Research On Parameter Identifiability Of Generator Excitation System And The Development Of Identification Software Package

With the development of the power system as well as the enlargement of the powergrid, the importance of the problem which deals with the stable operation in power grid isbecoming more and more significant. The parameters of excitation systems have a greatimpact on the results of the analysis and calculation in power system. Thus, it’s urgent tocarry out the work of excitation system parameter identification. On the other hand, due tothe limitation of the used model structure for excitation systems, some parameters could notbe successfully identified merely by measured data. So, it would be meaningful to analyzethe identifiability of the model parameters of excitation systems. This paper focuses on theidentification and identifiability of the model parameters of excitation systems.In this paper, the purpose and significance of excitation system parameteridentification has been briefly analyzed and the theory of the parameter identification hasbeen introduced. A literature review of excitation parameters of domestic and internationalresearch has been performed to illustrate the importance of parameter identifiability. Thewhole text contains the following parts:Firstly, the concept of parameter identification is described. Trajectory sensitivity isintroduced to identify the relationship between the identifability of different parameters. Aqualitative conclusion of the relationship is achieved. Based on the relationship, a newmethod defined as the Multiple Rounds Parameter Identification is proposed. Parameteridentification of user-defined models and standard excitation models is carried to verify theeffectiveness of this method.Secondly, linear correlation analysis on the trajectory sensitivity of relevantparameters is performed. Method to identify representative relevant parameters and theprocess to select cluster of relevant parameters is introduced. A formula is deduced to evaluate the parameter identification results of relevant parameters. Results show that themethod used in this paper is especially useful for identifying relevant parameters.Thirdly, the parameters of excitation system limitation is identified and analyzed;parameters identification and evaluation is carried out on IEEE DC1A and IEEE ST2A typestandard excitation system models. The simulation results would be instructive to relevantissues of parameter identification in actual systems.Finally, a software package of excitation system parameter identification is developedin MATLAB platform. Based on field test data and practical models, it has variousfunctions, such as data processing, parameter identification and checking. In order to meetthe demand of the actual production, the software package has also developed an interfacebetween PSASP and the data center database of State Grid.