Study into effects of stator resistance variation on direct torque controlled surface permanent magnet synchronous motor drive

In the recent past decade, direct torque controlled (DTC) permanent magnet synchronous motor drives have been widely utilized in many relevant applications, as they offer numerous advantages compared to other control schemes. In fact, for the stator flux estimation of such scheme the motor parameter dependency is much less than the previous control schemes and it is just concerned with stator resistance. In practice, the stator resistance is prone to large variations caused by temperature which indeed are very likely to occur. The mismatch between actual and estimated resistance could deteriorate the performance of the DTC drive by introducing errors in the stator flux linkage estimation especially at lower speeds. This paper analytically investigates different effects of stator resistance variations on the performance of the direct torque controlled SPMSM drives while the simulation results are also provided.