Trouble running low bemf bldc on IMM101T

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User19730
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First question asked First reply posted
Hi, I'm new to iMotion and have trouble running small bldc which is for hdd spindle with recently bought EVAL-IMM101T-046

I've measured and configured parameter with MCEWizard, but the wizard complains that it can not set low back emf constant.

I thought IMM100 is supposed to be used for small bldc, am I doing something wrong?

Below is measured parameters

I would definitely be appreciated for any help, thank you.

Nidec 275F-42MY-01
Rated Amps = 0.6 A
Motor Poles = 12
Stator Resistance = 2.975 ohms / phase
Inductance = 0.3822 mH / phase
Back emf constant = 0.1260V / 44.64Hz * 6 * 3.4 = 0.5758V
(according to https://www.infineon.com/dgdl/Infineon-How-to-Measure-Motor-Parameters-ApplicationPresentation-v01_0...)
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User19730
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First question asked First reply posted
I finally managed to get it run sluggishly,

- change norminal DCP to much lower 24V, changed high side resistor to 200k
- make minimal rpm much higher so flux is picked up.
- set starting open loop current ramp to 100%

I still have trouble tuning to start with angle sensing and rotating with attachment inertia throws Flux PLL out-of-control exception.
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snget2
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1. Is this 3 phase motor?
2. What is motor max speed, or rated speed?
3. Are you able to run the motor normally without a load?
4. How is start up with no load?
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User19730
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First question asked First reply posted
snget2 wrote:
1. Is this 3 phase motor?
2. What is motor max speed, or rated speed?
3. Are you able to run the motor normally without a load?
4. How is start up with no load?


Thank you for stopping by,

1. it is 3 phase bldc motor
2. I was able to run the motor up to 9000+ RPM with DRV11873
3. Running in open loop works, but it fails when changing to closed loop with speed control.
does not seem to work properly with loads in both open/closed loop, I assume it may handle the load since initial angle sensing is able to jerk with the load.
4. Open loop accelerating is ok, after that either Flux PLL out-of-control or Gatekill Fault throws

I've attached photo of disassembled motor for reference:

4474.attach
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snget2
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5 sign-ins First like received 25 replies posted
1. Did you Verify parameters are properly measured? Resistance, for example, should be (phase-to-phase / 2). When running the motor without load, check the Flx_M trace value. If it is > 2048 counts, increase Ke value until Flx_M is stable and at 2048 counts. Next, follow the Software Reference Manual v1.3 Section 4.
2. IMM101T-046 is meant for high voltage (230VAC line connected applications). It is not optimized for low voltage applications. Consider our other evaluation boards for low voltage
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