Abstract
The power fluctuations of grid-connected photovoltaic (PV) systems have negative impacts on the power quality and stability of the utility grid. In this study, the combinations of a battery/supercapacitor hybrid energy storage system (HESS) and the PV power curtailment are used to smooth PV power fluctuations. A PV power curtailment algorithm is developed to limit PV power when power fluctuation exceeds the power capacity of the HESS. A multi-objective optimization model is established to dispatch the HESS power, considering energy losses and the state of charge (SOC) of the supercapacitor. To prevent the SOCs of the HESS from approaching their lower limits, a SOC correction strategy is proposed to correct the SOCs of the HESS. Moreover, this paper also investigates the performances (such as the smoothing effects, losses and lifetime of energy storage, and system net profits) of two different smoothing strategies, including the method of using the HESS and the proposed strategy. Finally, numerous simulations are carried out based on data obtained from a 750 kWp PV plant. Simulation results indicate that the proposed method is more economical and can effectively smooth power fluctuations compared with the method of using the HESS.
Highlights
Photovoltaic (PV) plays a vital role in the field of renewable energy, and a large number of PV plants have been built in various countries, such as China, US, and Germany [1]
It has been shown that connecting several PV plants that are far apart can reduce the overall volatility of PV power [6], and it is a simple method to smooth power fluctuations
This paper assumes that the maximum fluctuation of power injected into the grid from PV should be less than 10 %Cpv/min, because this requirement is adopted by the Puerto Rico Electric Power Authority (PREPA) to restrict the power fluctuations of PV [5]
Summary
Photovoltaic (PV) plays a vital role in the field of renewable energy, and a large number of PV plants have been built in various countries, such as China, US, and Germany [1]. The main idea of this approach is that the upward power fluctuation can be reduced by adjusting the actual operating point of the PV converter below its maximum power point (MPP) [3,9,10] This smoothing method cannot smooth downward power fluctuations caused by the fall of solar radiation. A power-sharing strategy of the HESS was developed to smooth the power fluctuations of PV [15], in which power spikes are absorbed by supercapacitor energy storage (SCES), and BES only needs to provide stable energy, the battery capacity can be reduced and its service lifetime can be prolonged [15]. HsatrrEeaStpSegraeienssednotPfeVtdhetinoHSsEmeScoStiooatnnhd4P.tVhTehpePoVcwopemropwflrueerchtceuunarsttiiavoienlmspeeanrrfetoardlmgisoacnruictshessemdo.fCintawsSoeecsdttiufofdneire3es,natinnsdcmlusoidmoitnuhglianttghioesntrcraoetnseutgrliotesls saatrreaetpaerngeaiseleysnzotefeddthaiennHdSEdecSistSicouannssd4e.dtThihenePSVceocpmtioopwnree5hr. eFcnuinsriatvalleiylmp, Seeernfctotiaromlngao6nripctehrsemsoe.fnCttwsastoehedsticufofdenirceelsnuatsnisodmnsoiomotfhutihlnaigtsiowsntroarretkes.guiletss aarree parneasleynzteeddainndSedcitsicouns4s.edThine cSoemctiporneh5e.nFsiinvaellpye, rSfeocrtmioann6cepsroefsetwntos dthifefecroennctlsumsiooontshoinfgthsitsrawteogrike.s are a2n.aDlyezfeindiatinodndoifscthuessPeodwinerSeFcluticotnua5t.iFoinnsalolyf,aSGecrtidon-C6opnrneescetnetds tPhVe cPolanncltusions of this work
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
