The indirect methods of control the output coordinates for the three-phase asynchronous electric motor

Author(s):  
Yu. N. Dementyev ◽  
A. D. Umurzakova
Author(s):  
Eduard Grekov ◽  
◽  
Alexei Bezgin ◽  
Viktor Sorokin ◽  
Ildar Yamansarin ◽  
...  

The energy indicators of the EKG-5 excavator lifting electric drive with thyristor power circuits have been determined according to the systems thyristor direct frequency converter - two-phase asynchronous electric motor, converter-DC motor and direct frequency converter - three-phase asynchronous electric motor. Losses in electric motors and converters have been determined, taking into account the specifics of their joint work in theefficiency for the excavation cycle were determined based on the results of calculating the simulation model, the initial data for which were the parameters of the excavation cycle of the lift drive of a real excavator. Distortion coefficients of the mains current were determined for two cases: during digging and during accelerated lowering of an empty bucket. For comparison, the energy indicators of the selected electric drives with a filter-compensating device were calculated. The analysis of energy indicators is made.


Author(s):  
K. V. Martynov ◽  
L. A. Panteleeva ◽  
D. A. Vasiliev ◽  
E. V. Dresvyannikova

THE PURPOSE. The asynchronous electric motor with a squirrel cage rotor is widely used in the electric driven industry and agricultural machinery. One of the possible ways to improve its energy characteristics is to use a combined 12-zone stator winding instead of the standard 6-zone one. However, in a combined winding with a parallel connection of the «star» and «delta» phases, the phases may not be loaded equally. Therefore, the main purpose of the work under analysis is to study the distribution of currents between the phases of the «star» and «delta» in the asynchronous motor with a combined winding.METHODS. The study was performed on the AIR71V4 engine, rewound onto a combined winding, in which the real ratio of the active resistances of the «delta» and «star» turned out to be 7% less than the theoretical one. The tests were carried out in no-load and short-circuit mode when powered from a three-phase network, as well as in short-circuit mode when one of the line wires is broken.RESULTS. The work gives the values of the currents flowing through the phases of the combined winding. For the experimental sample, the deviation of the obtained currents from the theoretical values is determined. Equations of currents are obtained when one of the linear wires is broken. Schemes for switching on the main contacts of a thermal relay for a motor with a combined winding are proposed.CONCLUSION. The results of the study showed that in an asynchronous motor with a combined winding, in which the real ratio of the active resistances of the «delta» and «star» is less than the theoretical one, the current is not proportionally distributed over the phases. The most preferred circuit for switching on a thermal relay is one in which its main contacts are connected to the «delta» phases, and the thermal relay must be three-pole.


2021 ◽  
Vol 313 ◽  
pp. 10002
Author(s):  
Diego José Maldonado Aguilar ◽  
Juan Antonio Auñón Hidalgo ◽  
Mauri Eskubi ◽  
Pablo Martínez

In this work, the results obtained in different tests performed on a Stirling cryocooler are shows, as well as a comparative analysis of these results with different load pressures. The prototype is a single-acting Stirling engine with a piston and displacer, which is used to liquefy air with helium as the working fluid; this is an integral Stirling (β-type). A three-phase asynchronous electric motor drives the Stirling engine and cooling, in the hot focus, is performed with a pressurized water circuit. In the cold focus are reached very low temperatures, around 75 K (-198 °C). The study has been developed at different load pressures of the working fluid and it shows a comparative analysis about the most important work parameters evolution. The parameters studied are the following: cooling water inlet and outlet temperatures, cold and hot focus temperatures, voltage and intensity consumed by the electric motor that drives the Stirling engine and quantity of liquid air obtained. The results show that it is very likely to use this configuration in industrial processes when they need cold and heat simultaneously.


2018 ◽  
Vol 58 ◽  
pp. 03016 ◽  
Author(s):  
I.V Naumov ◽  
N.V. Savina ◽  
M.V. Shevchenko

One of the main operation modes that characterizes power quality in distribution networks is asymmetry of three-phase voltage system. Operation of an induction motor (IM) with disturbed voltage symmetry in the supply network can not be considered as a rated one. The system of voltages applied to the stator winding of IM under these conditions contains positive- and negative-sequence components. This worsens the performance characteristics of IM essentially. In order to balance the 0.38 kV network operation and enhance the efficiency of the three-phase electric motor operation it is suggested to use a special balancing unit (BU) that minimizes the negative-sequence components of current and voltage. The operation modes of the obtained system “supply source – induction motor – balancing unit” are simulated within the MATLAB software package of applied programs, which allows one to assess the impact of low quality of power on the operating characteristics of the electric motor and the efficiency of the balancing unit to increase the “durability” of the motor under the asymmetrical power consumption.


2019 ◽  
Vol 124 ◽  
pp. 02017
Author(s):  
A. Andreev ◽  
M. Andreev ◽  
D. Kolesnihenko ◽  
R.R. Dyganova ◽  
G.T. Merzadinova ◽  
...  

The authors propose an algorithm for identifying the parameters of a controlled asynchronous electric drive in real time, which provides calculation of stator and rotor resistances which change as a function of temperature. The algorithm is based on the analysis of a current tube of electric motor phase with the subsequent calculation of resistances.


Sign in / Sign up

Export Citation Format

Share Document