Modeling and Analysis of Sensor Error Effects on DC-Link Current Ripple in Switched Reluctance Machine Drives

Harmonic injection in dc-link current through phase current shaping is a well-known method to reduce the dc-link ripple in Switched Reluctance Machine (SRM) drive system while maintaining the machine performance. However, this method is susceptible to the accuracy of the position and the current sensors. This paper presents an analytical approach to model the effect of sensor errors on the dc-link current ripple in the SRM drive system. At first, inverter current is modeled utilizing the Fourier series representation of both the phase current and the switching function. Then, the expression for the dc-link current is obtained after considering the amplitude and phase contribution coming from the dc-link capacitor and the battery dynamics. Subsequently, position and current sensor errors in the SRM drive system are included in the analytical modeling, and the expressions for the additional harmonic content in the dc-link current ripple are achieved. Finally, the effect of sensor errors is verified using simulation and experimental results.