Implementation and control of small-scale hybrid standalone power generation system employing wind and solar energy

This paper presents an implementation and control of a hybrid standalone power generating system (HSPGS) based on a wind turbine (WT) and a solar-photovoltaic (PV) array. A squirrel cage induction generator (SCIG) is coupled with a WT for electromechanical energy conversion. The frequency and amplitude of voltage at AC bus, as well as, power quality improvement at the point common coupling (PCC) are achieved by controlling the three-leg voltage source converter (VSC) using decoupled nonlinear control algorithm. A battery energy storage system (BESS) is reinforced in the hybrid system to ensure power leveling under wind, solar and load fluctuations. For obtaining the maximum power from a solar PV array and to regulate the output DC voltage, a DC-DC boost converter is controlled using perturbation and observation technique. Moreover, a dump load is tied at DC bus to ensure stability of control and to protect the BESS and solid state switches from overvoltage at DC bus during the period of fully charged battery. The proposed HSPGS and its control algorithms are modeled in MATLAB/Simulink and its performance is tested in real time under presence of balanced/unbalanced, linear/nonlinear loads and change in climate conditions.