On equivalent circuit structures for empirical modeling of turbine-generators

This work is aimed at extending a discussion offered concerning a paper presented at the 1993 IEEE/PES Winter Meeting (Boldea and Nasar, 1987) which attempted to show that the "differential leakage" was not required and, in general, seriously questioned the need for a third-order model. Unfortunately, the simplifications were possible only using a per-unit system not compatible with industry standards and current engineering practices for saturation analysis. In this paper, mathematical reasoning is combined with maximum-likelihood estimation from actual SSFR data to show that, for network structures preserving the main-field magnetizing impedance, the differential leakage contributes significantly to the dynamic response and proves mandatory for adequately modeling rotor impedance. Besides, the claim made that a third-order model may not be sufficiently parsimonious is not home out by further verification of the author's own data end extensive experience with real SSFR data from a 1100 MVA turbine-generator. >

[1]  I. M. Canay,et al.  Causes of Discrepancies on Calculation of Rotor Quantities and Exact Equivalent Diagrams of the Synchronous Machine , 1969 .

[2]  J. Schoukens,et al.  A maximum likelihood estimator for linear and nonlinear systems-a practical application of estimation techniques in measurement problems , 1988 .

[3]  I. Kamwa,et al.  A frequency-domain maximum likelihood estimation of synchronous machine high-order models using SSFR test data , 1992 .

[4]  Jr. J.L. Kirtley.  On turbine-generator rotor equivalent circuits , 1994 .

[5]  M. Savino,et al.  EXACT RELATIONSHIPS BETWEEN PARAMETERS AND TEST DATA FOR MODELS OF SYNCHRONOUS MACHINES , 1983 .

[6]  G. Shackshaft,et al.  New approach to the determination of synchronous-machine parameters from tests , 1974 .

[7]  G. J. Rogers,et al.  Synchronous-machine model including eddy currents , 1973 .

[8]  L. N. Hannett,et al.  Determination of synchronous machine stator and field leakage inductances from standstill frequency response tests , 1988 .

[9]  R. G. Farmer.  Second Benchmark Model for Computer Simulation of Subsynchronous Resonance IEEE Subsynchronous Resonance Working Group of the Dynamic System Performance Subcommittee Power System Engineering Committee , 1985, IEEE Power Engineering Review.

[10]  D. W. Auckland,et al.  Generator model for power system studies , 1990 .

[11]  I. M. Canay.  Physical significance of sub-subtransient quantities in dynamic behaviour of synchronous machines , 1988 .

[12]  S. A. Nasar,et al.  Unified treatment of core losses and saturation in the orthogonal-axis model of electric machines , 1987 .

[13]  Philippe Viarouge,et al.  Three-transfer-function approach for building phenomenological models of synchronous machines , 1994 .

[14]  Ali Keyhani,et al.  Maximum likelihood estimation of generator stability constants using SSER test data , 1991 .

[15]  V. Brandwajn.  Representation of MAagnetic Saturation in the Synchronous Machine Model in an Electro-Mlagnetic Transients Program , 1980, IEEE Transactions on Power Apparatus and Systems.

[16]  Jaime Avila-Rosales,et al.  Nonlinear Frequency Dependent Transformer Model for Electromagnetic Transient Studies in Power Systems , 1982, IEEE Transactions on Power Apparatus and Systems.

[17]  J. H. Fish,et al.  Saturation Functions for Synchronous Generators from Finite Elements , 1987, IEEE Power Engineering Review.

[18]  A. S. Morched,et al.  A high frequency transformer model for the EMTP , 1993 .

[19]  Ronald G. Harley,et al.  The General Theory of Alternating Current Machines , 1975 .

[20]  M. R. Iravani,et al.  Impact of synchronous machine constants and models on the analysis of torsional dynamics , 1992 .

[21]  Innocent Kamwa,et al.  A minimal realization approach to reduced-order modelling and modal analysis for power system response signals , 1993 .

[22]  A. W. Rankin.  Per-Unit Impedances of Synchronous Machines - II , 1945, Transactions of the American Institute of Electrical Engineers.

[23]  Philippe Viarouge,et al.  Identification of generalised models of synchronous machines from time-domain tests , 1991 .

[24]  D.c. Lee,et al.  Power System Stabilizers for Thermal Units: Analytical Techniques and On-Site Validation , 1981, IEEE Transactions on Power Apparatus and Systems.