A quasi-automated generation control strategy for multiple energy storage systems to optimize low-carbon benefits

Integrating a battery energy storage system(ESS)with a large wind farm can smooth the intermittent power obtained from the wind farm,but the smoothing function will not be achieved if multiple ESSs are used to smooth the fluctuations in individual wind power plants in a distributed pattern.Therefore,this study focuses on the development of a control strategy to optimize the use of multiple ESSs to accelerate the adoption of wind energy resources.This paper proposes a quasi-automated generation control(QAGC)strategy to coordinate multiple ESSs,which responds to the grid dispatch demand rather than smoothing out the intermittent power from individual wind farms.The aims of QAGC are to ensure that multiple ESSs provide a service that is as balanced as possible,so more wind power systems at various scales can be accepted by the grid,as well maximizing the low-carbon benefits of ESSs.The effectiveness of QAGC is demonstrated by using data from an actual gigawatt scale cluster of wind plants.

Reversible storage of multiple light pulses in the EIT atomic medium

In this paper, we first present a full numerical simulation for the trapping and retrieval procedure of eight continuing '1' Guassian pulses (i.e., '11111111') in the electromagnetically induced transparency (BIT) medium. This simulation shows that an BIT medium has the ability to store multiple light pulses in a shape-preserving way. And we also, for the first time, give the formula evaluating the maximum number of pulses that can be stored by an EIT medium at one time. This work reveals a new possible way to the reversible storage of the photonic information.

Contingency Reserve Evaluation for Fast Frequency Response of Multiple Battery Energy Storage Systems in a Large-scale Power Grid

Recently,the fast frequency response(FFR)service by large-scale battery energy storage systems(BESSs)has been successfully proved to arrest the frequency excursion during an unexpected power outage.However,adequate frequency response relies on proper evaluation of the contingency reserve of BESSs.The BESS FFR reserve is commonly managed under fixed contracts,ignoring various response characteristics of different BESSs and their coexisting interactions.This paper proposes a new methodology based on dynamic grid response and various BESS response characteristics to optimise the FFR reserves and prevent the frequency from breaching the under-frequency load shedding(UFLS)thresholds.The superiority of the proposed method is demonstrated to manage three large-scale BESSs operating simultaneously in an Australian power grid under high renewable penetration scenarios.Further,the proposed method can identify remaining battery power and energy reserve to be safely utilised for other grid services(e.g.,energy arbitrage).The results can provide valuable insights for integrating FFR into conventional ancillary services and techno-effective management of multiple BESSs.

Gradually activated lithium uptake in sodium citrate toward high-capacity organic anode for lithium-ion batteries

Lithium-ion batteries(LIBs)have been used to power various electric devices and store energy,but their toxic components by using inorganic materials generally cause serious environmental issues when disused.Recently,environmentally friendly and naturally abundant organic compounds have been adopted as promising electrode materials for next-generation LIBs.Herein,a new organic anode electrode based on sodium citrate is proposed,which shows gradually activated electrochemical behavior and delivers a high reversible capacity of 776.8 mAh·g^(-1)after 1770 cycles at a current density of 2 A·g^(-1).With the aid of the electrochemical characterization,Fourier-transform infrared(FTIR)and X-ray photoelectron spectroscopy(XPS)analysis,the lithium uptake mechanism of sodium citrate-based anodes is identified to be a combination of three-electron lithiation/delithiation and fast Li+intercalation/deintercalation processes,in which Faradaic reactions could offer a theoretical contribution of312 mAh·g^(-1)and intercalation pseudocapacitance would provide extra capacity.This work demonstrates the great potential for developing high-capacity organic electrodes for LIBs in future.