Mechanical characteristics of the doubly-fed machine and its use in the hoist electric drive

Abstract

Currently, a large number of existing mine hoisting units use the electric drive based on asynchronous motor with a rotary station. Despite the fact that such drives have a large overload capacity and linear (within the working areas) mechanical characteristics, they have drawbacks, first of all, significant energy losses. The promising way of their modernization, as well as design of new drives based on a phase-wound rotor motor, is the use of the scheme of a doubly-fed electric machine. The paper outlines the requirements for the electric drive of a mine hoisting unit, in particular, for its mechanical characteristics; the analysis of the mechanical characteristics of the doubly-fed machine in asynchronous and synchronous modes, as well as changes in the active resistance of the rotor was carried out; the working sections of characteristics are indicated; the operating modes of the machine are compared to the sections of the speed diagram of the hoisting unit; the rationale for the combined control of the machine with the change in operating modes directly during operation is shown.