Design and Realization of Intelligent Phase-controlled System for Permanent Magnetic Actuator of AC Contactor

Abstract

When the AC contactor switches the capacitor bank, the phase angle of the power grid is random, so the electromagnetic transient process will generate large inrush current and overvoltage, causing large disturbance to the power system. A set of AC contactor with permanent magnetic actuator (PMA) and its intelligent phase selection control system are designed to solve this problem. Firstly, the PMA is designed. The dynamic characteristics of the actuator are simulated and analyzed in ANSOFT to meet the performance requirements of phase selection control. Then the principle of phase selection control and the strategy of switching capacitor bank are analyzed. Based on this, the software and hardware of intelligent phase selection control system are designed, including phase selection control module, IGBT driver module and coil discharge module. Finally, the experimental verification is carried out on the designed AC contactor. The test results show that the phase selection errors of the designed intelligence system are within 1°, and the contactor closing and opening time deviations are within 0.5ms, which means the system can effectively realize the closing and opening control at the specified phase angle.