Development and prospect of direct‐current circuit breaker in China

Abstract

The direct-current circuit breaker (DCCB) is the most ideal choice for DC fault isolation in DC grids. Despite a late start, China's research and development on the DCCB have made outstanding achievements. This article provides a brief glance of current China's DCCB development status. It begins by sorting out the technical route according to the topology of DCCB. Then it systematically summarises both mechanical and hybrid DCCBs with focussing on the aspects of topology structure and principle, key technology and characteristics, prototype development and application. It is apparent that Chinese scientists and engineers confronted the worldwide problem of large capacity DC breaking, and put forward a comprehensive solution which consists of an innovative topology structure based on coupled negative voltage circuit, breaking throughs on the key technologies such as highly controllable and reliable fault current commutation, millisecond-level ultra-fast and efficient electromagnetic repulsion mechanism, high tolerance and high stability power electronic switch, low residual voltage and fast response energy consumption device, etc. The article states that the world's first set of hybrid high-voltage (HV) DCCB, and the first set of mechanical HV DCCB have been developed. These DCCBs will soon be deployed to the DC grids which have the highest voltage levels therefore require the strongest breaking capacity. These achievements are leading the world in the development and application of DCCB. The article also discusses the overall development trends of DCCB in the areas of new topologies, key technological breakthroughs and application scenarios, etc. These discussions serve as references for DCCB's future technological advancement and its ever-expanding applications. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Current interruption tests of HVDC circuit‐breakers: Requirements, methods and a testing case

“…A lot of emerging innovative HVDC CBs are under development or have commenced operation. The detailed current interruption technology, variety of topologies and key performance indicators of these HVDC CBs can be found in [4,7,11,15,16,[23][24][25][26][27][28][29][30]. With these many HVDC CBs flourishing, a unified standard to verify the performance of the equipment is necessary.…”

“…A number of HVDC CBs have been installed in several pilot MT-HVDC projects in China, amongst which the most recent development is the implementation of the ±500 kV Zhangbei four-terminal meshed grid [4][5][6][7]. In EU, HVDC CB prototypes developed by different manufacturers were tested by full-power tests in the PROMOTioN project [8][9][10].…”

Parameters design of voltage sharing components for the series multi‐break mechanical switch

“…The hybrid DC circuit breaker has the advantages of sizeable current handling capability and fast interruption, so it has become a research hotspot in the field of VSC-HVDC systems [5,6]. To meet the requirement of operating rapidity, the mechanical switches of hybrid HVDC circuit breakers usually adopt the form of series multi-break [7,8]. However, the distributed capacitances can cause the voltage distribution of fast mechanical switches to unbalance during the interruption process [9], so the appropriate voltage sharing measures are needed.…”

A capacitor-based DC circuit breaker for HVDC power grid

“…DC circuit breakers (DCCBs) can soon isolate the fault area and maintain the normal operation of the nonfault area. Traditionally, DCCBs are divided into mechanical, solid-state and hybrid DCCBs (Bucher and Franck, 2016)- (Chen et al, 2021). Several mechanical DCCBs use semiconductors such as thyristors to improve the interruption performance, obscuring the boundary between mechanical and hybrid DCCBs (Wen et al, 2018)- (Wu et al, 2020a).…”