Operation modes of frequency converter in the rotor circuit of induction motor drive of a mine hoist

Abstract

The electric drive of a hoist must ensure the formation of the required tachogram and the diagram of driving forces. The tachogram depends on the type of lifting vehicles. For hoist electric drives based on a wound-rotor induction motor, it is possible to use a frequency converter in the rotor circuit to control the motor speed and torque. When designing a converter, the problem arises of determining the operating modes of its bridges and the current direction between them. The article analyzes the operating modes of the hoisting motor in accordance with various sections of the tachogram of the unit and the connection between the mechanical and electrical coordinates of the drive. The analysis carried out in the work makes it possible to obtain and implement methods for determining the parameters of the frequency converter in the rotor circuit and developing an algorithm for controlling the converter bridges to ensure the required tachogram and driving force diagram.