A new integrated regulation strategy and modelling for wind turbine with battery energy storage system

Abstract

Recent decades have seen a great penetration of renewable energy in electricity supply market. However, the intermittency of wind energy requires careful control of wind turbine (WT), for which a promising solution is to combine wind turbine with a battery energy storage system (BESS). This motivates our work on regulation strategy and modelling for the wind turbine with battery energy storage system (WT/BESS). We propose a new integrated regulation strategy (IRS) for WT/BESS which includes a dual-hysteresis charging/discharging mechanism for BESS and a cooperative output adjustment scheme for WT. The advantages of the proposed IRS are triple-folds: 1) the output fluctuation of WT/BESS is smoothed remarkably; 2) the status of charge (SOC) of BESS is kept in a suitable range for most of the time, which can improve the service life of BESS; 3) the phenomenon of chattering is escaped effectively. To describe the dynamics of the WT/BESS supervised by the proposed IRS, a model of composite switched system with multiple equilibria is developed, in which the switching strategy is related to three factors simultaneously, i.e., the variation of wind speed point, the working mode change of BESS and the control method of WT. The effectiveness of the proposed IRS is demonstrated by comparing several numerical simulations with other existing results.