An accurate dynamical model of induction generator utilized in wind energy systems

Abstract

Due to the advantages of a self-excited induction generator (SEIG), it plays a main role in sources of renewable energy, such as wind turbines (WT). The regulation of terminal voltage and frequency is poor under variable rotor speed and load conditions at stand-alone operation mode. The generator terminal voltage depends on the excitation capacitance which can be controlled by a capacitor bank and static voltage compensator. The dynamical model of the machine is described by differential equations in D-Q axes transformations of the synchronously rotating frame. Many models of analysis are proposed in the literature. In those models, several approximations are used to simplify the process of calculations, such as neglecting the iron core resistance, stray load resistance, stator and rotor leakage reactance, and magnetic saturation. In this work, a comprehensive dynamic model of the SEIG-WT is performed to analyze the system performance under transient and steady-state conditions. This dynamic model considers the effect of all machine parameters variation. New analytical formulas are used for to accurate calculation of minimum and maximum values of excitation capacitance and generator rotor cut-off and maximum speed. The dynamic model results are partially compared with experimental results, and accurate agreement is shown.

A Taguchi method-based optimization algorithm for the analysis of the wind driven-self-excited induction generator

“…However, to implement these functions, it is mandatory to find a suitable initial guess, which needs a basic understanding of the problem in order to estimate it. A dynamic model that of wind driven SEIG is developed in [28] for analyzing the system performance during both transient and steady-state conditions. However, the analytical formulas used in this model are based on all the parameters of SEIG for the calculation of the rotor speed and excitation capacitance.…”

Experimental determination of minimum capacitor for self-excitation of induction generators

“…A capacitor self-excited asynchronous generator (SEIG) offers certain advantages over a conventional synchronous generator as an isolated electrical power source. These advantages include reduced unit cost, a brushless rotor, the absence of a separate DC source, and ease of maintenance [3]- [6]. In this modes, capacitors are utilized to provide the requisite reactive power for self-excitation of the induction generator [7].…”