Adaptive Loss Model Control for Robustness and Efficiency Improvement of Induction Motor Drives

Indirect Field Oriented Control (IFOC) can provide an excellent dynamic response in Three Phase Induction Motor (TIM) drives and is widely used in the industry. Still, as a considerable part of the electrical energy is used to drive motors, intense research has been carried out to reduce the energy consumption of the induction motor drives and improve their efficiency. In this paper, a high-efficiency Smooth-IFOC (SIFOC) scheme is proposed and implemented experimentally with improved current controllers and the Loss Model Control (LMC) technique, which achieves up to 41% reduction in energy consumption compared to the traditional IFOC approach. The main contribution is the new Adaptive LMC (ALMC) control scheme, which includes two recursive adaptation algorithms to minimize the LMC technique sensitivity to the variation of the motor parameters. The algorithms are derived considering MRAS concept and both active (P) and reactive (Q) power to estimate the stator and rotor bandwidths, which are used to update the ALMC controller. The SIFOC-ALMC approach is verified experimentally, with up to 7.2% energy savings compared to SIFOC-LMC. Moreover, since the traditional IFOC controller is sensitive to rotor bandwidth variation, estimating this parameter improves the robustness of the SIFOC drive system.