Off-Grid Renewable Generation Control without Energy Storage

Abstract

This paper addresses the power-sharing of an off-grid generation system including renewable resources without energy storage. Initially, a modified MPPT P&O algorithm is employed to adapt the operation of a photovoltaic array subjected to variations in power demand. Further adjustments are performed to employ the same procedure on a self-excited induction generation extracting wind power. The aforementioned improvements allowed the regulation of DC-link voltages experiencing underloading conditions, restricting their ranges to operational limits of power inverters. Moreover, a parallel combination of both generation units is achieved in terms of a droop power-sharing scheme. Simulation results performed in the SimScape toolbox of MATLAB are presented, confirming the appropriate operation of the off-grid system under variations in demand and power supply conditions. Ongoing work is aimed at the experimental verification on a laboratory prototype for the numerical predictions given.