Frequency control in an isolated wind‐diesel hybrid system with energy storage and an irrigation water supply system

Abstract

Wind‐Diesel Hybrid Systems (WDHSs) integrate wind turbines into diesel power systems, reducing costs and emissions in isolated grids. Due to the no‐load consumption of the Diesel Generators (DGs), fuel savings are only possible when the DGs are shut down. This requires a proper implementation of the frequency control to avoid perturbations because of the wind speed variations. During wind‐only (WO) operation, the Synchronous Machine (SM) generates the isolated grid voltage and the frequency controller varies the energy stored/supplied by an Energy Storage System and consumed by the controllable loads to balance the power. In this paper, a Battery‐based Energy Storage System (BESS) uses Li‐Ion batteries with a Dual Active Bridge (DAB) and a grid‐tie inverter connected to the isolated network. The controllable load is an Irrigation Water Supply System (IWSS), consisting of a pump supplying water to a reservoir tank. The pump is driven by a variable speed drive that uses a Permanent Magnet Synchronous Motor (PMSM). The coordinated control of BESS and IWSS gives full priority to the BESS for harnessing the wind potential whereas the IWSS consumes the excess of wind power. The full Wind Diesel Power System (WDPS) is modelled and simulated to validate the proposed system for different case scenarios.