Bosch pyroswitches/pyrofuses> 1 bash& EV's wiring is shot

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Bosch pyroswitches/pyrofuses> 1 bash& EV's wiring is shot

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https://www.wired.com/story/evs-fire-pyroswitches-cut-risk-shock-crash/
EVs Fire Up Pyroswitches to Cut Risk of Shock After a Crash
10.06.2019  Alex Davies

[images  
https://media.wired.com/photos/5d97dafc01e4a400082613b3/master/w_2560%2Cc_limit/Transpo_carcrash_KGGNX5.jpg
Photograph: Alamy

https://media.wired.com/photos/5d97daa428aa88000843488a/master/w_1280%2Cc_limit/Transpo_Bosch_Airbag_IC_Print-(300-dpi).jpg
EV chip  Bosch developed the CG912 semiconductor chip for triggering
airbags, but it works just as well for sparking a tiny guillotine to cut an
electric vehicle’s high-voltage cables.  Illustration: Bosch
]

Electric cars run on 400 volts or more. So automakers are designing systems
to protect EMTs and others from exposed wires following a collision.

After more than a century of powering their wares with engines that produce
hundreds of small, carefully controlled explosions each minute, the auto
industry is moving toward a battery-driven future. But that doesn’t mean one
without any helpful explosions. Last month, industry supplier Bosch revealed
details on what it calls the pyrofuse, a new safety tool for electric cars.

When the system detects a crash, its uses a bit of combustion to fire small
wedges into the high-voltage cables, severing the connections between the
battery and the power electronics. The idea is to reduce the risk of
electrocution for first responders.

Here’s why that’s necessary: Conventional cars run about 12 volts of power,
but many electrics use 400 volts. The new Porsche Taycan uses double that.
That power bump has pushed the auto industry to develop new ways to keep
everybody safe. Along with careful insulation of battery packs and
high-voltage components, automakers and suppliers have developed a variety
of pyrotechnic safety switches that activate in the event of a crash.
Autoliv’s Pyroswitch throws a switch to disconnect the power source from the
circuit board. Tesla has patented an “arc-suppressing gas blast in
pyrotechnic disconnect” [
https://insideevs.com/news/334322/tesla-patents-pyrotechnic-battery-safety-device/
] that appears to work similarly.

Bosch’s system goes further by actually cutting wires. “It’s a secure
disconnection,” says Thorsten Koepke, the company’s product manager for
semiconductors, “a physical opening of the wire.” His team produced the chip
that uses deceleration and other data from the car to identify a crash. They
originally developed the chip for use in airbags, but it serves the same
function here. The exact workings of the system, including the conditions
under which it will trigger, are up to the automaker, but the general idea
is that the chip triggers a small explosion, similar to the chemical
reaction that inflates an airbag. But here it will launch wedges into the
wires in question—as many as eight, if the car has a motor at each wheel,
Koepke says. And while Bosch declines to name its clients, Koepke says it’s
already in use in cars on the road.

“It’s like a little guillotine.”
 -Huseyin Hiziroglu, Kettering University

Pyroswitches are relatively common, but this use case is novel, says Huseyin
Hiziroglu, an electrical engineer at Kettering University in Flint,
Michigan. “It’s like a little guillotine.” One that looks to save lives
instead of take them but that delivers the same sort of permanence. The
downside of this safety-minded system is that repairing a crashed electric
car will involve installing a lot of new wiring. Which means, most likely,
spending a lot of money. “I’m sure it will be quite expensive,” Hiziroglu
says.

Jason Siegel, a research scientist at the University of Michigan who studies
lithium-ion batteries, says pyrofuses “can provide a much-needed safety net
for first responders.” But it’s not clear that taking the extra step of
severing the wires will change how EMTs and others approach a crashed
vehicle, since they won’t know that the little guillotine has done its work.
“I don’t see first responders reaching for a [voltage-measuring] Fluke meter
to check if the wires are live before cutting when someone is trapped in the
vehicle,” he says.

There are more than a million electric cars roaming American roads, but, so
far, worries around high-voltage crashes haven’t come to fruition. Andrew
Klock, who works on EVs and other emerging issues for the National Fire
Protection Agency, says he doesn’t know of any first responders who have
been zapped. The nonprofit group has trained 225,000 EMTs, firefighters,
police, and others to deal with electric cars in the past decade. Relatively
simple advice has proven effective. “You just stay away from any broken
cables,” Klock says. First responders who need to cut someone out from a
mangled vehicle can check the agency’s Emergency Field Guide, which collects
and standardizes key information on all the electric car models on the
market, to make sure they’re well clear of any cables or components that
could deliver a deadly shock. Stay away from those, Klock says, “and you’re
gonna be OK.”

Still, as automakers launch an onslaught of high-voltage, battery-powered
cars in the coming years—more than 18 million are expected by 2030, by one
estimate—more EVs will end up on the side of the road. And for those charged
with taking care of them, a little insurance delivered by a little explosion
may not be a terrible idea.
[© wired.com]


https://www.forbes.com/sites/edgarsten/2019/10/01/small-explosions-aimed-at-defusing-ev-post-crash-safety-issues/#655eecb93319
Small Explosions Aimed At Defusing EV Post-Crash Safety Issues
Oct 1, 2019  When an electric or hybrid-electric vehicle is in a crash, a
series of little explosions may just do the trick to help ensure the safety
of occupants, first responders and rescue workers ... Bosch (IC) ...
pyrotechnical safety switch system, or pyrofuse, to set off a series of mini
explosions, blowing out ... sections of cable ... shutting off ... power ...
https://specials-images.forbesimg.com/imageserve/5d9290b4793bd50006e975af/960x0.jpg


+ (v)
https://cleantechnica.com/2019/09/30/how-strong-is-the-tesla-model-3-roof-this-accident-helps-to-show-us/
How Strong Is The Tesla Model 3 Roof? This Accident ...
September 30th, 2019  The video shows Daigle just driving down the street in
his Model 3 when a car pulls out in front of him. He swerved to the right
and crashed into a street sign ...
https://youtu.be/3J1yeiBFVrk




For EVLN EV-newswire posts use:
 http://evdl.org/


{brucedp.neocities.org}

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Re: Bosch pyroswitches/pyrofuses> 1 bash& EV's wiring is shot

Electric Vehicle Discussion List mailing list
Seems this could create as many hazards as it stops. First, the author
mentions the pyroswitch might fail. So you still have to execute
caution. Other failures could happen, too:
- the "hot" cut wire could touch the chassis due to deformation during
the crash
- some other short-to-chassis from the battery could occur
- not all vehicles may have a pyroswitch
- the disconnection might arc and start a fire

On top of that, as they say, it creates substantial additional expense
to repair. Do you want that every time you go over a really bad pothole
:)

Safety features are paramount, so I support the intent. Not sure this is
a good solution, though.

Peri

------ Original Message ------
From: "brucedp5 via EV" <[hidden email]>
To: [hidden email]
Cc: "brucedp5" <[hidden email]>
Sent: 08-Oct-19 1:09:04 AM
Subject: [EVDL] Bosch pyroswitches/pyrofuses> 1 bash& EV's wiring is
shot

>
>https://www.wired.com/story/evs-fire-pyroswitches-cut-risk-shock-crash/
>EVs Fire Up Pyroswitches to Cut Risk of Shock After a Crash
>10.06.2019  Alex Davies
>
>[images
>https://media.wired.com/photos/5d97dafc01e4a400082613b3/master/w_2560%2Cc_limit/Transpo_carcrash_KGGNX5.jpg
>Photograph: Alamy
>
>https://media.wired.com/photos/5d97daa428aa88000843488a/master/w_1280%2Cc_limit/Transpo_Bosch_Airbag_IC_Print-(300-dpi).jpg
>EV chip  Bosch developed the CG912 semiconductor chip for triggering
>airbags, but it works just as well for sparking a tiny guillotine to cut an
>electric vehicle’s high-voltage cables.  Illustration: Bosch
>]
>
>Electric cars run on 400 volts or more. So automakers are designing systems
>to protect EMTs and others from exposed wires following a collision.
>
>After more than a century of powering their wares with engines that produce
>hundreds of small, carefully controlled explosions each minute, the auto
>industry is moving toward a battery-driven future. But that doesn’t mean one
>without any helpful explosions. Last month, industry supplier Bosch revealed
>details on what it calls the pyrofuse, a new safety tool for electric cars.
>
>When the system detects a crash, its uses a bit of combustion to fire small
>wedges into the high-voltage cables, severing the connections between the
>battery and the power electronics. The idea is to reduce the risk of
>electrocution for first responders.
>
>Here’s why that’s necessary: Conventional cars run about 12 volts of power,
>but many electrics use 400 volts. The new Porsche Taycan uses double that.
>That power bump has pushed the auto industry to develop new ways to keep
>everybody safe. Along with careful insulation of battery packs and
>high-voltage components, automakers and suppliers have developed a variety
>of pyrotechnic safety switches that activate in the event of a crash.
>Autoliv’s Pyroswitch throws a switch to disconnect the power source from the
>circuit board. Tesla has patented an “arc-suppressing gas blast in
>pyrotechnic disconnect” [
>https://insideevs.com/news/334322/tesla-patents-pyrotechnic-battery-safety-device/
>] that appears to work similarly.
>
>Bosch’s system goes further by actually cutting wires. “It’s a secure
>disconnection,” says Thorsten Koepke, the company’s product manager for
>semiconductors, “a physical opening of the wire.” His team produced the chip
>that uses deceleration and other data from the car to identify a crash. They
>originally developed the chip for use in airbags, but it serves the same
>function here. The exact workings of the system, including the conditions
>under which it will trigger, are up to the automaker, but the general idea
>is that the chip triggers a small explosion, similar to the chemical
>reaction that inflates an airbag. But here it will launch wedges into the
>wires in question—as many as eight, if the car has a motor at each wheel,
>Koepke says. And while Bosch declines to name its clients, Koepke says it’s
>already in use in cars on the road.
>
>“It’s like a little guillotine.”
>  -Huseyin Hiziroglu, Kettering University
>
>Pyroswitches are relatively common, but this use case is novel, says Huseyin
>Hiziroglu, an electrical engineer at Kettering University in Flint,
>Michigan. “It’s like a little guillotine.” One that looks to save lives
>instead of take them but that delivers the same sort of permanence. The
>downside of this safety-minded system is that repairing a crashed electric
>car will involve installing a lot of new wiring. Which means, most likely,
>spending a lot of money. “I’m sure it will be quite expensive,” Hiziroglu
>says.
>
>Jason Siegel, a research scientist at the University of Michigan who studies
>lithium-ion batteries, says pyrofuses “can provide a much-needed safety net
>for first responders.” But it’s not clear that taking the extra step of
>severing the wires will change how EMTs and others approach a crashed
>vehicle, since they won’t know that the little guillotine has done its work.
>“I don’t see first responders reaching for a [voltage-measuring] Fluke meter
>to check if the wires are live before cutting when someone is trapped in the
>vehicle,” he says.
>
>There are more than a million electric cars roaming American roads, but, so
>far, worries around high-voltage crashes haven’t come to fruition. Andrew
>Klock, who works on EVs and other emerging issues for the National Fire
>Protection Agency, says he doesn’t know of any first responders who have
>been zapped. The nonprofit group has trained 225,000 EMTs, firefighters,
>police, and others to deal with electric cars in the past decade. Relatively
>simple advice has proven effective. “You just stay away from any broken
>cables,” Klock says. First responders who need to cut someone out from a
>mangled vehicle can check the agency’s Emergency Field Guide, which collects
>and standardizes key information on all the electric car models on the
>market, to make sure they’re well clear of any cables or components that
>could deliver a deadly shock. Stay away from those, Klock says, “and you’re
>gonna be OK.”
>
>Still, as automakers launch an onslaught of high-voltage, battery-powered
>cars in the coming years—more than 18 million are expected by 2030, by one
>estimate—more EVs will end up on the side of the road. And for those charged
>with taking care of them, a little insurance delivered by a little explosion
>may not be a terrible idea.
>[© wired.com]
>
>
>https://www.forbes.com/sites/edgarsten/2019/10/01/small-explosions-aimed-at-defusing-ev-post-crash-safety-issues/#655eecb93319
>Small Explosions Aimed At Defusing EV Post-Crash Safety Issues
>Oct 1, 2019  When an electric or hybrid-electric vehicle is in a crash, a
>series of little explosions may just do the trick to help ensure the safety
>of occupants, first responders and rescue workers ... Bosch (IC) ...
>pyrotechnical safety switch system, or pyrofuse, to set off a series of mini
>explosions, blowing out ... sections of cable ... shutting off ... power ...
>https://specials-images.forbesimg.com/imageserve/5d9290b4793bd50006e975af/960x0.jpg
>
>
>+ (v)
>https://cleantechnica.com/2019/09/30/how-strong-is-the-tesla-model-3-roof-this-accident-helps-to-show-us/
>How Strong Is The Tesla Model 3 Roof? This Accident ...
>September 30th, 2019  The video shows Daigle just driving down the street in
>his Model 3 when a car pulls out in front of him. He swerved to the right
>and crashed into a street sign ...
>https://youtu.be/3J1yeiBFVrk
>
>
>
>
>For EVLN EV-newswire posts use:
>  http://evdl.org/
>
>
>{brucedp.neocities.org}
>
>--
>Sent from: http://electric-vehicle-discussion-list.413529.n4.nabble.com/
>_______________________________________________
>UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
>ARCHIVE: http://www.evdl.org/archive/index.html
>INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org
>Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
>

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Re: Bosch pyroswitches/pyrofuses> 1 bash& EV's wiring is shot

Electric Vehicle Discussion List mailing list
Am I missing something?  Isn't this what main contactors are for?  

Besides, I don't think its a new idea.  This document

https://www-esv.nhtsa.dot.gov/proceedings/24/files/24ESV-000163.PDF

seems to date from a couple of years ago (I could be wrong about that,
however).

David Roden - Akron, Ohio, USA
EVDL Administrator

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Re: Bosch pyroswitches/pyrofuses> 1 bash& EV's wiring is shot

Electric Vehicle Discussion List mailing list
On Tue, 8 Oct 2019 at 15:57, EVDL Administrator via EV
<[hidden email]> wrote:

> Am I missing something?  Isn't this what main contactors are for?

A short circuit of the main battery bus during an impact could weld
contactors, particularly as there may be contact bounce due to the
impact.

A fuse might not blow, because the sustained fault current isn't high enough.

A one time operable disconnect sounds like a good idea. Cutting cables
doesn't, but then that is probably just bad reporting of the actual
process.

--
Paul Compton
www.morini-mania.co.uk
www.paulcompton.co.uk (YouTube channel)
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