AN UTILITY FRIENDLY DIRECT TORQUE CONTROL TECHNIQUE OF THREE PHASE INDUCTION MOTOR WITH TWO LEVEL INVERTER USING 180 DEGREE CONDUCTION MODE

摘要

The vector control is still very complex to implement. As a consequence of the perseverant efforts of various research engineers, an improvised scalar method known as Direct Torque Control (DTC) was invented. This method considerably alleviates the computational burden on the control platform while giving a performance which is comparable to that of a vector controlled drive. In this paper, the DTC scheme employing a Voltage Source Inverter (VSI) is possible to control directly the stator flux linkage and the electromagnetic torque by the optimum selection of inverter switching vectors. The selection of inverter switching vector is made to restrict the flux and torque errors within the respective flux and torque hysteresis bands. This achieves a fast torque response, low inverter switching frequency and low harmonic losses. The proposed scheme is described clearly and simulation results are reported to demonstrate its effectiveness. The entire control scheme is implemented with Matlab/Simulink.