三机无刷励磁系统建模和参数计算分析

Modelling and Parameter Calculation Analysis of Three-Machine Brushless Excitation System

发电机励磁系统性能是反映电力系统稳定性的重要指标,对励磁系统进行准确的建模和参数计算是保证电力系统稳定性分析结果真实可靠的前提。以北京某热电厂25MW汽轮机组的三机无刷励磁系统为研究对象,基于现场试验结果对励磁系统参数进行了计算,采用FM模型建立了励磁系统数学模型及参数进行稳定计算,并将三机无刷励磁汽轮发电机的空载阶跃响应特性仿真结果与试验结果进行对比分析,进而验证了所得励磁系统模型参数的准确性,可为电力系统稳定分析及电网日常生产调度提供可靠依据。

The performance of the generator excitation system is an important indicator to reflect the stability of the power system.The accurate modelling and parameter calculation of the excitation system are prerequisites for ensuring the authenticity and reliability of power system stability analysis results.Taking the three-machine brushless excitation system of a 25 MW steam turbine unit of a thermal power plant in Beijing as the research object,this paper is based on the field test results to calculate the excitation system parameters,and then based on FM model to establish the mathematical model and parameters of excitation system used for stability calculation.Finally,the paper compares the simulation results of no-load step response characteristics of the brushless exciter generator with the experimental results,and verifies the accuracy of the obtained excitation system model parameters,which can provide reliable basis for power system stability analysis and daily production scheduling of power grid.