Operation and Experimentation of a Current Commutated Hybrid DC Circuit Breaker for HVDC Transmission Grids

We developed a current commutated hybrid direct current circuit breaker (DCCB) for high-voltage direct current transmission systems. The transmission losses of the developed DCCB are considerably low because a normal current path includes only mechanical switches. Fast mechanical switches and a commutation circuit can achieve a fast current interruption. We also developed a test method for DCCBs, which permits the use of existing facilities such as AC generators. We tested a scaled-down 10-kV hybrid DCCB with the developed test method. The test results proved the operation principle of the hybrid DCCB and the efficiency of the test method.