摘要
虚拟同步发电机(VSG)控制的并网逆变器在电网电压跌落时存在功角暂态失稳及过电流现象,为此提出一种VSG暂态控制策略。根据VSG功角特性,推导出有功功率与功角暂态稳定性之间的联系,并基于VSG暂态电流特性,分析VSG无功动态响应特性与暂态功角变化的关系。在此基础上,以角频率偏差、有功功率偏差及有功功率偏差变化率三者的正负作为功角特性曲线的区间划分依据,设计出有功功率偏差系数分段自适应调节策略,通过控制有功功率偏差抑制功角增大,并对VSG输出过电流进行抑制,基于等面积准则证明了VSG的暂态稳定性。仿真分析结果表明,采用所提控制策略能够有效消除VSG控制并网逆变器的功角暂态失稳及过电流现象,且无论暂态期间是否存在稳定运行平衡点,所提策略均可确保VSG功角稳定。
The virtual synchronous generator(VSG)controlled grid-connected inverter exhibits transient instability and overcurrent phenomena during grid voltage drops.Therefore,a transient control strategy for VSG was proposed.According to the active power angle characteristics of VSG,the relationship between active power and transient angle stability was derived.Based on the transient current characteristics of VSG,the relationship between the dynamic response characteristics of VSG reactive power and the change of transient power angle was analyzed.On this basis,taking the positive and negative of angular frequency deviation,active power deviation and change rate of active power deviation as the interval division basis of the power angle characteristic curve,a piecewise adaptive adjustment strategy for the active power deviation coefficient was designed.By controlling the active power deviation,the increase of power angle is suppressed,and the output overcurrent of VSG is suppressed.The transient stability of VSG is proved based on the equal area criterion.Simulation results indicate that the proposed control strategy effectively eliminates the transient instability and overcurrent phenomena of the grid-connected inverter controlled by VSG.Furthermore,regardless of the presence of a stable operating equilibrium point during the transient period,the proposed strategy ensures stability of the VSG power angle.
作者
张赟宁
谢永辉
张磊
蔡明磊
ZHANG Yunning;XIE Yonghui;ZHANG Lei;CAI Minglei(School of Electrical and New Energy,China Three Gorges University,Yichang 443002,China;Hubei Provincial Engineering Research Center of Intelligent Energy Technology,China Three Gorges University,Yichang 443002,China;Nanping Power Supply Company,State Grid Fujian Electric Power Co.,Ltd.,Nanping 353000,China)
出处
《电机与控制学报》
EI
CSCD
北大核心
2024年第8期104-114,共11页
Electric Machines and Control
基金
国家自然科学基金(52007103)。
关键词
并网逆变器
虚拟同步发电机
暂态稳定
电网电压跌落
过电流抑制
自适应调节
grid-connected inverter
virtual synchronous generator
transient stability
grid voltage sag
overcurrent suppression
adaptive regulation
