Magnetic Saturation Analysis of Cylindrical Synchronous Machine by Perturbation Series Expansion and a Method for Steady State Characteristics Calculation

Abstract

Power system dynamic performance is very much affected by synchronous machines model. In particular, magnetic saturation gives substantial effects and its physical interpretation is usually complicated and difficult. Therefore saturation phenomenon has been studied long in the field of electric power system and machine analysis. Recently numerical magnetic field analysis such as FEM are widely used to consider this effect, but it needs heavy computation of large dimension matrix and necessary computing time is too long for us to apply it to multi machine power system analysis. From the viewpoint of power system analysis more sophisticated and compact model is highly required. This paper proposes a new method to take into account effects of magnetic saturation in a synchronous machine with a cylindrical rotor. It gives the additional calculation which represent the effects of magnetic saturation using so called perturbation series method applied to the nonlinearity in the magnetic permiability. Using the model generator it is confirmed that the proposed method shows good accuracy even in heavily loaded condition, in which linear analysis failed.