Interested In Electric Power

[jmedia]

Hello all,
I have recently started researching electric power for vehicles as I hope to be involved in some sort of alternative propulsion for vehicles with my career someday. I scowered some threads and found some basic info about EVs. The components of the motor, controller, batteries and charger (and others, I am still learning) although I am still a bit confused when it comes to "transmissions".

I started reading about a company I believe aligned with chrysler that created an electric Jeep accompanied with a gas or diesel(i forget) generator in the vehicle to recharge the batteries while driving.

I was curious what complications arise from charging batteries while driving.

Along a different subject, I have browsed the internet and I am still confused DC and AC motors.

My ultimate (and very far away) idea (and a I am very aware that it is far fetched) is to have plans on how to create a Wrangler or Willy's sized EV vehicle with a diesel generator in it, that is as capable as its gasoline counter-part. I know that electric engines can put out the torque and power necessary, its just all about providing enough energy for the motor to do it.

I am just spitballing my dreams right now, thanks for reading and I hope you are not laughing too hard at me

[NeilBlanchard]

DC motors use permanent magnets and AC use coils in both the stator and the rotor. I too am a little confused by the controllers -- I've heard that some DC motors use AC controllers.

AC are often more efficient than most DC motors, but some of the newest DC motors are better still. Powerful permanent magnets are more expensive than doing windings, but if the design can avoid the need for reduction gears, then you can regain the cost advantage, and also keep the overall efficiency higher.

I need to learn more about the controllers, and how/if they differ between DC and AC systems.

[jmedia]

Thanks! I had a slight understanding of DC and AC already, but that helps. I got a more than basic understanding of how ICEs work and it annoyed me how inefficient they are so I started looking into EVs

[jmedia]

So ideally I would need a generator that could output more power than the motor was draining.
And why don't more people use automatics attached to the motor, they a headache to wire? I know I would want a transmission to make highway use more reasonable.

Sorry, just writing my ideas out.
Thanks!

[Daox]

Automatic transmissions aren't as efficient as manual transmissions, so you loose range & power. Neither of which are an overabundance on most EVs.

[Ryland]

with DC motors there are series wound motor with the field coil connected in series with the armature.
Shunt wound motors the field coil is in parallel.
A SepEx motor looks like a Shunt wound motor on paper but has a smaller field coil that gets a lower voltage as the field coil is sepperatly excited (aka Sep-Ex), this allows for better speed control and easy regen braking but apparently (from what I read) not as much brute torque.
A permanent magnet motor does not have a field coil to create the magnetic field, instead it's field magnets are regular magnets, this might sound nice but they tend to produce electrical noise (you will hear the motor running over your radio) and electromagnets can produce a stronger field when needed, the advantage of them is that they work as generators as well so regen braking is easy!
All DC motors need brushes.
Some AC motors have brushes but depending on the AC motor design the job of the brushes can be switched to the solid state electronics of the controller, this means that instead of having a choice of 12 controllers like I have to pick from for my DC electric car, I might have a choice of two, one that is designed for that motor and one that was custom built for that motor and if I had to guess it would cost more then you think your entire project is going to cost, I might be wrong so please keep an open mind and look and research for your self of course!

As far as transmissions go, most people I talk to don't shift there EV much, if ever but instead use the transmission as a simple way to attach the motor to the drive axles without building their own differential.
"wiring up" to an automatic should be simple, but it would be like running with tires that were half flat, your car would feel sluggish, non of that joy you get out of driving an electric car.

[jmedia]

Originally Posted by Ryland

with DC motors there are series wound motor with the field coil connected in series with the armature.
Shunt wound motors the field coil is in parallel.
A SepEx motor looks like a Shunt wound motor on paper but has a smaller field coil that gets a lower voltage as the field coil is sepperatly excited (aka Sep-Ex), this allows for better speed control and easy regen braking but apparently (from what I read) not as much brute torque.
A permanent magnet motor does not have a field coil to create the magnetic field, instead it's field magnets are regular magnets, this might sound nice but they tend to produce electrical noise (you will hear the motor running over your radio) and electromagnets can produce a stronger field when needed, the advantage of them is that they work as generators as well so regen braking is easy!
All DC motors need brushes.
Some AC motors have brushes but depending on the AC motor design the job of the brushes can be switched to the solid state electronics of the controller, this means that instead of having a choice of 12 controllers like I have to pick from for my DC electric car, I might have a choice of two, one that is designed for that motor and one that was custom built for that motor and if I had to guess it would cost more then you think your entire project is going to cost, I might be wrong so please keep an open mind and look and research for your self of course!

As far as transmissions go, most people I talk to don't shift there EV much, if ever but instead use the transmission as a simple way to attach the motor to the drive axles without building their own differential.
"wiring up" to an automatic should be simple, but it would be like running with tires that were half flat, your car would feel sluggish, non of that joy you get out of driving an electric car.

Thanks for all the great info, I'll have to research some of that as I don't understand it all (again EV noob)

But I feel like some shifting would be necessary to a bit more efficient because once you hit highway speeds the ev motor would be spinnin like crazy

[NeilBlanchard]

Well, if it is direct drive like with hub motors or motors set up like those in the FVT eVaro, then the RPM's are actually quite low. 1000RPM with typical 15" wheels (~25" tire diameter) would equal ~74MPH.