Current limiting type hybrid direct-current circuit breaker based on power electronic combination switch

The invention discloses a current limiting type hybrid direct-current circuit breaker based on a power electronic combination switch. The current limiting type hybrid direct-current circuit breaker comprises a mechanical switch, the power electronic combination switch, a snubber circuit, a current limiting circuit and a freewheel diode. The mechanical switch is mainly used for normal working currents passing a direct-current line. The power electronic combination switch is connected with the mechanical switch in parallel, and comprises an IGBT valve set T1 and a thyristor set T2. The snubber circuit is connected with the power electronic combination switch in parallel, comprises a capacitor CT, a first resistor RT and a first diode DT, and is used for limiting the voltage build-up rate of the two ends of the power electronic combination switch when the line is broken. The snubber circuit is connected with the mechanical switch in series, and comprises an inductor L, a second resistor RL and a second diode DL. The freewheel diode is connected with a direct-current load in antiparallel, and is used for the follow currents of a line inductor and load energy after the line is cut off. A failure pre-processing control strategy is adopted and can observably shorten the line disconnecting time after a failure occurs.