3-DIMENSIONAL EDDY-CURRENT CALCULATION WITH INTEGRAL-EQUATION METHOD FOR TRANSFORMERS

To calculate eddy current on multiply connected magnetic substances, t he frequency domain volumetric integral method has been developed, Thi s method requires no air space grid; therefore, it is suitable for com plicatedly structured objects such as transformers, Verification tests using simple plates show good agreements with analytical solutions. T wo application tests to transformers are presented, In the Ist test wh ich examines the magnetic flux density in the clamping plate, the calc ulated results agree with the measured ones within 10 to 30%. In the 2 nd test which compares the calculated eddy current density with the me asured temperature rise on the clamping plate, their results agree for the distribution property, Suitbility of this method for eddy current evaluation in power transmission equipment is confirmed.