Design and Simulation of a DC Electric Vehicle Charging Station Interconnected with a MVDC Network

Due to a rapidly aging electric transmission and distribution infrastructure, an increased demand for energy, an increased awareness of climate change and greenhouse gas pollution, and an increased cost of fuel there is a need to produce and deliver energy more efficiently. This thesis attempts to provide a solution to these constraints through advancements in DC power architectures. Medium Voltage Direct Current (MVDC) infrastructure serves as a platform for the interconnection of renewable electric power generation, including wind and solar. Abundant loads such as industrial facilities, data centers, commercial office buildings, industrial parks, and electric vehicle charging stations (EVCS) can also be powered using MVDC technology. MVDC networks are expected to improve efficiency, through reductions in power electronic conversion steps and by serving as an additional layer between the transmission and distribution level voltage for which generation sources and loads could directly interface with smaller rated power conversion equipment. This thesis provides an introduction to battery energy storage system technology, and primarily investigates an EVCS powered via a MVDC bus. A bidirectional DC-DC converter with appropriate controls serves as the interface between the EVCS and the MVDC bus. Two scenarios are investigated for testing and comparing EVCS operation: 1) EVCS power supplied by the interconnected MVDC model and 2) EVCS power supplied by an equivalent voltage source. The ability of the battery charger (synchronous buck converter) to isolate faults in next generation DC power systems is explored. Each of the investigated components is modeled and simulated utilizing the PSCAD simulation environment then analytically validated