3D harmonic model of the end region for turbogenerators
Purpose - The large size of models and long computing time prevent the creation of full-scale, three-dimensional models of end region of turbogenerators. Only exact three-dimensional model can illustrate complex phenomena of end region losses. Also some methods of decreasing such losses cannot be simulated in two-dimensional models. The purpose of this paper is to focus on a method of creating three-dimensional models of turbogenerators' end regions for calculations of eddy current losses. Design/methodology/approach - Time-stepping is the most expensive part of computation. A harmonic model would be free from that disadvantage and it can provide a tool to make an accurate, fully three-dimensional model of a steady state for different loads and provide results in a reasonable time. Findings - The research focuses on the method of creating three-dimensional models of turbogenerators end region for calculations of eddy current losses. By using two-dimensional, time-stepping models and empirical loss functions for a main flux and three-dimensional models for eddy current losses from a perpendicular flux of an end connections, it is found that fast analysis of that complex part of a machine can be achieved. Originality/value - The approach proposed in the paper is a universal and novel method of calculation losses of turbogenerators' end regions. Combining two-dimensional and three-dimensional models provides advantages of both known methods: fast computation time from simplified models and good representation of complex geometry of a machine.
modelling end region turbogenerators eddy currents eddy current losses turbines electric generators finite element method 3d modelling methods