As the fast fault isolating device of flexible high voltage direct current(HVDC)network

HVDC circuit breaker is becoming the essential device to construct the HVDC network

and can strenuously support the high-efficient large-scale renewable energy integration and consumption. In this paper

a novel commutation-based topology of hybrid HVDC circuit breaker is proposed. Compared with the existing topology

the proposed only needs half the insulated gate bipolar transistors(IGBTs)by applying H-bridge commutation modules and unidirectional breaking modules to achieve bidirectional breaking. Therefore

it is more economical and reliable. The topology and breaking principle of hybrid HVDC circuit breaker are introduced in detail

and a pre-breaking control strategy and a soft-closing control strategy are proposed to reduce the breaking time and closing-operation impact. Besides

a full-scale prototype with 500 kV rated voltage

3 kA rated current

25 kA breaking current

and less than 3 ms breaking time is developed to comprehensively test the performances of the proposed HVDC circuit breaker. The experiment results validate the feasibility and effectiveness of the proposed solution.