一种平抑光伏系统输出波动的储能容量优化方法

为了平抑含光伏系统的输出功率波动,提出了一种基于离散傅里叶变换(Discrete Fourier Transform,DFT)的储能容量优化方法。该方法针对光伏发电特性和储能充放电时间响应特性,利用DFT对光电输出功率偏差进行频谱分析,在不同的时间范围内,采取不同的控制机制,调用相应不同类型的控制容量以补偿功率偏差。基于频谱分析结果,结合储能系统的经济性,确定储能系统最优容量。计算结果表明,所提方法能够以较小的储能容量将光伏发电预测均方根误差RMSE由2.2994%~10.0832%降低至0,大幅减小了光伏系统对电网的冲击和系统备用容量需求,提高了电网对光伏发电的接纳能力。

A capacity optimization of energy storage system for output smoothing of photovoltaic station

A capacity optimization of energy storage system based on discrete Fourier transform is presented to inhibit the adverse effects of photovoltaic power generation fluctuations. The method takes into account the characteristics of photovoltaic power generation and charge-discharge response time properties of energy storage system. The spectrum analysis results of photovoltaic power generation fluctuations are obtained through DFT. In different time periods, to compensate the power deviation, different control mechanisms and control capacity are in use. Based on the spectrum analysis results and combined with the economics, a capacity optimization of energy storage system can be determined. Results indicate that the root mean square error (RMSE) of photovoltaic power prediction can be reduced from 2.2994%~10.0832% to 0 by a relatively small capacity of energy storage system determined by the presented method. The method could sharply relieve the impact of photovoltaic power generation on the grid, reduce system reserve capacity requirements, and enlarge the space to accommodate photovoltaic power.