Starting mode optimization of the tower crane luffing mechanism

Loveikin V. S., Romasevich Yu. A., Stekhno A. V.
Hoisting and transport equipment, 2020, №1(62)
The article presents a method that allows to minimize the losses of electrical energy in the asynchronous electric drive of the tower craneʼs luffing mechanism during its start-up. In order to carry out the calculation the known mathematical model of an asynchronous motor has been supplemented by the differential equation of motion of luffing mechanism, which describes the stage of the rope becking off. A considerable number of electric drives of the modern tower cranes are equipped with frequency inverters. They have tuning parameters (duration of increasing of frequency of supply voltage, initial supply voltage of electric motor, and type of characteristic of increasing of frequency of supply voltage). Therefore it has been suggested to determine such value of these parameters that allow to reduce energy losses in the luffing mechanism. A modified Particle Swarm Method (ME-PSO) has been applied in the study. It allowed to find the global minimum of the function of energy losses. The optimal values of the duration of increasing of frequency of supply voltage, initial voltage of supply of asynchronous electric motor, and the type of characteristic of increasing of frequency of supply voltage for drives of the luffing mechanism for four tower cranes are determined: КБ-674, 200 EC-H 10 (Liebherr), MTD 128 (Potain) and 5 LC 5010 5t (LINDEN COMANSA). The convergence analysis of the modified algorithm (ME-PSO) has been carried out and a comparative analysis of energy losses have been performed (the compared characteristics are: direct start and different characteristics of increasing the frequency of the supply voltage).
tower crane, luffing mechanism, electric drive, energy losses, optimization, parameters, modified PSO algorithm, MISO function
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