Cost Reduction of a Hybrid Energy Storage System Considering Correlation Between Wind and PV Power

Abstract

A hybrid energy storage system (HESS) plays an important role in balancing the cost with the performance in terms of stabilizing the fluctuant power of wind farms and photovoltaic (PV) stations. To further bring down the cost and actually implement the dispatchability of wind/PV plants, there is a need to penetrate into the major factors that contribute to the cost of the any HESS. This paper first discusses hybrid energy storage systems, as well as chemical properties in different medium, deeming the ramp rate as one of the determinants that must be observed in the cost calculation. Then, a mathematical tool, Copula, is explained in details for the purpose of unscrambling the dependences between the power of wind and PV plants. To lower the cost, the basic rule for allocation of buffered power is also put forward, with the minimum energy capacities of the battery ESS(BESS) and the supercapacitor ESS(SC-ESS) simultaneously determined by integration. And the paper introduces the probability method to analyze how power and energy is compensated in certain confidence level. After that, two definitions of coefficients are set up, separately describing energy storage status and wind curtailment level. Finally, the paper gives a numerical example stemmed from real data acquired in wind farms and PV stations in Belgium. The conclusion presents that the cost of a hybrid energy storage system is greatly affected by ramp-rate and dependence between the power of wind farms and photovoltaic stations, in which dependence can easily be determined by Copulas.

A review on the influence of intelligent power consumption technologies on the utilization rate of distribution network equipment

“…Applying intelligent power consumption technologies to improve the utilization rate of distribution network equipment can significantly reduce the required distribution network investment. Renewable and sustainable energy is widely used in power industry due to its great development potential, cleanliness and low pollution [2]. However, the application of renewable and sustainable energy in power industry is affected by geography, weather and other factors, which can cause fluctuations of distribution network and result in unnecessary losses.…”

Coordinated voltage regulation of hybrid AC/DC medium voltage distribution networks

“…In these circumstances, real time regulations of controllable devices should be applied to remain the voltage of important buses, which consequently also reduce undesirable DG curtailments and load shedding. DGs and energy storage systems (ESSs) have been investigated to achieve real-time voltage regulation in distribution networks [6][7][8][9][10][11][12]. Moreover, in order to increase transfer capacities and DG accommodations, some AC lines can be converted into DC ones and forms a hybrid AC/DC distribution network by connecting existing AC lines through voltage source converters (VSCs) [13].…”

“…An Optimal control management of ESSs is proposed to mitigate the fluctuation and intermittence of renewable generations in [10]. The correlation between DGs is considered in a hybrid energy storage system in [11]. Reference [12] establishes an optimal economic operation mode for community microgrid incorporating temperature controlling devices with DGs and ESS.…”

Analysis of voltage stability uncertainty using stochastic response surface method related to wind farm correlation

“…The relationships between active power P e that is supplied by the wind generation source and wind speed v are expressed as [14,20]:…”

“…In this paper, Frank Copula function [19][20][21][22] is considered as the connection function of joint probability distribution of wind farms. The respective distribution function and density function of Frank Copula can be expressed as:…”