Science and Education Publishing American Journal of Electrical and Electronic Engineering 2328-7357 4 2 2016 5 5 Different Methods of Speed Control of Three-Phase Asynchronous Motor 62 68 EN G. C. Diyoke Department of Electrical and Electronic Engineering, Michael Okpara University of Agriculture, Umudike Abia State, Nigeria Okeke C. Uchechi Aniagwu AJEEE2016423 10.12691/ajeee-4-2-3 2015 12 5 2016 4 7 2016 5 3 Asynchronous motors are the most widely used electrical motors due to their reliability, low cost, ruggedness and robustness. However, asynchronous motors do not inherently have the capability of variable speed operation. Due to this reason, earlier dc motors were applied in most of the electrical drives. But the recent developments in speed control methods of the asynchronous motor have led to their large scale use in almost all electrical drives. In this paper, various methods of speed control of induction (asynchronous) motors such as variable rotor resistance, variable stator voltage, constant Volts/hertz control, frequency variation, pole changing, etc., were carried out and MATLAB software was used to develop the codes for the analysis of these methods.