Application of 100 kJ/50 kW high-temperature superconducting magnet energy storage system in micro-grid

超导磁储能系统（superconducting magnetic energy storage,SMES）能够实现与电网之间的快速功率交换,对于增强电网稳定性,改善电能质量具有重要意义。本文针对一套100 kJ/50 kW高温超导磁储能系统,对其超导磁体设计与低温系统,功率调节系统的拓扑及控制策略设计、主监控系统的设计分别进行了阐述和分析。为了验证整个磁储能系统的性能,进行了相关的开环功率调节实验。实验结果表明,整套系统运行良好,SMES能够快速的响应主监控系统发出的功率指令,实现SMES与电网之间快速的功率交换。基于上述对SMES的分析和实验测试,结合云电科技园微电网的拓扑,给出了几种SMES在微电网中应用的试验方案,以验证SMES在微电网中应用的性能和作用。     

Application analysis of a superconducting fault current limiter-magnetic energy storage system for the wind farm

风力发电所面临的两大重要问题是低电压穿越能力弱和功率输出不稳定。为了同时解决这两个问题,我们提出了超导限流-储能系统,并进行了单机系统的仿真研究,证实了该方案的有效性。然而对于风电场的应用,目前尚无研究。本文将超导限流-储能系统的应用扩展到风电场,分析了其提高低电压穿越能力和稳定有功功率输出的机理,并进行了仿真研究。从仿真结果来看,超导限流-储能系统能够同时提高风电场所有风机的低电压穿越能力,并能有效地平滑整个风电场的有功输出功率。考虑不同风机的互补效应,将该系统应用于风力发电场与直接应用于单台风机相比,其储能量和功率输出的要求可以大大降低,从而可以有效地减少系统总成本,因而具有更好的应用前景。     

A 150 kJ/100 kW directly cooled high temperature superconducting electromagnetic energy storage system

高温超导磁储能系统（SMES）是一种功率型的储能装置,本文介绍了国内自主研发的150 kJ/100 kW直接冷却高温超导磁储能系统的总体结构和基本试验结果。高温超导磁体由Bi2223/Ag和YBCO两种超导带材绕制而成,通过直接冷却方式将储能磁体成功冷却到了17 K左右。经测试,储能磁体的直流临界电流达到180 A,临界储能量157 kJ,磁体中心场强4.7 T;该SMES能快速独立地在四象限进行有功功率和无功功率交换,响应速度小于10 ms;在电力系统动态模拟实验中,SMES有效抑制了电力系统中因发电机机端短路故障引起的功率振荡。     

An updated review of energy storage systems: Classification and applications in distributed generation power systems incorporating renewable energy resources

The demand of electric energy is increasing globally, and the fact remains that the major share of this energy is still being produced from the traditional generation technologies. However, the recent trends, for obvious reasons of environmental concerns, are indicating a paradigm shift towards distributed generation (DG) incorporating renewable energy resources (RERs). But there are associated challenges with high penetration of RERs as these resources are unpredictable and stochastic in nature, and as a result, it becomes difficult to provide immediate response to demand variations. This is where energy storage systems (ESSs) come to the rescue, and they not only can compensate the stochastic nature and sudden deficiencies of RERs but can also enhance the grid stability, reliability, and efficiency by providing services in power quality, bridging power, and energy management. This paper provides an extensive review of different ESSs, which have been in use and also the ones that are currently in developing stage, describing their working principles and giving a comparative analysis of important features and technical as well as economic characteristics. The wide range of storage technologies, with each ESS being different in terms of the scale of power, response time, energy/power density, discharge duration, and cost coupled with the complex characteristics matrices, makes it difficult to select a particular ESS for a specific application. The comparative analysis presented in this paper helps in this regard and provides a clear picture of the suitability of ESSs for different power system applications, categorized appropriately. The paper also brings out the associated challenges and suggests the future research directions.     

A review of electrical energy storage technologies for renewable power generation and smart grids

储能技术是突破可再生能源大规模开发利用瓶颈的关键技术,是智能电网的必要组成部分.在储能市场商业化雏形阶段,系统性的比较分析各类储能技术的性能特点,为未来市场发展提供筛选技术路线的框架基础至关重要.本文阐述了储能技术在可再生能源发电和智能电网中的作用,对物理储能(抽水蓄能,压缩空气储能,飞轮储能),电化学储能(二次电池,液流电池),其它化学储能(氢能,合成天然气)等储能技术进行了系统的比较与分析,最后提出储能技术的发展趋势.     

Stabilization and control of tie-line power flow of microgrid including wind generation by distributed energy storage

High penetration of wind generation in electrical microgrids causes fluctuations of tie-line power flow and significantly affects the power system operation. This can lead to severe problems, such as system frequency oscillations, and/or violations of power lines capability. With proper control, a distribution static synchronous compensator (DSTATCOM) integrated with superconducting magnetic energy storage (SMES) is able to significantly enhance the dynamic security of the power system. This paper proposes the use of a SMES system in combination with a DSTATCOM as effective distributed energy storage (DES) for stabilization and control of the tie-line power flow of microgrids incorporating wind generation. A new detailed model of the integrated DSTATCOM-SMES device is derived and a novel three-level control scheme is designed. The dynamic performance of the proposed control schemes is fully validated using MATLAB/Simulink.     

Smart grid adds to renewable resources hosting capacity: Collaboration of plug‐in hybrid electric vehicles in Volt/VAr control process

This paper develops an efficient energy management approach to increase the renewables share in energy provision of smart distribution grids (SDGs). Voltage violation ends in curtailment of renewables generations and, hence, decreases the economic success of distribution companies. To avert such deficits, this study fosters the collaboration of SDG components in an intelligent Volt/VAr control process. The investigated SDG is characterized with high penetration of photovoltaics (PVs), dispatchable distributed generations (DDGs), plug‐in hybrid electric vehicles (PHEVs), and infield control devices say as under‐load tap‐changing transformers (ULTCs). In charge stations, PHEVs are coupled to the SDG through bidirectional inverters which are offering simultaneous exchanges of active and reactive powers. Thus, regarding the PHEV aggregators, optimal schedules of active power charge/discharge signals with their inductive/capacitive reactive power provisions are determined. This notion effectively increases PV power injections and, consequently, provides significant monetary savings. Besides, this mechanism reduces ULTC tap operations in Volt/VAr control process maintaining its nominal lifetime. The proposed approach is formulated as a mixed‐integer non‐linear programming (MINLP) and solved based on DICOPT solvers in general algebraic modeling system (GAMS). Effectiveness of the proposed approach is explored on a typical distribution test system. The obtained results show 8.94% increment in harvested PVs power and hence 5.24% reduction on daily operation cost of SDG.     

Thermal energy storage in building integrated thermal systems: A review. Part 1. active storage systems

Energy consumed by heating, ventilation and air conditioning systems (HVAC) in buildings represents an important part of the global energy consumed in Europe. Thermal energy storage is considered as a promising technology to improve the energy efficiency of these systems, and if incorporated in the building envelope the energy demand can be reduced. Many studies are on applications of thermal energy storage in buildings, but few consider their integration in the building. The inclusion of thermal storage in a functional and constructive way could promote these systems in the commercial and residential building sector, as well as providing user-friendly tools to architects and engineers to help implementation at the design stage. The aim of this paper is to review and identify thermal storage building integrated systems and to classify them depending on the location of the thermal storage system.     

Dynamic performance assessment of an isolated wind–diesel power system with superconducting magnetic energy storage unit under turbulent wind and load disturbances

This paper presents modelling and control aspects of an isolated wind–diesel system equipped with a superconducting magnetic energy storage (SMES) unit. The SMES unit is located at the induction generators' terminal bus, for exchanging real and reactive powers in four quadrants, with the wind–diesel system. The system components are modelled by non‐linear equations for accurate dynamic performance assessment and the SMES unit is modelled as a controllable current source. The control of the SMES unit is exercised through a multi‐input–multi‐output (MIMO) self‐tuning regulator (STR). The STR uses the local voltage and frequency measurements and generates appropriate signals for the control of the SMES unit. The SMES coil current deviation forms a part of one of the regulated variables of the STR for achieving a continuous control. The complete model of the hybrid system is developed and the parameters of the STR are adjusted for quality improvement of the power supply under turbulent wind. The scheme is then tested for load disturbances. The simulation results show the positive impact of the proposed scheme on the quality of the power supply both under turbulent wind as well as load disturbances. Copyright © 2002 John Wiley & Sons, Ltd.     

Electric energy storage systems in a market-based economy: Comparison of emerging and traditional technologies

Unlike markets for storable commodities, electricity markets depend on the real-time balance of supply and demand. Although much of the present-day grid operate effectively without storage technologies, cost-effective ways of storing electrical energy can make the grid more efficient and reliable. This work addresses an economic comparison between emerging and traditional Electric Energy Storage (EES) technologies in a competitive electricity market. In order to achieve this goal, an appropriate Self-Scheduling (SS) approach must first be developed for each of them to determine their maximum potential of expected profit among multi-markets such as energy and ancillary service markets. Then, these technologies are economically analyzed using Internal Rate of Return (IRR) index. Finally, the amounts of needed financial supports are determined for choosing the emerging technologies when an investor would like to invest on EES technologies. Among available EES technologies, we consider NaS battery (Natrium Sulfur battery) and pumped-storage plants as emerging and traditional technologies, respectively.     

Review of flywheel energy storage systems for wind power applications

风力发电可以解决能源短缺和环境污染等问题,但由于风速随机性和间歇性的特点导致风电输出电压、功率和频率存在较大波动,因此风电的大规模并网会对现有电网的稳定运行造成不利影响。飞轮储能是一种高效无污染的储能技术,而且通过合理的控制策略和控制设备可实现电网调频及短时间调峰以解决大规模风电并网带来的问题。本文主要介绍了飞轮储能在风力发电领域的应用背景、飞轮储能的结构原理和目前国内外在飞轮储能控制策略方向的研究进展。     

Analysis of diabatic compressed air energy storage systems with artificial reservoir using the levelized cost of storage method

A detailed analysis has been carried out to assess the thermodynamic and economic performance of Diabatic Compressed Air Energy Storage (D‐CAES) systems equipped with above‐ground artificial storage. D‐CAES plant arrangements based on both Steam Turbine (ST) and Gas Turbine (GT) technologies are taken into consideration. The influence of key design quantities (ie, storage pressure, turbine inlet pressure, turbine inlet temperature) on efficiency, capital and operating costs is analysed in detail and widely discussed. Finally, D‐CAES design solutions are compared with Battery Energy Storage (BES) systems on the basis of the Levelized Cost of Storage (LCOS) method. Results show that the adoption of D‐CAES can lead to better economic performance with respect to mature and emerging BES technologies. D‐CAES ST based solutions can achieve a LCOS of 28 €cent/kWh, really close to that evaluated for the better performing BES system. Interesting LCOS values of 20 €cent/kWh have been attained by adopting D‐CAES plant solutions based on GT technology.     

Multiple effects of energy storage units on combined cooling,heating and power (CCHP) systems

Albeit numerous studies discussing manifold issues of combined cooling, heating and power (CCHP) systems, there is still lack of theoretical studies indicating to what extent the energy mismatch and the deviating working conditions affect the CCHP performance, absence of reports systematically summarizing the multiple effects of energy saving units (ESUs), and deficiency of research quantifying the benefits from ESUs to energy savings. The shortage of such studies will confuse some CCHP designers when a CCHP system is designed. Therefore, in this research, theoretical discussions have been undertaken about the energy mismatch issue between CCHP systems and their users as well as the multiple effects of ESUs on CCHP systems. An improved calculational method of energy storage rate (ESR) has been adopted to evaluate the energy savings performance of CCHP systems. Two general heat‐to‐electricity ratios (R_user for CCHP users and R_CCHP for CCHP systems) have been used to quantify the energy mismatch between CCHP systems and their users. In the regime of ‘priority of providing cooling’, the ESR reaches its maximum when R_user is equal to R_CCHP. Otherwise, the ESR tends to decrease rapidly, especially when the electrical demand must be supplemented from the grid. Furthermore, when the CCHP system produces more electricity than required, the payment mode of extra electricity from the CCHP system will significantly affect the ESR. Therefore, it is imperative to reach an international consensus regarding the dispose of extra CCHP products. The theoretical analyses also corroborate the advantages of incorporating an ESU into a CCHP system. The ESU enables the CCHP system components to operate at their optimal working conditions. Meanwhile, the power generation unit and the absorption refrigerator capacities can then be reduced. Moreover, the ESU also promotes the productivity of electricity and ensures an undiminished ESR regardless of what extra electricity payment mode is adopted. Copyright © 2016 John Wiley & Sons, Ltd.     

Systematic development and application of a fuzzy logic equipped generic energy storage system for dynamic stability reinforcement

Even though fuzzy logic has been tremendously utilized in power systems, it has often been termed as far from complete due to the in-existence of a systematic procedure. Here, we report a systematic development and application of a fuzzy logic equipped generic energy storage system (GESS) for dynamic stability reinforcement in a conglomerate power system. While ensuring a stabilizing performance by minimizing a quadratic stability index, the reactive and real-power trajectories of GESS are determined. The proposed control strategy is optimized offline using a genetic algorithm (GA) optimization and cast with mixed integer programming mathematics to dispatch an optimal template of series weights, grades of membership and decisive fuzzy rules. The dynamic behavior of the dc link is also assimilated in the detailed GESS modeling using cascaded proportional-integral controllers. A perspective of a combination of flywheel energy storage system and superconducting magnetic energy storage is traversed by approximating the inherent loop dynamics of the storages by a GA-tuned first-order system. The role of the said storage devices in manifestation of exogenous wind power intermittency as well as concentrated short circuits is investigated. A wind farm integrated, reoriented form of an exemplar multibus network is adopted as the model system to authenticate the potency of the presented control strategy.     

A review on theory and application of chemical heat pump in thermal energy storage

化学热泵是高效,环保的新型能源技术,在余热回收,储热,可再生能源等领域具有广泛的应用前景.本文综述了化学热泵系统的一般理论和在储热技术中的应用,介绍了化学热泵系统技术在反应与工质对选择,传热强化以及工业研究与应用等方面的发展.     

储能技术在中小型风力发电系统中的应用

讨论了储能技术的分类及应用范围,并对中小型风力发电系统的结构及其系统中储能的作用进行了阐述。同时分析了碳纳米管超级电容器储能、氢储能、超级电容器和蓄电池混合储能三种很有前途储能技术在中小型风力发电系统中的应用。     

A smooth co-ordination control for a hybrid autonomous power system (HAPS) with battery energy storage (BES)

The standalone hybrid power system constitutes a synchronous generator driven by a diesel engine, renewable energy source (wind) apart from a battery energy storage system. A coherent control strategy to regulate the voltage and frequency of the standalone grid is proposed in this paper. The system is simulated using Matlab/Simulink for preliminary validation and further tested on a laboratory prototype which involves a TMS320LF2407A DSP controller to digitally implement the control strategy. The dynamic behavior of the system is perused through the direct connection of an induction machine. The control strategy is verified for step changes in load and variation in wind power.     

Two-layer robust optimization framework for resilience enhancement of microgrids considering hydrogen and electrical energy storage systems

This paper presents a two-layer framework for improving the resilience of a 118-bus active distribution network consisting of four microgrids, which includes hybrid storage systems, electric buses (EBs), and the direct load control (DLC) program. In the proposed model, the uncertainties of RESs generation, demand, and EBs’ mobility are considered, and the robust optimization approach is used to tackle them. In the first layer, the planning of each microgrid is done separately and the energy purchase/sale request is sent to the control center. Then in the second layer, the control center performs the planning of the main network according to the requested program of the microgrids. Note that in this layer, the control center is able to rearrange the distribution feeder and send EBs to vital points of the network. Finally, the validity of the proposed model is evaluated through the implementation on seven case studies and the results show that the presence of hydrogen and electrical storage devices reduces forced load shedding (FLS) by 45.03% and 12.19%, respectively, during emergency situations. In addition, the results indicate that robust planning and the use of EBs for network recovery increase the resilience index by 3.35% and 3.98%, respectively.     

含水层储能技术的应用及储能条件的分析

能源问题已经成为制约现代社会发展的重要问题,地下含水层储能为现代城市能源的短缺以及环境的保护提供了一个很好的解决途径,同时可以减少废气(CO2、SO2等)的排放。介绍了地下水储能的基本原理、意义、在空调领域的应用及其实现的条件。     

微网系统中电池储能系统应用技术研究

随着可再生能源发电技术的发展,能够整合分布式发电系统的微网成为满足日益增长的电力需求、节省投资和提高能源利用率的一种有效途径。储能系统作为微网必要的能量缓冲环节,其作用越来越重要。文章概述了电池储能系统的基本特性,分析了电池储能系统的运行及控制原理,并详细阐述了其在微网中的作用。基于蓄电池的储能系统,不仅能起到能量缓冲的作用,还能提供短时供电、缓冲微网中负荷波动、改善微网电能质量,对提高微网的经济效益具有重要作用。