The hybrid direct current circuit breaker（DCCB） is one of the most ideal choices for DC current breaking and fault isolation in DC grids. In this paper

the current development status of hybrid DCCB is summarized. Firstly

the technical routes are comparatively analyzed and sorted out according to the topology of DCCB. Then

the key technologies of the hybrid DCCB

including commutation mode

power electronic switch

fast mechanical switch

control protection and energy supply

energy absorption

and so on

are systematically summarized. To solve the worldwide problem of large capacity DC breaking

domestic and foreign scholars have performed extensive research

put forward a comprehensive solution which consists of an innovative topology structure

and have made a breakthrough at the key technologies such as highly controllable and reliable fault current commutation

millisecond-level ultra-fast and efficient electromagnetic repulsion mechanism

high tolerance and high stability power electronic switch

and low residual voltage and fast response energy consumption device. Moreover

the application scenarios of hybrid DCCB are analyzed

and the typical applications of hybrid DCCB are introduced. The engineering application of the world’s first set of hybrid high voltage DCCB and the first set of three-port DCCB is realized in China

and the engineering application of hybrid DCCB with the highest voltage level and strongest breaking capacity in the world is also realized in China. Meanwhile

the overall development trends of hybrid DCCB are discussed

providing references for DCCB’s future technological advancement and its ever-expanding applications.