Optimal control implementation of the three-phase induction machine based on adaptive drive system

The aim of the paper is to contribute to the rationalization and the optimization of the used energy, to minimize the energy consumption of the main worldwide consumer; the three-phase squirrel cage induction motors. In industry application field the transient regimes (desired and accidental) are dominant. The optimal control is used in order to obtain the optimal speed response of the vector controlled induction motor drive system. The optimal control is based on the solution of the Matrix Riccati Differential Equation (MRDE). The high performance drive systems are strong related to the accurate knowledge of the motor parameters. Therefore, a Model Reference Adaptive Control (MRAC) is proposed. The optimal speed shape serves as reference signal to the MRAC system. In this way, the output speed of the adaptive system will track the optimal speed reference with no error, conducting indirectly to energy minimization of the entirely drive system. The proposed adaptive control mechanism will assure the robustness to the external disturbances and to the unmodeled dynamics, by tracking accurately the optimal speed reference. The obtained robust electric drive system combines the energetic performances of the optimal control with the features of the adaptive control, the solution being applicable to the industrial drive systems. The proposed solution is tested by using numerical simulations on the specific cycle of an elevator drive system.