采用特征值法和Prony法相结合的PSS自适应控制

Adaptive Control of PSS Based on Eigen Value Analysis and Prony Analysis

随着互联电力系统的规模日益增大,系统互联引发的低频振荡问题已成为危及电网安全运行、制约电网传输能力的最主要因素之一。通常采用离线配置电力系统稳定器(PSS)来实现抑制低频振荡的目的。但是由于电力系统的实时性,在发生大扰动时,事先整定好的PSS对电力系统低频振荡的抑制效果并不理想,因此考虑采用PSS的自适应控制。提出一种采用特征值分析法和Prony分析方法相结合的PSS自适应控制。低频振荡发生后,通过滑动数据窗的方法缩短Prony辨识时间,先辨识得到频率较高的振荡模式,选取主导振荡模式在线配置PSS,在Prony方法辨识出振荡模式之前采用离线配置参数。克服了Prony在线辨识在低频振荡应用中的局限性。通过对4机2区系统的分析,得出在线配置PSS相对于离线配置PSS的优越性。验证了通过Prony方法在线配置PSS参数的可行性。

With the size of intereonneeted power system increasing, low-frequency oscillation has been the danger of power system and the most important factor of power transmission capacity constraints. Usually power system stahilizer is off-line configured to suppress low-frequency oscillation. However, when power system is in the event of large disturbances, the prior settings of PSS do not work very well. Adaptive control of PSS is uecessary. The paper proposes a method of adaptive control based on Eigenvalue analysis and Prony analvsis. The time of Prony identification is shortened thruugh the way of sliding data window. Firstly identify the oscillation mode of higher frequency, then select the dominant oscillation mode online to coordinate the parameter of PSS. Before the dominant oscillation mode is identified, the parameter which is coordinated offline is applied. This will overeome the limitations of the application of Prony to identify the low frequency oscillation online. Through Ihe analysis of the four machlne-two sides system, it is concluded that the PSS coordinated online works better than the one coordinated offline. The paper verified /he feasibility of PSS parameters which is coordinated through Prony analysis online.