The Study Of Interaction Between PSS And HVDC On The Inhibiting Effect Of Low Frequency Oscillation

Both PSS and HVDC can damp low frequency oscillation effectively, but PSS and HVDC would destroy stability of power system and cause the low frequency oscillation, even the power system collapse, if using them at the same time to damp low frequency oscillation. The interaction is complicated, so the thesis discusses it through simulating the power system. The thesis uses the PSCAD/EMTDC to regulate the parameter of PSS and HVDC and analyze the interaction.Firstly, the mechanism of the low frequency oscillation is explained in the thesis. The mathematic models of generator, excitation system, PSS and HVDC are also studied in detail. Then the effects of the parameters of these models on low frequency oscillation in a singular generator environment are simulated. The simulating reports indicate that excitation system, PSS and HVDC damp low frequency oscillation effectively. Finally, the power system model of several machines is established. The interaction effect is studied by regulating the parameters of the two controllers.The simulating reports of several machines power system indicate that low frequency oscillation can damp more effectively and the power system stability can be improved, when the parameters of the two controllers were regulated properly at the same time.