Two Dimensional Field Analysis of Cylindrical Synchronous Machine by Variables Separation and a Fast Calculation Method of Steady State Characteristics

Abstract

This paper proposes a new method for the magnetic field analysis of a synchronous machine with a cylindrical rotor. It gives the two dimensional magnetic field distribution in the machine by solving a partial differential equation which describes the steady state balanced operation. Radial and rotational components of the magnetic permiability and resistivity are independently defined to take into account the magnetic anisotropy inherent in its slotting structure. The study machine is divided into several coaxial cylinders, where the potential distribution is described by a few parameters, which are to be solved to satisfy the boundary value conditions between every neighboring cylinders.
The proposed method is applied to a model generator, and the calculation results are well agreed to FEM analysis which has been shown to agree well with measured data. Because it needs no massive numerical calculation, high computing speed is expected which enables us to apply it to multi machine power system analysis. Moreover, it can be expected to handle the effects of magnetic saturation by combinatorial use with the perturbation based scheme.