New Online Loss-Minimization-Based Control of an Induction Motor Drive

This paper presents a new loss-model-based controller for an induction motor drive. Among the many loss minimization algorithms (LMA) for an induction motor, a loss-model-based approach has the advantages of fast response and high accuracy. However, the performance of the loss-model controller (LMC) depends on the accuracy of the modeling of the motor drive and losses. In the development of the loss model, there is always a tradeoff between accuracy and complexity. This paper presents a new LMC to determine an optimum flux level for the efficiency optimization of the vector-controlled induction motor drive. An induction motor (IM) model in d-q coordinates is referenced to the rotor magnetizing current. This transformation results in no leakage inductance on the rotor side, thus the decomposition into d-q components in the steady-state motor model can be utilized in deriving the motor loss model. The suggested LMC is simple, but leakage inductances are not omitted. The complete closed loop vector control of the proposed LMC-based IM drive is successfully implemented in real-time using digital signal processor board DS 1104 for a laboratory 1/3 hp motor. The effectiveness of the proposed scheme is demonstrated through simulation and experimental results.