柔性励磁系统抑制次同步振荡仿真分析

次同步振荡可能会对汽轮发电机的转轴产生严重的威胁,而传统晶闸管励磁系统使用附加励磁阻尼控制器对次同步振荡的抑制效果有限,需要为发电机配置如STATCOM的额外装置。相较于传统晶闸管励磁系统,柔性励磁系统具有双阻尼通道且相互耦合作用小,因此柔性励磁系统相较于传统晶闸管励磁系统对次同步振荡有更强的抑制能力。本文采用Matlab编程对发电机存在的轴系扭振模态进行了计算,并针对其中可能发生次同步振荡的模态设计了基于柔性励磁系统的无功控制器与传统励磁调节通道配合。本文在PSCAD/EMTDC平台上搭建了采用柔性励磁系统的IEEE次同步振荡第一标准模型,验证了柔性励磁系统对次同步振荡的抑制效果。

Simulation and Analysis of Suppressing Subsynchronous Oscillation Using Flexible Excitation System

The subsynchronous oscillation may seriously threaten the shaft of steam turbine generator,but the supression effect of supplementary excitation damping controller on subsynchronous oscillation is not good.It’s necessary to configure an additional device like STATCOM for the generator.Compared with the traditional thyristor excitation system,the flexible excitation system has two damping channels and two channels have weak coupling effect.Therefore,the flexible excitation system has a stronger supression effect than traditional excitation system.This paper uses Matlab to calculate the potential shafting torsional modals of generator,then designs reactive power controller based on flexible excitation system for the modals in which subsynchronous oscillation may occur cooperated with traditional excitation regulation channel.This paper builds IEEE first benchmark model for subsynchronous resonance using flexible excitation system on PSCAD/EMTDC,and the simulation results show that flexible excitation system can supress subsynchronous oscillation in the power system.