MODELING THE OPERATION OF THE ELECTRIC DRIVE OF A FREIGHT ELEVATOR INSTALLATION

Abstract

An elevator installation is considered as a single electromechanical system, which, in turn, is divided into mechanical (cabin, counterweight, kinematic links, and gearbox) and electrical (electric motor and static converter) subsystems. The operating mode of the elevator's electric drive depends on the purpose of the elevator and the conditions of use. For example, freight elevators are characterized by a more uniform load schedule with a certain cyclicality due to the transportation of goods. In an unregulated electric drive with a speed of up to 2 m/s, the electrical subsystem is a single- or two-speed asynchronous electric motor with a squirrel-cage rotor. Currently, there is a growing trend towards the use of frequency-controlled asynchronous electric motors in buildings, as this solution improves the convenience of movement and the accuracy of the car's stopping, and also has a certain energy-saving effect.

The paper presents a study of the characteristics of an asynchronous electric motor for an automated electric drive of a freight elevator. A classification of electric drives for elevator installations is presented, with an explanation of their advantages and disadvantages. The natural mechanical and electromechanical characteristics were constructed using a specialized program running in the MATLAB software complex. Since manufacturers of asynchronous electric motors often do not indicate the actual resistance of asynchronous electric motors with a squirrel-cage rotor, the resistance of this electric motor was calculated in the MATLAB software package. The transient processes of the electric drive of the elevator installation were also constructed using the transient processes program in the frequency converter-asynchronous electric motor system with an intensity controller based on a T-shaped equivalent circuit in the MATLAB software environment.