Eddy current and skin effect in edgewise wound copper coils

Solutions for a 13-turn edgewise-wound copper coil have been obtained using linear eddy-current and skin-effect finite-element programs. The finite-element solutions for a frequency range of 60 to 360 Hz are used to calculate losses for the case of air and constant-permeability iron cores for the edgewise-wound coil. The finite-element solutions are compared to test values with and without an iron core. Calculated AC-to-DC resistance ratios compare favorably with test results for air cores and depend on the interlamination resistance for iron cores. Solutions for a shorted turn are examined using the eddy-current and skin-effect code. The shortest-turn solutions illustrate that the field distortion near the coil allows the shorted turn to be identified