Control Strategy for an Off-Grid Photovoltaic System in Haiti

Abstract

This paper proposes a control system for an off-grid photovoltaic system, which can be used to improve the electricity access in poor or developing countries. The PV system is composed of three independent closed-loop converters, connected to a common dc voltage bus. The objective of the proposed control system is to adequately control the power flow through these converters and the dc bus independently on the solar irradiation and the charge/discharge of the battery-bank while providing the power to the ac loads. To achieve this goal, the power injected to the dc link is monitored by using two integrated control loop that compute the difference between the input and output power levels to inject or to extract it from the battery bank under distinct operating points. Simulation results are included for an 1.6 kW PV system to validate the proposed control strategy.