基于Prony辨识的自适应PSS的设计及研究

目前区域间低频振荡正成为影响电力系统稳定以及限制电网传输能力的重要因素。然而作为系统中最重要的抑制低频振荡的设备电力系统稳定器(PSS),目前往往采用离线整定的方法,未能考虑实际系统多样的运行方式,往往不能很好地提供阻尼从而抑制振荡。本文提出了一种基于改进Prony分析的在线自适应PSS设计方法。本方法通过改进的Prony分析在线求取低频振荡中各状态变量的频率、阻尼、初始相位。在阻尼不满足要求的情况下,通过加入强制阻尼并计算其加入前后暂态电势与发电机转速之间夹角的变化,得出此运行方式下由励磁系统及发电机的励磁绕组产生的相位滞后相位信息,进而得出最佳的PSS整定参数。最后以一个两区域四机仿真分析充分表明了所设计控制器的有效性。

Self-turning PSS Design Using Prony Analysis

With the development of the electric power system,area mode low-frequency oscillation is an important factor to effect the stabilization and the transmission of the power system.At present,the off-line method is used to calculate the parameters of power system stabilizer(PSS),whereas the multi-running modes of the real system are not taken into account.It will result in the low-frequency oscillation of the power system because of the lacking of damping.In this paper a method is designed based on Prony analysis to adjust the parameters of self-turning PSS on line.This method is to calculate frequency,damping and phase of the state variables.Through measuring the phases between transient voltage and rotate speed of generator before and after adding the damping,it is possible to calculate the phase between excitation system and excitation wind of generator and the optimal parameters of PSS.Simulation analysis is used to prove the validity of the method.