光储系统并网功率波动平抑及储能优化配置

Grid-Connected Power Fluctuation Suppression and Energy Storage Optimization Configuration of Photovoltaic-Energy Storage System

【目的】电池储能是保证光伏发电系统可靠性、提高光伏发电利用率的有效手段之一,但在光储电站中存在功率波动平抑难、储能容量配置不合理等问题,为解决这些问题,开展了相关研究。【方法】针对能量型电池储能,分析了调度模式和自主模式特性,提出了一种基于储能运行在调度模式的光储系统限功率平抑策略,以实现功率平抑和减少储能充放电频繁切换。建立了以最小光储系统弃电损失为优化目标,以功率波动越限概率等作为约束条件的优化模型,并利用算法对储能配置进行求解和优化。以西藏朗明桑珠孜50 MW光储电站为例,验证了所提平抑策略的有效性。【结果】所提平抑策略在不增加储能充放电切换次数的前提下,将光储系统并网功率波动越限概率由25.64%降至6.41%,且并网功率波动越限概率为5%时,该50 MW并网光伏电站储能系统最优配置为14.5 MW/94 MW·h。【结论】所提抑策略及储能优化配置方法可为并网光储电站优化设计和运行提供技术参考。

[Objectives]Battery energy storage system is one of the effective means to ensure the reliability of photovoltaic(PV)power generation system and improve the utilization rate of PV power generation.However,there are some problems in the PV-energy storage power station,such as the difficulty of power fluctuation suppression and the unreasonable configuration of energy storage capacity.In order to solve these problems,relevant research was carried out.[Methods]For energy-based battery energy storage,the characteristics of scheduling mode and autonomous mode were analyzed,and a power-limited suppression strategy of PV-energy storage system based on energy storage operation in scheduling mode was proposed to realize power suppression and reduce the frequency of energy storage charge/discharge switching.The optimization objective of minimizing abandoned power losses in the PV-energy storage system was established,with constraints such as the probability of power fluctuation exceeding the limit.An algorithm was used to solve and optimize the energy storage configuration.Taking the 50 MW Sangzhuzi PV-energy storage power station in Langming,Tibet as an example,the effectiveness of the proposed grid-connected power suppression strategy was validated.[Results]The proposed grid-connected power suppression strategy can reduce the probability of power fluctuation exceeding the limit from 25.64%to 6.41%without increasing the frequency of energy storage charge/discharge switching.When the probability of grid-connected power fluctuation exceeding the limit is 5%,the optimal configuration for the energy storage system of the power station is determined to be 14.5 MW/94 MW⋅h.[Conclusions]The proposed power fluctuation suppression strategy and energy storage optimization configuration method can provide technical reference for the optimal design and operation of grid-connected PV-energy storage system.