摘要
提出适用于弱电强磁系统发生多回线跨电压不接地故障时的短路电流计算方法,在此基础上计算了跨电压不接地故障时短路点对地电压,分析了该电压与两系统电源电动势相角差和系统阻抗比之间的关系,得到了阻抗比不同时短路点对地电压的最大值,并与正常运行时的对地电压作对比,以评估低电压系统内过电压大小。在PSCAD软件中建模验证了短路电流计算方法和过电压计算的准确性。
A method of calculating the short circuit current under non-grounded cross-voltage fault in mixedvoltage transmission lines is proposed for strong magnetic and weak electricity system. On this basis,the voltage at fault point is calculated. Meanwhile,the relationship between this voltage and the electromotive force phase angle difference of the two systems is analyzed,likewise the relationship between this voltage and the impedance ratio. Consequently,the maximum voltages at fault point in different impedance ratios can be obtained,which enables the overvoltage evaluation in low-voltage system compared to the voltages in normal operation. Simulative results on PSCAD verify the accuracy of the proposed method for the short circuit current and over voltage calculation.
出处
《电力自动化设备》
EI
CSCD
北大核心
2018年第1期116-120,共5页
Electric Power Automation Equipment
基金
国家重点基础研究发展计划(973计划)项目(2012-CB215206)
中央高校基本科研费专项资金资助项目(2015XS-12)~~
关键词
混压同塔
跨电压故障
复合序网图
过电压
阻抗比
mixed-voltage on same tower
cross-voltage fault
composite sequence-network
overvoltage
impedance ratio
