Motorpoles
- Thread starter Efu
- Start date
major
10 kW
Hi,
Number of poles = 120 * frequency / RPM. Frequency is in Hz or cycles per second.
Rotate motor at known RPM. Measure frequency of the signal generated on motor phase leads with frequency meter or oscilloscope.
Or, apply known frequency to motor leads and measure RPM. Then use above formula.
Magnetic poles only come in pairs. So you will necessarily have an even number, ie. 2, 4, 6, ... 18, ... 40, etc.
major
Number of poles = 120 * frequency / RPM. Frequency is in Hz or cycles per second.
Rotate motor at known RPM. Measure frequency of the signal generated on motor phase leads with frequency meter or oscilloscope.
Or, apply known frequency to motor leads and measure RPM. Then use above formula.
Magnetic poles only come in pairs. So you will necessarily have an even number, ie. 2, 4, 6, ... 18, ... 40, etc.
major
Thanks for answer
Was kinda hoping i could just turn the wheel and feel resistance on each pair.
You got any good link on wiring and setup to do it?
Motor is
Item features:
Application: Motorcycle/ E-scooter/ Electric bicycle/ Wheelchair/ Electric tricycle/etc.
1. wheel: standard international A356 aluminum heat treatment.
2. magnetic steel: standard 38H
3. iron core: DW350 lamination
4. Hall: Honeywell can resist high temperature: 150
All info i can find
Was kinda hoping i could just turn the wheel and feel resistance on each pair.
You got any good link on wiring and setup to do it?
Motor is
Item features:
Application: Motorcycle/ E-scooter/ Electric bicycle/ Wheelchair/ Electric tricycle/etc.
1. wheel: standard international A356 aluminum heat treatment.
2. magnetic steel: standard 38H
3. iron core: DW350 lamination
4. Hall: Honeywell can resist high temperature: 150
All info i can find
There are many possible configurations so just feeling the cogging won't tell you enough.
You could apply 5v or 9v to one of the hall sensors and put a meter on the signal line, then count how many times it toggles in one revolution. This would tell you how many magnets there are. It has to be an even number.
You could apply 5v or 9v to one of the hall sensors and put a meter on the signal line, then count how many times it toggles in one revolution. This would tell you how many magnets there are. It has to be an even number.
Efu said:
Yes. Typically all 3 have the same power wires. Then just measure one signal as you make a revolution.
So for sure you have 20 magnet poles. Just wild guess you probably have 18 stator poles.
Depends maybe on the controller. I would use 20.
Have tested 20 but rpm and speed dont match. Set the poles to 40, and rpm matches speed.
Was hoping i could increase speed a little but i dont know if motor is at max rpm.
Have 360 rpm freewheel.
From manual.
Up to 70,000 electric RPM standard. (Electric RPM = mechanical RPM * motor pole
pairs;Motor pole pairs=Motor poles/2).
E rpm=360*(40/2)
Erpm=7200
Is this max rpm of motor?
Was hoping i could increase speed a little but i dont know if motor is at max rpm.
Have 360 rpm freewheel.
From manual.
Up to 70,000 electric RPM standard. (Electric RPM = mechanical RPM * motor pole
pairs;Motor pole pairs=Motor poles/2).
E rpm=360*(40/2)
Erpm=7200
Is this max rpm of motor?
The motor could be limited by the battery voltage and BEMF of the motor or there could be some kind of speed limiting in the controller. Sometimes its hard to tell the difference. One test would be to get it going full speed then apply a small amount of load (use the brake) and see if the speed drops. If you are BEMF limited, the speed will drop slightly with a small load. If you are electronically limited, the speed will stay exactly the same with a small load.