一种利用混合储能系统平抑风光功率波动的控制策略

摘要

储能系统作为一种能量缓存装置，在风光储一体化发电系统中发挥着至关重要的作用。将储能的功能定位于平抑风光输出功率波动。为满足系统对功率和能量两方面的需求，利用超级电容和蓄电池两种互补元件组成混合储能系统对可再生能源出力波动进行两级平抑，提出了基于移动平均算法的控制策略，在此过程中，依据功率波动量大小及储能单元的荷电状态对移动步长进行实时优化。通过对蓄电池和超级电容的灵活、准确、快速控制，实现了风光输出功率波动的平抑，有效改善了风光出力波动引起的电能质量问题，并延长了蓄电池的循环寿命。在PSCAD/EMTDC环境下搭建系统模型，仿真验证了控制策略的有效性。%Energy storage system which works as an energy buffer plays a vital important part in hybrid wind/Photovoltaic/energy storage system. In this paper the function of energy storage system is to smooth the output curve of wind and Photovoltaic power. High power density ultra-capacitor and high energy density battery are made use of to smooth output of renewable energy with two-stage control. A control strategy based on moving average algorithm is proposed. In the process of smoothing output power,SOC level of energy storage unit and fluctuation of wind and Photovoltaic power are considered to optimize the time constant in real time. Through the swift and flexible control of energy storage system,it can realize the improvement of power quality and life extension of battery. The hybrid wind/Photovoltaic/energy storage system is simulated in the PSCAD/EMTDC software. Simulation results demonstrate the efficacy of proposed control strategy. This work is supported by Jilin Province Science & Technology Development plan item(20130206038GX).