In this paper the speed of an induction motor can be controlled by varying input Voltage or frequency or both. Variable voltage and variable frequency for Adjustable Speed Drives (ASD) is consistently obtained from a three-phase Voltage Source Inverter. Voltage and frequency of inverter can be simply controlled by using PWM techniques, which is a very important aspect in the application of ASDs. A number of PWM techniques are there to obtain variable voltage and variable frequency supply such as PWM, SPWM, SVPWM to name a not many along with the various modulation strategies SVPWM is one of the mainly efficient techniques as it has enhanced performance and output voltage is comparable to sinusoidal. The analysis involves the relationship between modulation signals and space vectors and the switching patterns of space-vector modulation and the trigger of power electronic device.