Rotor Voltage Dynamics in the Doubly Fed Induction Generator During Grid Faults

• Published in: IEEE transactions on power electronics Vol. 25; no. 1; pp. 118 - 130
• Main Authors: Lima, F.K.A., Luna, A., Rodriguez, P., Watanabe, E.H., Blaabjerg, F.
• Format: Journal Article Publication
• Language: English
• Published: New York, NY IEEE 01.01.2010; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: AC generators; Algorithm design and analysis; Algorithms; Applied sciences; Circuit faults; Control electrònic; Control systems; Convertors; current control; Electric generators; Electric potential; Electric power; Electric power plants; electric variables control; Electrical engineering. Electrical power engineering; Electrical machines; Electrical power engineering; Electricity; Energia eòlica; Enginyeria electrònica; Exact sciences and technology; Faults; Generadors elèctrics; Generators; High voltage or high current generators; Induction generators; Inverters; Non classical power plants; Power quality; power system faults; Power systems; Prototypes; Regulation and control; Rotors; Strategy; Various equipment and components; Voltage; Voltage control; Wind energy generation; wind power generation; Wind power plants; Wind turbines; Àrees temàtiques de la UPC; Prototype; Asynchronous generators; Power system stability; Wind generator; Implementation; power system faults; Low voltage; Coding; Shaft; Voltage stability; Converter; Voltage dip; Overcurrent; Electric fault; Damaging; Inverter; current control; electric variables control; Control system; Theoretical study; AC generator; AC generators; Algorithm; Rotor; Electrical network; Double supply machine; System simulation; wind power generation
• ISSN: 0885-8993; 1941-0107; 1941-0107
• DOI: 10.1109/TPEL.2009.2025651

This paper presents a new control strategy for the rotor-side converter (RSC) of wind turbines (WTs) based on doubly fed induction generators (DFIG) that intends to improve its low-voltage ride through capability. The main objective of this work is to design an algorithm that would enable the system to control the initial overcurrents that appear in the generator during voltage sags, which can damage the RSC, without tripping it. As a difference with classical solutions, based on the installation of crowbar circuits, this operation mode permits to keep the inverter connected to the generator, something that would permit the injection of power to the grid during the fault, as the new grid codes demand. A theoretical study of the dynamical behavior of the rotor voltage is also developed, in order to show that the voltage at the rotor terminals required for the control strategy implementation remains under controllable limits. In order to validate the proposed control system simulation, results have been collected using PSCAD/EMTDC and experimental tests have been carried out in a scaled prototype.