Optimal vector control to a double-star induction motor

The problem of energy optimization of a Double Star Induction Motor (DSIM) using the concept of a Rotor Field Oriented Control (RFOC) can be treated by an Optimal Control Strategy (OCS). Using OCS, a cost-to-go function can be minimized and subjected to the motor dynamic equations and boundary constraints in order to find rotor flux optimal trajectories. This cost-to-go function consists of a linear combination of magnetic power, copper loss, and mechanical power. The Dynamic equations are represented by using a reduced Blondel Park model of induction motor. From the Euler-Lagrange equation, a system of nonlinear differential equations is obtained, and analytical solutions of these equations are achieved so as to obtain a time-varying expression of a minimum-energy rotor flux. The current study discusses a saturation model with respect to the rotor flux, which has significant influence in the motor's parameters. A comparative study of simulation results given from conventional and optimized RFOC proves the presented strategy's validity and effectiveness.