Modelling a Wireless Power Transfer System for LD Electric Vehicles Using a Self-Oscillating ZVS Inverter

Charging of EVs is of significant importance because of the complex power –electronics, batteries, motor and other electronics involved. EVs have short range due to the limitations of battery technology also; the charging process is very slow as compared to traditional gasoline pumps. Even the fastest EV charging station would take up to one hour to charge it completely. This required engineers to work on different aspects in order to improve the scope of EVs. Wireless Power transfer (WPT) is one of the major research areas for EV charging vision. Wireless energy was explained by tesla and has existed since then, but is development has picked up the pace from the last 2 decades. Some research works related to WPT has been going on like, system analysis and control, path guides, antenna optimization, high frequency inverter topologies, etc. Efficient power transfer is achieved at MHz frequency but such high frequency cannot be used to transfer high power. This is due to the limitations of the power electronic components used. MHz frequencies are used for small applications like wireless phone charging, whereas for EV charging frequency range is (3.3kHz-100kHz), frequencies higher than this will increase the losses within the circuit. Various research papers have shown promising result and the current technology needs more and more refinement for making it to the market. The main module utilizes transmitting and receiving coils with air core medium. We know that air core provides loose coupling and coupling coefficient (k) is less than 0.5. It is similar to inductive power transfer (IPT). IPT is in use for many other applications as well. Our work is based on WPT for LD vehicles where we try to use ZVS inverters for high power transfer. This will reduce the charging time and has a potential to be developed as dynamic charging system for the vehicles.