Improved Performance of Induction Motor Using Magnetic Energy Recovery Switch

This paper discusses applications of a magnetic energy recovery switch (MERS) to induction motor drive. The MERS is a series compensation device, which can control voltage and input power factor. Characteristics and operation principles of voltage control and power factor correction by MERS are described. Some applications of the MERS to induction motor drive are investigated. Series capacitor compensation may cause some unstable situation. Electrical oscillations caused by the self-excitation with series capacitor are discussed. Experimental results show the MERS also can cause the same problems since the MERS works as a series capacitor. A 5.5 kW experimental system was developed. Damping control by terminal voltage feedback is investigated. Experimental results show that damping control is effective for improving stability of the induction motor drive with MERS. Starting and steady state characteristics are evaluated experimentally.