© April 2020 | IJIRT | Volume 6 Issue 11 | ISSN: 2349-6002 IJIRT 149156 INTERNATIONAL JOURNAL OF INNOVATIVE RESEARCH IN TECHNOLOGY 189 Novel three Phase Variable Frequency Drive Reshma K.Kadu 1 , Dr.D.R. Tutkane 2 , Rahul Juneja 3 , Pravin Mandvikar 4 1 MTECH (PEPS) 3 MTECH (PEPS) 4 MTECH (IPS) Abstract- This paper is intended to provide a novel and simpler way of speed control three phase induction motor using simultaneous The wide range control technique of three speed of induction motor has presented. With this technique the speed control is obtained by changing speed using simultaneous control of frequency and the three voltages which are spaced by 120o with respect to each other at all frequency. The variable frequency drive works principle, it's the electronic controller specifically designed to change the frequency and control signal voltage supplied to the controller and thereby the stator of three phase induction motor. Index terms- Variable Frequency Drive (VFD), Inverter, Induction Motor, Rectifier I.INTRODUCTION Variable frequency drives (VFD) can control the speed of an induction motor by converting fixed frequency and fixed voltage magnitude to variable frequency and variable voltage magnitude at motor terminals, and thus, provide significantly improved process control, energy saving, and soft motor starting. The common VFD structure comprises of an AC/DC rectifier, a dc link, inverter, additional control and protection circuits. The dominant type of VFDs is the pulse-width-modulation (PWM)- controlled voltage source inverter type [1]. t. As complex non-linear power electronics equipment, VFDs are more sensitive to voltage sags than older mechanical systems. The control and protection circuits in VFDs could disconnect the drives to protect their components during large voltage sags [1]. The sensitivity of VFDs to voltage sags are affected by many factors such as voltage sag types, loading and operating condition of the drives, threshold settings in the protection of the drives, and the control method etc [2]. Most drives will trip when voltage sags are below certain values. However, when the drives are able to ride-through voltage sags and remain in service .industrial facilities is required for power systems dynamic studies. In this paper, a generic dynamic modeling technique for VFD-motor systems able to ride through power system disturbances is proposed. The wide variety of settings, operating modes, and operating conditions of a VFD compound the challenges involved in characterizing motor-VFD systems. One area of interest in terms of application is operation of VFDs under voltage unbalance. VFDs, like other power equipment, are often subjected to voltage quality issues that are inherent in industrial power supply systems. Unbalanced voltage operation has been well covered in literature for sinusoidal powered induction machines. References such as [3]- [8] have discussed the subject of unbalanced voltage operation of VFDs. II. IGBT In the low power field where the MOSFET plays the major role, the switching frequency is normally subject to system efficiency and/or magnetic considerations instead of device limitations. In the medium power field, where the IGBT plays the major role, the situation changes. At the lower end, the limitation of the device does not dominate since the lower-rating IGBT is normally fast enough. However, when the power rating is higher, the IGBT switching speed decreases and the switching losses increase significantly. The practical switching frequency is thus subject to the limitation of the device. III .PROPOSED TOPOLOGY The block diagram below contains three separate sections to indicate the basic working principle of a VFD:  The Rectifier