Consideration of CSI drive for SRM compared with VSI drive

This paper presents a consideration of the Current Source Inverter (CSI) drive for Switched Reluctance Motor (SRM) compared with the Voltage Source Inverter (VSI) drive. General SRM drive method is the current hysteresis control by using the VSI. However, a disadvantage of this drive is the current falling time is slow at the switching off period. On the other hand, the CSI drive for SRM has some advantages, fast di/dt is realized, constant current during on-state is realized and so on. However, the CSI drive has a fatal disadvantage which is large di/dt in the phase shift period resulting huge voltage spike by the back EMF. Then, in order to protect the switching devices from the voltage spike, the voltage clamp type current source inverter for the SRM drive has been proposed. The proposed drive method can suppress the voltage spikes. In this paper, the brief characteristics of the proposed CSI circuit are shown by some simulations. Moreover, in order to verify the proposed circuit phenomenon, a small size circuit is made and some experiments are performed by driving a small SRM.