Protection of power transformers against 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

Geomagnetically Induced Currents and Their Effect on Power Systems by Trevor Hutchins

A Novel Flux-Based Protection Scheme for Power Transformers

Internal Turn-Turn faults (TTF) are the most common failures in power transformers, which could seriously reduce their life expectancy. Although common protection schemes such as current-baseddifferential protection are able to detect some of the internal faults, some other minor ones (such as TTFs andshort circuit near the neutral point) cannot be detected by such schemes. Likewise, these rela...