Design and development of energy efficient sensorless direct torque controlled induction motor drive based on real time simulation

This paper presents energy efficient direct torque controlled sensorless induction motor drive using space vector modulation. The entire design and optimisation of controller parameters of the drive is carried out using hardware-in-the-loop (HIL) simulation. The simulation is performed in real time using TMS320F240 digital signal processor. The dynamic machine model with 5 state variables is solved in real time to determine the state variables. These variables are then used to estimate the various output quantities. Using the same controller and software used in HIL simulation, and with additional signal conditioning interface circuitry, the results obtained from real time simulation are experimentally validated on a 1.5-kW induction motor drive. A simple method based on minimum average input power is proposed to determine the optimal flux reference at light loads. A method for online-controller parameter tuning is also proposed so as to have an optimal dynamic as well as steady state performance.