Study On Lacking-damping Of Power System And Its Control

With the continuous spreading of scale in power system and introducing of fast exciter system, the problem of low frequency oscillation which is arosed because of lacking-damping becomes worse and worse. This paper analyzes the mechanism reasons of insufficient-damping, then analyzes and compares primarily the effect of restraining the low frequency inter-area oscillation of Power system stabilizer(PSS) and reinforcement of the connection between two bulk power grids. This paper opens out the relatively large impedance of tie-lines in weakly interconnected systems could greatly reduce the damping of these system, puting forward the conception of negative damping effect of the weak tie-lines between power grids, and indicates the reinforcement of the connection between two bulk power grids is a essential correspondingly way to solve the low frequency inter-area oscillation. As an actual system example, Northwest Power Grid in 2007 was testified. Presuming upon this paper has some reference value for the development of Northwest 750kV Power Grid and UHV of china.