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

From: Peter Bernard Ladkin < >
Date: Wed, 10 Apr 2013 11:57:24 +0200


Martyn,

On 4/7/13 7:14 PM, Martyn Thomas wrote:
> I assume you have seen
> http://raeng.org.uk/news/publications/list/reports/Space_Weather_Summary_Report.PDF
>
> 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?

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).

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: http://www.oecd.org/governance/risk/46891645.pdf I haven't looked at it yet.

PBL Prof. Peter Bernard Ladkin, Faculty of Technology, University of Bielefeld, 33594 Bielefeld, Germany Tel+msg +49 (0)521 880 7319 www.rvs.uni-bielefeld.de



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systemsafety_at_xxxxxx Received on Wed Apr 10 2013 - 11:57:32 CEST

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