T
The Phantom
The usual technique for measuring the leakage of a two-winding transformer
is to short one winding and measure the inductance at the other winding.
Imagine a two-winding transformer with one winding (denote this the
primary) having a self inductance of L1, and a winding resistance of R1.
The other winding (the secondary) has a self inductance of L2 and a winding
resistance of R2. The mutual inductance between the two windings is m.
Develop an expression for the impedance (involving the complex frequency s)
seen at the primary if the secondary is shorted.
This impedance will have a real part and an imaginary part. A good LCR
meter can measure both parts, and will probably be able to display the
imaginary part as an inductance. Is this really the leakage inductance?
Under what conditions might it not be a good value for the leakage
inductance?
Can anybody beat Jim Thompson to the punch in developing the complex
impedance expression?
is to short one winding and measure the inductance at the other winding.
Imagine a two-winding transformer with one winding (denote this the
primary) having a self inductance of L1, and a winding resistance of R1.
The other winding (the secondary) has a self inductance of L2 and a winding
resistance of R2. The mutual inductance between the two windings is m.
Develop an expression for the impedance (involving the complex frequency s)
seen at the primary if the secondary is shorted.
This impedance will have a real part and an imaginary part. A good LCR
meter can measure both parts, and will probably be able to display the
imaginary part as an inductance. Is this really the leakage inductance?
Under what conditions might it not be a good value for the leakage
inductance?
Can anybody beat Jim Thompson to the punch in developing the complex
impedance expression?