Control Strategies to Smooth Short-Term Power Fluctuations in Large Photovoltaic Plants Using Battery Storage Systems

Energies

Javier Marcos¹  Iñigo de la Parra²  Miguel Garc໚²  Luis Marroyo² 

[1] Department of Electrical and Electronic Engineering, Public University of Navarre (UPNa), Campus Arrosadia s/n, Edificio de los Pinos, Pamplona 31006, Spain;

关键词: grid-connected photovoltaic (PV) plants;    power fluctuations smoothing;    control strategies;    energy storage sizing;   

DOI  :  10.3390/en7106593

来源: mdpi

【 摘 要 】

The variations in irradiance produced by changes in cloud cover can cause rapid fluctuations in the power generated by large photovoltaic (PV) plants. As the PV power share in the grid increases, such fluctuations may adversely affect power quality and reliability. Thus, energy storage systems (ESS) are necessary in order to smooth power fluctuations below the maximum allowable. This article first proposes a new control strategy (step-control), to improve the results in relation to two state-of-the-art strategies, ramp-rate control and moving average. It also presents a method to quantify the storage capacity requirements according to the three different smoothing strategies and for different PV plant sizes. Finally, simulations shows that, although the moving-average (MA) strategy requires the smallest capacity, it presents more losses (2–3 times more) and produces a much higher number of cycles over the ESS (around 10 times more), making it unsuitable with storage technologies as lithium-ion. The step-control shown as a better option in scenery with exigent ramp restrictions (around 2%/min) and distributed generation against the ramp-rate control in all ESS key aspects: 20% less of capacity, up to 30% less of losses and a 40% less of ageing. All the simulations were based on real PV production data, taken every 5 s in the course of one year (2012) from a number of systems with power outputs ranging from 550 kW to 40 MW.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.