scholarly journals Analysis of asymmetrical operating conditions of a power system for different models of synchronous generators

2019 ◽  
Vol 28 ◽  
pp. 01004
Author(s):  
Piotr Pruski ◽  
Stefan Paszek
Keyword(s):  
Steady State ◽  
Power System ◽  
Transmission Line ◽  
High Voltage ◽  
Synchronous Generator ◽  
Operating Conditions ◽  
Synchronous Generators ◽  
High Voltage Transmission Line ◽  
Input And Output ◽  
Short Circuits

In the paper, the waveforms of the output quantities of different mathematical models of a synchronous generator operating in a power system (PS) are compared. In the investigations, it was assumed that the PS consisted of a generating unit (including, among others, a synchronous generator) connected to a bus by a high voltage transmission line. The disturbances of the steady state in the form of symmetrical and asymmetrical short-circuits in a selected place of the transmission line were considered. In the generator model, the subtransient asymmetry was taken into account. The XT and RL models of the synchronous generator when assuming different input and output quantities of the system were investigated.

scholarly journals Synchronous Generator Model Parameter Estimation Based on Noisy Dynamic Waveforms

2016 ◽  
Vol 67 (1) ◽  
pp. 21-28
Author(s):  
Sebastian Berhausen ◽  
Stefan Paszek
Keyword(s):  
Parameter Estimation ◽  
Power Systems ◽  
Power System ◽  
Objective Function ◽  
Estimation Method ◽  
Synchronous Generator ◽  
Voltage Regulation ◽  
Operating Conditions ◽  
Synchronous Generators ◽  
Generator Voltage

Abstract In recent years, there have occurred system failures in many power systems all over the world. They have resulted in a lack of power supply to a large number of recipients. To minimize the risk of occurrence of power failures, it is necessary to perform multivariate investigations, including simulations, of power system operating conditions. To conduct reliable simulations, the current base of parameters of the models of generating units, containing the models of synchronous generators, is necessary. In the paper, there is presented a method for parameter estimation of a synchronous generator nonlinear model based on the analysis of selected transient waveforms caused by introducing a disturbance (in the form of a pseudorandom signal) in the generator voltage regulation channel. The parameter estimation was performed by minimizing the objective function defined as a mean square error for deviations between the measurement waveforms and the waveforms calculated based on the generator mathematical model. A hybrid algorithm was used for the minimization of the objective function. In the paper, there is described a filter system used for filtering the noisy measurement waveforms. The calculation results of the model of a 44 kW synchronous generator installed on a laboratory stand of the Institute of Electrical Engineering and Computer Science of the Silesian University of Technology are also given. The presented estimation method can be successfully applied to parameter estimation of different models of high-power synchronous generators operating in a power system.

scholarly journals Analysis of Synchronous Generators’ Local Mode Eigenvalues in Modern Power Systems

2021 ◽  
Vol 12 (1) ◽  
pp. 195
Author(s):  
Jožef Ritonja ◽  
Boštjan Polajžer
Keyword(s):  
Power Systems ◽  
Power System ◽  
Transmission Lines ◽  
Negative Impact ◽  
Synchronous Generator ◽  
Operating Conditions ◽  
Local Mode ◽  
Synchronous Generators ◽  
Systematic Analysis ◽  
Local Modes

New energy sources, storage facilities, power electronics devices, advanced and complex control concepts, economic operating doctrines, and cost-optimized construction and production of machines and equipment in power systems adversely affect small-signal stability associated with local oscillations. The objective of the article is to analyze local oscillations and the causes that affect them in order to reduce their negative impact. There are no recognized analyses of the oscillations of modern operating synchronous generators exposed to new conditions in power systems. The basic idea is to perform a numerical analysis of local oscillations of a large number of synchronous generators in the power system. The paper represents the local mode data obtained from a systematic analysis of synchronous generators in the Slovenian power system. Analyzed were 74 synchronous generators of the Slovenian power system, plus many additional synchronous generators for which data were accessible in references. The mathematical models convenient for the study of local oscillations are described first in the paper. Next, the influences of transmission lines, size of the synchronous generators, operating conditions, and control systems were investigated. The paper’s merit is the applicable rules that have been defined to help power plant operators avoid stability-problematic situations. Consequently, boundaries were estimated of the eigenvalues of local modes. Finally, experiments were performed with a laboratory-size synchronous generator to assess the regularity of the numerically obtained conclusions. The obtained results enable the prediction of local oscillations’ frequencies and dampings and will be useful in PSS planning.

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