Formula E

[Tommy Cookers]

....... OTOH EMs work at max torque for a much wider range of rpm so they´re infinitely more versatile and the reason except size they the same no matter how different is the task

the FE task helps the designer of EMs and their drives because the rpm and torque range is small as the max speeds are low
torque needs current and rpm needs voltage

Sorry but both statements are wrong. Torque needs power, not current, and power can be produced with high voltage and low current, low voltage and high current, or both similar.
And rpm don´t need voltage at all either, I fly RC planes with a motor that spins at 40k rpm with a 14V battery. IMHO 40k rpm is high rpm, and 14V low voltage

no they're not wrong
motor action F=BIL says that torque is proportionate to current
the voltage required to drive 1 Ampere current through a given motor will change proportionate to rpm

roughly .....
car starter motors produce max torque at 0 rpm when given 12 Volts
because the 'back emf' is 0 Volts the armature experiences a pd of 12 V so the current (and torque) is max (huge)
car starter motors produces zero torque at maybe 1000 rpm given 12 Volts
because the 'back emf' is 12 Volts the armature experiences a pd of 0 Volts the current (and torque) is zero
so if you wanted huge torque at 1000 rpm you'd need to give the motor 24 Volts

the drive of your drone motor will have an effect amounting to current managing (invisible to you) whereby .....
the armature doesn't experience anything like the pd changes as above
(the motor isn't on-line to the battery - it's driven by a series of pulses of managed voltage unconnected to battery voltage)

the EV and FE motors will also have internal current managing
that's how they operate at constant torque at low rpm and constant power at rpm above the constant torque range

but whatever the FE current (torque) managed limit is
FE will want to develop rather high torque at high rpm (to go fast down the straights)
so its drive will need to have a 'large' current capability (proportional to the 'large' torque limit) - sometimes unused
and a 'large' voltage capability (like the above starter motor 24 Volt example) - sometimes unused

due to this there is some element of inefficiency or waste
(as you have said regarding the constant torque/constant power ICE)
that element of inefficiency (greater on F1 tracks or LeMans) could be reduced by gearshifts
agreed gearshifts are not worthwhile in FE

[Andres125sx]

no they're not wrong
motor action F=BIL says that torque is proportionate to current
the voltage required to drive 1 Ampere current through a given motor will change proportionate to rpm

Voltage and rpm are directly proportional with any EM, that´s obvious. Manufacturers provide a kv (rpm/v) as a basic data for any EM for a reason, but I can´t see any relationship with torque here

roughly .....
car starter motors produce max torque at 0 rpm when given 12 Volts
because the 'back emf' is 0 Volts the armature experiences a pd of 12 V so the current (and torque) is max (huge)
car starter motors produces zero torque at maybe 1000 rpm given 12 Volts
because the 'back emf' is 12 Volts the armature experiences a pd of 0 Volts the current (and torque) is zero
so if you wanted huge torque at 1000 rpm you'd need to give the motor 24 Volts

the drive of your drone motor will have an effect amounting to current managing (invisible to you) whereby .....
the armature doesn't experience anything like the pd changes as above
(the motor isn't on-line to the battery - it's driven by a series of pulses of managed voltage unconnected to battery voltage)

The weird scenario is the starter motor, wich need to provide torque at 0rpm and don´t need to work at higher rpm

Power on electric motors is defined by voltage provided and current draw, increase any of them and you increase power. That´s what any motor need to run x load, power. They don´t care if that´s provided by 10A at 100v or 100A at 10v (while there´s available a motor with the correct kv obviously)


Sorry Tommy but I can´t see what you´re trying to explain

[mzso]

the FE task helps the designer of EMs and their drives because the rpm and torque range is small as the max speeds are low
torque needs current and rpm needs voltage

that's why the electrical energy efficiency of gearless road (or F1/Le Mans) EV acceleration will be lower than that in FE

Actually it's only current that matters. It's the current that induces the magnetic fields that rotate the motor. Voltage is just a factor in generating the required amount of current.

[Tommy Cookers]

...... It's the current that induces the magnetic fields that rotate the motor. Voltage is just a factor in generating the required amount of current.

the voltage to drive a given current (torque) will need to be increased if rpm is to increase
unless maybe you mean induction machines ?
are you saying FE uses induction machines and doesn't use synchronous machines ?

[Andres125sx]

Not quite a fair comparison. A plane prop doesn't deal with friction on the blades to the same degree a wheel has to with the contact with the ground. The force that acts against it is the mass of the plane plus it's wind resistance. The prop will spin as fast as you ask it to do regardless of speed of the plane. A tyre has constant friction from the ground trying to slow it down.

Rambling but the point is electric props don't need a great deal of power to spin as fast as they can. They are only push/pulling air.

Even air can produce some heavy forces, I can easily hear the higher rpm when the plane accelerates. But I get your point and agree to some degree, but you said it yourself, don´t need a great deal of power, it´s a matter of power, not voltage. It can be higher voltage, but it can also be achieved with higher current and a higher kv motor

Until battery technology gets amazing it's going to be though to get F1 speeds for a full race out of just electric power the batteries are adding too much weight. Making more powerful motors will just waste battery iand add weight.

Agree energy density have to improve 4x at least just to be considered a threat. We need a new technology for that so it´s not going to be next year

[mzso]

...... It's the current that induces the magnetic fields that rotate the motor. Voltage is just a factor in generating the required amount of current.

the voltage to drive a given current (torque) will need to be increased if rpm is to increase
unless maybe you mean induction machines ?

You said "torque needs current and rpm needs voltage". But both need current, and current needs voltage. It's not like one is exclusively responsible for rpm and the other for torque.

are you saying FE uses induction machines and doesn't use synchronous machines ?

Nope.

[tpeman]

Ok, tell me if I'm wrong, but isn't Di Grassi's hits from behind pretty illegal. He did it to Wehrlein, and now to Lopez as well. I mean, they give penalties for some very small insignificant details are harsh. Meanwhile Di Grassi and Rowland's move on Massa remain unpunished.

[marmer]

Another good race just need to tighten up on some of the rules on cars getting away with going into the back of one another. Feels like it would be quite easy to give a power punishment to drivers and drive through for repetitive offensses

[AMG.Tzan]

Watching Formula E makes me understand why some drivers were dumped from F1 teams...! It's like F1 drivers are on a different level compared to FE drivers...but there are always exceptions of course!!
Anyway, racing is getting better in FE and with more and more manufactures it makes it an interesting championship! I am following it full time this year!!

[maximusfuadius]

Ok, tell me if I'm wrong, but isn't Di Grassi's hits from behind pretty illegal. He did it to Wehrlein, and now to Lopez as well. I mean, they give penalties for some very small insignificant details are harsh. Meanwhile Di Grassi and Rowland's move on Massa remain unpunished.

Definitely need to address that! Looks like you can just move people out of your way! Bumper car racing! Will definitely follow more this year though, I thi6its an important series

Sent from my SM-G950W using Tapatalk

[Zynerji]

Omg. It's NASCAR with slower, but higher tech cars!

[Scorpaguy]

...yep, a a bit of "rubbin' is racin'", but F1 used to do some of that back in the day. Today, F1 is so fast and the cars so intricately engineered, "rubbin" is likely to crash out the "rubber" and the "rubee". These FE cars are a lot slower and more robust...also pretty darned identical in performance. Thus, if you want to pass, a bit of "rubbin" may be necessary...esp. on the tracks they race upon.

As for now, I will enjoy both F1 and FE...eventually, we will just have an amalgam two.

[Juzh]

I found the last race pretty entertaining, except for the UNREAL amount of team radio. Horrible directing in this regard. When leader crossed the checkered flag there was team radio 10-15s before that and like 30s after. Commentators obviously didn't want to remain silent for the whole minute when the race was ending and you can imagine the horrible mess that was happening with 5 people talking all at once. Completely ruined the ending for me and switched off 30s after the flag.

[Timothycaund]

This years champion and future champions will be the driver who wins the most races.

Yay or nay?

[jjn9128]

This years champion and future champions will be the driver who wins the most races.

Yay or nay?

That's normally how it works isn't it?