Executive Summary : | The Indian government aims to achieve electric vehicles (EVs) accounting for 30% of private cars, 70% of commercial vehicles, and 80% of two and three-wheelers by 2030. These EVs absorb real power from the electric grid to charge batteries and provide ancillary services like voltage regulation, frequency restoration, and peak load support, known as the vehicle-to-grid (V2G) concept. However, with increasing installation of photovoltaics (PVs), it is challenging to provide continuous, reliable, and efficient operation of the new reconfigured electric grid with massive EV charging station installation. Hybrid distribution grids offer a flexible solution to power management problems, but various challenges need to be addressed for seamless operation. A new equipment called smart transformer (ST) is proposed to address these challenges. ST is an alternative to line frequency transformers in electric distribution grids and has effective control, communication, and energy management capabilities. This project aims to utilize ST's DC links to integrate EV charging stations in the electric grid, rather than connecting them through conventional LFTs. The impacts of connection at MV and LV DC links will be investigated, along with optimal power and energy management algorithms to satisfy operational constraints. Optimal sizing of power converters is crucial for the financial viability of the proposed system. Investigation will focus on finding suitable sizing of different power converters and placement in the flexible distribution system. A new control and power management strategy will be developed for economical operation of ST-based EV charging stations with significant PV installation. Stability and robustness analysis will be carried out to understand associated problems and develop appropriate methodologies for a stable system. |