Influence of Load Model on PSS Parameter Tuning

Coefficients of K₁~K₆, the synchronous torque coefficients and the damping torque coefficients of single machine infinite bus system with load in machine side are derived. The influence of load model on the size and phase of the input signals of PSS and PSS parameter setting is analyzed based on a hydropower generating units in Yunnan, and the results are verified through small signal stability analysis of a three machine and nine bus system. The research shows that the load model has a certain degree of influence on the time constant and magnification of PSS. The influence on system stability is different under different circumstances when the load and PSS is interacting. The role of PSS should be taken into account while analyzing the influence of load model on power system stability. The influence of load model in machine side cant be ignored during the PSS parameter setting.