An effective standalone hybrid wind-photovoltaic water pumping system with reduced power converter count

Abstract

This article proposes a standalone hybrid wind-photovoltaic (PV) water pumping system (WPS) with minimal power electronics interface, simple composite control, and optimal energy management strategy (EMS) for effective utilization of both renewable sources. The proposed system consists of classic Perturb and Observe (P&O) algorithm applied to the boost converter of the solar PV system and voltage regulation algorithm/hill-climbing MPPT algorithm with zero steady-state oscillation (ZSSO) applied to bidirectional voltage source converter (VSC) of wind energy conversion systems (WECS) for optimal power extraction at all times. The constant voltage to frequency (V/F) ratio is ensured at the point of common coupling (PCC) for the entire operating range to avoid saturation in the self-excited induction generator (SEIG) and the induction motor (IM) pump. The energy management strategy is devised to effectively harness renewable energy from both sources while ensuring the DC-link voltage stability. The system forms compelling proposition, given the least converter count to integrate solar-PV and wind energy employing easy to implement control algorithms with optimal energy extraction. The results of simulation and experimental studies on the proposed system reveal the effectiveness of the composite controller in terms of energy utilization, constant flux operation, and power balance for the entire operating range. Additionally, system exhibits acceptable dynamic and steady-state behavior against variations in wind velocity, solar irradiation, and load. © 2021 John Wiley & Sons Ltd.