At least 3000 HVAC Phase Inverters are needed in North America to cope with Geomagnetically induced currents from magnetic storms

Some ~3000 HVAC Phase Inverters are needed in North America to cope with Geomagnetically induced currents from magnetic storms

Abstract

In the global High Voltage Transmission trade, Phase Inverters are modified circuit systems designed to break off contact with the source of the abnormal

excess AC or DC voltage (excess DC voltage can be a geomagnetic storm caused problem for HVDC transmission systems as well)
or abnormal AC frequency or phase
or improper DC bias (as is common with Geomagnetically induced currents)

Ergo, Phase Inverters are key to islanding a mains AC or DC transmission system when transmission line conditions are exceeded.

What is the effect of a geomagnetic storm on a HVAC transmission system?

HVAC : Geomagnetically induced currents = unsustainable DC bias levels.
HVDC : Geomagnetically induced currents = random "AC like" bias levels.

HVAC or HVDC, geomagnetically induced currents are a problem. HVAC however dominates the North American mains power networks, with about 98% of all 250kv+ routes being HVAC. Ergo, the solution must primarily address HVAC's problems.

HVAC : Geomagnetically induced currents = unsustainable DC bias levels.

Yes, geomagnetic storms are that simple. DC bias sensing circuits generally must be omnipresent in any HVAC transmission system to work at all. However, mostly DC bias sensing is not coupled with phase inverter islanding.

DC bias sensing must be coupled with phase inverter islanding, and it must be a universal feature of mains power systems that are anywhere near the North Pole or Arctic Circle.

DC bias behaviours

DC bias can and does vary in magnetic storms, but at very low frequencies like 1 Hz to 2 Hz. Often the DC bias during a geomagnetic storm may be 0.5 hz. The frequency of DC bias variation itself is not the problem, it is the large induced DC currents that the HVAC transmission system must cope with -- and generally for witch it is not designed to handle.

The Phase Inverter Granularity Solution

The more phase inverters the are placed at the borders of a HVAC transmission system, the more capable the system is with respect to self islanding during geomagnetic storm events.

General principals

Phase Inverter Islanding should be quasi-linearly based on population density, latitude and systematic risk.
Phase Inverter Islanding should only make reasonable and logical modifications to the grid, but not in a way to increase management complexity.
Phase Inverter Islanding should at a bare minimum be at the State or Province level, but county or regional district level should be preferred for areas of higher population density.
Each islanding solution should be cost limited to 2 million SDRs. Islanding generally should run about half this cost, but in more rural regions 500k SDRs is a reasonable baseline expected cost.

References

Technology

Template:Electricity delivery (overall topic)
Category:Electric power distribution ()
Category:Power station technology ()
Power inverter (changes AC <--> DC)
Black start (when a power grid goes down, power stations have to be restated cold)
Capacity factor (an important factor when restarting electrical grids)

	Created by		Initial idea		Initial draft		Current document		Last revision		Revision state
	Max Power		15 November 2011		09 May 2013		22 July 2013		22 July 2013, cleanup		Initial