A Novel Variable Width PWM Switching Based Buck Converter to Control Power Factor Correction Phenomenon for an Efficacious Grid Integrated Electric Vehicle Battery Charger Saurav Das Dept. of Electrical and Electronic Engineering Independent University,Bangladesh Dhaka, Bangladesh Email: saurav@iub.edu.bd Khosru M. Salim Dept. of Electrical and Electronic Engineering Independent University,Bangladesh Dhaka, Bangladesh Email: khosru@iub.edu.bd Dhiman Chowdhury Dept. of Electrical Engineering University of South Carolina Columbia, South Carolina, United States of America Email: dhiman@email.sc.edu Abstract—This paper proposes an innovative approach to utilizing Buck converter as an ideal Power Factor Correction (PFC) controller where variable width Pulse Width Modulation (PWM) switching signals are generated and implemented to reliably control the voltage and current conversion phenomena. The developed converter topology is tactically utilized to de- sign an efficacious grid-connected electric vehicle charger with substantially ameliorated line Power Factor so that the system loss can be averted in the case of AC-DC charging circuits. In order to ensure the sustainability of the proposed method, PSIM simulation software has been used to emulate a simulation model of a Battery charging system for Electric vehicles. The simulated output and evaluated performance parameters provide almost unity Power Factor (PF) with a Total Harmonic Distortion (THD) rate of 4.62% which is lower than the maximum allowable value recommended by IEEE519. The simulation outcome corroborates the efficiency and validity of the proposed framework. Index Terms—Battery charger, Buck converter, Discontinuous conduction mode, Control unit, Electric vehicle, Grid-connected, Power Factor Correction, Pulse Width Modulation, Total Har- monic Distortion. I. I NTRODUCTION According to the International Energy Outlook report, the transportation sector is going to increase its share of oil consumption up to 55% by the year 2030; which indicates an alarming situation for the developing and underdeveloped countries where heavy dependence upon importing fossil fuel is evident [1]. To mitigate this problem, Electric Vehicles (EV) would be an immaculate and pragmatic solution where the objective of making zero carbon emission environment can also be achieved [2]. As these EVs are mostly run by rechargeable batteries and the batteries are charged from the national grid, an efficient and effective charging mechanism must be followed to ensure and maintain the proper power quality (shape and magnitude stability of the input voltage and current) of the power grid system. Since this charging process involves two-stage AC to DC power conversion (mostly diode bridge rectifier is used which acts as the prominent reactive component), the non- linear circuitries inject the lower order harmonics into the utility and such practice is responsible for the degradation of power factor, substantial voltage distortion and the high crest factor of the national grid [3], [4]. Additionally, the Total Harmonic Distortion (THD) rate of the line current provided by the grid varies from 3% to 28.11% with a Power Factor of 0.96 while charging batteries for typical EVs; these statistics clearly indicate a significant amount of degradation of utility power qualities and poor load power regulation and maintenance. Similar and even worse consequences may occur when simultaneously a large number of EVs are connected to the national grid for battery charging purpose [5]. A considerable amount of research has been conducted over the years regarding this Power Factor Correction issue with grid integrated battery charging topologies. Controlling ap- proaches have been pursued in both unidirectional and bidirec- tional ways. In the unidirectional charging system, the control- ling algorithm works only for Grid to Vehicle (G2V). Whereas the bidirectional controlling mechanism allows functionality of both Grid to Vehicle (G2V) and Vehicle to Grid (V2G) aspects. In the G2V system, the energy flows from the power grid to the EV. On the other hand, the V2G system allows the energy flow to the power grid from the stored energy in EV batteries when it is requested from the grid operators [6]. This energy feedback process is commonly referred to as regeneration mechanism. Battery charger based on Buck-Boost PFC Controller for Plug-in EV in Continuous Conduction Mode (CCM) has been reported in [7]–[10]. In these papers, a complex methodology called line frequency current shaping scheme, controlled by Proportional-Integral (PI) controller has been used to achieve almost unity power factor (0.99). This PI controller includes inner current control loop and outer voltage control loop to stabilize the dynamic behavior of the charging circuit. To generate the switching pulses of the Proc. of the 2017 IEEE Region 10 Conference (TENCON), Malaysia, November 5-8, 2017 978-1-5090-1134-6/17/$31.00 ©2017 IEEE 262