Impact of Stray Load and Iron Losses on Vector Control of Small Induction Generators

Abstract

This paper presents the analysis of detuning induced by the stray load and iron losses in vector-controlled self-excited induction generators (SEIGs). Previously, the stray load loss impact has been examined only for induction motors. Detuning in vector-controlled induction machines (IMs) is caused by a mismatch between the actual IM and the corresponding mathematical model. This usually implies disagreement between the actual and assumed values of IM parameters or between the actual and modeled phenomena. The detuning is characterized by a misalignment between the actual and reference flux vector (i.e., flux angle error) or by a non-unity ratio of actual to reference flux vector magnitudes (i.e., flux magnitude error). The presented 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 system is built in the MATLAB-Simulink. 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.