Development of the C-dump topology-based four-level converter for switched reluctance motor drives

Abstract

Demand for brushless and commutator-less motor drives is increasing day by day for industrial applications. So improvement in switched reluctance motor (SRM) drives remains an important research area due to cheap and maintenance free motor construction. In literature, various converter topologies and their control strategies are described, however the C-dump-based converter topologies have gained interest owing to its ability to retrieve the stored magnetic energy. This can be further utilised to achieve desirable performance characteristics. The paper addresses the development of a drive system for a four phase, 8/6 switched reluctance motor. The drive system consists of a power circuit and its control scheme. The power components are designed for a 4-phase, 3 hp, 8/6 SRM which is used to obtain the experimental results. A simple PI-based speed control scheme is implemented which is suitable for low power applications such as cooling fan, blower, etc. A C-dump-based converter is proposed which allows reduction of switching losses, especially in the low speed range and it eliminates energy intake from the source during energy discharge process.