Methods for determining linear synchronous machine parameters

Abstract

A survey of metho& for determining synchronous machine equivalent electrical circuit parameters is presented. These equivalent circuits are the basis for computer analysis and simulation. Circuit parameters developed for rotary synchronous machine Similar linear synchronous machine (Lw parameters are not as well developed. This paper suggests methods for obtaining machine parameters appropriate to LSM modeling. modeling are in wide use. 1: IntroductionIt is usefbl to develop mathematical models of electromagnetic (EM) machines to explain their electric, magnetic, and mechanical behavior. Parameters for these models are evaluated by direct measurement, derivation from test results, analysis, estimation, or a combination of these. There has been a wealth of experience with rotary synchronous EM machine (RSM) parameters. Although well documented, the methods from which these RSM parameters are derived are not so well known.Experience with linear synchronous EM machine (LSM) parameters is not nearly so extensive. This paper reviews methods used to obtain RSM parameters to suggest means for procuring LSM parameters. 2: RSM parametersFor RSM's, it has been generally accepted to use circuit models based on Park's transformation [l]. Usually RSM's have three phase ac stator windings, a rotor dc field winding, and several rotor damper or amortisseur windings. Higher order models have more windings; reduced order models eliminate windings. Reduced order models are adequate for steady state 0-8186-5320-5/94 $03.00 0 1994 IEEE 411 analysis. inductive reactances (X = oL).Circuit windings are often expressed as Park's equations transform the stator three phase quantities into a new reference frame which moves with the rotor. The new variables are expressed in terms of direct and quadrature axes quantities. Classical machine theory uses this two-axis transformation to derive the equivalent circuits and corresponding parameters.

A virtual testbed for characterizing synchronous generators based on time domain tests

“…Techniques to determine synchronous-machine model parameters can be viewed as two groups: frequency and time domain techniques [1][2][3][4][5][6][7][8][9][10][11][12]. Some of these tests can be applied to a running machine and other to a still machine.…”

“…Some of these tests can be applied to a running machine and other to a still machine. Considering running machines, several tests have been used such as shortcircuit, open circuit, load rejection, field flux decay, among others, [1][2][3][4][5][6]. Characterizing the machine model involves d-q axis modeling considering constant speed in order to reduce complexity.…”