| In recent years,wind power has been vigorously grown as a significant energy source with its benefits of sustainability,zero pollution,and mature technology.However,by reason of the connatural randomness,reverse peak regulation,and variability of wind energy,it is a huge challenge for wind farms to accurately report wind power planned power,and the dispatch and safe working of the power system is also influenced.At present,in my country’s wind farms,most of the forecasted power is reported directly as planned power.Due to the limitation of weather conditions and the characteristics of wind energy,the forecast error of wind power still exists.To a certain extent,the reliable realization of planned grid-connected power can be ensured by wind storage combined power generation,but energy storage is expensive and capacity is limited.Therefore,the optimal configuration and control strategy of the energy storage system used to track wind farm power generation plans are studied in this paper.The main contents are as follows.(1)The working principles of wind power generation,batteries and super capacitors are analyzed.PNGV and series RC equivalent models are selected as equivalent simulation models of batteries and super capacitors,respectively,and a hybrid energy storage system based on batteries and super capacitors is constructed.At the same time,the grid-connected topology of the energy storage system in the wind farm is also devised,and the wind storage co-simulation system platform on the basis of Matlab software is constructed.(2)In view of the fact that the energy storage capacity demand is largely determined by the cumulative error distribution,a hybrid energy storage system capacity optimization configuration method based on prediction error correction is proposed.The prediction error correction strategy is formulated by analyzing the relationship between the required energy storage capacity collocation and the forecasting error distribution,and the wind power reporting plan power is intended on the basis of the wavelet packet decomposition technology.Then,the capacity optimization model of the hybrid energy storage system including the entire lifecycle expense of the hybrid energy storage system,the compensation degree of wind farm forecast error and the benefit of wind farm power generation is established.In order to make the model solution more accurate,the Particle Swarm Optimization(PSO)is improved by Differential Evolution(DE),and the improved DE-PSO algorithm is used to obtain the optimal configuration of the hybrid energy storage system.The feasibility and economy of the proposed method are proved through the analysis of influencing factors of energy storage configuration and simulation comparison.(3)In order to reduce the over-limit time of energy storage and prolong the life of energy storage,a two-layer fuzzy control scheme for mixture energy storage system combined with ultra-short-term wind power prediction is suggested.Future variations in wind power are evaluated on the basis of wind power forecasting.The actual energy storage dynamic state of charge is combined with the adjustment requirements of the planned tracking command.The throughput power of the energy storage system is repeatedly corrected by the double-layer fuzzy rule to ensure the safe operation of the energy storage system and the multi-task execution of the power plan tracking target.The simulation results show that compared with the traditional single-layer fuzzy control,the proposed control strategy can improve the accuracy of grid-connected power while effectively reducing the energy storage limit time,which has higher reliability and superiority. |
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