Hvordan vil det låte FØR nivået blir så høyt at dette inntreffer?
Electric transformer failures, like this dramatic one, are a risk if solar storms create extra electrical currents in the Earth's magnetosphere
The AC/DC Problem
Technically, geomagnetically induced currents aren't that strong compared with the currents that normally flow between power plants and electricity consumers. For electricity to travel long distances, it needs to be transformed to high voltage and back again, to limit energy loss due to resistance in the transmission wires.
Trouble arises because the extra currents from solar storms are direct current (DC) flows, and the electricity transmission system is used to handling alternating current (AC) flows, said EPRI's Lordan.
(Related: "Upgrading the Electric Grid With Flywheels and Air")
The extra DC flows saturate transformers, which start to overheat, causing their insulation to break down and their parts to experience accelerated aging. Above a certain temperature, a transformer will fail.
At the same time, the saturated transformer starts to consume what's known as reactive power.
"When you look at power in the system, there's real power—like that in incandescent light bulbs—and then there's 'imaginary' power called reactive power, measured in vars," Lordan said.
Reactive power is produced when the current and voltage are out of phase. This type of power flow needs to be carefully managed to keep the voltage steady in transmission lines.
During a solar storm, however, any saturated transformers draw on more reactive power than what normal control equipment can handle. This can lead to voltage collapse, when it's no longer possible to push the needed power through transmission wires.
Even without a full collapse, fluctuating voltage in the transmission system can cause the grid to become unstable, which can impact transformers, relays, capacitors, and even the generators at power plants
Hårtørkere etc. blir småtterier i forhold.
Solvind/induksjon fra sola
·Metning i jernkjerner (transformatorer)
·Til en viss grad lastapparater med DC-komponenter
·Med mer
Helge Seljeseth MSc Research Scientist
ph+47 73597200 fax+47 73597250 mob+47 91586231
Energy systems / Power system asset management
SINTEF Energy Research www.energy.sintef.no
