Analysis of an Enhanced SEIG Model Including Iron Losses

Abstract

This paper presents an enhanced dynamic model of a self-excited induction generator (SEIG) with iron losses. The iron losses are represented in the induction machine model with an equivalent resistance connected in parallel with the magnetizing reactance. Since these losses vary with the air-gap flux and the stator frequency, a series of no-load tests were performed using sinusoidal supply of various frequencies to determine this variation. The air-gap flux influence on the iron losses can be expressed by means of the corresponding iron loss current. Consequently, an enhanced induction generator model, including the equivalent iron loss resistance as a function of both stator frequency and iron loss current, was built in the MATLAB Simulink environment. In addition, this is, to the best knowledge of the authors, the first SEIG model which includes variable iron losses that is entirely built in MATLAB Simulink. The performance of the proposed model is analyzed through simulation under various operating conditions and compared with the conventional SEIG model in which the iron losses are neglected. Theoretical results obtained from the proposed model have been verified experimentally. It is shown that neglecting the iron losses could cause severe inaccuracies in the SEIG analysis, especially when a SEIG is driven by a variable speed prime mover such as wind turbine.

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.