基于VSG的光伏发电系统建模与仿真研究

Research on Modeling and Simulation of Photovoltaic Generation System Based on VSG

光伏发电往往通过电力电子接口接入电网,使得系统面临频率和电压稳定性等方面的挑战。结合光伏发电的输出特性,提出了一种基于虚拟同步发电机(VSG)的光伏发电系统变流器控制策略。首先,综合光伏阵列、升压电路、脉冲宽度调制和最大功率跟踪控制模块,搭建了光伏发电系统的仿真模型。其次,基于传统同步发电机运行机制,提出了有功频率控制和无功电压控制方法,实现了有功功率控制和调频调压的双重功能,完成了光伏发电系统的运行控制。最后,分析了不同光照强度和不同温度下光伏阵列的输出特性,并在负荷功率扰动条件下,开展了系统的直流侧逆变电压、虚拟同步发电机输出有功功率和系统频率等特性研究。通过MATLAB/Simulink,验证了虚拟同步发电机思想及控制方法的正确性和有效性。

Photovoltaic power generation is normally connected to the grid through power electronic interface,which makes the system face the challenges of frequency and voltage stability.According to the output characteristics of photovoltaic power generation,a new inverter control strategy based on virtual synchronous generator(VSG)for photovoltaic power generation system is presented.Firstly,the simulation model of the photovoltaic power generation system is established by integrating photovoltaic array、BOOST circuit、pulse width modulation(PWM)and maximum power tracking control modules.Secondly,the active power frequency control method and the reactive power voltage control method are proposed based on operating mechanism of the traditional synchronous generator,the dual functions of active power control and frequency/voltage modulation are realized;and the operation control of the photovoltaic power generation system is completed.Finally,the output characteristics of photovoltaic array under different light intensity and temperature are analyzed;and under the condition of load power disturbance,the characteristics of DC-side inverter voltage,virtual synchronous generator output active power and system frequency are studied.The validity and effectiveness of the proposed control strategy are verified by the simulation results based on simulation platform of MATLAB/Simulink.