RFORMANCE EVALUATION OF CONVENTIONAL PI CONTROLLER BASED DIRECT TORQUE CONTROL STRATEGY FOR SPEED CONTROL OF INDUCTION MOTOR UNDER HIGHLY VARIABLE LOAD CONDITIONS

Direct torque control (DTC) is one of the most excellent speed regulation strategies for induction motor via controlling of torque. The purpose is to control effectively the torque and flux. Direct torque control is the first technology to control the real motor control variables of torque and flux. This method made the motor more accurate and fast torque control, high dynamic speed respon se and simple to control. The reference value can be calculated using the flux and torque estimated and also motor parameter. In the conventional DTC strategy, speed control of motor is performed by employing PI controllers. Usually the performance of conv entional PI controller, employed in DTC, is found satisfactory during the motor speed regulation. But the scenario of speed regulation with this controller, highly dependent on the system load characteristics. This paper presents a complete performance eva luation of conventional PI controller based DTC strategy for the speed regulation of induction motor under highly variable load conditions. For the implementation and performance evaluation a versatile simulation package, MATLAB/SIMULINK 2012(b) has been u tilized