[SystemSafety] Solar Storms and Charging Procedures for Electric Cars

[Peter Bernard Ladkin]

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