Commutation failure (CF) is an inherent problem faced by line commutated converter high voltage direct current (LCC-HVDC) technology. To completely solve the problem of CF

we have proposed a novel hybrid commutated converter (HCC) technology based on reverse blocking integrated gate commutated thyristor

which can utilise two methods for commutation: enhanced grid voltage commutation and active turn-off forced commutation. In this paper

the topology and operating principle of HCC are proposed. Then

the control and protection strategy is designed based on the current variation trend under AC faults. To verify the effectiveness of HCC in mitigating CF

a 120-kV/360-MW HCC-HVDC model is built in PSCAD/EMTDC

adopting LCC at the rectifier side and HCC at the inverter side. Based on this model

HCC steady-state and fault transient stresses are analysed. Various AC faults are simulated and the performance of HCC-HVDC is compared with LCC-HVDC. Finally

the results show that the HCC topology and proposed control strategy can solve CF under all fault conditions with almost the same attributes as LCC

such as large capacity

low cost

low loss and high reliability

which is meaningful for the application of HCC to the HVDC transmission system.