Re: [SystemSafety] Solar Storms and Charging Procedures for Electric Cars

From: Martyn Thomas < >
Date: Wed, 10 Apr 2013 15:30:03 +0100

On 10/04/2013 10:57, Peter Bernard Ladkin wrote:
> Martyn,
> On 4/7/13 7:14 PM, Martyn Thomas wrote:
>> I assume you have seen
>> Which of the phenomena is seen as creating a hazard for EV charging?
> I think Section 9 is relevant: Avionics and Ground Systems. The report
> sees solar energetic particles (SEPs) as the main problem for ground
> electronics, and not geomagnetically-induced currents (GICs).
> However, I wouldn't know whether GICs would be a concern with an
> active charging system. Can anyone help?

My understanding is that you need a long run of conductor before GIC's become significant, except around transformers that have a major magnetic field of their own that interacts with the earth's magnetic field.

But I'm no expert.

> I do know somewhat more about SEPs, since I looked quite hard at what
> was known about cosmic rays, about a decade ago, and talked to the
> particle physicists in Bielefeld about them, during the course of
> trying to figure out what was known about single-event upsets (SEUs)
> in electronics, and to what level of radiation, and what kind, people
> and electronics in commercial aircraft at cruise altitudes on various
> routes might be subject. There seemed to me a lot of mantras floating
> around from various quasi-authoritative sources but talking to the
> particle physicists I had many responses of the sort "how do they
> (think they) know that? We don't!"
> The SEP increase raises the question of an increase in quantity, and
> diversity, of SEUs, since the spectrum of SEPs in a solar storm is not
> well understood, according to the report. Since SEUs disrupt the logic
> of the electronic circuitry, it seems to me to be possible that the
> protective electronics in both vehicle and charging system (Mode 3
> columns and wall boxes, Mode 2 in-cable control protective devices,
> ICCPDs) can be altered. In particular, one might worry about the Type
> A and Type B residual current devices that are likely to be required
> (Type A in a charging device, Type B in a car, although this is
> currently under discussion in Germany). RCDs used to be
> electromechanical, but the Type A and Type B boxes, as well as the
> short-circuit and over-current protections that are usually
> incorporated into the boxes as well, are primarily electronics. There
> are also discussions about protective communication devices carried
> inside the cables, such as a control pilot. The electronics needed to
> make such things functional would also potentially be susceptible to
> SEPs and their atmospheric byproducts (that is, an increase in
> cosmic-ray intensity).

As weight is a lesser problem than in aircraft, perhaps chargers and RCDs could be adequately screened or duplicated.


> There have been events with MOSFETs in rail operation which have been
> plausibly put down to cosmic-ray-induced SEUs. I don't know if (and,
> if so, what) MOSFETs might be used in electric road vehicles.
> Kelly Mahoney also pointed me towards a 2011 document from the OECD:
> I haven't looked at
> it yet.
> Prof. Peter Bernard Ladkin, Faculty of Technology, University of
> Bielefeld, 33594 Bielefeld, Germany
> Tel+msg +49 (0)521 880 7319
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systemsafety_at_xxxxxx Received on Wed Apr 10 2013 - 16:30:11 CEST

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