Measurement of Leakage inductance in transformers

Posted by: shyamzz on 02/01/2011

Hi,

What is the exact method to measure leakage inductance using normal LCR meter.
I tried to measure the leakage inductance using commonly available LCR meter. The leakage inductance i get is not anywhere near to the value specified by my transformer manufacture. The test report he gave specifies the leakage inductance is less than the max required by design generated by PI Xls . But when i measure the leakge inductance is 4 times high.

My transformer manufacture test report says:

1. Inductance @1 khz /300mv/series pin(1-3) = 444uH
2.Leakage inductance at 100Khz/300mv/S pin(1-3)with all windings shorted= 8.77uH (which is <13.3uH specified by PI Xls)
3.HV Test (1-3) to (4-6)= 2.5KVAC/5sec

The LCR meter he used is Precision LCR Meter from Agilent 4284A.

Does the measurement varies the device they use and the commonly available LCR meter.

Thank you.

Regards,
ShamSundar.E

Comments

Hello Sham,

If your measurement is that much off compared with the report I can not see any reasonable explanation. Make sure you use the same voltage level and frequency for the test signal and any other winding is short circuited (except for the primary winding you measure). Agilent 4284A is quite precise if is not defective. Use a calibrated inductor and see if your meter gives you the right value. Check the measurement connection and the terminals to be clean.

Cheers,
PI_Crusher

What about the Bias winding, should it be also shorted ot it should be open?

ShamSundar.E
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