Research on grid-connected photovoltaic power generation technology based on FREEDM system

Solar is a kind of new energy, and photovoltaic power generation is an important way of distributed generation; FREEDM system is a kind of Energy Internet model, which is presented by Professor Alex Q. Huang from North Carolina State University in 2008. Combining the advantages of photovoltaic power generation and FREEDM system, this paper proposes a kind of grid-connected photovoltaic power generation technology based on FREEDM system. With the help of MATLAB/simulink software, we build the model of photovoltaic array and solid state transformer that is the core part of FREEDM system, and realize the goal of maximum power point tracking. The output of photovoltaic array can not only be connected into the low voltage AC power grid through single phase inverter, but also can be connected into 10 Kv grid through solid state transformer and three phase inverter. Among them, we adopt active frequency drift method in the model of single phase inverter, high-frequency transformer in DC/DC converter and voltage source converter topology based on d-q vector control system in the model of three phase inverter.