Induction motor control with space vector modulation

In industrial applications electric motors drives provides the control of speed, torque, energy given to the load from mains supply by means of motor shaft. In the past DC drives were widely used for variable speed control. Today with the development of AC drive technology high performance speed and torque control can be obtained with the use of economic and robust induction motor. In recent years, researches on the induction motors have been concentrated on the areas of field oriented control (FOC) and direct torque control (DTC) methods, which provide high performance control and are based on vector control. Space vector theory, voltage source inverter model, space vector modulation, the mathematical model and transient behavior of the induction motor are fundamental subjects in high performance induction motor control. In this study, Space Vector Modulation method which is used in AC motor control is studied. Space Vector Modulation method is compared with sinusoidal PWM and square wave PWM methods. It is exposed that space vector modulation technique is using the DC Bus Voltage more effectively, it is suitable for vector operations, and the three phase sinusoidal voltages can be produced by only one rotating vector. In Space Vector Modulation method the less THD value is produced compared to the sinusoidal PWM at the same switching frequency. By using voltage source inverter and a microcontroller open loop control of induction motor is realized. Theoretical analysis is verified with experimental results. Keywords: Inverter, Scalar Control, Vector Control, Direct Torque Control, Variable Frequency Drivers, Induction Motor, Space Vector Modulation.