Speed control of three phase induction motor using two level vector control

Abstract

The main objective of this project is to introduce the non-conventional approach of speed control of ac induction machine that is vector control or field oriented control of induction motor. The advantages of vector control and need of vector control is explained, also the need of field oriented control of induction motor is mentioned and the various methods of FOC is illustrated. The project entitled “Speed Control of Three Phase Induction Motor Using Two Level Vector Control” is conducted at control and instrumentation division of one of the premier research institute of India Bhabha Atomic Research Centre, Trombay, Mumbai where we implemented the dynamic modelling of three phase induction motor and two level space vector pulse width modulation is also implemented on matlab Simulink along with the detailed study of field oriented control of three phase induction motor. Induction motor or asynchronous motor is the most extensively used in the industrial, commercial, residential settings as these motors are simple and robust in construction having low cost and minimum maintenance, high dependability and sufficiently high proficiency due to these conveniences ACIM are most widely used in industrial applications. However, control of ACIM is more difficult than the control of DC machines, with the help of scalar methods speed can be control as it is simple to implement but it has the coupling effect thus it is responsible for slow response which leads to oscillations due to higher order effect. But in many operations and machinery in industries sensitive revolutions and torque adjustment have to be peripheral with high accuracy, so dc motor drives were generally used variable speed drives because of the simplicity of control due to decoupling between armature current and the field current. This study has been undertaken to investigate the speed control ACIM using field oriented control. The principle of vector control of electric drives is based on the control of both the magnitude and the phase of each phase current and voltage. for this purpose, the study of available conventional and non-conventional approaches has been presented. This report also presents a clear study which illustrates introduction of efficient vector control of ACIM.