Aboutcleggsan Expertise All technical areas of Electronics Engineering.
Experience BSEE, MBA, Design, R&D, University Research.
Senior Life Member of IEEE. Life Fellow of AES.
Organizations IEEE, Consumer Electronics Society, Audio Engineering Society.
Broad teaching experience; work experience mostly in consumer electronics and conversion from analog to digital technologies. Pioneer in digital audio at all levels.
Question Dear sir,
I am not sure the questions that I have need to be directed to a person with your back round or if they should be sent to someone that works in some other area. My quandary is this: I am trying to find out what size in inches/HP/wattage/or any other unit of measure, what size electric motor I need to push an electric vehicle down the road at approx. 70-75mph. I have a very heavy vehicle estimates of 5800-6000 lbs. and it has a drag coefficient comparable to a Hummer Say 3.5-4.0. The final drive ratio is a 3.0 differential, and I plan on using an automatic transmission (manual would be OK too)that has overdrive of approx. .79:1, though I am not sure that number is accurate. If I need to I can have a manual transmission built to have a pretty tall ratio if I need it. Additionally, I will need information as to how much sustained power will be needed to have a continuous duty cycle. Mainly level ground... although some hills may be encountered. I recognize that the tire size will have an effect on all this as well... but those are easily adapted to improve the ratios.
If this is an area I am wasting your time and valuable knowledge with, please direct me to someone who might have expertise in this area.
I sincerely appreciate your consideration.
All the best,
Dean
Answer Yes, this is out of my direct area; but an interesting question. It is one that I would delve into if I had the time to do so as we would both gain a lot of knowledge.
There are some quantitative hurdles to go through to calculate the power requirements you would need. And, being automotive in nature it requires someone with experience in the amount of extra power to accelerate a big object like that and the motor requirements during acceleration as opposed to the steady state.
You might just start by looking at the Hummer with combustion engine and work those requirements back into a motor driven system. In any event, you will need a pretty hefty motor system and some pretty heavy batteries to power it up.
Please try the other experts on the EE list; they may have good skill in this area.
