Design and implementation of a solar-powered wireless charging station for electric vehicles

In this thesis, a solar-powered wireless charging station is designed and experimentally implemented by integrating the environmentally dependent, time-varying characteristics of photovoltaic (PV) energy sources with the wireless charging requirements of battery-based systems such as electric vehicles (EVs). The primary objective of the study is to ensure stable tracking of the maximum power point (MPP) under variable atmospheric conditions, while simultaneously identifying an optimal modulation strategy capable of minimizing switching losses in the resonant tank. Within this scope, Pulse Density Modulation (PDM) is comparatively analyzed alongside Enhanced Pulse Density Modulation (EPDM) and Improved Pulse Density Modulation (IPDM), which have been reported in the literature to improve converter efficiency, for use in power control and Maximum Power Point Tracking (MPPT) algorithms. The electromagnetic and circuit-level design of the system is carried out using Ansys Maxwell 3D and PSIM simulation environments, while experimental validation is performed on a laboratory-scale prototype operating at an 85 kHz resonant frequency, controlled by an STM32-based digital control unit, and scaled to a power level of 1 kW. In the experimental studies, a programmable PV simulator is employed to represent different solar irradiance conditions, and an RC-based load model is implemented to emulate the charging behavior of an electric vehicle battery. The experimental results demonstrate that, under low and medium irradiance levels (250 W/m²–500 W/m²), the IPDM method provides higher average power transfer and system efficiency compared to PDM and EPDM by maintaining a more stable resonant current envelope. As the irradiance level increases and the system operates in the high-power region (750 W/m²–1000 W/m²), the switching behaviors of all modulation methods are observed to physically converge due to the increased pulse density, resulting in similar overall system efficiencies of approximately 92%. These findings indicate that the IPDM approach offers advantages in terms of MPPT stability and energy transfer continuity under variable environmental conditions, while performance differences among modulation methods naturally diminish at high power levels.