Solar activity and transformer failures in the Greek national electric grid
Solar activity and transformer failures in the Greek national electric grid
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太阳活动和希腊国家电网变压器故障
DOI：
10.1051/swsc/2013055
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发表时间：
2013
影响因子：
3.3
通讯作者：
I. P. Zois
中科院分区：
文献类型：
--
作者：
I. P. Zois
目标：我们研究太阳活动对希腊国家电网大型变压器（150 kV 和 400 kV）的短期和长期影响。方法：我们使用数据分析和各种统计方法和模型。结果：与 PPC 希腊的普遍看法相反，我们发现太阳活动对希腊这样的中纬度国家的大型变压器产生了相当大的短期（即时）和长期影响。我们的结果可概括如下： 对于短期影响：1989-2010 年期间，有 43 个“暴风雨天”（即 Ap ≥ 100 的日子），在暴风雨天正负 3 天期间发生了 19 起故障，在暴风雨天正负 7 天期间发生了 51 起故障。所有这些故障都可能与地磁感应电流 (GIC) 直接相关。简要介绍了明确的案例。对于 1989 年至 2010 年同一时期的长期影响，我们有两个主要结果： 每年变压器故障的数量似乎遵循太阳活动模式。然而，变压器故障的最多数量发生在太阳活动最大之后的大约半个太阳周期。使用各种新定义的长期太阳活动指数表示的太阳活动与每年变压器故障数量之间存在统计相关性。这些新的长期太阳活动指数是使用本地（来自希腊地磁站）和全球（行星平均值）地磁数据定义的。应用线性和非线性统计回归，我们计算回归方程和相应的确定系数。
Aims: We study both the short term and long term effects of solar activity on the large transformers (150 kV and 400 kV) of the Greek national electric grid. Methods: We use data analysis and various statistical methods and models. Results: Contrary to common belief in PPC Greece, we see that there are considerable both short term (immediate) and long term effects of solar activity onto large transformers in a mid-latitude country like Greece. Our results can be summarised as follows: For the short term effects: During 1989–2010 there were 43 “stormy days” (namely days with for example Ap ≥ 100) and we had 19 failures occurring during a stormy day plus or minus 3 days and 51 failures occurring during a stormy day plus or minus 7 days. All these failures can be directly related to Geomagnetically Induced Currents (GICs). Explicit cases are briefly presented. For the long term effects, again for the same period 1989–2010, we have two main results: The annual number of transformer failures seems to follow the solar activity pattern. Yet the maximum number of transformer failures occurs about half a solar cycle after the maximum of solar activity. There is statistical correlation between solar activity expressed using various newly defined long term solar activity indices and the annual number of transformer failures. These new long term solar activity indices were defined using both local (from the geomagnetic station in Greece) and global (planetary averages) geomagnetic data. Applying both linear and non-linear statistical regression we compute the regression equations and the corresponding coefficients of determination.