励磁系统PSS2A模型的负阻尼案例分析

Analysis on Negative Damping of PSS2A Model of Excitation System

对广西平班电厂机组发生低频振荡事件进行了现场调查,并在电力系统分析软件(BPA)和实时数字模拟仿真系统(real time digital simulator,RTDS)上对事件过程进行了仿真重现。通过对平班电厂的实际励磁调节器装置与RTDS互连闭环仿真试验,暴露了PSS2A模型由于计算不准确而产生在高频段(1 Hz以上)提供正阻尼、低频段(1 Hz以下)提供负阻尼的现象,从PSS2A模型的机理上分析了该现象产生的原因,并确定本次事件的主要原因是PSS2A模型的角速度信号被误屏蔽,导致了PSS在投入状态下提供负阻尼。

This paper introduces investigation for one low frequency oscillation accident of the unit in Guangxi Pingban power plant and simulation of this event by using electric power system analysis software BPA and real time digital simulator sys- tem. By interconnection and closed loop simulation testing for practical excitation regulator and RTDS, it points out that in- accurate calculation of PSS2A may produce positive damping in high frequency section （over 1 Hz）while negative damping in low frequency section（ under 1 Hz）. On the basis of mechanism of PSS2A model, it analyzes reasons for the phenomena and confirms the main reason for this accident is wrong shielding for the angular velocity signal of PSS2A.