孤网发电机调速系统参数定量调整理论分析

Analysis on quantitative parameter adjustment of speed governor in isolated power grid

为了分析调速系统对孤网一次调频频率响应的影响,合理调整其工作模式及参数,以孤网一次调频的频率响应特性作为研究对象,提出了一次调频评价指标。在此基础上,利用根轨迹及主导极点分析法从理论上分析了调速系统中调差系数、参与一次调频的机组比例、油动机时间常数及发电机惯性时间常数各线性环节对孤网调频性能的影响。并以孤网静态频率特性为出发点,分析了死区、调频上下限及OPC动作定值等非线性环节对调频性能的影响,提出了相应参数定量调整的方法,为孤网调速系统参数调整提供了理论依据。

In order to analyze the impacts that speed governor system has on the primary frequency regulation in isolated power grid, based on the frequency response characteristic, evaluation index for primary frequency regulation is proposed. And the influence on the primary frequency regulation by governor static difference coefficient, the ratio of generator participating in primary frequency regulation, the generator inertia time constant, and the governor time constant is analyzed by using root locus and predominant pole. The function of dead band, first frequency modulation limit and OPC （over-speed protection control） is argued. Meanwhile, based on static frequency characteristic curves, and methods for quantitative parameter adjustment are proposed.