2016 International Conference on Computer Communication and Informatics (ICCCI -2016), Jan. 07 – 09, 2016, Coimbatore, INDIA Power Factor Correction in BLDC motor Drives Using DC-DC Converters R.Pireethi*, R. Balamurugan Department of Power Electronics and Drives, K.S.Rangasamy College of Technology (Autonomous) K.S.R Kalvi Nagar,Tiruchengode, Namakkal, Tamilnadu, India, Ph./Fax: 04288 274741-44/04288 274860 *corresponding author, e-mail: pireethu@gmail.com, nrbals@gmail.com Abstract—This thesis deal among Power Factor Correction (PFC) in Brushless motor drives by comparing various DC-DC converter topologies. To improve the Power quality (PQ) power factor corrected converter is essential. VSI is used for speed control. In order to condense conduction loss and quantity of components diode bridge rectifier is eliminated. It is used to operate in DICM mode. The BLDC motor is fed by diode bridge rectifier with a elevated rate of DC-link capacitor. It consequences in extremely distorted supply current and a poor power factor. A new bidirectional bridgeless isolated cuk converter is used to achieve power factor near to unity. when compared to conventional Converters Circuit efficiency is further improved. Keywords— Power Quality (PQ), Power Factor Correction (PFC), Bridgeless converters, cuk Converter, Bridgeless isolated cuk converter, Brushless dc motor(BLDC) . I. INTRODUCTION BLDC motors are recommended for an ideal choice in many applications due to the absence of mechanical commutator.It causes low EMI problem and hence it need less maintenance. BLDC motor is more energy efficient than brushed DC-motors. The BLDC motor is smaller because its body has less heat to dissipate. It is applicable in many household appliances such as washing machine, air conditioner, fan, water pump and refrigerator. Some of the advantages such as higher efficiency, no voltage drop across brushes, reduced size and low electric noise[3]. BLDC motor consists of no commutator and brushes. Rotor consists of Permanent Magnet ,where stator consists of number of windings.So the current direction of the conductor on the stator controlled electronically. Hall sensor is used to determine the position during commutation. Rotor position depends on the accurate position with stator. It has semiconductor switches to turn the stator winding on and off at appropriate time. Switches current from winding to winding forcing the rotor to turn by varying pulse motor is rotated[16]. Electronically commutated motors are different from other motors like brushless DC motors.In brush-type motors, commutation is done with a commutator and graphite brushes. In an electronically commutated brushless motor, it is achieved by switching electronics.It obtain information on the position of the rotor by means of sensors with the help of microprocessor.Electronic commutation is achieved by using an three phase voltage source inverter (VSI) [10] . BLDC motor is connected after the diode bridge rectifier (DBR) and DC link capacitor. when DC link voltage is higher than the supply voltage .It draws current only for a small duration. 978-1-4673-6680-9/16/$31.00 ©2016 IEEE Therefore, peaky current is strained from the AC supply, it has elevated rate of harmonics which lead to deprived power factor (PF) [14].Power factor correction (PFC) converters are used to improve power factor.The requirement of sensor plays major role in determining overall cost of the system. There are two mode of operation such as Continuous inductor current mode (CICM) and discontinuous inductor current mode (DICM) [4]. In the entire switching period the current in inductance remains continuous. In CICM, or continuous conduction mode (CCM), whereas the current becomes discontinuous in DICM or DCM mode. 2-Voltage and 1-Current sensors are required in CCM mode and it has lower current stress. In DICM single voltage sensor is required.It has low voltage stress and cost is low [7]. In conventional method cuk converter is used for power quality improvement at AC supply. It maintain constant DC link voltage.High switching loss is occurred so the bridgeless configuration is introduced. II. BRIDGELESS CONVERTER A. Types of Bridgeless converter Bridgeless means Diode Bridge is eliminated at front end. It reduces the number of semiconductor components. Switching loss and power losses is reduced. It usually occurs in a diode bridge and as a result overall system efficiency is improved. The occurrence of two semiconductors switches in the current path throughout interval it consequence in a smaller amount conduction losses [19]. B. Bridgeless Boost converter Figure 1 shows the Bridgeless Boost Converters. A bridgeless boost converter with low common mode noise is presented in this paper. The numbers of components are condensed by the magnetic components such as transformer and inductor on same core. Bridgeless power factor correction (PFC) circuit topologies is used to maximize the power supply efficiency and conduction loss is reduced and the number of semiconductor components in the current path is condensed. By replace a couple of bridge rectifiers and employ an boost inductor is implemented. In bridgeless type, one rectifier is get rid of from the contour path reduce the conduction loss.The further type work mutually in continuous conduction mode (CCM) and discontinuous conduction mode (DCM). This figure 1 utilize the totem-pole collection in the reverse recovery performance of the anti parallel diode.It can work only in DCM mode .It makes CCM operation impractical. High common-mode noise produced in realistic application is vulnerable by a lofty frequency switching. This implementations does not bear from the lofty noise problem [19].