Adam Farabaugh
02-20-2015, 07:50 PM
Hey all,
I'm from the Univ. of Pennsylvania. We're a pretty young electric team working on our first car. We are working out kinks from our first car amidst manufacturing our second one and are hoping we could crowdsource a solution to one of these problems.
1) Unitek's NDrive software/motor software will not allow us to set a current limit at 250A. On the settings tab, we cannot set above 85% peak current limit, which is one problem. When we set it to 85%, the software dispalys 270.5A I-pk limit. However the controller does not actually follow this limit. It instead follows a number on the speed tab which changes proportionally to the I-pk-eff on the settings tab, with an experimentally determined I-peak-limit = .28 * I-lim-actual. For example, when the percent on the settings tab is 85%, the I-lim-actual on the speed tab is 681 (unit labeled as percent, but obviously screwed up). This lets us push 191A.
2) Has anyone successfully gotten field-weakening to work with emrax motors? Our controller's response doesn't change at all if we mess with the field weakening settings.
We're going after the manufacturer for answers as well, but thought we'd reach out because we know other teams have run these controller/motor combos and may have worked through this before. Any answer which leads to the problem resolved is a round of beers for your team at Lincoln!
Thanks guys,
Adam
I'm from the Univ. of Pennsylvania. We're a pretty young electric team working on our first car. We are working out kinks from our first car amidst manufacturing our second one and are hoping we could crowdsource a solution to one of these problems.
1) Unitek's NDrive software/motor software will not allow us to set a current limit at 250A. On the settings tab, we cannot set above 85% peak current limit, which is one problem. When we set it to 85%, the software dispalys 270.5A I-pk limit. However the controller does not actually follow this limit. It instead follows a number on the speed tab which changes proportionally to the I-pk-eff on the settings tab, with an experimentally determined I-peak-limit = .28 * I-lim-actual. For example, when the percent on the settings tab is 85%, the I-lim-actual on the speed tab is 681 (unit labeled as percent, but obviously screwed up). This lets us push 191A.
2) Has anyone successfully gotten field-weakening to work with emrax motors? Our controller's response doesn't change at all if we mess with the field weakening settings.
We're going after the manufacturer for answers as well, but thought we'd reach out because we know other teams have run these controller/motor combos and may have worked through this before. Any answer which leads to the problem resolved is a round of beers for your team at Lincoln!
Thanks guys,
Adam