适用于柔性直流电网的新型多端口混合式直流断路器

混合式直流断路器(HCB)是柔性直流电网直流侧故障隔离的优选方案，但是HCB高成本限制了其大规模应用的可行性，此外架空线路较高的故障概率要求HCB具备自适应重合闸功能。为此，提出了一种适用于柔性直流电网的新型多端口HCB，分别给出了其在故障隔离和自适应重合闸阶段的控制策略，详细分析了其工作原理和内部动态过程并推导了关键参数的设计方法。不同工况下的电磁暂态仿真和物理实验结果表明，该直流断路器能够通过多条直流线路共用昂贵的主断开关大幅降低制造成本，通过旁路故障线路及其上的限流电抗器降低避雷器的耗能时间和容量需求，并且具备控制简单、易于实现的自适应重合闸功能。

Novel multiport hybrid DC circuit breaker suitable for flexible DC grid

The HCB(Hybrid DC Circuit Breaker) has been considered as an ideal way to isolate the fault on DC-side of flexible DC grid. However, its high cost has seriously limited the feasibility of its large-scale application. In addition, the high fault probability of the overhead lines requires HCBs to have adaptive reclosing capability. Therefore, a novel MHCB(Multiport Hybrid DC Circuit Breaker) suitable for flexible DC grid is proposed, its control strategies in the stages of fault isolation and adaptive reclosing are put forward, its working principle and internal dynamic process are analyzed in detail, and the design method of key parameters is deduced. The electromagnetic transient simulations and physical experiments under different working conditions show that the proposed MHCB greatly reduces the manufacturing cost by sharing the expensive main breaker by multiple DC lines, reduces the energy dissipation time and capacity requirement of the arresters by bypassing the fault line and the current-limiting reactor on it, and has the adaptive reclosing function that is simple to control and easy to implement.