ESTIMATION of THERMAL STATE of AC ELECTRIC MOTORS of TRUNK GAS PIPELINES COMPRESSOR STATIONS

Abstract

The relevance of the research is caused by the requirements for equipping the main technological equipment of compressor stations of trunk gas pipelines with monitoring systems. These systems should provide a reliable assessment of the current technical condition of the compressor station and predict its dynamics in the interval between measurements. The information received from the sensors is not always sufficient for such prediction, which necessitates the use of modeling-based approaches. The main aim of the research is to reveal the possibilities of monitoring the thermal state of large AC motors stator winding by analytical methods and modeling methods using information obtained from temperature sensors. Objects: AC motors of electric drive gas compressor units. Methods: analytical methods, as well as simulation using thermodynamic models of an electric motor based on thermal circuits with lumped parameters. Results. The authors have obtained analytically the relations that allow an approximate assessment of large AC motors stator winding thermal state based on a three-mass thermal circuit. The paper introduces the results of modeling based on thermal circuits with lumped parameters of heating the stator winding of a large AC electric motor with radial cooling channels. It is shown that this approach allows one to obtain the temperature distribution along the winding in the axial direction, which makes it possible to relatively accurately estimate the thermal state of the winding, avoiding the use of very computationally demanding approaches based on the finite element method and computational flow dynamics. It is proposed to use the residual thermal resource of the stator winding to predict its approximate service life based on information about the winding temperature obtained from temperature sensors or from a thermodynamic model.