Nonlinear Magnetic Field Analysis of DC Machines, Part III: Equipotential Plots Drawn by Computer

A computer program for establishing the equipotential plots in the cross section of a dc machine is described. The necessary steps are as follows: 1) scanning of the gridlines in the cross section to find the points of definite magnetic potentials from the discrete vector potential; 2) finding the location of the point of the mesh section containing the given vector potential by interpolation; 3) expressing the positions of the points in rectangular coordinates and finding and printing out all points of the same vector potentials by a CalComp computer. This procedure is carried out for several values of the vector potentials to obtain a comprehensive plot of flux lines.