1时域场路耦合计算原理.doc

GIC频率变化对变压器偏磁程度的影响* 方 舟1，王泽忠1，潘 超2，闫 磊3，赵莉莉3，郭若颖4 (1.华北电力大学高电压与电磁兼容北京市重点实验室，北京 102206 2.东北电力大学，吉林 吉林，132012 3.山西朔州供电公司，山西 朔州 036002 4.山西太原供电公司，山西 太原 030012) 摘要：近年来随着我国电网电压等级的升高，电网规模的扩大，地磁活动引起的电网异常现象引起了人们的关注。对于频率一般为0.1Hz到0.001Hz的地磁感应电流，电网计算模型采用直流等效原则，即地面感应电势等效为直流电源，系统元件等效为电阻，忽略电感。但地磁感应电流频率的变化影响变压器的偏磁程度，从而影响地磁感应电流计算的精确度。采用时域场路耦合法，建立变压器模型，利用磁场模型计算动态电感，电路模型求解电流，分析不同频率下变压器动态电感和励磁电流的数值波形，确定其偏磁程度。结果表明，当中性点之间的地面感应电势(ESP)一定时，频率为0.1Hz到0.002Hz时变压器并未饱和，GIC若按照直流计算存在不同程度的误差，频率越低误差越小；频率低于0.002Hz时变压器饱和，可按直流进行计算。 关键字：变压器，偏磁，地磁感应电流，频率，时域场路耦合 中图分类号：TM406 文献标识码：A 文章编号：1001-1390（2014）00-0000-00 Effects of GIC’s Frequency Variation on the Transformer Bias FANG Zhou1, WANG Ze-zhong1, PAN Chao2, YAN Lei3, ZHAO Li-li3, GUO Ruo-ying4 (1. Key Laboratory of High Voltage EMC, North China Electric Power University, Beijing 102206, China. 2. Northeast Dianli University, Jilin 132012, Jilin, China. 3. Shanxi Province Electric Power Co. Shuozhou Branch, Shuozhou 036002, Shanxi, China. 4. Shanxi Province Electric Power Co. Taiyuan Branch, Taiyuan 030012, China) Abstract: Recently as power grid voltage level rises in China and with the expansion of the grid, the problems some abnormal phenomena of the power grid such as transformer noise caused by geomagnetic induced current activities have aroused great concern. Owing to As for the frequency of the geomagnetic induced current (GIC) whose general frequency ranging generally ranges from 1Hz to 0.001Hz, the grid computing model usually uses adopts DC equivalent principles, namely the earth surface potential (ESP) being equivalent to the DC power supply, system components modeled as being equivalent to resistors, and inductors inductance being ignored. But the frequency variation of GIC effects affects the transformer bias and thereby affects the accuracy of the GIC calculation. With the time domain field circuit coupled coupling as the method, we use a transformer model was built, the dynamic inductance was calculated by the magnetic mod