Use the same power stage for EV controller and charger - Fuel Economy, Hypermiling, EcoModding News and Forum

KUSAW · 10-30-2011, 07:42 AM

Dear all GURUs,
Reading cheap controller and charger, is it also possible to combine both functionality with in one box?
1. Using one micro controller with 2 stored programs?
2. Using same power stage with relays/small contractor combination?
3. Using two separate control stage, one for motor controller and the other one for charger?
The reason behind is for more money saving in box, power stage (IGBT or MOSFET) etc....
Just though
Will be very happy to hear opinions,experience sharing, tutorial or.....
Best regards,
Kukuh

Ryland · 10-30-2011, 12:11 PM

In short, no.
The charger is taking AC power and converting it to the DC voltage that the batteries want then is monitoring that voltage to adjust it and turn off, that monitoring is part of the key to fully charged happy batteries.

I saw a combination charger speed controller the other day and looking at the guts inside of it the charger was at one end of the case and the speed controller was at the other end, there was a little bit of communication between them and they were both hooked to the batteries, but the biggest thing they had in common was that they were put in the same box.

CollinK · 10-30-2011, 08:49 PM

It actually depends. A three phase motor controller is used to alternating current on it's outputs. There is no reason that the power stage on a three phase controller could not also take incoming AC and turn it into voltage destined for a battery. After all, that is exactly what regen is. However, this sort of scheme will only allow one to charge a battery at up to the AC peak voltage. Even then the incoming AC waveform will only be at peak voltage for a very short period of time (well... an infinitely small time technically...) So it is more likely to be able to charge at the RMS value for the incoming voltage or less. That limits you to a 120V pack charger if you use 120V input. To charge at higher voltages you'd need 240V or three phase or you'd have to add hardware to create a boost converter or use a transformer. The transformer is obviously the easiest approach but a suitably rated transformer would be huge and heavy.

At any rate, the reason you don't normally find a hybrid charger/controller is not because it can't be done but because it's more complicated to do hybrid and just plain easier to do it separately. But, if you really want to do it there's always a way. It would even technically be possible to do it with a DC controller but wouldn't be as straightforward as with an AC controller.

sawickm · 10-31-2011, 09:32 AM

Quote:

Originally Posted by KUSAW

Reading cheap controller and charger, is it also possible to combine both functionality with in one box?

This is a link to a open source project that discusses integrating the inverter and charger as one unit.

SourceForge.net: Charger - tumanako

- Mark

Ryland · 10-31-2011, 10:01 AM

With regenerative braking you can't over charge your batteries unless you start out at the top of a large hill with a charged battery so making a 3 phase motor controller have regenerative braking means that you have a rectifier and some crude way to throttle it, and the input voltage is going to be pretty well matched to the battery pack because it's coming back from the motor that the pack was designed to run, it's also seeing just a fraction of the power that the regular speed controller would ever see as well.

KUSAW · 11-12-2011, 08:55 AM

Thanks to all of opinion. Actually I was considering to utilize driver and power stage for motor controller while driving a vehicle and in the other hand use them as driver and power stage while charging the battery pack from AC source, as a charger.....