Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - Paul and Sabrina's Cheap 3 Phase Inverter (AC Controller) with Field Oriented Control

thingstodo · 06-16-2017, 01:11 PM

I now have 3 of the 4 Ranger EV's at home and have spent some time looking through the various connectors and parts of the vehicles.

The motor is a Permanent Magnet AC motor (what is the different between PMAC and Brushless DC or BLDC?), but I have no ratings on voltage or max speed.

The Sevcon Gen 4 AC controllers are rated for 650A and have a 48V DC pack (somewhere around 43V is low voltage cutout and the original Lead-acid charger floats at 57.6V). The docs don't mention a boost circuit and I cannot locate an inductor so I expect that the motor is driven directly by PWM of the pack voltage. Speed is limited to 25 kph but I am confident that is a setting in the controller and not a limitation of the motor.

There is encoder feedback although I won't know what voltage until I get a service manual.

Paul - driving this motor (eventually) with my AC controller - would I need to load different firmware or is that a setting change? I have a lot of work to do getting everything else working first, before I venture into replacing the controller and running it at higher top end speed.

I think it would make an interesting video to start from 'here is a motor mounted in a vehicle drive train' and progressing through 'there is not much info on the motor but we entered what we had', 'here is how we did the initial tune' and finally 'this is how it runs after we played with the tuning some more'. It will likely be at least a year before I get to that point though.

What do you think?

06-16-2017, 01:11 PM	#3130 (permalink)
thingstodo Master EcoModder Join Date: Sep 2010 Location: Saskatoon, canada Posts: 1,488 Ford Prefect - '18 Ford F150 XLT XTR Tess - '22 Tesla Y LR Thanks: 749 Thanked 565 Times in 447 Posts	2011 Polaris Ranger EVs I now have 3 of the 4 Ranger EV's at home and have spent some time looking through the various connectors and parts of the vehicles. The motor is a Permanent Magnet AC motor (what is the different between PMAC and Brushless DC or BLDC?), but I have no ratings on voltage or max speed. The Sevcon Gen 4 AC controllers are rated for 650A and have a 48V DC pack (somewhere around 43V is low voltage cutout and the original Lead-acid charger floats at 57.6V). The docs don't mention a boost circuit and I cannot locate an inductor so I expect that the motor is driven directly by PWM of the pack voltage. Speed is limited to 25 kph but I am confident that is a setting in the controller and not a limitation of the motor. There is encoder feedback although I won't know what voltage until I get a service manual. Paul - driving this motor (eventually) with my AC controller - would I need to load different firmware or is that a setting change? I have a lot of work to do getting everything else working first, before I venture into replacing the controller and running it at higher top end speed. I think it would make an interesting video to start from 'here is a motor mounted in a vehicle drive train' and progressing through 'there is not much info on the motor but we entered what we had', 'here is how we did the initial tune' and finally 'this is how it runs after we played with the tuning some more'. It will likely be at least a year before I get to that point though. What do you think? __________________ In THEORY there is no difference between Theory and Practice In PRACTICE there IS!