大区联网条件下四川电网低频振荡再分析

The Analysis of Low-frequency Oscillations of Sichuan Power Grid in Large Regional Interconnections

结合诱发低频振荡的四大主要因素和四川实际电网的特点,揭示了大区联网条件下四川电网容易出现低频振荡的原因。通过对四川电网进行低频振荡再分析,研究了网架结构的变化、运行条件、发电机励磁和PSS模型参数以及串补对主导低频振荡模式阻尼的影响。运用多机电力系统二阶解析解对线性一阶解进行二阶非线性修正,通过比较分析一阶和二阶相关因子,有助于发现和认识与主导低频振荡模式相关性最强的发电机组,对配置PSS抑制低频振荡有指导意义。

Combination of the four major factors leading to low - frequency oscillations and the characteristics of the actual power grid for Sichuan, Reveals the reasons why Sichuan power grid under large regional interconnections is prone to low - frequency oscillations. By means of resume analysis of dominant inertial modes for Sichuan power grid , the damping effects of the changes of power grid structure, different operating modes, excitation and PSS models, series compensators are researched, The explicit second order solutions of multi - machines system are used to amend the first order linear solutions with second - order nonlinear impaction, by comparison of the first order and second order participation factors, it can help to find the most related generators of dominant inertial modes, and can made guiding sense of PSS disposition and low - frequency oscillations suppression.