Space Vector Modulation Based Field Orientated Control of Induction Motor

Abstract

Speed control of Induction Motors has always been the matter of interest for all the industries. Various control methods are available for speed control of Induction Motor. Scalar control method is one such method which is widely used as it aims to control the steady state response by simply changing the amplitude and fundamental frequency of the supply voltage.This method can be easily implemented but gives limited speed accuracy and poor dynamic torque response. As a result the concept of Vector Control came into picture. The base of the vector control lies in the fact that it provides the decoupling between the flux and electromagnetic torque producing component of the Induction Machine. With this the dynamic response as good as a DC motor can be achieved with desired characteristics. We have included all the calculations needed for the development of the vector control model of an Induction machine and showed the corresponding responses after the implementation of vector control. Then, as all the manufacturing systems are susceptible to a wide range of parameter fluctuations and perturbations, the system may become unstable if they exist in significant amounts. So the solution to this problem lies in the fact of introducing controllers in the system. The most simple and robust controller is the PI controller. But again the problem is tuning of the controller parameters. Several intelligent algorithms are proposed to tune the parameters of the controller. Some optimal algorithms are Simulated Annealing, Genetic Algorithm, Particle Swarm Optimization etc. As a part of our dissertation we have implemented the two of the above optimization techniques namely GA & PSO to fine-tune the parameters of the Induction Motor's speed PI controller. All the necessary details regarding the implementation of the techniques have been clearly described in the dissertation. All the results and models are simulated in the Matlab Environment. Finally the results obtained from the two methods are compared to each other to give a final impression of their utility to tune the controller parameters.