Sensing Techniques and Systems to Aid Inductive Wireless Power Transfer in Electric Vehicles - Design and Development.

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Name of the Speaker: T. V. Jeshma (EE17D041)
Name of the Guide: Prof. Boby George
Date/Time: 21st October 2022, 3.30 pm

Electric vehicles (EVs) are an excellent alternative to gasoline-powered vehicles when it comes to sustainability and the reduction of environmental pollution. Inductive power transfer (IPT) based charging has been gaining popularity over plug-in EVs as it helps to have reduced battery capacity as well as improved convenience and safety while charging. IPT in EVs could be either static or dynamic. In the research work conducted and presented in the thesis, some of the important sensing challenges faced in the design of the IPT system for the charging of EVs are addressed. The efficiency of the IPT reduces drastically as the misalignment between the primary and secondary pads increases. To help to improve the misalignment and hence the efficiency of the wireless charging, a magnetoresistive (MR) sensor-based system is designed and developed. In the design of the IPT highway, one of the challenges faced is the detection of EV, to enable charging, as it travels along the highway. A sensor system was developed to detect the EV approaching the primary (ground) pad laid on the highway, so as to enable charging when it detects sufficient coupling between the primary and secondary (vehicle) pads. Another challenge faced in commercial IPT systems is that the primary pad should be able to interoperate with different types of secondary pads. For this, an MR sensor-based sensing technique was developed to identify the type of secondary pad so that the primary is energized in the correct mode. Following this a suitable sensing technique was developed for vehicle-to-grid (V2G) applications, to reliably detect the ground pad and sense its configuration before the actual V2G power transfer is initiated. The sensing techniques designed to address these challenges were optimized for the number of sensors and the sensor positions, using numerical analysis and finite element analysis. This was followed by detailed experimental studies to validate the functionality of the sensor systems. The proposed sensor systems need very less additional hardware which in turn reduces the overall system cost and its complexity. It can be easily integrated into new as well as existing primary/secondary pads. As the primary coil isn’t fully powered during the sensing phase, it saves power as well as limits human exposure to unwanted magnetic fields. As these systems are based on magnetic sensing, the performance is less likely to be affected due to dust, snow, oil, etc. Details of the work done and conclusions made will be presented in the talk.