Robust adaptive control for direct torque controlled induction motor drives

A new, simple, high performance, robust control strategy for induction machines is proposed. The Bristol University developed Minimum Controller Synthesis technique, which is simpler than conventional Model Reference Adaptive Control techniques, is further developed and, for the first time, included in a Direct Torque Control strategy. A rigorous mathematical proof, not presented here, has shown that stability is guaranteed. The new control scheme is compared with the widely used PI control strategy for speed transient, sudden load disturbance and non-linear torque variations. In all cases, the new strategy exhibits significant improvements in performance.