Wyniki 1-1 spośród 1 dla zapytania: authorDesc:"Alexandra POTAPENKO"

Process Simulation in Induction Motor where Short-Circuit Rotor Bar is Failed during Run-down Regime DOI:10.15199/48.2018.06.06

Czytaj za darmo! »

Damages from operation of an induction motor (IM) with a short-circuit rotor when its bars are broken are mainly expressed in increased power consumption [1]. At the same time, the cost of power over consumption for the year of operation of such IM often exceeds the cost of engine itself[2]. Due to this fact there are many proposals on how to diagnose this type of damage during operation[3,10-23]. However most of them cannot be realized because of the effect of electric network parameters fluctuations, IM vibrations and resistance moment variation load on the measured signal. These effects can be ignored if IM diagnosis is carried out during run-down regime[3, 24-25]. However under these conditions development of such a diagnostic system without process simulation in IM is impossible. IM run-down regime starts when it is disconnected from the power network. Immediately after IM switching off the currents in stator winding become equal to zero and currents in rotor winding remain the same as they were at the moment of shutdown. Thereafter due to the fact that active resistances are available in the rotor windings attenuation of them occurs. At the same time speed of rotor rotation slows down under the impact of resistance moment in IM bearings, its air fan and drive mechanism. As a result EMF is changed in stator windings not only in terms of magnitude but in frequency. Mathematical model of induction motor In order to simulate processes occurring when IM runsdown with a broken rotor bar it is convenient to use a mathematical model differential equations of which are compiled by the method of loop currents for phase-to-phase voltages[4]. According to this mathematical model, taking into account Fig. 1 (K keyswitch closed) and application (1)                    =[...]

 Strona 1