A STUDY OF THE FREQUENCY START INDUCTION MOTOR WITH REGULATION LAW E/f = const

Abstract

Theoretical and experimental study of the frequency of the induction motor starting AIR71A2U3 at law E / f = const regulation. Power and energy are shown starting performance as to the en- gine inlet, and the inverter input. In mathematical modeling the equivalent circuit parameters, which are nonlinear coefficients in the system of differential equations are different for different points of consideration are the start and as a result of electromagnetic calculation under appropriate voltages and frequencies in the engine inlet considering the saturation of the magnetic circuit and the displacement current in the rotor winding. Non-linear coefficients of the equations, as well as losses in the magnetic steel, and additional me- chanical losses are different for each of the law of frequency management and change at every step of the integration of the system of differential equations. Their determination is made in the analysis of the static modes. Accounting for the aforementioned loss components allows to specify calculation of energy perfor- mance under transient conditions. It is proposed to calculate the value of the motor voltage corresponding to certain frequencies of the supply voltage and rotor speed on the analytic dependence. Found voltages used in solving systems of nonlinear equations describing the start mode. The energy efficiency of the analyzed start taking into account all the components of the energy losses.