SVG is the representative of latest technology in the present reactive power compensation field. SVG is connected to the power grid, acting as a variable reactive current source. Its reactive current may rapidly track variation of load reactive current and automatically compensate reactive power required by the system. Because SVG responds very fast, it's also called static synchronous compensator (short for STATCOM). Basic principle of static var generator: connect the auto phase commutating bridge circuit to the power grid via reactor, properly regulate phase and amplitude of output voltage in the AC side of bridge circuit or directly control current in the AC side so that the circuit may absorb or generate the compliance reactive current to realize reactive compensation in a dynamic manner. In the meantime, it can inhibit voltage flicker, keep it stable, track and compensate harmonic current, absorb several low order harmonics of power distribution system and balance inter-phase reactive power. The low-voltage static var generator (SVG) is mainly composed of controller, isolation switch (circuit breaker), contactor, IGBT Bridge, drive circuit, protection system, connecting electric reactor, DC capacitance, etc. The controller detects phase A, C (phase A, B, C of three phase four wire system) reactive power (current), produces control signal, drive on/off of IGBT, generates reactive current as per requirement so that the system power factor constantly approaches