Electric car - construction

Apr 18, 2015 9 Replies

Hi.



I would like to hear your opinion regarding the controller setup.



Controller that am planning to use is able to deliver 100A continually and 200 peak ( for 5 seconds ) on 72V.



Controller has inbuilt current and temperature protection but i dont know if 200A peak would be enough for standard drive. Am guessing that motor can pull 300 A easily so this controller could be a problem.



Btw. motor is running at 2200 rpm and it will be used on 600 kg car.



Should i go with this controller ?


No. I would look for a unit rated for higher amperage.

I had a Alltrax NPX4834 controller (Rated 300 amp peak 275 amp for 2 hours) on a gokart that weighed less than 160kg. From a standing start it would draw just over 250 amps which would gradually decrease to 40 amps at full speed. I perused this forum for a while before putting my kart together. It is a great source of knowledge.

formatting link
What HP is you motor? Voltage rating? Amp rating? Mikek

---------------- I was just noticed that i didnt write motor details :-) Motor is DC 72V / 87 A , 5KW, 2200rpm

I am user on DIYEC how quite some time but i didnt get reply so i was post it here. Am little short on production time :-). Btw. diyelectriccar IS the main source for such stuff.

------------------

---------------- I just noticed that i didnt write motor details Motor is DC 72V / 87 A , 5KW, 2200rpm

I am user on DIYEC for quite some time but i didnt get reply so i post it here. Am little short on production time :-)

Btw. diyelectriccar IS the main source for such stuff i agree with that.

Your controller would be hopelessly underrated for such a motor.

NT

Hmm, that may be a bit weak. I built an electrified VW bug about 30 years ago. I had a 48 V battery stack, and it ran great around town on 250 A. That's 48 * 250 = 12 KW. Your 72 x 100 = 7200 W. Unless this thing is REALLY small and light, it won't be anywhere enough.

600 kg? Your batteries are likely to have to weigh something like 300 kg to get any running time at all, so that doesn't keave much for the rest of the car, unless you have lithium batteries.

Jon

Oh, my electrified VW used a GE jet engine starter/generator with a 13 A field controller, and just put the full 48 V battery across the armature. That was rated at 400 A continuous, and something like 1300 A for one minute during engine start. It was a 28 V motor/gen, but ran fairly well at 48 V. I don't know how long the motor would have lasted under those conditions.

Jon

----------------------------- I bout before cca 2 years, one kit for open source dc motor controller project. The controller is from

formatting link

Unfortunately we didn't complete it. It looks that now is a good time to do this :-) Max current is 500A and it can run over 30 min on 200A. Maybe it can run longer, but this was not tested.

If someone has used this controller, any input is welcome !

Best regards.

Hmm, That's what I did, 28v motor run on 48 volts. Mine was only rated at 56amps. But every time we drove it, it got maxed out for a short time at 250 amps. Until the last time. It last a couple years before the smoke came out. Mikek

Motors have a point where more current doesn't give them any more torque because the core saturates. Permanent magnet motors also have a point where the magnets will be depolarized by too strong of a field.

I will not see posts from astraweb, theremailer, dizum, or google because they host Usenet flooders.

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required