Determination of iron alloy used in motor or generator laminations

[jared1313]

Hi there,

I have a BLDC that I would like to model as a generator. How might I determine the type of iron alloy used in the laminations so I can account for this in the model? I thought that maybe there would be an industry accepted method of determining the core material based on hysteresis and losses. I hoping to avoid sending a sample to a metallurgist. I prefer to identify a simple method of somehow testing the metal using electronic test equipment.

Thanks,
Jared

 

[jpts]

Epstein frame test is the common way, but you can't apply it for the existing motor. You would need to make sample strips from the same batch where core laminates were manufactured and measure them in a special setup (so it's not actually that simple way)

I would suggest to contact motor manufacturer and ask for lamination grade. They might not be willing to share this info, but you can always try

Alternative way would be to model it as a motor with few different grades, and see which matches the best vs measurements

 

[jared1313]

Thank you jpts. I did stumble across the name epstein test while trying to google this, but I wasn't sure if there were other methods as well. I thought there might be a way to back out the permeability in a way similar to testing ferrite and toroidal cores and trying to match up to know materials. It does sound a bit beyond my means at this time.

I did attempt to contact the manufacturer which is based out of China, but they never responded. I believe the company is Hang Hong Motor (

http://www.hanghongmotor.com/en/),

but I am not positive. This is the BLDC used in the so called "Hover Board" devices that kids seem to be riding all the time these days. Since the hover boards are so inexpensive I assume the lamination material is nothing exotic as that would certainly drive up the cost.

I do like the idea of modeling it as a motor with differing grades and comparing the results with my measurements.

Thanks,
Jared

 

[jpts]

Yeah, then it's probably something very cheap and commonly used grade. According to my experience from Chinese motor manufacturing, 50WW470 -grade is one of the most common grades, and one of the cheapest (if not the cheapest) while still offering rather good performance. Attached you can find its performance characteristics in case you want to do some modeling. If I would have to guess, I would choose this grade to start with

 

[jared1313]

Awesome! Thank you for that suggestion and for sharing the file as well as your knowledge. That is a great jump start! I would never have had any idea what they commonly use in their motors.