Dynamic Simulation of a Standalone Photovoltaic Hybrid System of a Remote house in Nigeria

Abstract

In the remote part of Nigeria, most households suffer from lack of electricity due to inaccessibility to the utility grid. This paper presents the simulation of a Photovoltaic (PV) hybrid system with battery and generator backup of an off-grid Stand-alone PV system for a house located in remote Benin City, Edo State in Nigeria. House peak load is 1.26kW and daily energy consumption is 3.4kWh, with no access to the electricity grid for fulfilment of load requirement to meet the basic electrical needs. The system is designed in Homer Pro and simulated using the Matlab Simulink software, it comprises of a 1.23kW PV made up of 4 modules (325W each with 2 in series and 2 in parallel), A MPPT (maximum power point tracking), a DC -DC buck converter, 4 backup battery of 12V, 350Ahr connected in series and a 4.8kW emergency generator system with a 1.6kW inverter which converts the output DC voltage of 48V from the converter to an alternating AC. The inverter is connected directly to a step-up transformer which boosts the voltage from to 220V AC for supply to the load. Result shows different scenarios and configuration. With a 50% State of Charge (SOC) of the battery and full electrical load, the PV charges the battery and supply power to the load. However, when the volatage of the battery is below 49V the emergency generator turns ON to charge up the battery. Whereas, in the scenario of 98% SOC of the battery, regardless of the load, the generator is not operational because the control of the generator automatically turns off when the battery is above 49V. The system dynamic simulation results and response to changing inputs are presented in this paper.