Development of a Nonlinear and Model-Based Online Loss Minimization Control of an IM Drive

Among the numerous loss minimization algorithms, a loss-model-based approach offers a fast response without torque pulsations. However, it requires the accurate loss model and the knowledge of the motor parameters. Therefore, a technical difficulty in deriving the loss-model-based controller (LMC) lies in the complexity of the full loss model and the online motor parameter adaptation. In an effort to overcome the drawbacks of LMC, this paper presents a new strategy for inverter-fed induction motors drives aiming for both high efficiency and high dynamic performance. A new LMC incorporating the effect of the leakage inductance and an adaptive-backstepping-based nonlinear controller are designed and combined with each other. Thus, online parameter adaptation of LMC can be obtained with no extra effort. The proposed control scheme is implemented in real time using digital signal processor board DS 1104. The simulation and experimental results demonstrate the effectiveness of the proposed scheme.