一种基于虚拟同步发电机的光储发电系统能量管理控制策略
A Management Control Strategy of Photovoltaic-storage System Based on Virtual Synchronous Generator
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摘要: 光伏微网是一种重要的可再生能源接纳方式,然而由于光伏电源输出波动性强以及缺乏惯性等问题,给微网运行带来了巨大的压力。为提高微网的运行稳定性和供电可靠性,在光伏电源侧配置储能,与受VSG控制的逆变器组成光储发电系统。设计了一种基于VSG的光储系统能量管理控制策略,对系统进行协调控制。控制的核心在于将光伏出力和储能荷电状态信息引入到VSG控制中,通过改变斜率和平移曲线的方式调整VSG的下垂特性,使光储系统根据运行状况主动改变功频输出和光能摄入,从而将储能荷电状态控制在安全范围内。最终实现光储系统的无互联信号自治管理及对微网运行的主动支撑。通过Matlab/Simulink工具搭建了仿真模型,对相关分析和所提方案进行了系统仿真和方法验证。Abstract: Photovoltaic microgrid is an important integration way for renewable energy resources. However, such issues as strong fluctuation output of photovoltaic generators and lacking inertia have brought tremendous pressure on microgrid operation. In order to improve the operation stability and reliability of microgrid, a photovoltaic-storage system is formed by energy storage equipped at the photovoltaic generator side and an inverter controlled by virtual synchronous generator (VSG). Based on VSG, a management control strategy is designed for photovoltaic-storage system to coordinate and control the system. The core of control is to introduce such information as photovoltaic power output and the state of charge of storage equipment into VSG control. Then the droop characteristic of VSG is regulated by way of changing slope and shifting curve. According to the operation condition, photovoltaic-storage system would automatically changes the power and frequency output as well as the input of photovoltaic power. Thus the state of charge of storage equipment is controlled within a safe range. In the end, an autonomous wireless control of photovoltaic-storage system and the active support for microgrid are realized. Relevant theoretical analysis and proposed scheme is verified by the simulation system built with Matlab/Simulink tool.