ELECTRIC VEHICLE WIRELESS CHARGING SYSTEM WITH VEHICLE-TO-HOME CAPABILITIES

Wireless Power Transfer (WPT) is a method that has been developed for about two decades to charge the battery pack in electric vehicles (EVs). It behaves convenient features: that charge EVs by a WPT system occurs without any physical contact. As power transfer takes place by magnetic coupling between two coils: which are placed under the road surface and onboard the vehicle. Therefore, with respect to wired EV charging, such a solution is more reliable as there are no connected items (cables, plugs and sockets), hence, there is no exposition of the connection items to the environment; moreover, it is more friendly, safe and secure as there are no plugs to insert, no cables on the sidewalk and much less chance of vandalism. The different challenges that are currently with the electric power grid impose in terms of a synergistic, progressive, dynamic, and stable integration of electric mobility. Their solution is through a bidirectional power flow system through EVs. In order to put these factors into a coherent framework for vehicle electrification in this thesis. The key contributions include the following areas: i) Grid-to-Vehicle, ii) Vehicle-to-Grid iii) Home-to-Vehicle, iv) Vehicle-to-Home, v) V2H Uninterruptible power supply have been discussed. The step-by-step mathematical design of all the converters and coil system takes place as per the SAE J2954 for EVs and Low Voltage grid according to CEI 0-02, for bidirectional wireless system for V2H (BWV2H) application. On this basis, the input and output specifications for the BWV2H can be designated. Subsequently, the active power involved at each conversion stage is calculated by the corresponding maximum current and voltage. This allows factors to determine the rating power of each power converter and of the passive elements arranging the BWV2H. The power sizings are of two different arrangements of BWV2H i.e., secondary in a chopper with cascade to the diode rectifier and a straightforward manner through the active rectifier was discussed. The thesis continues with the study and analysis of converter losses at different stages together with the series-series (S-S) compensating coils, via two distinct approaches to control the power converters. The operation of converters in SAHFWPT and DAHFWPT are controlled by the extended phase shift and dual phase shift methods respectively. Moreover, in this study, I analyzed the operation and losses of the uni-directional power flow of the WPT system, i.e., from the DC bus on the primary side to the battery load on the secondary side. The loss estimation includes high frequency switching losses, conduction losses, hard turn on and turn off losses coil losses, etc. Finally the efficiency of both arrangement are compared with respect to the internal phase shift angle of converters or input power. Further, study is to review the effects of the different states of the control between primary and secondary H-bridge converters in WPT. However, in this arrangement the power regulated, in terms of active and reactive power takes place by changing external phase shift angle between both H-bridge by using DPS modulation method. It seems that the controller can work with a wide range of active and reactive power setups. Its helped in eliminate hard switching with small amount of reactive power drawn from source. Finally, it includes discussion that control algorithms for BWV2H system only with the primary and secondary active H-bridge converter for battery charger. Its focuses on the power conversion stages that are needed for a charging work and grid synchronization at home. The algorithms are built one by one in the continuous time domain using techniques based on the analysis of Bode diagrams of the transfer functions involved in the operation of the system. Using simulations made in the Matlab/Simulink environment, each algorithm's performance has been checked on its own.