Real and Reactive Power Control of Induction Motor Drives

Induction motors are considered the workhorse in the majority of industrial applications. Their rugged, low-maintenance, and efficient designs keep finding new forms of use nowadays. In this work, power control strategies of induction motor drives based on principles of Direct Torque Control and Model Predictive Control are investigated. The proposed methods control the real and reactive power flow into/out of the machine by selecting and applying proper voltage space phasors to the stator. First, the impact of voltage space phasors on real and reactive power variations is explored. Based on these observations, two methods to choose the appropriate voltage space phasors are proposed based on: six-sector and twelve-sector direct power control, and model predictive power control. Methods to calculate reference and motor powers are then introduced. The presence of high currents during the motor start-up period is analyzed and solutions to limit them are proposed. Finally, simulations using ®Matlab ™Simulink are carried out to test the performance of the control strategies under different operating conditions, including presence of motor parameter variations