Experimental studies on drive performances of wound field synchronous motor drive integrated with ZSI

This paper presents experimental studies on drive performances of wound field synchronous motor (WFSM) integrated with Z-source inverter (ZSI) system. WFSM is a non-permanent magnet machine and employs two field coils as dc field mmf sources. The conventional WFSM drive uses a three phase inverter for the armature windings and a dc chopper for the field coils, separately. On the other hand, ZSI works as a three phase inverter with a function of dc voltage boost-up by using an impedance-network inserted between the DC-bus and the three phase inverter. The impedance-network consists of two dc reactors and two capacitors. The “integrated” means that in the proposed drive system, two field coils of WFSM are employed not only as dc field mmf sources for the motor, but also as dc reactors for the impedance-network. Thus, the proposed system eliminates the use of DC chopper, resulting in size and cost reductions as the total drive system. The comparison of operable range between the conventional system and the proposed system through various experimental studies using a test drive system is demonstrated and discussed.