International Journal of Advances in Engineering & Technology, July 2013. ©IJAET ISSN: 22311963 1373 Vol. 6, Issue 3, pp. 1373-1380 SINGLE–PHASE BRIDGELESS PFC FOR PI CONTROLLED THREE PHASE INDUCTION MOTOR DRIVE Sweatha Sajeev 1 and Anna Mathew 2 1 Department of Electrical and Electronics Engineering, Rajagiri School of Engineering & Technology, Kerala, India 2 Assistant Professor, Department of Electrical & Electronics Engineering, Rajagiri School of Engineering & Technology, Kerala, India ABSTRACT A current regulation under IEC-555 imposes requirements on the harmonic current content, which can be sent back to utility lines for all consumer electronic devices consuming more than 75W of power. To meet that requirement, the active Power Factor Correction (PFC) must be employed. The most common PFC solution, a boost converter, requires the use a full-bridge diode rectifier ahead of the boost converter in the circuit. This design greatly impairs the efficiency, as the two diodes in the bridge rectifier are in the direct power path for either positive or negative half-cycle of input ac line voltage. Thegoal of this paper is to propose a topology for induction motor drive with reduced components in the rectifier bridge. The utilization of 2 switches replacing 4 switches in the rectifier bridge of induction motor drive helps to implement a low-cost system for various applications. The static power converter side is implemented by a single-phase bridgeless pfc cascaded with a six-switch inverter. The new bridgeless PFC converter operates directly from the ac line, the proposed system consists of a single-phase rectifier with a bridgeless power factor correction circuit; six switch inverter to feed the motor. In this configuration, a standard three-phase squirrel cage induction machine is used. Speed control is employed using PI controller based on volts/hertz technique. Simulation results are provided to illustrate the operation of the systems. K EYWORDS: Bridgeless rectifier, power factor correction (PFC), induction motor drive, low-cost, closed loop constant V/f speed control. I. INTRODUCTION Single-phase motors have often been used in consumer electronics, hence a single to three- phase converters are in demand [1]. As the amount of equipment using conventional diode rectifiers increases, harmonic input currents are becoming a problem. Harmonic current limits are recommended by the IEC standards (IEC 555). With the stringent requirements of power quality, power-factor correction (PFC) has been an active research topic in power electronics, and significant efforts have been made on the developments of the PFC converters. In general, the bridgeless PFC topology may improve efficiency and reduce the conduction loss by reducing the number of semiconductor components in the line current path. The electric drive systems used in industrial applications are increasingly required to meet the higher performance and reliability requirement. Today above 90% of all industrial motor applications use three phase induction motors because they are simple in design, easy to maintain, and are less costly than other designs . Out of the several methods of speed control of an induction motor the closed loop constant V/f speed control method is most widely used. In this method, the V/f ratio is kept constant which in turn maintains the magnetizing flux constant so that the maximum torque remains unchanged. Thus, the motor is completely utilized in this method. This paper proposes a single-phase to three-phase inverter operation for the motor drive, which uses V/f control strategy. The objective of this paper is to improve the performance of the induction motor drive by reducing the conduction loss. The proposed paper constitutes four sections; initially the characteristic of the conventional rectifier circuit is described. Next, the implementation of bridgeless