直流断路器失灵的故障隔离及其在嵌入式直流系统的适用性分析OA

As a key device for clearing the DC fault current,the DC circuit breaker(DCB)has a complex topology and numerous components.As a result,its failure probability in engineering applications is higher,and the corresponding failure scenarios are also diverse.To solve these problems,a fault isolation method for DCB failures is proposed,and its applicability in an embedded DC system is analyzed.First,three different DCB topologies are analyzed,and their ex-ternal characteristics under different component failures are summarized.A monitoring algorithm for DCB operation sta-tuses is proposed,and an identification criterion for classifying failures is formulated,which classifies the DCB opera-tion statuses into normal operation,slight failure and severe failure.Second,according to the DCB operation statuses,different backup fault isolation schemes are proposed,such as short-time blocking of converter and AC circuit breaker tripping.Third,with the combination of the development features of Jiangsu power grid,the characteristics of the em-bedded DC system are analyzed,and the applicability of the proposed method in this DC system is examined.Simula-tion results prove that the proposed DCB operation status monitoring method can accurately distinguish the operation sta-tuses.The backup fault isolation scheme can clear the fault current in time and complete the transfer of DC power in the embedded DC system to AC transmission lines,ensuring the safe operation of the system under DC faults.