Power Generation, Transmission and Distribution
Technical Lecture Session
Fault Protection for Utility Interface Converters
Circuit breaker, DC power, circuit protection
Protection against circuit faults represents a major technical challenge in emerging DC transmission and distribution power networks. This paper proposes a new DC hybrid circuit breaker (HCB) architecture that relies on a switching-mode Transient Commutation Current Injector (TCCI) circuit instead of the prior-art Load Commutation Switch (LCS). The TCCI in the electronic path remains in a standby mode with near-zero power loss under normal conditions but can rapidly generate a pulse current to precisely track the fault current, and facilitate current commutation from the mechanical to the electronic path. A 600V/20A HCB prototype experimentally demonstrates that a fault current of 40A is commutated within 10µs, and a high-frequency small AC ripple current is maintained afterward.