Influence of Airgap Curvature on the Flux Distribution in Saturated Homopolar Alternators

The two dimensional, non-linear potential equation for saturated homopolar generators is established in circular cylindrical coordinates. The boundary conditions are discussed. The partial differential equation and the boundary conditions are transformed into difference form as preparation for a computer program. A non-uniform polar system of meshes is described and the difference formulae for these is given. The flow chart of a computer program applicable to an IBM 7090 computer is diagrammed. Over-relaxation and alternating direction relaxation techniques are explained. The flux distribution at no-load in a 95 KVA, 115/200 V, 3,400 cps three phase alternator is found with this program. Computed results compare very closely with test results.