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Induction motor sevcon gen4 issue

Posted: Jan 06 2020 8:57pm
by Inwo
8kw induction motor runs fine using s6 80v controller in 2000lb vehicle.
Same motor runs great using s4 80v gen4 in <1000lb vehicle.

S4 in the heavy vehicle chatters harshly at low speed and high torque demand.
I don't know the proper term for this. Cavitation, cogging?

Turning the drive profile torque down to 60% works, but at high cost in acceleration.

It may be as simple as clipping on overcurrent. Although full throttle in torque mode is fine when over a couple thousand rpm.

A way to limit torque at low rpm may cover up the problem.

Lower performance is expected with the smaller controller, but not this extreme.

Re: Induction motor sevcon gen4 issue

Posted: Jan 07 2020 11:39am
by www.recumbents.com
It sounds like the controller is having a hard time staying in sync at lower RPMs. Is it using hall sensors to determine the motor phase?

Warren

Re: Induction motor sevcon gen4 issue

Posted: Jan 07 2020 11:53pm
by Inwo
No, it's an induction motor with ab sensor.
Same motor and programming works fine in s6.
Am I wrong to expect it to work with s4 at lower performance?

It may be hitting a hard current limit and clipping. I would expect it to lock out in that case.

I'm looking for a way to limit torque at low rpm. It runs fine cutback to 60% torque.
I can start in a reduced torque mode, then switch to 100% drive profile, with good results.
I'm looking into triggering drive 2 from low speed.

My dld does not seem to have a table that sets torque/rpm.

Does someone have a new file for an 8kw induction motor?

Re: Induction motor sevcon gen4 issue

Posted: Feb 07 2020 11:42pm
by Inwo
More sevcon induction motor questions.
What do you suppose Polaris is trying to accomplish with this slip map?
Extracted from 2012 Ranger 8kw 48v s6 gen 4. I am using this in another vehicle.
Log shows full throttle and torque. Performance is lacking. Less than 300amps under heavy load. 6000rpm limit. Not hitting drive profile limit. Limited by torque to 6000rpm and 30mph.

Re: Induction motor sevcon gen4 issue

Posted: Feb 07 2020 11:45pm
by Inwo
Compare to this from a 72v e-zone 7kw s4 gen4 induction motor drive.
I have both files if someone needs them.
zone oem slip.gif
zone oem slip.gif (79.92 KiB) Viewed 714 times

Re: Induction motor sevcon gen4 issue

Posted: Mar 02 2020 8:42pm
by OpenGB4
Hello Inwo - Do you have the dvt software running on a PC? Can you provide some COB data library files?

Re: Induction motor sevcon gen4 issue

Posted: Mar 02 2020 8:45pm
by OpenGB4
I working on a EV setup with the ME-1507 IPM motor for Polaris RANGER UTV. I'll try to get a SEVCON GEN4 S4 to run this motor. However, a better controller choice appears to be the SME AC-X1 375/188A model; which still has very long lead time. Do you have a EV system on a Ranger?

Re: Induction motor sevcon gen4 issue

Posted: Mar 06 2020 1:39pm
by Inwo
I don't have a ranger, but I have the controller and files. S4 and s6 gen 4 controllers. Also 8kw induction motors and big Pmac motors for transaxle mount.
I was hoping to run higher voltage, but the ranger files from s6 48v won't run in an 80v s6.

Re: Induction motor sevcon gen4 issue

Posted: Apr 05 2020 5:18am
by voltaic-freak
Inwo wrote:
Mar 06 2020 1:39pm
I don't have a ranger, but I have the controller and files. S4 and s6 gen 4 controllers....
Hey, i've got a bust controller out of my ranger, would you consider selling your S6 Gen 4?

Re: Induction motor sevcon gen4 issue

Posted: Apr 12 2020 11:31pm
by Inwo
Yes, I would.
I have files now, so I can clone another, but I paid good money for my s6 controllers.