A model of the back-to-back converter is set up and implemented in the simulation tool PSS/E as a user-developed model. This model is applied with that of the doubly-fed induction generator (DFIG), described in previous parts of this work [parts II and I]. The latter models variable-speed wind turbines in power stability investigations. Subjected to a short circuit fault, there will be a risk of converter blocking, followed by tripping of the wind turbine [1, 3]. The main reasons of blocking are over-current in the rotor converter and over-voltage in the dc-link. The DFIG model, with representation of the back-to-back converter, results in (a) more accurate replication of the current in the rotor converter and (b) improved computation of the dc-link voltage. These improvements are compared with the model with representation of the rotor converter only. Hence, the DFIG model with representation of the back-to-back converters might be preferred, in practical investigations of power system stability, to models with representation of the rotor converter only.
AkhmatovV., Modelling of variable-speed wind turbines with doubly-fed induction generators in short-term stability investigations, Proceedings of 3rd International Workshop on Transmission Networks for Offshore Wind Farms, April 11–12, 2002, Stockholm, Sweden.
2.
AkhmatovV., Variable-speed wind turbines with doubly-fed induction generators. Part I: Modelling in dynamic simulation tools, Wind Engineering, pp 85–108, Vol 26, issue 2, 2002.
3.
AkhmatovV., “Variable-speed wind turbines with doubly-fed induction generators. Part II: Power system stability”, Wind Engineering, pp 171–188, Vol 26, issue 3, 2002.
4.
HeierS., Windkraftanlagen im Netzbetrieb, 2. Aufl., Teubner, Stuttgart, 1996, 396 p.
5.
ZhangL.WatthanasarnC.ShepherdW., Application of a matrix converter for the power control of a variable-speed wind turbine driving a doubly-fed induction generator, IECON Proceedings (Industrial Electronics Conference), 1997, vol. 2, pp. 906–911.
6.
CadirciI.ErmisM., Double-output induction generator operating at sub-synchronous and super-synchronous speeds: Steady-state performance optimisation and wind-energy recovery, IEE Proceedings-B, Electric Power Applications, vol. 139, No. 5, 1992, pp. 429–442.
7.
GrudP., State of the art offshore wind technology, Workshop Offshore-Windenergienutzung Technik, Naturschutz, Planung, Deutsches Windenergie-Institut GmbH, Wilhelmshafen, 27 June 2000.
8.
Eltra, Specifications for connecting wind farms to the transmission network, 2nd Edition, Eltra Transmission System Planning, 26 April 2000, ELT2099–411a.
9.
NetzE.ON, Ergänzende Netzanschlussregeln für Windenergieanlagen, Zusätzliche techniche und organisatorische Regeln für den Netzanschluss von Windenergieanlagen innerhalb der Regelzone der E.ONNetz GmbH, 01. December 2001.
10.
Ercot, Request for proposal: Ercot wind generation models and model validation, 10 April 2002, Texas, USA.
11.
AkhmatovV.KnudsenH., An aggregate model of a grid-connected, large-scale, offshore wind farm for power stability investigations – importance of windmill mechanical system, Int. J. of Electrical Power & Energy Systems, vol. 242002, no. 9, pp. 709–717.
12.
AkhmatovV.KnudsenH.NielsenA.H., Advanced simulation of windmills in electric power supply, Int. J. of Electrical Power & Energy Systems, vol. 22, issue 6, July/ 2000, pp. 421–434.
13.
PenaR.ClareJ.C.AsherG.M., Doubly-fed induction generator using back-to-back PWM converters and its application to variable-speed wind-energy generation, IEE Proc.-Electr. Power Appl., vol. 143, No. 3, May 1996, pp. 231–241.
14.
GjengedalT.GjerdeJ.O.SporildR., Assessing of benefits of adjustable speed hydro machines, Paper BPT99–439–21 Proceedings IEEE Power Tech 99 Conf., Budapest, Hungary, Aug. 29–Sept. 2. 1999.
15.
PenaR.S.CardenasR.J.AsherG.M.ClareJ.C., Vector controlled induction machines for stand-alone wind energy applications, Conference Record of the 2000 IEEE Industry Applications Conference, 8–12 Oct. 2000, vol. 3, pp. 1409–1415.
16.
NæssB.I.UndelandT.M.GjengedalT., Methods for reduction of voltage unbalance in weak grids connected to wind plants, In Proceedings of IEEE/Cigre Workshop Wind Power and the Impacts on Power Systems, Oslo, Norway, 17–18 June 2002.
17.
Eel-Hwan KimSung-Bo OhYong-Hyun KimChang-Su Kim, Power control of a doubly fed induction machine without rotational transducers, Proceedings of The Third International Conference on Power Electronics and Motion Control, PIEMC2000, 15–18 Aug. 2000, vol. 2, pp. 951–955.
18.
SvenssonJ., Grid-connected voltage source converter – Control principles and wind energy applications, Technical Report no. 331, March 1998, Chalmers University of Technology, Göteborg, Sweden.
19.
SchauderC.MehtaH., Vector analysis and control of advanced static VAR compensators, IEE Proceedings-C, vol. 140, No. 4, July 1993, pp. 299–306.
20.
MüllerS.DeickeM.De DonckerR.W., Adjustable speed generators for wind turbines based on doubly-fed induction machines and 4-quadrant IGBT converters linked to the rotor, Conf. Record of the 2000 IEEE Industry Applications Conf., 2000, vol. 4, pp. 2249–2254.
RøstenH.Ø.UndelandT.M.GjengedalT., Doubly-fed induction generator in a wind turbine, In Proceedings of IEEE/Cigre Workshop Wind Power and the Impacts on Power Systems, Oslo, Norway, 17–18 June 2002.
23.
GE Wind Energy, Patented VAR control technology, GE Wind Energy, General Electric Company, GEA-13345 (05/02 5M).
24.
TapiaA.TapiaG.OstolazaJ.X.SaenzJ.R.CriadoR.BerasateguiJ.L., Reactive power control of wind farms made up with doubly fed induction generators, PPT 2001, 2001IEEE Porto Power Tech. Conf., 10–13 Sept. 2001, Porto, Portugal, vol. 4, 6 pp.
25.
AkhmatovV., Variable-speed wind turbines with doubly-fed induction generators. Part IV: Not-interrupted operation feature at grid faults with converter control coordination, Wind Engineering, submitted article.
26.
ØyeS., Unsteady wake effects caused by pitch-angle changes, IEA R&D WECS Joint Action on Aerodynamics of Wind Turbines, 1st Symposium, London 15th October 1986, pp. 58–79.
27.
SørensenJ.N.KockC.W., “A model for unsteady rotor aerodynamics”, J. of Wind Eng. and Industr. Aerodyn., vol. 58, 1995, pp. 259–275.
28.
SnelH.SchepersJ.G., “Engineering models for dynamic inflow phenomena”, J. of Wind Eng. and Industr. Aerodyn., vol. 39, 1992, pp. 267–281.
29.
IbrahimE.S., “Digital simulation of electromagnetic transients”, Electric Power Systems Research, vol. 41, 1997, pp. 19–27.
30.
ZingerD.S.MuljadiE., “Annualized wind energy improvement using variable speeds”, Industrial and Commercial Power Systems Technical Conference, 1997. Conference Records, Paperspresented at the 1997 Annual Meeting, IEEE 2097, 11–16 May2097, pp. 80–83.
31.
LangeB.BarthelmieR.HøjstrupJ., “Description of the Rdsand field measurement”, Report Ris-R-1268(EN), Ris National Laboratory, Roskilde, Denmark, May 2001, 59 p.
