×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Switched Reluctance Motor Inductance Test

Switched Reluctance Motor Inductance Test

Switched Reluctance Motor Inductance Test

(OP)
Dear All,

I have done an inductance and winding resistance test for 75 KW SRM Motor. How could I determine whether the motor is in good condition or not based on the Inductance test result. The test has been done offline.

1) Inductance test at 100 HZ using LCR Meter :
A1-A2 @ 100Hz Lmin = 0.93
A1-A2 @ 100Hz Lmax = 4.38
A phase Lmax/Lmin Ratio = 4.38/0.93

B1-B2 @ 100Hz Lmin = 1.63
B1-B2 @ 100Hz Lmax = 5.24
B phase Lmax/Lmin Ratio = 5.24/1.63

C1-C2 @ 100Hz Lmin = 0.44
C1-C2 @ 100Hz Lmax = 0.48
C phase Lmax/Lmin Ratio = 0.48/0.44

2) Insulation Resistance Test at 1000 V:
A1 or A2 to earth = 0.8 GΩ
B1 or B2 to earth = 0.9 GΩ
C1 or C2 to earth = 0.9 GΩ

A1 –B1 = 2.2 GΩ
A1 –B1 = 2.1 GΩ
A1 –B1 = 2.2 GΩ

3) Winding Resistance Test :
A1 - A2 = 0.4 Ω
B1 - B2 = 0.3 Ω
C1 - C2 = 0.3 Ω


Thank you.

RE: Switched Reluctance Motor Inductance Test

What about inductance variation with respect to the rotor position?
Was the test performed on an assembled motor, or with the rotor removed?

John

RE: Switched Reluctance Motor Inductance Test

(OP)
The test has been made on assembled motor. We just rotate the rotor and take the inductance reading without knowing the rotor position.

RE: Switched Reluctance Motor Inductance Test

I don't know much about SR failure modes, but I don't see how you could get any torque out of Phase C, since the torque is proportional to dL/dTheta. I am also uncomfortable about the difference between A and B values.

RE: Switched Reluctance Motor Inductance Test

An assembled motor can, will, and does give erroneous winding test results.

John


RE: Switched Reluctance Motor Inductance Test

(OP)
According to R.Krishnan,‘‘Switched Reluctance Motor Drives, Modeling, Simulation, Analysis, Design, and
Applications’’
. The range of the ratio between unaligned and aligned inductance should be 0.07 < Lmin/Lmax < 0.18 which Lmin is unaligned and Lmax is aligned rotor. Can it be used as reference since we don't know the rotor position?

RE: Switched Reluctance Motor Inductance Test


Watch your LCR meter as you rotate the motor slightly between rotor bars you will see quite a change, I think in
EE speak this is called "Q" factor however I agree with previous replies, position of rotor is significant.

Chuck

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources