DC short circuit current happened in multi-terminal HVDC system by developing a high voltage DC circuit breaker (DCCB) suitable for development needs of DC transmission system in our country, and this does good to improve the safety and stability of the power system operation, as well as the power supply reliability. This paper puts forward a layout structure of active loop suitable for DCCB based on the study of artificial current zero technology, which adopts the modular design, converter capacitor with compound insulating overcoat and the stable structure scheme of fixing frame and diagonal member. The layout structure simplifies the electric connection of converter capacitor and also increases the overall stability of active loop which has verified by the simulation of good seismic performance. The layout structure establishes a basis for engineering design of DCCB based on artificial current zero technology in situation of high voltage and large capacity.