具有自动隔离故障能力的直流固态断路器OA

Solid state circuit breaker(SSCB),compared with mechanical circuit breakers,has received much atten-tion in short-circuit protection of DC network due to its such advantages as arc-free current interruption upon short circuit occurrence and high reliability.In this paper,a DC SSCB with automatic fault isolation capability is designed.The SSCB consists of a short-circuit judgement module and a fault current buffer module which,in case of short cir-cuit,can clear the fault current without an external control system.The different operating states of this solid-state circuit breaker is analyzed,the corresponding mathematical model is set up and used as the theoretical basis for pa-rameter design.After completion of the design,it is compared with the existing solid state circuit breaker in short cir-cuit interuption simulation at 10 kV/500 A DC network.The simulation result shows that after addition of the SSCB with automatic fault isolation capability,the operation loss of the transmission line is only increased by 0.025%,there-fore the circuit breaker does not affect the normal operation of the circuit.After the occurrence of short circuit fault of the DC network,the circuit breaker can automatically interrupt within 5 ms and smoothly absorb the fault current so that the peak voltage sustained by the SSCB does not exceed 1.5 times the line voltage,thereby providing reliable pro-tection for the DC network.