Effect of the GICs on magnetic saturation of asymmetric three‐phase transformer

Abstract

The most commonly used models in geomagnetic-induced currents (GICs) studies neglect the hysteresis phenomenon. In relation to this, the authors present an approach to integrate the hysteresis phenomenon to the finiteelement model (2D-FEM) for the effects of the GIC which considers the current, as an input quantity. These currents are obtained by a dynamic electromagnetic model that the authors developed, and are compared with the results obtained by experimentation. This is the first time that this phenomenon has been shown in three-phase transformers with load. They also provide other practical responses in relation to other papers in which their studies concern the imbalance GIC bias on the asymmetric three-phase transformers with no-load while the majority of the transformers operate on load.

Real‐time detection of vulnerable power system areas to geomagnetic disturbance

“…x t g t − τ e − j2π f t dt (8) where τ and f denote the time shift in the window and frequency components, respectively. Considering the prior knowledge about the frequency content of the GMD events, a suitable window is expected to have a frequency response with a steeply decreasing magnitude.…”

“…Geomagnetic disturbance (GMD) is a kind of natural event that can induce a voltage in the ground layers and transmission systems and drive the geomagnetically induced current (GIC) in power grids. Very low-frequency nature of GIC within 0.1-100 mHz range causes quasi-dc effects with detrimental consequences in the power system [1][2][3][4][5][6][7] and transformers [8,9]. The March 1989 Hydro-Quebec power system blackout due to GMD is a prominent event that left nine million people without power for more than eight hours.…”

Characteristic analysis and design of novel high‐frequency shell‐type coaxial transformer

“…In this step, the initial design result is revised and verified through FEM. The usefulness of the proposed SCTR can also be confirmed in the design stage using FEM [34][35][36][37][38]. The characteristics of the electric equipment are closely related to the magnetic field distribution in the equipment.…”

A Review of Geomagnetically Induced Current Effects on Electrical Power System: Principles and Theory

“…14). Thus, the transformers draw an extremely large and asymmetrical exciting distorted current, which is rich in even and odd harmonics [2,113,114,165,191,206,207]. These harmonics can trigger the relays improperly, overheating the generators and transformer's windings and cores, which causes unstable operations of the power system and might result in long-term damage of the system's components.…”