中文摘要：

为解决光伏发电系统受光照、温度等外部环境因素影响大、输出功率波动频繁以及并网电流谐波含量大等问题，在分析光伏并网发电系统输出功率特性的基础上，提出一种基于蓄电池和超级电容复合储能的并网功率平滑控制策略。详细分析不同光照、温度环境下系统输出功率的特性及其对电网的影响，给出复合储能型光伏并网发电系统的实现方案，并提出改进的系统并网控制方法，实现系统并网功率高、低频波动分量的平滑控制。仿真结果表明：该控制策略能有效平抑系统输出功率波动，同时降低并网电流的谐波含量。

英文摘要：

PV generation systems are greatly affected by external environmental factors such as solar radiation and temperature, etc., the output power fluctuates a lot and too much harmonics may be injected into grid along with the gridconnected current. In order to solve these problems, the smoothness control strategy based on composite energy storage composed of battery and ultra-capacitor was proposed after analyzing the output power characteristics of PV generation system. The effect of output power characteristics of the system on the grid under different radiation and temperature conditions was analyzed in detail. And then the implementation scheme of grid-connected PV generation system with composite energy storage was presented, and the improved grid integration control strategy was proposed to smooth the high and low frequency fluctuations of the power injected into grid. The simulation results show that the proposed strategy can effectively suppress the system output power fluctuations, and reduce the harmonics content of grid-connected current.