Keywords: Harmonic Analysis, Harmonic Distortion Factor, Induction Motor Drive, PWM Inverters, PWM Technique, Switching Frequency. Abstract In this paper presents a literature survey on improvement of power factor and reduction of harmonics in three phase induction motor by Pulse Width Modulation (PWM) techniques. Also presents the current status of the improvement of power factor and reduction of harmonics in three phase induction motor by PWM techniques. Authors strongly believe that this survey article will be very much useful to the researchers for fi nding out the relevant references in thefi eld of improvement of power factor and reduction of harmonics in three phase induction motor by PWM-techniques. 1 Introduction Variable frequency ac drives are increasingly used for various applications in industry and traction. Due to the improvement of fast-switching semiconductor power devices, voltage source inverters (VSI) with PWM control, fi nd particularly growing interest. Control methods that generate the necessary PWM technique has been discuses extensively in the literature. Two basic concepts may be distinguished for small and medium-size drives the current controlled PWM has proved to be advantageous. For big drives employing inverters with low switching frequency. A new technique for high-frequency conversion has been proposed to reduce the component stress of voltage and current and the switching losses in the traditional PWM converter. The PWM inverter driving the machine is then required to excite the machine with these current commands. Various techniques have been devised by many researchers for controlling the output current of a PWM voltage-fed inverter. A current control technique has also been devised for three-phase PWM ac/dc converters. Switching frequency should be increased by decreasing switching losses to achieve higher power density and faster transient response in well known PWM dc–dc converters. A new active snubber cell is proposed to contrive a new family of PWM converters. This snubber cell provides perfectly zero voltage transition (ZVT)