Influence of load on noise and vibration of voltage and current controlled switched reluctance machines

The influence of different operating modes and their associated control parameters on the acoustic noise and vibration of a switched reluctance machine is investigated. Noise and vibration measurements are presented in both frequency and time domains, together with measurements of the sound pressure level. It is found that hard chopping results in significantly noisier operation than soft chopping, and that current control also results in higher noise levels compared to voltage control, due to the random nature of the switching events. Further, it is found that noise and vibration increase with both speed and load. In general, an increase in noise and vibration can be attributed to an increase in the rate of decay of current at phase turn-off, regardless of the control strategy.