EVALUATION OF THE ELECTROMAGNETIC TIME-CONSTANT OF SCIM ROTOR AND ITS INFLUENCE ON VFD DYNAMIC CHARACTERISTICS

Abstract

In hoisting mechanisms equipped with VFD-fed three-phase squirrel-cage induction motor
(SQIM), slow response of the drive during starting is observed; such delay in response negatively impacts the operator. This paper presents an explanation of the reasons of the delay in the motor torque growth at starting based on experimental results and analysis. The effect of inertness, determined by the electromag- netic time-constant of the motor rotor is analyzed. In literature, the evaluation of the electromagnetic time- constant of the SCIM rotor is limited to 6-pole motor. However, in this paper, simplified analytical relation- ships, linking the rotor electromagnetic time-constant of a SQIM with the motor power and number of poles
(for p=4-10), are obtained on experimental basis. A comparison of VFD starting with a preliminary magnet- ized/demagnetized motor is performed; a significant decrease in the delay growth of the motor torque with preliminary magnetization is shown. Based on the implementation of the functions of modern VFDs, the pro- cess of smooth backlash taking-up in the kinematic transmission for slewing mechanism of a portal crane is presented.

Author Biographies

Камаль Абдальмажид Хандакжи, Тafila Technical University

Associate Professor, Department of Electrical Power and
Mechtronics, Tafila Technical University

Сергей Николаевич Радимов, Odessa National Polytechnic University

Professor, Doctor of Science, Odessa National Polytechnic University

Александр Валерьевич Горячев, Ltd Scientific Production Enterprise "Privodserviceplus"

Head of Ltd SPE “Privodserviceplus”

Евгений Михайлович Кокошко, Odessa National Maritime University

Senior lecturer at Odessa National Maritime University

Published
2017-05-10
How to Cite
Хандакжи, К. А., Радимов, С., Горячев, А., & Кокошко, Е. (2017). EVALUATION OF THE ELECTROMAGNETIC TIME-CONSTANT OF SCIM ROTOR AND ITS INFLUENCE ON VFD DYNAMIC CHARACTERISTICS. Electrotechnic and Computer Systems, (25(101), 17-25. https://doi.org/10.15276/eltecs.25.101.2017.02
Section
Automated electromechanical systems

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