Vector-controlled optimal drive system for the induction motor

The motor drives are the major consumers of the electrical energy. There are two main ways for energy saving: to use the advanced techniques of the optimal control and to adapt a solution to the existing drive systems in order to increase the energy efficiency. In order to find an answer to this challenge, in this paper a very cheap and efficient solution is proposed. The proposed electrical drive system is obtained in two steps: firstly, the optimal control based on the energetic criteria is used in order to obtain the optimal speed response; secondly, the optimal speed response is used as reference to the existing conventional drive system. The obtained efficient electric drive system combines the energetic performances of the optimal control with the features of the conventional drive control, the solution being applicable to the industrial drive systems. The optimal control solution is based on the integration of the matrix Riccati differential equation (MRDE) and it is computed on-line. The optimal control has three components: the state feedback, the forcing component to achieve the desired state and the compensating feed forward of the perturbation. It is tested by using numerical simulations on the specific cycle of an elevator drive system and implemented to an industrial drive system.