Detuning Induced by Stray Load and Iron Losses in Small Vector-Controlled Induction Motors

Abstract

Detuning in vector-controlled induction motor (IM) drives is characterized by a misalignment between the actual and reference flux vectors (i.e., flux angle error) or by a non-unity ratio of actual to reference flux vector magnitudes (i.e., flux magnitude error). Such detuning generally occurs either due to the disagreement between the actual and assumed values of IM parameters or due to phenomena not accounted for in the control algorithm. This paper presents a comprehensive analysis of the detuning induced by the stray load and iron losses in voltage-fed vector-controlled IM drives. The analysis encompasses load torques up to the rated value and rotor flux values down to 50% of the rated value. For this purpose, an IM model is utilized in which the stray load and iron losses are modeled as variable with respect to the operating frequency, flux, and torque. The simulation model of the considered IM drive is built in the MATLAB-Simulink environment. Three small IMs (1.5 kW) of different efficiency and rotor material have been considered.

Mateo Bašić

Full Professor | Department of Power Electronics and Control

Full professor at the Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture in Split, with recent research interests related to the fields of power electronics and renewable energy sources, with a special focus on energy-efficient control of inverters, battery systems, wind turbines, photovoltaic sources and self-excited induction generators in microgrids - both in island operation and in grid-tie operation.

Dinko Vukadinović

Full Professor | Department of Power Electronics and Control

Full professor at the Faculty of Electrical Engineering, Mechanical Engineering, and Naval Architecture in Split, specialized in modern control systems for power electronic converters, electric motors, and generators. At the Power Electronics Research Laboratory, he leads experimental projects and develops advanced methods for regulating electrical machines and converters, while supervising doctoral research in these areas.

Ivan Grgić

Assistant Professor | Department of Power Electronics and Control

Assistant professor at the Faculty of Electrical Engineering, Mechanical Engineering and Architecture in Split, specialized in the research of power electronic converters in photovoltaic systems and microgrids. Currently, he teaches courses in the areas of control engineering, digital electronics, electrical engineering, electrical machines and transformers.