Voltage sag suppression techenique based on fast vacuum circuit breaker(FVCB) and artificial current zero crossing is proposed. The voltage sag suppression module is composed of FVCB, current limiting reactor and artificial zero crossing branch in parallel. In normal operation the FVCB is closed. A single break 12-kV vacuum interrupter(VI) is used in the FVCB. A electromagnetic repulsion actuator is used to provide a opening velocity with of 6.5m/s and a closing velocity of 3.0 m/s. When a voltage sag happens, short-circuit current flows through the FVCB and the FVCB immediately opens within 0.5ms, after 2.5ms the artificial zero crossing branch generates a inverse-phase high-frequency current to make the arc extinguishing. After that the short-circuit current flows through the current limiting reactor so the amplitude of it is limited and the bus voltage is well maintained. The overvoltage generated during interruption is suppressed by the metal oxide arrester.

Voltage sag, fast vacuum circuit breaker(FVCB), artificial current zero crossing