基于虚拟同步发电机控制策略的风光并网技术

Technology of Wind and Photovoltaic Power Connected to Grid Based on Virtual Synchronous Generator

以风电、光伏为代表的分布式能源需要依靠并网逆变器接入电网。随着分布式新能源在电网中的渗透率不断攀升,逆变器低惯量和欠阻尼等缺陷愈发明显,稳定性问题愈发严重。虚拟同步发电机(Virtual Synchronous Generator,VSG)技术借鉴了同步发电机运行机制,将其融合到电力电子逆变器控制策略中,提高了电力系统的稳定性。借助虚拟同步机技术,介绍了风力虚拟同步机(Wind Power VSG,WP-VSG)和光伏虚拟同步机(Photovoltaic VSG,PV-VSG)结构及其动态性能。在MATLAB/Simulink仿真软件中的仿真试验验证了PV-VSG结构及相应控制策略,证明了在光伏出力波动时能为微电网提供频率支撑。

The distributed energy,represented by wind power and photovoltaic power,needs to be connected to the power grid by grid connected inverters. With the increasing penetration of distributed new energy in the power grid,the defects of inverters,including low inertia and weak damping,become more and more obvious,and the stability problem appear more and more serious. Virtual synchronous generator （VSG） technology is referred to the synchronous generator operation mechanism,and it is integrated into the power electronic inverter control strategy,which improves the stability of the power system. In this paper,with the help of virtual synchronization technology,the structure and dynamic performance of wind power VSG （WP-VSG） and photovoltaic VSG （PV-VSG） were introduced. The simulation experiment in MATLAB/Simulink simulation software verified the PV-VSG structure and corresponding control strategies. Andit was proved that it could provide frequency support for the micro grid when photovoltaic output had fluctuated.