Analysis And Inhibition Of Low Frequency Oscillation In Powerfomer Transmission System

As the inter-connection of large area of power grid, and the urgency of ultra high voltage transmission of power in our country, it is very important to realize mutual power supply between northern and southern area, and inter-area power supply, also profitable to power system economical operation. However, accompanying power grid inter-connection scale continuously increasing, the problem of low frequency oscillation (LFO) has become the most important matter to perplex the development of power grid. It is an important project for experts in states to choose reasonable method to inhibit LFO. Power system stabilizer is the most important method to inhibit LFO currently, applying as widely as control method changing.This paper's research target focus on a powerformer, on the base of analysis of low frequency oscillation (LFO) in lacking damper way, powerformer transmission system was analyzed in the LFO situation, when it occurs LFO, using multi-band power system stabilizer (MB-PSS) to control. In the simulation, choice of input signal and parameter, and contrasting with traditional power system stabilizer (PSS) control effect etc, which were all simulated in this paper. Simulation results indicate that control effect of MB-PSS is better than traditional when parameter matching reasonably. By the single powerformer system analysis, excitation link was analyzed because it influence control effect of PSS, which can make excitation link matching with PSS better. Load style was simulated which it can cause LFO, provide theory basis for LFO caused by running and stopping power load.For the simulation result of utilization of PSS more universal, this paper simulates the four inter-connected powerformer system, which the system occurs LFO, appears the effect of PSS obviously different from the effect of single powerformer system, matching the PSS to the different style powerformer in the inter-connected system, simulation results show that the control effect is differently for choosing different fixing mode. At last, all of the four powerformers are fixed with PSS, the simulation results indicate that the utilization of MB-PSS have good inhibition effect for LFO. It provide theoretical and simulation basis for control measures of powerformer transmission system which occurs LFO.