Dynamic simulation of a microgrid system for a university community in Nigeria

In this research, the optimal PV size of the system was first determined with the aid of OpenSolar, PVWatts and REopt software for an annual energy consumption of 969,000kWh as compared to that obtained from HOMER Pro software. The result obtained was then used to design and simulate the dynamic model of the campus microgrid system in MATLAB/Simulink environment. The designed system in Simulink consists of PV size of 675.2kW comprised of 1350 modules each of 500W, with 25 connected in series and 54 in parallel, a utility grid of 50Hz, 6MVA, 33 kV transmission network with a power transformer of 2.5MVA, 33/11 kV and a distribution transformer of 750 kVA, 11/0.415 kV and a backup generator of 1.5 MVA rating. The system dynamics was considered under three conditions which includes PV + grid mode, PV + generator mode and only generator mode. Simulated results include transient responses observed when the utility grid and the generator were connected to the network separately through their respective toggle switches. Waveform of power, voltage and current through the varied electric load of the system for various conditions are presented in this paper.