摘要
模拟同步发电机特性的分布式发电系统对大电网呈友好特性,然而,虚拟同步发电机(VSG)在并网瞬间可能存在较大冲击电流。为此,文中提出一种基于虚拟功率和电压频率二次控制的预同步单元,实现VSG离网和并网间的无缝切换。在此基础上,详细分析了惯性、阻尼和调差系数对功频调节特性的影响。仿真和实验结果表明:所提出的预同步控制能实现VSG不同模式之间的平滑切换,且与传统预同步控制相比,控制简单;同时,所研究控制策略具有较好的有功功率、无功功率跟踪性能。
The distributed power generation system simulating the characteristics of synchronous generators is grid-friendly to the large power grid.However,a large dash current may be generated at the instant the virtual synchronous generator（VSG）is connected to the grid.This paper proposes a pre-synchronization unit based on the virtual power and the secondary frequency and voltage regulation to achieve seamless transform between the off-disconnection and grid-connection of VSG.Accordingly,the influence of inertia,damping and droop coefficients on the frequency regulation characteristics is analyzed in detail.Simulation and experimental results show that the proposed pre-synchronization control is able to achieve seamless transform between different VSG modes,which is simpler than the conventional pre-synchronization control,while having agood active and reactive power tracking performance.
出处
《电力系统自动化》
EI
CSCD
北大核心
2016年第12期124-129,178,共7页
Automation of Electric Power Systems
基金
国家自然科学基金资助项目(51277150)
陕西省工业公关项目(2013K07-05)
陕西省教育厅产业化培育项目(14JF020)~~
关键词
虚拟同步发电机
二次调频
二次调压
并网逆变器
虚拟功率
预同步
virtual synchronous generator（VSG）
secondary frequency regulation
secondary voltage regulation
grid connected inverter
virtual power
pre-synchronization
