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 %.