Multi‐objective control and operation of grid‐connected small hydro‐solar PV‐battery energy storage‐based distributed generation

Abstract

This work deals with the implementation, control and operation of a reconfigurable small hydro-solar photovoltaic (PV)-battery energy storage (BES)-based distributed generation system (DGS) working in isolated mode (IM) and grid connected mode (GCM). The DGS consists of a hydro generation-based on a PMSG integrated with a PV array supported by the BES. It operates in an IM during the grid outage and when the grid is available, it synchronizes and operates in GCM. A frequency adaptive comb filter-frequency locked loop (FLL)-based control is adopted to estimate errorless phase angles of the hydro generator and grid voltages for quick and accurate grid synchronization. A third-order band pass filter-based control technique is used to extract fundamental component of load currents and determine switching pulses to VSC. The overall multi-objective control is used to maintain voltage and frequency of the system at the point of common coupling during IM and GCM. The power quality of grid and generator currents are maintained at non-linear loads. The modified perturb and observe-based control technique is used to extract maximum power from the PV array and it provides drift-free operation during the change in insolation with de-rating capability to protect the BES from overcharging in IM.