Rotor heating effects from geomagnetic induced currents

Gish, William B.; Feero, W.E.; Rockefeller, G. D.

doi:10.1109/61.296248

Cited by 24 publications

(5 citation statements)

References 4 publications

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“…When a generator is tripped by the relay, the reliability of the power network would be decreased and would lead to a whole system blackout in the worst scenario [205,210,211].…”

Section: B Effect On the Generatorsmentioning

confidence: 99%

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

et al. 2020

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Geomagnetically induced current (GIC) has been a significant concern for the electrical power grid in high latitudes for decades. Its origin starts in the Sun; during extreme space weather, the magnetic field of the Earth varies rapidly. This variation induces electric fields at the Earth's surface and leads to GICs in manmade technologies. Power systems are the most affected by this induced current, which causes halfcycle saturation of power transformers and other issues. Understanding the behaviours and chain effects of this phenomenon is the key consideration in modelling the hazards to technological systems from space weather. In this paper, a comprehensive review of space weather, geomagnetic disturbances (GMDs) and GICs and their impacts on the power systems in both high and mid-low latitude regions is presented. Additionally, we highlight the most commonly used methods to model and calculate geoelectric fields at the Earth's surface and GIC in the power systems with respect to DC and AC analysis. In addition, we have classified the GIC effects on the different power system components. Moreover, the possible solutions and mitigation techniques to eliminate or reduce these effects based on different GIC blocking devices are reviewed in this work. This work provides researchers and power system operators a shortcut road path to understanding GIC phenomena, modelling and calculations, effects, and mitigation of these effects.

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“…When a generator is tripped by the relay, the reliability of the power network would be decreased and would lead to a whole system blackout in the worst scenario [205,210,211].…”

Section: B Effect On the Generatorsmentioning

confidence: 99%

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

et al. 2020

View full text Add to dashboard Cite

show abstract

“…There is also a greater chance of damage to shunt capacitors, static var compensators, and harmonic filters. Generators can experience rotor heating from saturation [6].…”

Section: Impacts Of Gic From Gmd/e3 On Power Gridmentioning

confidence: 99%

HEMP Transformer Defense Through Power Electronics

Burkes

Vincent

2019

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High altitude electromagnetic pulse (HEMP) generated by exoatmospheric nuclear burst has the ability to affect the electric power grid. The main power grid components, cables and transformers, act as large antennas that have current induced in them from the HEMP. These currents are called geomagneticallyinduced currents (GIC), and they can occur during geomagnetic disturbances from HEMP or solar flares. HEMPs produce pulses with high electric field strengths that breakdown the dielectric of most electronics and, it is broken into three stages: E1 pulse with a microsecond width, E2 the falling trail of the pulse, and E3 a constant DC component. Oak Ridge National Laboratory has proven that transformers fitted with lightning arrestors do not receive damage from E1 and E2 pulses. However, the DC component of the E3 causes the transformer's core to saturate and induce rapid heating that damages the transformer. SRNL is developing a power electronic system that is connected to the neutral of the high voltage side of large power transformers (LPT). This system will inject the inverse of the DC effect from the HEMP into the primary side of the transformer canceling out the E3 waveform and protecting the transformer from half-cyclesaturation. This year SRNL successfully simulated removing the DC injected and accurately simulated saturation on the transformer. Intellectual Property Review This report has been reviewed by SRNL Legal Counsel for intellectual property considerations and is approved to be publically published in its current form.

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“…On average, solar activity as measured by monthly sun spot numbers follows an 11-year cycle [46][47][48][49][50][51][52][53].…”

Section: Sunspot Cycles and Geomagnetic-disturbance Cyclesmentioning

confidence: 99%

“…The ESP acts eventually as an ideal voltage source impressed across the grounded-neutral points and because the ESP has a frequency of one to a few millihertz, the resulting GICs can be determined by dividing the ESP by the equivalent DC resistance of the paralleled transformer winding and line conductors between the two neutral grounding points. The GIC is a quasi-direct current, compared to 50 or 60 Hz, and GIC values in excess of 100 A have been measured in transformer neutrals [46][47][48][49][50][51][52][53].…”

Section: Earth-surface Potential (Esp) and Geomagnetically Induced Cumentioning

confidence: 99%

Harmonic Models of Transformers

2008

Power Quality in Power Systems and Electrical Machines

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Extensive application of power electronics and other nonlinear components and loads creates single-time (e.g., spikes) and periodic (e.g., harmonics) events that could lead to serious problems within power system networks and its components (e.g., transformers). Some possible impacts of poor power quality on power transformers are 9 saturating transformer core by changing its operating point on the nonlinear ~-i curve, 9 increasing core (hysteresis and eddy current) losses and possible transformer failure due to unexpected high losses associated with hot spots, 9 increasing (fundamental and harmonic) copper losses, 9 creating half-cycle saturation in the event of even harmonics and DC current, 9 malfunctioning of transformer protective relays, 9 aging and reduction of lifetime, 9 reduction of efficiency, 9 derating of transformers, 9 decrease of the power factor, 9 generation of parallel (harmonic) resonances and ferroresonance conditions, and 9 deterioration of transformers' insulation near the terminals due to high voltage stress caused by lightning and pulse-width-modulated (PWM) converters.Pfe = Phys + Peddy = ghys (Bmax)Sf + geddy(Bmax)2f 2, (2-1) where Phys, Peddy, Bmax, and f are hysteresis losses, eddy-current losses, maximum value of flux density, and fundamental frequency, respectively. Khys is a constant for the grade of iron employed and Keddy is the eddy-current constant for the conductive material. S is the Steinmetz exponent ranging from 1.5 to 2.5 depending on the operating point of transformer core.9 Elsevier Inc. All rights reserved. I ~,H I i r 9 FIGURE 2.4 Magnetic field strength inside and outside of a conductor. / / I i \ % o 9 "% ~Ho3 / %% u / / %

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Rotor heating effects from geomagnetic induced currents

Cited by 24 publications

References 4 publications

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

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

HEMP Transformer Defense Through Power Electronics

Harmonic Models of Transformers

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