考虑爬坡功率有限平抑的高渗透率光伏电网储能配置策略

随着光伏发电渗透率的提高,电网需有较大调频备用容量应对光伏功率的随机大幅波动。储能系统(ESS)的快速充放电能力能够对光伏发电出力的大幅波动进行快速平抑,以减小电网调频所需备用容量。但目前储能成本相对较高,无法完全依赖储能来应对光伏功率的大幅度爬坡。为此,文中首先提出了利用有限容量的储能实现光伏爬坡功率有限平抑的控制策略,对光伏出力大幅度波动进行有效平抑。然后,考虑电网调频容量需求与储能配置容量的相互制约关系,建立了ESS投入后调频成本计算的数学模型,并以等效收益最大为优化目标实现ESS能量容量和功率容量的优化配置。最后,利用遗传算法对优化模型进行求解,并通过某高渗透率光伏电网验证了该方法的有效性。

Capacity Optimization Strategy of Energy Storage System for Power Grid with High Penetration of Photovoltaic Considering Limited Smoothing of Photovoltaic Ramping Power

With the increase of photovoltaic(PV)penetration, the power grid needs a large capacity of regulation reserve to cope with the large random fluctuation of PV power. The energy storage system(ESS)can easily deal with the large fluctuation of PV power due to its fast charging and discharging capability, which can reduce the reserve capacity needed for frequency regulation. However, ESS cannot be used to cope with the PV power fluctuation independently owing to its high price. Therefore, this paper proposes a new strategy which uses limited ESS to smooth PV ramping power, to effectively suppress large fluctuations of PV output. Considering the restriction relation between regulating reserve and energy storage capacity, a mathematical model is developed for the calculation of frequency regulation costs after applying ESS. And the energy capacity and power capacity of ESS are optimally configured with the goal of maximizing equivalent return. Finally, the genetic algorithm(GA)is used to solve the optimization model, and simulation results based on a power grid with high penetration of PV are presented to verify the effectiveness of the proposed method.