چكيده به لاتين
High pollution and low efficiency of fossil fuels cause greater use of smart grid in transportation and so, utilizing of electric vehicle have been welcomed. There are several methods for charging these vehicles, but the best is DC fast charging method. On the other hand, necessity of using and designing multiport bidirectional DC-DC converters, because of utilizing regenerative braking, storage elements and renewable energy like solar power, have been developed. As a result, cost, volume and number of elements have been decreased. The major methods of designing multiport converters are isolated and non-isolated method. Isolated converters consist of buck and boost, but non-isolated converters are bridge topologies using transformer.
In this thesis, topology and modeling of a three-port bidirectional DC-DC converter have been presented and several scenarios are considering to satisfy thesis’s purposes which using PV cells and regenerative braking of electrical railway to charge an electric vehicle. Also this topology could interface with a storage element such as a battery. The first port of low voltage side is connected to PV system and using of MPPT caused to receiving maximum power of this port. The second port is connected to battery. Also the output port of converter is connected to charging station. Duty cycle and phase shift angle are parameters which are respectively controlled to realize the MPPT (power distribution between low voltage ports) and power flow between two sides of converter.
Performance of proposed converter in different conditions of load demand and PV power generation in a one-day scenario has been analyzed. The output voltage and current, battery current, phase shift angle and duty cycle are main parameters of proposed converter that are analyzed. Simulation is performed in MATLAB-Simulink.
Keywords: electric vehicle, DC fast charging, three-port bidirectional DC-DC converter, PV system, performance of converter in a one day
