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تسجيل مستخدم جديدImmediate and delayed responses of power lines and transformers in the Czech electric power grid to geomagnetic storms
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تأليف
Michal v{S}vanda
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Eruptive events of solar activity often trigger abrupt variations of the geomagnetic field. Through the induction of electric currents, human infrastructures are also affected, namely the equipment of electric power transmission networks. It was shown in past studies that the rate of power-grid anomalies may increase after an exposure to strong geomagnetically induced currents. We search for a rapid response of devices in the Czech electric distribution grid to disturbed days of high geomagnetic activity. Such disturbed days are described either by the cumulative storm-time $Dst$ or $d(textit{SYM-H})/dt$ low-latitude indices mainly influenced by ring current variations, by the cumulative $AE$ high-latitude index measuring substorm-related auroral current variations, or by the cumulative $ap$ mid-latitude index measuring both ring and auroral current variations. We use superposed epoch analysis to identify possible increases of anomaly rates during and after such disturbed days. We show that in the case of abundant series of anomalies on power lines, the anomaly rate increases significantly immediately (within 1 day) after the onset of geomagnetic storms. In the case of transformers, the increase of the anomaly rate is generally delayed by 2--3 days. We also find that transformers and some electric substations seem to be sensitive to a prolonged exposure to substorms, with a delayed increase of anomalies. Overall, we show that in the 5-day period following the commencement of geomagnetic activity there is an approximately 5--10% increase in the recorded anomalies in the Czech power grid and thus this fraction of anomalies is probably related to an exposure to GICs.
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English: Solar eruptive events affect the close neighbourhood of the Earth. They also affect human infrastructure, power grids mainly, due to the induction of electrical currents. Only recently the attention was drawn not only to large flares, but al
so to estimate the long-term effects of increased solar activity by statistical methods. We analyse the failure rates in the main Czech power transmission system operated by the Czech national operator v{C}EPS. We show that the effects of solar activity on failure rate in the main Czech power grid cannot be excluded even for central-european country. This is a preliminary study. Czech: Eruptivni projevy slunev{c}ni aktivity ovlivv{n}uji bezprostv{r}edni kosmicke okoli nav{s}i Zemv{e} a postihuji prostv{r}ednictvim indukce elektrickych proudr{u} i pozemskou infrastrukturu, zejmena rozvodne sitv{e} silove elektv{r}iny. Teprve v poslednich letech byla vv{e}novana pozornost nejen hodnoceni bezprostv{r}ednich dopadr{u} silnych eruptivnich udalosti na zav{r}izeni rozvodne sitv{e}, ale take statistickemu zhodnoceni vlivu zvyv{s}ene slunev{c}ni aktivity. Ve spolupraci s v{C}EPS, a.s., jsme statisticky vyhodnotili v{c}etnost zavad na zav{r}izenich patev{r}ni rozvodne sitv{e} v{C}R v zavislosti na urovni slunev{c}ni aktivity a ukazujeme, v{z}e vliv nahlych eruptivnich udalosti na zavadovost zav{r}izeni v{c}eske rozvodne sitv{e} nelze vylouv{c}it.
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