The paper presents the two-dimensional, field-circuit model of a high power synchronous generator verified by measurements. The model enables determining the waveforms of electromagnetic quantities in steady and transient states. Verification of the model was based on comparison of the measured and calculated waveforms after a disturbance in the voltage regulation system of a TWW-200-2 generator operating in Połaniec Power Plant. There are also presented the field methods for determining electromagnetic parameters (synchronous reactances and time constants) when using the distributions of static and quasi-static, magnetic and electromagnetic fields calculated by the finite element method (FEM). The set of these parameters was used as the starting parameters of the optimization algorithm for estimation of electromagnetic parameters of the synchronous generator circuit model. The dynamic waveforms under the generator load conditions calculated by the finite element method are the basis of parameter estimation. The parameter estimation of the generator model was performed with the use of the least squares method.
The paper presents parameter estimation of the mathematical model of a synchronous generator with the electromechanical excitation system working in the power system. The generator mathematical model expressed by the standard parameters of X, T type and including the stator magnetic circuit saturation was used for investigations. The dynamic waveforms caused by introduction of an additional signal PRBS to the voltage regulator are the basis for estimation. The influence of the two-input stabilizer PSS3B reaction on the quality of the generator electromagnetic parameter estimation for the system with and without the stabilizer was investigated. The least square method was applied to parameter estimation, while the gradient method was used for optimization of the mean square error.
The paper presents field methods for determining electromagnetic parameters (inductances, resistances and time constants) of a synchronous generator mathematical model containing one equivalent damper circuit in each rotor axis. The magnetostatic and the electromagnetic harmonic field distributions calculated by the finite element method were used. Nonlinear characteristics of machine inductances were presented which illustrate the saturation effect. Particular attention were drawn to the problems of determining subtransient time constants of the generator.
The paper presents results of scientific reasearches of large power induction motors. In chapter 2 are presented the causes of bearing currents forming supplied from line voltage. The figure 2 are presented influence rotational speed on the bearings resistance. The figure 3 are presented bearing current density versus life curve. The figure 5 are presented equivalent measurement system. In the chapter 4.2 are presented laboratory results. Figures 8 and 9 show characteristics determining influence of avarage bearing temeperature, shaft voltage and rotational speed on bearing current. Conclusions drawn from laboratory researches are presented in chapter 5.
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W pracy przedstawiono dwuwymiarowy polowo-obwodowy model hydrogeneratora zainstalowanego w elektrowni szczytowo-pompowej w Żydowie. Model uwzględnia uzwojenie ułamkowe w stojanie, klatkę tłumiącą w wirniku, nieliniowe charakterystyki magnesowania rdzeni magnetycznych i ruch obrotowy wirnika. Weryfikację modelu polowo-obwodowego przeprowadzono w oparciu o porównanie zmierzonych i obliczonych metodą elementów skończonych charakterystyk biegu jałowego i trójfazowego zwarcia.
EN
A two-dimensional, field-circuit model of a hydrogenerator, installed in the Pumped Storage Power Plant Żydowo, is presented in the paper. This model accounts for the fractional-pitch stator winding, the rotor damper squirrel-cage, nonlinear magnetization curves and the rotor motion. Verification of the model have been carried out by the comparison of computed characteristics using the finite element method no-load and short-circuit characteristics with those obtained from measurements.
In the work there is presented a field-circuit model of a high power synchronous generator which enables determining the waveforms of electromagnetic quantities in steady and transient states. Verification of the field-circuit model was performed based on comparison of the measured and calculated with finite element method waveforms at a step change of the voltage regulator reference voltage of the generator operating under no load conditions in Połaniec Power Plant. The dynamic waveforms of the generator operating in a power system under load conditions, in which the transient state was caused by a step change of the field voltage, were the basis for estimation of the generator model electromagnetic parameters. Estimation of the generator model parameters was performed with use of the least square method.
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W pracy przedstawiono dwuwymiarowy, polowo-obwodowy model generatora synchronicznego dużej mocy, umożliwiający wyznaczanie przebiegów wielkości elektromagnetycznych w stanach ustalonych i nieustalonych. Weryfikację modelu przeprowadzono w oparciu o porównanie zmierzonego i obliczonego napięcia stojana na biegu jałowym generatora typu TWW-200-2 pracującego w Elektrowni Połaniec. Estymację parametrów przeprowadzono przy pomocy metody najmniejszych kwadratów.
EN
A two-dimensional, field-circuit model of a high-power synchronous generator is presented in the paper. It enables determining the waveforms of electromagnetic quantities in steady and transient states. The model verification was performed basing on the comparison of the measured and computed stator voltage under no-load state of a TWW -200-2 generator operating in Połaniec Power Plant. Parameter estimation was carried out by means of the least square method.
The paper presents the method for determining electromagnetic parameters of a high power synchronous machine based on analysis of transient waveforms caused by small disturbances in the field winding under no-load condition. The waveforms were calculated by the time-stepping finite element method when using a two-dimensional field-circuit model of the machine worked out in the Maxwell program of Ansoft Corporation. The model takes into account non-linear B-H characteristics of magnetic cores, eddy current action in solid parts of the rotor, the rotor motion, as well as the power supply of machine windings from voltage sources. The transient state was initiated by a change in the field voltage of several percents in the form of a step or pseudorandom signal (PRBS) at no load and constant rotor speed. Basing on the determined transient waveforms in the field-circuit model, the parameter estimation of the selected mathematical circuit models of the machine was performed using the least square method. An optimisation algorithm from the Matlab/Simulink package was applied to minimise the mean square error.
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W artykule opisano pomiarowe metody estymacji parametrów modeli matematycznych elementów składowych zespołów wytwórczych pracujących w Krajowym Systemie Elektroenergetycznym (KSE). Przedstawiono metody wyznaczania parametrów modeli generatorów synchronicznych, układów wzbudzenia z regulatorami napięcia oraz turbin parowych wraz z układami regulacji prędkości. Przy estymacji parametrów poszczególnych modeli analizowano m.in. odpowiedzi układów przy zrzutach mocy i zmianach napięcia zadanego (skokowych i pseudolosowych) w układzie regulacji napięcia generatora. Ponadto na podstawie badań symulacyjnych przedstawiono wpływ wartości parametrów modeli matematycznych (często przyjmowanych arbitralnie) na przebiegi nieustalone napięć i mocy chwilowych zespołów wytwórczych, występujące w stanach normalnych i awaryjnych KSE.
EN
In the paper there are described measurement methods for parameter estimation of the mathematical models of component elements of generating units operating in the Polish Power System (PPS). When estimating the parameters of particular models, there were an alysed, among others, the responses of the systems at load rejection and changes (step and random) of the reference voltage in the generator voltage regulation system. Moreover, based on simulation investigations, there is presented the influence of the mathematical model parameters (of ten assumed arbitrarily) on transient waveforms of different quantities, among others currents and voltages of the generating units, occurring under normal and emergency conditions of the PPS operation.
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