基于灵敏度分析的同步发电机参数辨识

发布时间：2019-04-02 04:06

【摘要】：随着电网规模不断扩大,对电网的安全运行提出了更大的挑战,而准确的模型参数是电力系统运行分析、仿真和故障诊断的基础,对电网安全运行有重要意义,故快速准确获得可靠的模型参数是保证电力系统安全运行的基本问题。发电机作为电网能量的来源,其参数的精确性对电网运行分析有十分重要的影响。本文在原有同步发电机参数辨识方案的基础上进行了改进,将对参数的灵敏度计算环节加入到参数辨识中,出一种以灵敏度分析为前提的同步发电机参数辨识方案,将辨识算法应用于Simulink仿真结果的辨识,并在PMU实测数据的环境下对辨识算法进行验证,取得了良好的辨识效果,证明方案具有实用性。本文介绍了同步发电机的基本方程和在此基础上推导出的几种实用模型,根据需要选定六阶同步发电机实用模型为参数辨识模型,并对六阶实用模型进行了可辨识性分析。简述了辨识的概念及同步发电机参数辨识的特点,介绍了同步发电机辨识的基本流程,并对辨识过程中用到的微分方程的数值解法和优化算法进行了叙述。简单了解几种灵敏度分析办法,选定轨迹灵敏度法作为同步发电机灵敏度分析的工具,对轨迹灵敏度法的分类和计算方法进行了叙述,最终确定选用摄动法计算同步发电机参数的灵敏度。利用Simulink建立仿真模型,得出在励磁电压发生扰动时同步发电机轨迹灵敏度的大小,分析了扰动大小和扰动时长对轨迹灵敏度大小的影响,根据各参数灵敏度的表现确定了发电机参数辨识方案。以MATLAB为工具搭建仿真平台模拟多种扰动下同步发电机的行为,利用基于灵敏度分析的参数辨识方案对模拟结果进行辨识,基于辨识结果对辨识方案进行可行性和通用性地分析。在搭建的仿真平台下对比了传统参数辨识方案和基于灵敏度分析的参数辨识方案,对两种方案的辨识结果进行分析,得出了不同方案的异同之处。简单介绍了PMU数据及其处理过程,将基于灵敏度分析的参数辨识方案应用于实测数据下且对方案进行了可行性、稳定性和精确性地分析。在实测算例下比较了传统参数辨识方案和基于灵敏度分析参数辨识方案的异同之处,分析两种方案的计算结果,得到基于灵敏度分析的参数辨识方案目标函数较小,参数辨识结果更加稳定,更贴近同步发电机实际运行行为的实验结果。
[Abstract]:With the expansion of power grid scale, the security operation of power grid is challenged more and more, and accurate model parameters are the basis of power system operation analysis, simulation and fault diagnosis, which is of great significance to the safe operation of power network. Therefore, fast and accurate obtaining reliable model parameters is the basic problem to ensure the safe operation of power system. As the source of power grid energy, the accuracy of generator parameters has a very important impact on the analysis of power grid operation. In this paper, based on the original parameter identification scheme of synchronous generator, the sensitivity calculation of parameters is added to the parameter identification, and a parameter identification scheme of synchronous generator based on sensitivity analysis is proposed. The identification algorithm is applied to the identification of Simulink simulation results, and the identification algorithm is verified in the environment of PMU measured data. Good identification results are obtained, and the scheme is proved to be practical. In this paper, the basic equation of synchronous generator and several practical models derived from it are introduced. According to the need, the practical model of six-order synchronous generator is selected as the parameter identification model, and the identifiability of the sixth-order practical model is analyzed. This paper briefly introduces the concept of identification and the characteristics of parameter identification of synchronous generator, introduces the basic flow chart of identification of synchronous generator, and describes the numerical solution and optimization algorithm of differential equation used in the process of identification. Several sensitivity analysis methods are simply understood. Trajectory sensitivity method is selected as a tool for sensitivity analysis of synchronous generators, and the classification and calculation method of trajectory sensitivity method are described. Finally, the sensitivity of parameters of synchronous generator is calculated by perturbation method. Based on the simulation model established by Simulink, the trajectory sensitivity of synchronous generator is obtained when the excitation voltage is disturbed, and the influence of the disturbance size and time length on the trajectory sensitivity is analyzed. According to the performance of the sensitivity of each parameter, the parameter identification scheme of the generator is determined. The simulation platform based on MATLAB is used to simulate the behavior of synchronous generators under various disturbances. The simulation results are identified by using the parameter identification scheme based on sensitivity analysis, and the feasibility and generality of the identification schemes are analyzed based on the identification results. Under the simulation platform, the traditional parameter identification scheme and the parameter identification scheme based on sensitivity analysis are compared, and the identification results of the two schemes are analyzed, and the similarities and differences between the two schemes are obtained. The PMU data and its processing process are briefly introduced. The parameter identification scheme based on sensitivity analysis is applied to the measured data and the feasibility, stability and accuracy of the scheme are analyzed. The similarities and differences between the traditional parameter identification scheme and the parameter identification scheme based on sensitivity analysis are compared, and the calculation results of the two schemes are analyzed, and the objective function of the parameter identification scheme based on sensitivity analysis is smaller than that of the traditional parameter identification scheme based on sensitivity analysis. The results of parameter identification are more stable and close to the experimental results of the actual operation behavior of synchronous generators.
【学位授予单位】：青岛大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM31

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