A Topology of H‐Type High‐Voltage DC Circuit Breaker with Current‐Limiting Function and its Control Strategy

Abstract

A high-voltage direct-current circuit breaker is a key equipment to construct a flexible direct current transmission system. Most of the existing design schemes have some shortcomings such as slow fault-breaking speed, poor current-limiting effect, large capacity of the arrester, and long reclosing operation time. To solve the above problems, this paper proposes an H-type high-voltage direct current circuit breaker with a current-limiting function. The current-limiting inductance is put into operation by judging the fault condition. It has good current-limiting ability in the process of fault-breaking and can maintain the dynamic performance of the power grid in the normal operation of the system. It has the advantages of fast fault-breaking speed, buffered energy consumption, early separation of fault points, and small capacity of the arrester. During reclosing operation, the transfer branch can be turned on at no-voltage. The different working states in the process of fault-breaking are analyzed theoretically based on the description of the topological structure and working principle. Finally, using the PSCAD/EMTDC simulation platform, the functional verification and system verification of fault-breaking and the reclosing operation process is conducted. Compared with the typical scheme, the simulation analysis shows the effectiveness and applicability of the function of fast fault-breaking and fault current-limiting.