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Inductance measurement ?

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ziumus
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Joined: 2018-09-14 10:33
Posts: 24
Inductance measurement ?

Hi,

I have problem with my custom board,inductance measurement are 2x times higher than official board vesc 4.12.

and inductance detection is lot noisier.

My board uses 3 low side current amplifiers AD8418.

Everything works fine except sometimes i got ABS_overcurrent.

When i adjust inductance manually , error is gone.

What can be cause wrong measurement ?

Thanks

 

 

 

El3ctr0n1c
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Last seen: 2 weeks 5 days ago
Joined: 2019-02-20 19:57
Posts: 4

Hi,

Can U show Your's custom PCB layout? MCU can measure board parasitic inductance. When Your's motor have low inductance error is more visible. Wrong inductance value in VESC results incorrect current control loop and it may be source of error. Try put low  ESR/ESL (ceramic,metal film caps) near to power stage (as close as possible to FETs) and try detection again.

 

 

ziumus
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Joined: 2018-09-14 10:33
Posts: 24

I will try to put capacitors closer to the mosfets.

Thanks

 

a.dahhak
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Joined: 2020-02-27 12:04
Posts: 17

 

 

Hi guys,

I have also false inductance measurement, but I think my problem is coming from the motor I use.

When I use a ready to run motor from T-motor everything seems fine, but when I try to mount my own motor (stator and rotor hooping), my measured inductance is different from a Dcy to another (picture below)

My motor runs fine at no load, but whenever there is a load it's struggling. Any help please ?

 

indc_measure.PNG

Abdelilah