Small-signal dynamic model and analysis of a fixed-speed wind farm - a frequency response approach

This paper introduces a small-signal dynamic model of a fixed-frequency (induction machine based) wind farm connected to an electrical power system. The model represents the system small-signal dynamics in the frequency range of a fraction of Hz to 50/60 Hz. The model includes the dynamics of the wind energy capturing mechanism, the rotating shaft system, the generator electrical system of each wind energy unit, the wind farm collector system, and the utility grid. Based on the proposed model, two performance indices are introduced to i) investigate sensitivity of the system modes, e.g., torsional modes, to the system parameters, and ii) evaluate the system capability to reject electrical and mechanical disturbances, e.g., a wind gust. The application of the model to the analysis of a system with two wind units is presented and the study results are validated based on comparison with the time-domain simulation results obtained in the PSCAD/EMTDC environment.

[1]  Scott D. Sudhoff,et al.  Analysis of Electric Machinery and Drive Systems , 1995 .

[2]  Nengsheng Bao,et al.  Active Pitch Control in Larger Scale Fixed Speed Horizontal Axis Wind Turbine Systems Part II: Non-Linear Controller Design , 2001 .

[3]  Nengsheng Bao,et al.  Active Pitch Control in Larger Scale Fixed Speed Horizontal Axis Wind Turbine Systems Part I: Linear Controller Design , 2001 .

[5]  S. A. Papathanassiou,et al.  Mechanical Stresses in Fixed-Speed Wind Turbines Due to Network Disturbances , 2001, IEEE Power Engineering Review.

[6]  Ying Hua Han,et al.  Grid Integration of Wind Energy Conversion Systems , 2000 .

[7]  E. N. Hinrichsen,et al.  Dynamics and Stability of Wind Turbine Generators , 1982, IEEE Transactions on Power Apparatus and Systems.

[8]  R. Swisher,et al.  Strong winds on the horizon: wind power comes of age , 2001, Proc. IEEE.

[9]  William Leithead,et al.  Drive-train characteristics of constant speed HAWT's : part I - representation by simple dynamic models , 1996 .

[10]  J. Edmunds,et al.  Principal gains and principal phases in the analysis of linear multivariable feedback systems , 1981 .

[11]  A. Laub,et al.  Feedback properties of multivariable systems: The role and use of the return difference matrix , 1981 .

[12]  S. K. Salman,et al.  Windmill modelling consideration and factors influencing the stability of a grid-connected wind power based embedded generator , 2003, 2003 IEEE Power Engineering Society General Meeting (IEEE Cat. No.03CH37491).

[13]  S. Salman,et al.  Windmill Modeling Consideration and Factors Influencing the Stability of a Grid-Connected Wind Power Based Embedded Generator , 2002, IEEE Power Engineering Review.

[14]  R. Iravani,et al.  Frequency-response analysis of torsional dynamics , 2004, IEEE Transactions on Power Systems.

[15]  Hartmut Logemann,et al.  Multivariable feedback design : J. M. Maciejowski , 1991, Autom..