Determination of inductances for pulsating current traction motor

Abstract

The object of research is a pulsating current traction motor. To improve the accuracy of its mathematical model, it is necessary to use the values of the parameters that are determined in experimental studies of the electric motor. In particular, it is important to use in the model of the electric motor inductance obtained experimentally. A method is proposed for calculating the inductance of the armature winding, main poles, additional poles and compensation winding and the total inductance of the traction motor armature circuit. The calculations are based on the results of the indirect inductance measurement method, in which the electrical values of various modes of power supply of the electric motor windings are directly measured, and the inductances are determined by auxiliary calculations. The inductances of the traction motor armature circuit have a non-linear dependence on the current flowing through them. The main difference of the study is that the measurements of the electrical parameters required for calculating the inductance are carried out over the entire range of operating currents of the windings. The essence of the proposed technique is to measure the active power in the armature winding, the winding of the main and additional poles, and the compensation winding, as well as in the armature circle as a whole when they are supplied with alternating current. According to the obtained values of active power losses and phase displacement, the corresponding reactive power losses are determined, with the help of which the inductances of the motor windings are calculated. Approbation of the methodology for calculating the conduction inductance for an electric motor of a pulsating current NB-418K6 (country of origin Russia), is used on electric locomotives of the VL80T and VL80k series (country of origin Russia). A scheme for measuring electrical parameters necessary for calculating inductance is proposed. The graphical dependences of the inductance on the armature current, built on the basis of calculations, confirmed the hypothesis about the nonlinear dependence of these inductances on the armature current. For further application of the results obtained in the simulation of the operation of the traction electric motor NB-418K6, a polynomial approximation of the total inductance of the armature circuit was performed.

Model of pulsating current traction motor taking into consideration magnetic losses in steel

“…With this end in view, based on the results for dependences of the armature circuit inductance and field winding inductance on the corresponding currents presented in the work [18], dependence of the armature current on the armature circuit flux linkage (Fig. 4) and dependence of field winding current from field current (Fig.…”

“…The work by [18] shows that both armature circuit inductance and inductance of field winding have a nonlinear dependence on armature current and field current respectively. In this regard, the model of the electrical part of the traction motor in the MATLAB software environment was implemented in the Special Power System section of the Simulink library.…”

Determination of voltage at the rectifier installation of the electric locomotive VL-80K for each position of the controller driver's

“…-armature winding inductance is a constant value; -magnetic losses in the engine steel are not taken into account; -losses from the action of eddy currents are not taken into account; -mechanical part of the drive is not connected; -model works on one fixed position of the train. Studies [3][4][5] show that the excitation winding inductance is a function of the excitation current, and the armature winding inductance is a function of the armature current. Moreover, these dependencies are non-linear.…”