A Novel Hybrid Line Commutated Converter Based on IGCT to Mitigate Commutation Failure for High-Power HVdc Application

In order to effectively reduce the commutation failure probability of the line commutated converter (LCC) based high-voltage direct current transmission system, a new hybrid LCC based on integrated gate commutated thyristor (IGCT) is proposed in this letter. In the proposed converter, a part of the thyristors is replaced by IGCTs. Reverse blocking IGCT is capable of withstanding bidirectional voltages and actively turningofffault currents, further interrupting the commutation failure process. The topology structure, high-power device, and the operation strategy are presented. Finally, the experimental results of a 30-kV/5-kA prototype verify the proposed scheme's effectiveness and correctness.