A hybrid sensorless SRM drive with eight- and six-switch converter topologies

This work presents a hybrid sensorless controller used with both the classical eight-switch converter and a reduced six-switch converter topology for switched reluctance motor (SRM) drives. The hybrid sensorless scheme consists of a sliding mode observer (SMO) based position sensorless approach for high speeds along with a low-resolution discrete sensor for low speeds and standstill. The hybrid position estimation switches between the SMO and the low-resolution sensor according to the speed sign and the position error difference between the SMO and the low-resolution sensor. The experimental results show the robustness of this hybrid, low-cost control approach with the two converter topologies.