高比例电力电子电力系统过电压(二):交流对称故障下暂时工频过电压机理  

Overvoltage of the Power System Integrated With High Proportion of Power Electronics Equipment(Ⅱ):Mechanistic Analysis of Transient Power Frequency Overvoltage Caused by AC Symmetrical Fault

作　　者：徐式蕴 孙华东 王姝彦 王晶 毕经天 XU Shiyun;SUN Huadong;WANG Shuyan;WANG Jing;BI Jingtian(China Electric Power Research Institute,Haidian District,Beijing 100192,China;National Power Dispatching and Control Center,Xicheng District,Beijing 100052,China)

机构地区：[1]中国电力科学研究院有限公司,北京市海淀区100192 [2]国家电力调度控制中心,北京市西城区100052

出　　处：《中国电机工程学报》2024年第5期1701-1711,I0003,共12页Proceedings of the CSEE

基　　金：国家自然科学基金项目(51977197,U2166601,51907179)。

摘　　要：随着新能源等电力电子设备占比的不断提升,故障扰动后引发的系统暂时工频过电压问题日渐凸显,严重时易引发新能源大规模脱网,威胁电网安全稳定运行。新能源发电设备的故障穿越特性直接影响过电压水平,亟需进行机理分析。该文首先分析交流对称故障下高比例电力电子电力系统过电压的引发原因,建立计及新能源故障穿越特性的过电压简化分析模型,并基于矢量关系解析三相短路故障后新能源机端过电压最大值;然后分析不同故障穿越策略和系统参数对新能源机端电压最大值的影响;提出防止新能源大规模脱网的故障穿越等效无功电流系数的取值区间,进一步综合考虑新能源故障期间的无功支撑要求和故障清除后的电压安全约束,分析不同系统强度下等效无功电流系数的合理取值区间;最后通过时域仿真验证理论分析的有效性。With the growing penetration of renewable energy sources,the problem of transient power frequency overvoltage caused by disturbance has become increasingly serious,which may lead to a large-scale off-grid accident of renewable energy sources and threat the operation of the grid.The low voltage ride through(LVRT) characteristics of the renewable energy sources directly affect the overvoltage level.There is an urgent need for in-depth research on overvoltage mechanism.This paper first analyzes the reason of overvoltage of high renewable penetration power system caused by AC symmetrical fault.Then a simplified model for analysis considering LVRT strategy of renewable energy sources is introduced.Further,after three-phase short-circuit fault clearance,the maximum overvoltage of the renewable energy source terminal is analyzed based on the vector relationship.Moreover,the influence of different LVRT strategy and system parameters on voltage rise is analyzed.Next,equivalent reactive current coefficient ranges avoiding off-grid accident are derived.Considering both reactive power support requirements of renewable energy during the fault and voltage safety constraints of renewable energy after fault clearance,the reasonable value ranges of the equivalent reactive current coefficient under different system strengths are analyzed.Finally,the time domain simulation is used to verify the validity of the theoretical analysis.

关 键 词：高比例电力电子电力系统 暂时工频过电压 机理分析 低电压穿越控制 

分 类 号：TM721[电气工程—电力系统及自动化]