摘要
随着非同步机电源在电网中的占比越来越大,有别于传统功角振荡的电网谐振不稳定问题逐渐显现。为此,文中提出了一种基于s域节点导纳矩阵的网络谐振分析方法,用以分析及抑制含非同步机电源电力系统的谐振问题。首先,介绍了两种非同步机电源的s域阻抗建模方法--小干扰线性化法和测试信号法,重点考虑了内环控制器和锁相环的影响。然后,给出了一套基于s域节点导纳矩阵的网络谐振结构分析方法,并提出了两个描述谐振模式的特征指标,用以确定其主要影响区域和敏感元件参数。最后,以某风电场并网系统为例,对该系统的谐振结构进行了分析,并针对其存在的谐振问题提出了相应的改善措施。分析表明,由于电力电子装置的负电阻效应,含非同步机电源的电力系统确实存在谐振不稳定的风险,需要加以抑制。
With the ever-increasing of unconventional generators in power system,the electrical network resonance instability problems gradually emerge,which is different from the conventional power-angle oscillation.For investigating and suppressing those problems,this paper proposes a resonance analysis method based on the s-domain nodal admittance matrix.Firstly,to describe the unconventional generator,two approaches to establish its s-domain impedance model are introduced,i.e.,the small-disturbance linearization method and the test-signal method.Specially,the inner-loop controller and the phase-locked loop(PLL)are considered in the modelling.Then,based on the s-domain nodal admittance matrix,the resonance structure analysis method of electrical network is proposed.Besides,two indices to determine the main influence area and the sensitive component parameters of the resonant mode are provided.Finally,the above details are illustrated in a wind farm integration system,whose resonance structure is analyzed and the corresponding suppression strategy for the unstable resonant mode is proposed.The analysis indicates that the power system with unconventional generators do have the risk of unstable resonance and need to be suppressed,due to the negative resistance effect of power electronic devices.
作者
邢法财
徐政
王世佳
XING Facai;XU Zheng;WANG Shijia(College of Electrical Engineering, Zhejiang University, Hangzhou 310027, China)
出处
《电力系统自动化》
EI
CSCD
北大核心
2019年第15期71-79,共9页
Automation of Electric Power Systems
基金
国家电网公司科技项目“复杂电网下新能源发电基地次/超同步振荡评估、抑制与防控技术研究”(SGXJ0000TKJS1800238)~~
关键词
非同步机电源
电网谐振
s域节点导纳矩阵
小干扰线性化法
测试信号法
unconventional generator
electrical network resonance
s-domain nodal admittance matrix
small-disturbance linearization method
test-signal method
