Error analysis in indirect rotor position sensing of switched reluctance motors

The phase excitation pulses of a switched reluctance motor (SRM) drive need to be properly synchronized with the rotor position for optimum torque production. Accuracy of this position information determines the efficiency and smoothness of the drive operation. This paper presents a method of analyzing the errors inherent to indirect rotor position sensing schemes. The error analysis in this paper breaks down the position error to its fundamental components in the position sensing system. As an illustration, the method is applied to two different indirect position sensing schemes. The same basic approach can be applied to evaluate other SRM position sensing schemes. The results are helpful in comparing the various sensing schemes, as well as focusing improvement efforts on the appropriate segment of the system