TVR series three-phase high-precision automatic AC voltage stabilizer, a new generation of intelligent regulated power supply, the input phase system is three-phase four-wire system, the output voltage is 220Vac phase voltage and the line voltage is 380Vac. Within the rated capacity range, it can be used at the same time for electrical equipment with a single-phase 220Vac or three- phase 380Vac power supply, and is equipped with delay, over voltage, under voltage, and over current protection functions.