Lifetime Extension of the High Voltage Asynchronous Machine in Relation to the Voltage Endurance Test

Abstract

Abstract The aim of the study is to achieve a simple, reliable and significant lifetime extension of the high voltage asynchronous machine in relation to the voltage endurance test. In order to achieve this goal, the focus was on achieving a longer-lasting and more stable insulation of the stator package of an asynchronous machine. Longer-lasting and more stable insulation of a stator is achieved by reinforcing the weak points on its prefabricated multiturn coils. These reinforcements were performed with standard insulating materials that are used for the production of the prefabricated multiturn coils (because of the fact that there is no data regarding the long-term behavior of new materials that show some better properties in laboratories, but only during short-term tests). With such reinforced weak spots on the basis of prefabricated models, they were made by the classical procedure with the use of standardized tools. In order to track the effects of the improvement of the insulation characteristics of a stator, an algorithm was developed based on the law of the increasing probability and on the determination of lifetime curves to the voltage endurance test. The lifetime curves were determined by the method of increasing voltage with the transformation of the obtained results to the corresponding results by the constant voltage method. The applied algorithm that was formed for the purpose of this study, had been verified with statistical reliability of 95 %. The combined measurement uncertainty of the measurement procedure was about 5 %.