PM Electrical machine V/Hz characteristic
PM Electrical machine V/Hz characteristic
(OP)
Hi guys, i would like to give me your opinions about a problem i have. In our university laboratory we have designed and built a permanent magnet electrical machine and when we test it the Voltage/Frequency characteristic is not constant as we expected. You can find the graph on the link below. We thought that the rotor is vibrated due that some of the rotation frequencies coincides on rotor's eigenfrequencies, but i have strong doubts about that. What is your opinion?





RE: PM Electrical machine V/Hz characteristic
Bill
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"Why not the best?"
Jimmy Carter
RE: PM Electrical machine V/Hz characteristic
One of three phases is linear and the other two are oscillated. Why this is happen?
Also i forgot to mention that we rotated the rotor using a drill, but we checked it four times with no changes.
RE: PM Electrical machine V/Hz characteristic
But, one phase good and two with issues suggests possible assembly issues.
Bad workmanship and turn to turn shorts.
Improper orientation of laminations.
Eddy currents due to shorted laminations.
Non uniform iron.
Uneven air gaps.
Please share some construction details.
Bill
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"Why not the best?"
Jimmy Carter
RE: PM Electrical machine V/Hz characteristic
The shaft's length is 90mm and the length of the active core is 45.
Can you tell me what other construction details do you need?