Novel Bidirectional Charging/Discharging Schemes in PV Supported EV-Battery Charging Station in a Hybrid AC/DC Microgrid

Abstract

Driven by the innovative revolution towards sustainable green technologies, the large-scale deployment of electrified transportation network is on the rise [1]. Although the transition of classical transport sector into electrified transportation network is considered as a best alternative in decarbonization and encountering global climate change [2]. However, a significant growth of diverse electrified logistics and fast charging stations in a classical power network can lead to numerous consequences for energy and power systems stability. Unmanaged charging of constant power load by DC fast charging can significantly stress the power grids and leads to stability, reliability, and operational challenges [3]. However, a well efficient and flexible demand-side charging framework can resolve the upfront challenges and provide the significant potential to support the power grid operations. In addition, managed Level-2, Level-3 and V2G charging/discharging strategies in electric vehicles charging stations can support the power grid in normal and extreme scenarios by voltage and frequency regulation, peak load shaving, active and reactive power compensations. This thesis convers a broad range of value streams including the stability enhancement of multiport charging stations and micro grids by managed bidirectional charging/discharging strategies, standalone alone operations of DC microgrid, coordinated control between electric vehicles charging stations and AC microgrids, monitoring and control of the dynamics of AC microgrids based on IEEE 14 test bus system. The aim of the energy management algorithms is to provide a more flexible approach in charging the growing load of electric vehicles and to support the decentralized AC microgrid. The proposed charging/discharging schemes of charging stations and coordinated control models are simulated using MATLAB/Simulink in various DC and AC grid operational scenarios. The results summarizes the effectiveness of charging/discharging strategies of electric vehicles batteries in stable operation of hybrid microgrid. Lastly, several factors affecting the stability of AC/DC hybrid microgrid and charging/discharging behaviours of energy storage have been highlighted and discussed along with critical research gaps and challenges in making the electrified transportation and power system more stable and reliable.

Date of Award	Aug 2023
Original language	American English
Supervisor	KHALIFA ALHOSANI (Supervisor)