Исследование самозапуска асинхронных двигателей 0,4 кВ собственных нужд электростанций

Abstract

The purpose of this work is to study the self-starting of induction motors for the auxiliary needs of power plants and substations as well as the mutual influence of motors on each other under short-term voltage dips and after voltage recovery on the buses to which these motors are connected. The object of the research is the operating VIII section with the capacity of 0.4 kV of the auxiliary service system with 9 induction motors of the heat and power plant no.1 in the city of Dushanbe (Republic of Tajikistan). Simulation modeling was carried out in the software package Electrical Transient Analyzer Program (USA) using algebraic and simplified differential equations to determine the values of indicators of static and dynamic stability of auxiliary needs of power plants and substations. As a result of modeling, the values of indicators of static and dynamic stability of the auxiliary needs system of power stations are determined. Based on the results obtained the margins of static and dynamic stability of auxiliary needs of power plants and substations are constructed and the conditions for implementing the optimal self-start, which allow to ensure uninterrupted operation of responsible mechanisms with induction motors at voltage dips are determined. The developed methods for studying the self-starting of power plant and substation auxiliary need induction motors ensures more accurate determination of the values of static stability voltages and dynamic stability time. The developed simulation model allows to specify and determine the success of induction motor self-starting in the systems of power plant and substation auxiliary needs. The developed methods are recommended for more precise selection of operating values for relay protection and automation as well as technological protection in the systems of auxiliary needs of power plants and substations with induction motors for more reliable operation of the main and auxiliary technological equipment.