本文回顾了飞轮储能技术研发50年的历程，分析了飞轮储能技术特点、应用领域以及关键技术问题。飞轮储能具有功率密度高、循环寿命长、响应迅速、能量可观性好以及环境友好的优点。当前，研制的飞轮储能系统单体能量为0.5~130 kW·h，功率为0.3~3000 kW。重点关注了飞轮用低成本高比强度新材料、高温超导磁悬浮技术。飞轮储能在电能质量调控、不间断过渡电源以及电网调频领域实现了商业化应用，在车辆混合动力领域的示范应用中实现节能20%~30%，处于产业应用的临界点。针对电网规模大功率、高能量储能需求，发展趋势是由数十千瓦时以下发展到百千瓦时，并通过阵列化组装成10~100 MW储能系统，放电时间可拓展到1 h。

The development of flywheel energy storage(FES) technology in the past fifty years was reviewed. The characters, key technology and application of FES were summarized. FES have many merits such as high power density, long cycling using life, fast response, observable energy stored and environmental friendly performance. A single flywheel stored energy of 0.5~130 kW·h in charging or discharging with power of 0.3~3000 kW. The frontier technologies include new materials of flywheel rotor, super-conducting magnetic bearing and high speed motor for FES. The commercial using of FES in power quality and uninterrupted power supply has a niche market share. The fuel saving in 20%~30% was realized in the hybrid power system using FES in vehicles. The FES technology is in a crisis of vehicles industrial application under the pressure from energy-saving and emission-reduction. For the grid application of renewable energy, the single FES stored energy of dozens of kWh should be increased to hundreds of kW·h. The power of FES array should be 10~100 MW and release power long as one hour.

The costs for solar photovoltaics, wind, and battery storage have dropped markedly since 2010, however, many recent studies and reports around the world have not adequately captured such dramatic decrease. Those costs are projected to decline further in the near future, bringing new prospects for the widespread penetration of renewables and extensive power-sector decarbonization that previous policy discussions did not fully consider. Here we show if cost trends for renewables continue, 62% of China’s electricity could come from non-fossil sources by 2030 at a cost that is 11% lower than achieved through a business-as-usual approach. Further, China’s power sector could cut half of its 2015 carbon emissions at a cost about 6% lower compared to business-as-usual conditions.

Energy's central place in economic, political and social systems-and the broad impacts that energy choices have on the natural world and public health-mean that new technologies often spur public reactions. Understanding these public responses and their drivers is important, as public support can influence new technology adoption and deployment. Here I review the literature on public perceptions of and responses to a wide range of new energy technologies. Unlike previous reviews that tend to focus on particular technologies or types of technologies, this Review covers both large-scale energy infrastructure projects, such as utility-scale wind and solar, fossil fuel extraction and marine renewables, as well as small-scale, 'consumer-facing' technologies such as electric vehicles, rooftop solar and smart meters. This approach reveals broad trends that may facilitate communication between policymakers, technologists and the public, and support the transition to a more sustainable energy system.

风电的高比例渗透削弱了电力系统的惯性与调频容量，储能凭借响应迅速、出力稳定等特点被广泛应用于电网的惯量支撑及频率调节工作。首先以双馈风机额定转速与有功出力为约束条件，基于转子超速控制设置最适功率预留系数，划分风机参与系统调频的风速范围。在此基础上，考虑系统频率支撑能力，提出一种风电机组与储能协调配合的调频方法。通过对储能有功出力与系统稳态恢复过程的分析，刻画了虚拟同步机控制策略下储能系统的动态频率调节特性，由此实现储能在应对系统不同工况与不同支撑需求下控制参数的最优配置。仿真结果表明，所提方法能够在保证系统调频需求的同时充分利用风电自身的调频容量，优化储能系统参数的配置结果，实现储能出力的平滑输出，提高系统的频率支撑能力。

The high proportion penetration of the wind power weakens the inertia and frequency regulation capacity of the power system. The energy storage system (ESS) is widely used in the inertia support and frequency regulation of the power grid with the characteristics of rapid response and stable output. Firstly, the rated speed and active power output of the doubly fed induction generator (DFIG) were taken as constraint conditions, and the optimal power reservation coefficient was set based on the rotor overspeed control to divide the wind speed range of the DFIG participating in the system frequency modulation. On this basis, considering the frequency support capacity of the system, a coordinated frequency modulation method of the DFIG and the ESS was proposed. Based on the analysis of the ESS active power output and system steady-state recovery process, the dynamic frequency regulation characteristics of the ESS under the control strategy of the virtual synchronous machine were described, so as to realize the optimal configuration of the control parameters of the ESS under different working conditions and different support requirements. Simulation results show that the proposed method can make full use of the frequency modulation capacity of the DFIG while ensuring the frequency modulation requirements of the system, optimize the configuration results of the ESS parameters, realize the smooth output of the ESS, and improve the frequency support ability of the system.

重力储能系统（gravity energy storage system，GESS）在充电过程中可以从电网或新能源场站吸收电能。当新能源场站功率波动导致充电功率不足时，可选择两条能流路径应对充电功率波动，即调节质量块数量或直接从电网吸收能量，但如何合理选择上述路径是工程应用中的难题。为解决上述难题，提出了一种基于效益分析的重力储能系统能流路径选择方法，实现新能源站功率波动下的充电效益最优。首先，以斜坡式重力储能系统为例，对其储能过程中两条能量流动路径进行了详细分析；其次，以效益最优为目标建立了效益分析模型，并提出了上述能流路径下的功率缺额阈值计算方法；最后，以配置250 kW斜坡重力储能系统的800 kW光伏电站为例，在新能源波动条件下对比分析了采用不同能流路径时的储能系统充电成本及效益，对所提方法进行验证。结果表明，所提方法能够及时调整重力储能系统充电功率，有效解决新能源发电量不足问题，同时系统充电效益可提高44.95 %。

Gravity energy storage system (GESS) can absorb power from the power grid or the new energy station during charging process. When insufficient charging power happens due to power fluctuation of the new energy station, two energy power flow paths of GESS can be selected to respond to charging power fluctuation, which are adjusting the number of masses or absorbing energy from grid directly. However, how to select the above paths reasonably is still a problem in engineering application. To solve the above problems, an energy flow path selection method of GESS based on benefit analysis is proposed to realize the optimal charging benefit under power fluctuation of new energy station. Firstly, taking a slope GESS as an example, two energy flow paths in the energy storage process are analyzed in detail. Secondly, with the objective of the optimal benefit, the benefit analysis model is established and power shortage threshold calculation method applied in the above energy flow paths is also proposed. Finally, in the example of a 800 kW photovoltaic power station with 250 kW slope GESS, the charging cost and benefit of energy storage system with different energy flow paths are compared and analyzed to verify the proposed method under the fluctuation of renewable energy. The results show that GESS’s charging power can be adjusted in time and power shortage of new energy power generation can also be effectively solved by using the proposed method. At the same time, power charging benefit of the system benefit can be improved by 44.95 %.

The increasing penetration of intermittent renewable energy sources has renewed interest in energy storage methods and technologies. This paper describes a gravitational potential energy storage method. A review of current storage methods that make use of the principle of gravitational potential energy is done, with a comparison given in terms of power, energy rating and round trip efficiency. One of these gravitational energy storage methods, involving moving a solid mass vertically up and down, is further analysed in terms of energy storage capacity, energy and power density and the levelised cost of storage. Two different hoisting methods are discussed, the first of which is the traditional drum winder hoist and the second is a proposed, multi-piston hoist based on the use of linear electric machines. The two hoist methods produce storage systems with distinctly different properties and storage applications.

重力储能具有安全性高、成本低、寿命长、存储能量无衰减、建设周期短及环境友好等优势。其中，斜坡式重力储能可以利用山体自然落差降低建设成本，并减少占用平地资源，是长时大容量储能领域的重要前瞻性技术之一。然而，斜坡式重力储能系统具有机械与电气动态高度耦合的特点，现有仿真模型难以完整描述其动态特性。针对该问题，本工作提出了一种斜坡式重力储能系统机械与电气联合仿真的多软件协同建模方法。首先，采用三维机械设计软件Solidworks建立包括斜坡、轨道、载重小车和质量块的机械系统框架模型；然后，将Solidworks中建立的模型导入多体动力学仿真软件Adams，并建立载重小车与链传动机构的联系，获得机械系统完整模型；最后，将Adams中的机械模型导入Simulink，并建立与电气模型的联系，从而获得机电联合仿真模型。将所提出的多软件协同仿真模型与Simulink独立仿真模型，在电网正常和异常工况下分别进行仿真对比，结果表明多软件协同仿真模型能够更加全面地描述斜坡式重力储能系统的动态特性。因此，多软件协同仿真模型能够更好地支撑对斜坡式重力储能的功率特性分析、安全性评估和机械参数优化设计等工作。

Gravity energy storage offers numerous advantages, including high safety, low cost, long lifespan, no attenuation of stored energy, short construction period, and environmental friendliness. In particular, slope gravity energy storage leverages the natural incline of mountains to reduce construction costs and minimize the use of flat land resources. The proposed technology is a promising approach for large-scale, long-term energy storage. However, slope gravity energy storage systems exhibit high coupling between mechanical and electrical dynamics, and the existing simulation model makes it challenging to fully describe their dynamic characteristics. To address this issue, this study introduces a multi-software collaborative modeling approach for the mechanical and electrical co-simulation of slope gravity energy storage systems. First, a mechanical system frame model, including the slope, track, load car, and mass block, was constructed using Solidworks, a three-dimensional mechanical design software. The model from Solidworks is then imported into the multi-body dynamics simulation software Adams, where the connection between the load car and the chain transmission mechanism is established, resulting in a complete mechanical system model. Finally, the mechanical model from Adams was imported into Simulink, where it was integrated with the electrical model to obtain a mechanical-electrical joint simulation model. The proposed multi-software co-simulation model was compared with an independent Simulink simulation model under normal and abnormal power grid conditions. The results indicate that the multi-software co-simulation model provides a more comprehensive description of the dynamic characteristics of slope gravity energy storage systems. Consequently, this model can better support the power characteristic analysis, safety evaluation, and mechanical parameter optimization design of slope gravity energy storage.

重力储能系统(GESS)因其长时、大容量、零自放电率、安全性高等优点受到广泛关注，而能效水平是影响GESS规模化推广应用的重要因素。首先，针对基于带传动的垂直式GESS，分析机械环节中动/定滑轮相对于轴承表面的滑动摩擦、曳引系统的球轴承摩擦、传动带相对于带轮的弹性滑动摩擦及电气环节中电机的铜耗、铁耗、风摩耗、杂散损耗，推导了系统各环节效率及损耗的理论计算方法。其次，针对所提理论计算方法设计了算例，算例结果表明，机械环节效率随质量块质量增加而略有减小；系统充电效率随质量块质量增加而先增加后减小；系统放电效率随质量块质量增加而增加；放电工况下，系统机械损耗占比与充电工况相比明显增加。最后，通过搭建1.1 kW样机对算例结果进行实验验证，实验结果表明，当质量块为127.35 kg时，充、放电状态下电机损耗实测占比分别为82.77%和72.42%，与算例得到的电机损耗理论占比80.56%和72.96%较为接近，且系统充、放电效率随质量块质量的理论变化曲线与实测曲线趋势相同，验证了所提能效分析方法的正确性和实用性。

The gravity energy storage system (GESS) has attracted extensive attention owing to its long-term operation, large capacity, zero self-discharge rate, and high safety. The energy efficiency level is a critical factor affecting the large-scale application of GESS. Firstly, for the vertical GESS based on belt drive, the sliding friction of the moving/fixed pulley relative to the bearing surface in the mechanical link, the ball bearing friction in the traction system, the elastic sliding friction of the drive belt relative to the pulley, and the copper loss, iron loss, wind friction, and stray loss of the motor in the electrical link are analyzed, and the theoretical calculation method for the efficiency and loss of each link of the system is derived. Secondly, a numerical example is provided for the proposed calculation method. The results show that the efficiency of the mechanical link decreases slightly as the mass block increases; the charging efficiency of the system initially increases and then decreases with increasing mass block; the discharging efficiency increases with the mass block; and under discharging conditions, the proportion of mechanical loss in the system is significantly higher than under charging conditions. Finally, a 1.1 kW prototype is built to verify the calculation results. The experimental results show that when the mass block is 127.35 kg, the measured motor loss proportions in charging and discharging states are 82.77% and 72.42%, respectively, which are close to the theoretical values of 80.56% and 72.96% obtained from the numerical example. The theoretical variation curve of the system's charging and discharging efficiencies with respect to the mass block exhibits the same trend as the measured curve, which verifies the correctness and practicability of the proposed energy efficiency analysis method.

抽水蓄能电站运行可靠灵活，能对负荷的急剧变化做出快速反应。但以往抽蓄电站运行时，负荷在机组间的分配通常未考虑各机组间运行特性的差异，使得运行时能耗增加。针对该问题，本工作考虑能量平衡约束和抽蓄机组运行约束，建立以抽蓄系统整体效率最优为目标的双层优化模型。上层模型主要优化抽蓄系统在电网中的调度模式以及为下层模型提供功率指令。下层模型主要依据水轮机效率与水泵效率差异，对负荷的功率需求在机组之间进行合理分配，以满足实际电网需求。算例结果表明，本工作所提策略有效提升了抽蓄系统运行效率，提高了抽蓄电站的经济效益。

The pumped storage power plant is reliable and flexible, with the ability to adapt swiftly to load changes. When the storage station was previously operational, the load distribution between units did not always take into account the differences in operation characteristics between the units, which resulted in higher energy consumption during operation. For this issue, this study considers energy balance and unit operation constraints and develops a two-layer optimization model with the optimal overall efficiency of the extraction and storage system. The top model primarily optimizes the grids storage system scheduling mode and gives power instructions to the bottom model. The lower model is mostly based on the difference in water turbine and water pump efficiency, and the loads power requirement should be evenly divided among the units to match the real power grid requirement. The results demonstrate that the proposed strategy effectively promotes the operation and economic efficiencies of the storage station.

储能是建设以新能源为主体的新型电力系统的重要支撑技术，对实现“碳达峰碳中和”目标具有重要意义。铁轨重力储能属于物理储能，具有规模大、成本低、效率高、环境友好以及无自放电等优势，应用前景广阔。本工作基于MATLAB/Simulink搭建了铁轨重力储能系统模型，分析了系统各个部件在储能过程和释能过程中的能量损耗情况，研究了载重车辆质量、车辆速度、斜坡坡度、斜坡高度和滚动摩擦系数等因素对系统效率的影响及其变化规律。研究结果表明，车辆速度、斜坡坡度、斜坡高度和滚动摩擦系数对系统效率的影响十分显著，降低速度和滚动摩擦系数以及适当增加坡度和高度，可有效提高系统效率；在设计工况下，载重车辆160 t、车速20 km/h、斜坡高度200 m、斜坡坡度7°、滚动摩擦系数0.006，对应系统的输出功率为1.04 MW，系统效率达76.20%。

Energy storage is an important supporting technology for constructing a new power system with new energy as the main body, which is of great significance to achieving the goal of carbon peak and carbon neutrality. Rail gravity energy storage belongs to physical energy storage, which has the advantages of large scale, low cost, high efficiency, eco-friendly, and no self-discharge, resulting in broad application prospects. In this study, a rail gravity energy storage system model was built based on MATLAB/Simulink, and the energy loss of each component of the system in the energy storage and energy release processes were analyzed. The influence of factors such as the mass of the vehicle, the speed of the vehicle, the inclination of the slope, the height of the slope, and the rolling friction coefficient on the system efficiency and their variation rules were studied. These factors significantly reduce the speed and rolling friction coefficient, and increase the slope and height appropriately, resulting in an efficient system. Under these design conditions, the load vehicle of 160 t the speed of 20 km/h, the slope of 200 m, the slope of 7°, and the rolling friction coefficient of 0.006 was achieved. The corresponding system output power and efficiency are 1.04 MW and 76.20%, respectively.

The basic requirements for the grid connection of the generator motor of the gravity energy storage system are: the phase sequence, frequency, amplitude, and phase of the voltage at the generator end and the grid end must be consistent. However, in actual working conditions, there will always be errors in the voltage indicators of the generator and grid terminals, resulting in transient impulse currents. In addition, due to the difference between gravity energy storage systems and conventional power generation units, frequent switching between charging and discharging operating conditions is required according to the needs of the power grid. Each switching requires the completion of the generator motor startup and grid connection. If there is always a significant error in the voltage indicators between the generator and grid terminals during frequent grid connection, stable transient surge currents will be generated. Without human intervention, long-term operation will bring hidden dangers to the safety of the grid connected system, leading to a series of consequences such as equipment aging and even damage. In response to the above issues, this article establishes a gravity energy storage power generation/motor grid connection model. Through simulation analysis, the variation law of the weight of the impact of different terminal voltage indicators on the grid connected transient impulse current is summarized. A grid connection method for gravity energy storage systems based on sensitivity analysis of voltage grid connection indicators is proposed. Through simulation verification, this method can significantly reduce the grid connected transient impulse current while improving the success rate of grid connection, The correctness and practicality of the proposed method have been fully verified.

框架式重力储能系统不受地理条件的限制，便于进行规模化的扩展和应用，是实现重力储能未来大规模商业应用的一种有效方式，逐渐受到人们的重视。基于对框架式重力储能系统的结构组成分析和成本计算，对框架式重力储能系统的经济性进行了分析，得到了不同系统容量的框架式重力储能系统的投资成本和平准化储能度电成本，可为框架式重力储能系统的项目建设和运营提供参考。

Frame gravity energy storage system is not limited by geographical conditions, easy to scale expansion and application, is an effective way to achieve large-scale commercial applications of gravity energy storage in the future, and gradually received people's attention. Based on the structural composition analysis and cost calculation of the frame gravity energy storage system, the economy of the frame gravity energy storage system is analyzed, and the investment cost and the quasi energy storage power cost of the frame gravity energy storage system with different system capacities are obtained, which can provide references for the construction and operation of the frame gravity energy storage system.