Posouzení vlivu uložení rotoru asynchronního motoru na velikost mechanických ztrát

Abstract

This thesis is concerned with the influence of embedding of an asynchronous motor's rotor on the quantity of mechanical losses. First part presents the analysis of the theory and an introduction to asynchronous machines. The first chapter contains a brief description of an asynchronous machine, its history, principle of its operation and its useful energy balance. The next chapter is concerned with production of asynchronous motors with a short-circuit armature. The description of production is aimed at Siemens s.r.o., branch in Mohelnice, which is the largest manufacturer of low-voltage motors in Europe. The production process is briefly described starting from manufacturing of stator and rotor sheetmetals up to complete assembly. This production mapping explains the company's operation and displays the complexity of production and the importance of synchronicity and linkup of individual stations of production. The manufacturing process of top-quality and top-reliability motors to be used by the customers is explained here. The next chapter is concerned with efficiency classes, their breakup, description and related standards. It also describes the influence of mechanical losses on the efficiency. The most important part is practical measurement, which was conducted on the premises of the test room of Siemens o.z. elektromotory Mohelnice company. This modern laboratory was used to generate data from measurements of rotor's embedding and its influence on motor's efficiency, which constitutes the main body of this thesis. Data are compiled in protocols, which are presented as attachments of the thesis. From these protocols, data regarding the effect of mechanical losses on efficiency are extracted and then compared using the Excel spreadsheet processor. The all-around evaluation of three measured types of embedding should then define which components effect the proportion of overall performance losses, which constitutes a benefit for the Siemens company and its end customers.