Buggies Gone Wild Golf Cart Forum - View Single Post

Fairtax4me · 11-12-2019, 10:29 AM

From my prior experience with much smaller AC brushless motors, there is a drastic difference in power consumption over a comparable power DC motor setup. I would expect anything from 10 - 30% (depending on how you drive the cart) increase in range over a DC motor. There is significantly less friction in the design because there are no brushes to slow the rotation of the armature. And because of the design of the motors there is less loss of energy due to heat because of the way the field coils are designed, and that there is no current having to pass across brush contact points to get to the armature. Less heat + less friction = more energy efficient from the start.

AC motors can actually regenerate a small amount of current that can be fed back into the batteries while the motor is running under power. Every revolution of the motor leaves one field coil un-powered and the magnetic field change through that coil is used to partly determine armature angle, which is useful for alot of functions of the controller, and is also useful because that change in the magnetic field sends a little bit of power back to the controller. If the controller is configured properly, it can reclaim some of that and put it back to the batteries, even while you're still pressing the go pedal.

I considered one of these Navitas AC kits for a project I'm looking into. I'm not entirely convinced of the reliability of the Navitas setup at this point. If Alltrax had one I wouldn't think twice.

11-12-2019, 10:29 AM	#6
Fairtax4me Bonafide Nincompoop Join Date: Dec 2015 Location: Charlottesburg Va Posts: 8,987	Re: Navitas ac conversion kit From my prior experience with much smaller AC brushless motors, there is a drastic difference in power consumption over a comparable power DC motor setup. I would expect anything from 10 - 30% (depending on how you drive the cart) increase in range over a DC motor. There is significantly less friction in the design because there are no brushes to slow the rotation of the armature. And because of the design of the motors there is less loss of energy due to heat because of the way the field coils are designed, and that there is no current having to pass across brush contact points to get to the armature. Less heat + less friction = more energy efficient from the start. AC motors can actually regenerate a small amount of current that can be fed back into the batteries while the motor is running under power. Every revolution of the motor leaves one field coil un-powered and the magnetic field change through that coil is used to partly determine armature angle, which is useful for alot of functions of the controller, and is also useful because that change in the magnetic field sends a little bit of power back to the controller. If the controller is configured properly, it can reclaim some of that and put it back to the batteries, even while you're still pressing the go pedal. I considered one of these Navitas AC kits for a project I'm looking into. I'm not entirely convinced of the reliability of the Navitas setup at this point. If Alltrax had one I wouldn't think twice.