| 引用本文: | 刘欣,黄少锋,张鹏,郑涛.混压同塔线路跨电压不接地短路时低压系统过电压计算[J].电力自动化设备,2018,(1): |
| LIU Xin,HUANG Shaofeng,ZHANG Peng,ZHENG Tao.Overvoltage calculation of low-voltage system for mixed-voltage on same tower transmission lines under unearthed cross-voltage fault[J].Electric Power Automation Equipment,2018,(1): |
|
| 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。 |
| 关键词: 混压同塔 跨电压故障 复合序网图 过电压 阻抗比 |
| DOI：10.16081/j.issn.1006-6047.2018.01.017 |
| 分类号:TM713 |
| 基金项目: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) |
|
| Overvoltage calculation of low-voltage system for mixed-voltage on same tower transmission lines under unearthed cross-voltage fault |
|
LIU Xin1,2, HUANG Shaofeng2, ZHANG Peng3, ZHENG Tao2
|
|
1.Electric Power Planning & Engineering Institute, Beijing 100120, China;2.State Key Laboratory of Alternate Electric Power System with Renewable Energy Sources, North China Electric Power University, Beijing 102206, China;3.State Gird DC Power Construction Branch Company, Beijing 100052, China
|
| Abstract: |
| A method of calculating the short circuit current under non-grounded cross-voltage fault in mixed-voltage 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. |
| Key words: mixed-voltage on same tower cross-voltage fault composite sequence-network overvoltage impedance ratio |
