HV Transformer Protection and Stabilization under Geomagnetically Induced Currents

Protection of Power Transformers Against Geomagnetically Induced Currents

The article examines the problem of saturation and failure of power transformers under geomagnetically induced currents and currents of the E3 component of high-altitude nuclear explosions. It also describes a special protective relay reacting on DC component in the transformer neutral current.

Comparison of methods for modelling geomagnetically induced currents

Assessing the geomagnetic hazard to power systems requires reliable modelling of the geomagnetically induced currents (GIC) produced in the power network. This paper compares the Nodal Admittance Matrix method with the Lehtinen–Pirjola method and shows them to be mathematically equivalent. GIC calculation using the Nodal Admittance Matrix method involves three steps: (1) using the voltage sourc...

Geomagnetically Induced Currents as Ground Effects of Space Weather

Transformer differential protection with fuzzy logic based inrush stabilization ¬リニ

Second harmonic restraint is still commonly used to discriminate fault current and transformer inrush conditions. Such approach, however, has some disadvantages and limitations. Therefore various other criteria signals for power transformer inrush discrimination have been analysed. The paper presents a new multi-criteria stabilization algorithm that employs fuzzy reasoning technique for better ...

Influences of various magnetospheric and ionospheric current systems on 1 geomagnetically induced currents around the world

14 Ground-based observations of geomagnetic field (B-field) are usually a superposition of 15 signatures from different source current systems in the magnetosphere and ionosphere. 16 Fluctuating B-fields generate geoelectric fields (E-fields), which drive geomagnetically induced 17 currents (GIC) in technological conducting media at Earth’s surface. We introduce a new Fourier 18 integral B-fiel...