Product Description: 1) Advanced technology -use PG-free vector frequency change AC speed regulating system to replace magnetic amplifier DC system. 2) Good performance of speed regulation - speed regulation range: 100:1, regulation accuracy: ± 0.2%. 3) Intellectualization of control system - various parameters set by software, self-learning and self-tuning PID current loop parameters, fault self-diagnosis. 4) Low operation cost - replaced by AC motor, the motor fault less happens, maintenance cost comes down. 5) Remarkable electricity-saving effect – comparing with the original magnetic amplifier systems it can save about 20%.