Study on transient characteristics of CCC-HVDC transmission systems

This paper mainly studies the transient characteristics of the HVDC with capacitor commutated converter (CCC-HVDC) and makes a comparative analysis with the HVDC with conventional converter (LCC-HVDC). The LCC-HVDC and CCC-HVDC models based on the Qinghai-Xizhang HVDC interconnection project are built in the environment of PACAD/EMTDC and their transient characteristics are simulated by imposing a variety of faults. Both with very weak receiving ac network, it indicates that CCC-HVDC scheme has a stronger ability in anti-disturbance and inhibiting the commutation failure when the fault occurs in the inverter side, and has better stability when the fault occurs on the DC line or rectifier side. The CCC-HVDC scheme can effectively overcome the shortcomings of the conventional HVDC link.