摘要
随着分布式能源的渗透率的提升,电网变得越来越弱。考虑到弱电网下并网逆变器接入点的等效电网阻抗往往随着线路阻抗、并网机组数量、负载以及系统运行方式等因素的变化而发生变化,因此针对目前2类主要的逆变器并网控制模式,即电流源模式(CSM)和电压源模式(VSM),从功率传输的单调性和阻尼特性与电网阻抗大小之间的关系出发,推导了CSM和VSM这2种模式的电网阻抗稳定运行边界,由此提出弱电网下基于电网阻抗自适应的双模式并网稳定控制策略:当电网阻抗较小时,逆变器在CSM下运行,而当电网阻抗较大时,逆变器切换到VSM下运行,使逆变器在更宽的电网阻抗变化范围内稳定运行。同时,提出CSM和VSM这2种模式之间的无扰动切换方案,并通过实验验证了上述分析的有效性和所提控制策略的可行性。
As the penetration rate of distributed energy increases,the grid becomes weaker and weaker.Considering that the equivalent grid impedance of the grid-connected inverter access point in a weak grid tends to be changed by some factors,such as the line impedance,number of grid-connected inverters,loads,and the system operation mode,etc.It is aimed at the two main types of the inverter grid-connected control mode,i.e.current source mode(CSM)and voltage source mode(VSM),from the relationship between monotonicity and damping characteristics of power transmission and grid impedance,the grid impedance stable operation boundary of CSM and VSM modes is derived in this paper.The grid impedance adaptation dual mode grid-connected stability control strategy in a weak grid is proposed.when the grid impedance is small,the inverter operates at CSM,and when the grid impedance is large,the inverter switches to operate at VSM,it will make the inverter operating stably over a wider range of grid impedance variations.A seamless switching scheme between CSM and VSM is also proposed in this paper,and the effectiveness of the above analysis and the feasibility of the proposed control strategy are verified by experiment.
作者
李明
张兴
郭梓暄
刘晓玺
陈巧地
马铭遥
Li Ming;Zhang Xing;Guo Zixuan;Liu Xiaoxi;Chen Qiaodi;Ma Mingyao(National and Local Joint Engineering Laboratory for Renewable Energy Access to Grid Technology,School of Electrical Engineering and Automation,Hefei University of Technology,Hefei 230009,China)
出处
《太阳能学报》
EI
CAS
CSCD
北大核心
2021年第7期86-93,共8页
Acta Energiae Solaris Sinica
基金
国家电网有限公司总部科技项目资助(《县级可再生能源独立供电系统接入弱电网的稳定性控制技术研究》)。
关键词
自适应控制系统
阻尼
稳定性
弱电网
并网逆变器
adaptive control system
damping
stability
weak grid
grid-connected inverter
