Search controller‐based online efficiency optimisation strategy for induction motor drives using modified adaptive quadratic interpolation

Abstract

A search control‐based new efficiency optimisation strategy for indirect vector controlled induction motor (IM) drive is proposed in this work. The online optimisation method considered in this regard is based on modified adaptive quadratic interpolation. The proposed strategy is employed in the flux loop of the speed control technique to decide the optimum flux component of stator current necessary to meet a particular drive operating condition. The selection of the optimum flux in this way, in fact, minimises the core loss of IM drive, thereby improving the overall efficiency of the drive depending upon the motor loading condition. Like the conventional search controllers, the algorithm is simple, immune to the machine parameter variation and does not require any additional circuitry for its implementation. The algorithm offers faster convergence, thereby preserving the dynamic response of the speed control loop. Analytical studies are done in MATLAB/Simulink and the results are validated experimentally in a 2.2 kW IM drive laboratory prototype.