基于广义短路比的电力电子多馈入系统小干扰概率稳定评估  

Probabilistic Stability Evaluation of Small Disturbances for Power Electronic Multi-infeed System Based on Generalized Short-circuit Ratio

作　　者：王冠中[1] 董炜[1] 辛焕海[1] 朱承治 WANG Guanzhong;DONG Wei;XIN Huanhai;ZHU Chengzhi(College of Electrical Engineering,Zhejiang University,Hangzhou 310027,China;State Grid Zhejiang Electric Power Co.Ltd.,Hangzhou 310007,China)

机构地区：[1]浙江大学电气工程学院,浙江省杭州市310027 [2]国网浙江省电力有限公司,浙江省杭州市310007

出　　处：《电力系统自动化》2018年第18期17-24,共8页Automation of Electric Power Systems

基　　金：国家重点研发计划资助项目(2017YFB0902000);国家自然科学基金资助项目(U1766206);国家电网公司科技项目(52110417000B)~~

摘　　要：广义短路比是一种反映多电力电子设备互联和交流电网强度对系统振荡影响的静态指标,可用于量化系统的小干扰稳定裕度。新能源发电功率的随机性导致多馈入系统的小干扰稳定裕度呈现出不确定性,为此,提出一种基于广义短路比的电力电子多馈入系统小干扰概率稳定裕度评估方法。首先,将额定运行条件下的广义短路比推广到适用于一般运行条件的广义运行短路比,从而能够量度电力电子设备任意输出功率时的系统小干扰稳定裕度;其次,由于广义运行短路比在数学上对应拓展导纳矩阵的最小特征值,而拓展导纳矩阵元素中包含不确定的输出功率,因此采用矩阵概率D稳定描述系统小干扰概率稳定评估问题;同时为克服在工程实践中获取输出功率准确概率分布的困难,采用期望和方差等部分概率信息来描述系统随机性,在此基础上结合广义矩理论将矩阵概率D稳定转化为易于求解的半定规划问题。最后,通过算例说明所提评估方法的有效性。The generalized short-circuit ratio is a static index which reflects the influence of the interconnection of multiple power electronic devices and the strength of AC power grid on the system oscillation,which can be used to quantify the small signal stability margin of the system.The randomness of renewable energy power generation in multi-infeed system causes the uncertainty of small-signal stability margin.Therefore,aprobabilistic stability evaluation method of small disturbances for power electronic based multi-infeed system based on generalized short-circuit ratio is proposed.Firstly,the generalized shortcircuit ratio under rated operating conditions is extended to generalized operation short-circuit ratio under general operating conditions to evaluate the small-signal stability margin when the power electronics equipment output arbitrarily power.Secondly,because of the generalized operation short-circuit ratio corresponding to the minimum eigenvalue of the admittance matrix in mathematics whose elements contain uncertain output power,the matrix probability D stability problem is used to describe the stability assessment of small disturbance probability systematically.At the same time,in order to overcome the difficulty of obtaining the accurate power output probability distribution in engineering practice,the expectation and variance of probability are used to describe the random information,based on which,the matrix probability D stability problem is transformed into semidefinite programming problem,which is easy to be solved with generalized moment theory.At last,an example is given to illustrate the effectiveness of the proposed method.

关 键 词：电力电子多馈入系统 广义短路比 小干扰稳定裕度 概率D稳定 

分 类 号：TM732[电气工程—电力系统及自动化]