Speed Control of VSI Fed IM Drive and Reduction of Common Mode Voltage Employing Look-Up Tables

Since the IM drives play a vital role for variable speed applications from fractional horse power to multi Mega-watt power, the control and estimation of induction motor drives constitute a vast subject. Nowadays, vector control and direct torque control (DTC) are popular for high performance drives. Even though these methods give better performance, the vector control method needs reference frame transformations and direct torque control gives large steady state ripples. To overcome these problems in the above methods mentioned, this paper presents an advanced vector control method for voltage-source inverter fed induction motors using sophisticated look-up tables. This method uses a predetermined look-up table instead of a much more time consuming pulse width modulation (PWM) procedure in conventional vector control for generating inverter gate signals. This approach gives faster torque response like in vector control methods and it also reduces ripples as in DTC method. To validate the proposed method numerical simulations have been carried out and compared with the existing algorithms. The simulation results confirm the effectiveness of the proposed method.