Geomagnetic Disturbance Characterization in the Hydro-Quebec Power System using AUTUMNX Data

Abstract

A geomagnetic storm is a disturbance of the earth magnetosphere caused by a charged cloud of plasma (also known as solar wind) released after a solar flare event. The time varying magnetic field leads to an electric field which results in geomagnetically induced currents (GICs). These currents induced in power lines flow to ground via substation transformers which cause saturation of the transformer cores, leading to transformer damage. In addition, the harmonics induced in the power lines cause unwanted relay operations and trip power lines, which compromise the stability of the power system. Such events led to the famous Quebec blackout in Mar. 1989 which left the province without power for 9 hours. According to Faraday’s Law of Induction, the change in geomagnetic field is directly related to the electric field that induces the GICs. In [1] statistical models of the geomagnetic time derivative were developed and tested using data from the CANOPUS array of magnetometers. Empirical models for the log of the mean and log of the variance were used to predict extreme geomagnetic disturbances induced by solar wind. In this report, the results obtained in [1] are verified using over a year of AUTUMNX data which is about the same number of data values as the 10 years of CANOPUS data. An investigation of the effect of GICs on power systems is also presented. The geomagnetic data from the AUTUMNX array of magnetometers is related to harmonic data from the Hydro-Quebec power network. In the future, this can help Hydro-Quebec predict and prevent events like the 1989 blackout.