Power Factor Correction (PFC) of AC-DC System using Boost-Converter of EV On-Board Charger Circuit and CC-CV Charging Algorithm

Abstract

Now a day, the interest in electric cars and plug-in hybrid vehicle technologies is increasing due to reduced fuel consumption and zero emissions. However, due to crucial issues such as high battery prices, cycle life of the batteries and lack of charging infrastructure, high EV adoption has not yet been achieved. Another big downside is that on the distribution system, the battery chargers cause unnecessary harmonics. Thus, different topologies of chargers for electric vehicles (EVB) play a significant role in growing the penetration of EV's. EV battery chargers can be configured as on board chargers or off-board chargers in an EV. EVB chargers can be classified according to their power levels and direction of flow. Based on the power ratings, the EV charger is divided into chargers Level 1, Level 2 and Level 3. Level 1 and Level 2 are equipped for slow home charging and public charging stations with a Level 1 power of less than 2kW and Level 2 for on-board charging of about 20KW. These chargers have a charging time of 14 to 18 hours. Level 3 off-board chargers are designed for fast charging using DC with power ratings of around 100kW with less than 30 minutes of charge time. Uni-directional or bidirectional power flow can be obtained on all power rates on the basis of power flow direction. For level 3 chargers, bidirectional power flow is there as they can provide power back to the grid during peak demand. A unidirectional on board charger for level 1 and level 2 chargers consist of AC/DC converter which should have high power density and high efficiency. An EV battery charger must ensure low distortion of the utility current to reduce the effect of the power quality and ensures high power factor to optimize the real power flow from the utility outlet. Nonlinear loads such as rectifiers, SMPS are present in the charger design circuit, the key source of harmonics. The aim is to present a new control scheme to compensate for the harmonic current produced by the diode rectifier to achieve a power factor that is closer to unity and to regulate the DC-bus voltage. This scheme uses one PFC Boost Converter that is connected to the rectifier of the diode to compensate for the harmonic current generated by the rectifier of a single phase. Generally accepted procedure for correcting the poor electronic power supply factor is by using of active approach method. The system has both active filters such as series, shunt and hybrid active filters, as well as Power Factor Correction circuits such as boost, buck, fly back converters. By removing current harmonics an active filter improves the quality of electricity.