Formula E

[Tommy Cookers]

contactless ie inductive charging has rather large losses

iirc the figure was 7% for a stationary vehicle (and more for moving vehicles)

[Big Tea]

contactless ie inductive charging has rather large losses

some years ago (in this thread ?) I dug out some figures on this

I know this (to some extent) but is this perception that stops many people going the EV rout.
The first reaction of the wife when I suggested it was 'what if we get stuck somewhere without electricity'.
And this was for a prius hybrid. Its all about perceptions now and I think will be for the next few years.

Edit.

This is partially or even fully made up by using zero when the car is not moving. This is a simple thing to understand, but none of the makers seem to be pushing it. We saw lots pushing the 'bonus' of having a ICE shut down automatically, and this includes replacement of restart parts and the charge in the battery, which also takes fuel. No mention of it in th electric car adds.

[J.A.W.]

There should be interest because someday, not tomorrow or in the very near future but someday it will take over and internal combustion powered cars will just be a memory.

That's on face value, a pretty bold claim - strad..

IMO, if the visceral sensation - the 'sound & fury', if you will - of ICE based racing goes, so will much of the fanbase interest..

Classic racing, featuring such 'real deal' machines - will surely draw that interest.. but hey, time'll tell..

Don´t worry JAW, there will always be vintage series for people reluctant to change like yourself

Hey, its not me who is "reluctant to change", I'm still waiting for FE to change emphasis from 'glib gimmickry' to 'real racing'..

[Tommy Cookers]

[quote="Big Tea"] ......using zero when the car is not moving. .........No mention of it in th electric car adds.[/quote]

I would expect the drive will be live ie still consuming power and the EM may be slightly energised

foot off-accelerator do EVs need handbrake at all times like a manual car or naturally stay still or creep like an automatic ?
don't they naturally hill-hold ?

[Big Tea]

......using zero when the car is not moving. .........No mention of it in th electric car adds.

I would expect the drive will be live ie still consuming power and the EM may be slightly energised

foot off-accelerator do EVs need handbrake at all times like a manual car or naturally stay still or creep like an automatic ?
don't they naturally hill-hold ?

I do not own one, but have driven a few times. First, as with a TQ auto, you have your foot on the brake anyway, so creep or roll does not matter really. Same when you pull away, there is no juggling with the clutch peddle so off one peddle onto another in less time than the car takes to realise nothing is holding it. I do not know if it does 'hold' TBH in normal driving I would not notice and quite probably the car has rollback brakes anyway. Almost sure there is no creep though.

Just checked, the car I drive has what they refer to in the blab as 'Hill-start Assist', so would not roll back anyway.

[mzso]

Solid state batteries seem to be the next step change in technology coming. That will be a very interesting time because I can see increased range with reduced weight.

I think that might be potentially a huge leap. Solid electrolytes make it possible the removal of graphite (or anything other than lithium) from the anode. This is a lot of mass.

The batteries used in Formula E aren't really all that cutting edge - as they're supplied to teams from Williams, next season by McLaren - the inverters and motors are where teams are allowed to spend and that's were the motorsport effect trickle down effect will be seen.

This is quite irrational from them. They should use the best prototype batteries that are available. Probably should even allow multiple manufactures to provide them if they can round up more than one.

[mzso]

I would expect the drive will be live ie still consuming power and the EM may be slightly energised

foot off-accelerator do EVs need handbrake at all times like a manual car or naturally stay still or creep like an automatic ?
don't they naturally hill-hold ?

It doesn't. There's no need to pass current through the motor when it's not used. (As such when you're not pressing the pedal it does nothing.)

[Tommy Cookers]

the drive will be using DC power even when producing the AC motor supply at a notional OV rms and 0 Hz
somewhat as your audio system amplifier consumes power even when you aren't giving it a signal to amplify

Big Tea's post imo seems to support my expectation that the motor has a residual energisation at 0% accelerator
this will prevent rollback on those typical apparently level surfaces that are not exactly level
why else is he using footbrake ?

and the fact that makers don't claim zero power consumption at rest suggests there isn't zero power consumption at rest


btw it wasn't me who turned this thread towards an EV campaign
but I'm happy to learn here from those with hard EV information - since we don't seem to have an EV thread as such

[Skippon]

Yes the inverter will consume some power at 0 speed but only in its control circuitry as it won't be switching current to the motor. The few 10s of Watts of that is near nothing compared to motor power..........
In FE the technical rules forbid "creep".

[Tommy Cookers]

a few tens of Watts quiescent power in the drive

I think when the accelerator is reading 0% that the EM/drive characteristic is to resist typical rollback or rollforward
and this would require additional electrical power

every day on level roads some manual car in front of me rolls back when the handbrake is released
globally many EV customers haven't driven a manual car so the somehow EV won't have this irritating manual car characteristic

[Skippon]

You switch the 3 upper legs of the three phase motor OFF (DC) and the three lower legs ON (DC). No current then flows in the motor and it is locked in position acting as a brake and there is no switching in the motor.

[Tommy Cookers]

ok
what motor is this ?

[Skippon]

3 Phase induction

[Tommy Cookers]

how can this electromagnetic locking action exist without some level of continuous expenditure of electrical energy ?

I have been paid to specify adjustable-current-limit power sources producing this way a settable motor locking torque

or perhaps you are thinking of the conventional mechanical motor holding brakes that are spring-hold/powered-free ?

RETRO-EDIT
now seems to me that the induction machine gives a resisting effect proportional to imposed rpm - more damper than brake
if uncontrolled - ie without outside control logic

[J.A.W.]

IMO, if the visceral sensation - the 'sound & fury', if you will - of ICE based racing goes, so will much of the fanbase interest..

I doubt it. All you need is fast cars and entertaining racing.

Sooner or later people will look down on the noisy ICE cars of the past with the same contempt a good chunk of them do on electrics' today. People can't see further than their nose.

Dunno 'bout that, since almost 1/2 a century ago, Hollywood depicted a 'futuristic' electromotive machine treating
both Ford & Honda's latest ICE-powered pursuit vehicles.. with "contempt", but somehow, it didn't 'catch on'...

https://www.youtube.com/watch?v=Y03zBX_q4TM