Hardware-in-the-loop simulation based design and experimental evaluation of DTC strategies

In this paper, a method for designing and implementing direct torque control of induction motor based on hardware-in-the-loop simulation (HIL simulation) is proposed. Two different strategies (1) Conventional direct torque control and (2) Space vector PWM based direct torque control are tested and implemented. The entire simulation is performed in real time using TMS320F240 digital signal processor. The dynamic machine model with 5 state variables is solved in real time in order to determine the state variables and hence 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 new tool known as "automatic code generation" is introduced, which is capable of generating assembly language code for real time simulation of electric drives. The results of real time simulation and those obtained from a laboratory prototype are presented.