Electromagnetic modeling of large hydro electrical generators using 2D finite element method

Abstract

With the ever increasing of the demand for electrical energy, the need for additional power has already become a reality in the energy supply market. In this context, increasing the power output of existing generators is considered as a promising and beneficial option. Unfortunately, the available methods today do not allow exploiting the full power potential of the existing generators with a precise evaluation of the impact of this increase on the residual lifetime. The challenge in uprating a large existing machine therefore is increasing the output power within the safety limits and without reducing the reliability of the system. One of the goals of Hydro-Québec is to develop new techniques which permit identification of units with potential for up rate. The understanding of the electromagnetic fields inside the generator and their implication in the losses is the first step to fulfil this goal. This thesis focuses on analyzing the electromagnetic field and establishing the magnetic core losses for different machine configurations and operating conditions. The electrical machine in question is a low-speed, salient poles synchronous generator. Initially, a literature review of the related subjects published in the last 20 years was investigated. Secondly, modelling analysis and simulation of large electrical machines using commercial software to compute the losses at the steady state was also done. Moreover, validation of this work and analysis is done using measurements of losses with emphasis on the core losses and magnetic flux density. The core loss matrix generated by FEM was also compared with the thermal calculation and measurements of the hotspots of the machine. The results from FEM simulation in comparison to the experimental measurements are presented for two machines (Manic 21 and Rapide-des-Quinze). The simulation and experimental results were in a good agreement.

Date	17 Dec 2014
Original language	American English
Awarding Institution	École de technologie supérieure
Supervisor	Kamal Al-Haddad (Supervisor) & Arezki Merkhouf (Co-supervisor)