Study Of Residue-matrix Based WPSS Design And Its Damping On Inter-area Oscillation

With the increasing scale of interconnected power system,the low-frequency oscillation,especially inter-area oscillation caused by wake connection of regional power networks,poses a threat to the stability and safety operation of the power system.Consequently,the study of power system low-frequency oscillation,especially control method based on Wide-Area Measurement System(WAMS),has become an active research area.Under the mentioned circumstance above,systematic investigation centered power system low-frequency oscillation is conducted in this thesis,where two major focuses are electromechanical modes identification and the damping of low frequency oscillation.In this thesis,the Eigensystem Realization Algorithm(ERA)is applied to power system for electromechanical modes identification.By conducting decomposition calculation on sampled impulse responses of the power system,ERA constructs a minimal realization of that system,and then identifies its electromechanical modes.Through comparing experiments on a New England 10-machine system with the small disturbance method,ERA has been verified to be effective in the case of power system electromechanical modes identification.Furthermore,a residue-matrix based method for Power System Stabilizer(PSS)design is conducted.This thesis modified the method to the placement and input-signal selection of Wide-area Power System Stabilizer(WPSS),and verified the effectiveness of the method by testing the designed WPSSs on the damping of two intra-area oscillation modes and one inter-area oscillation mode in the New England system.Additionally,this thesis studied the impact of input signal selection on the performance of PSS.Wide-area signal,local signal and combined signal are used as the input signal for the PSS in the New England system respectively.Comparison among the performance of PSS in each case showed that,as for the damping of inter-area oscillation,wide-area signals are preferable to local signals;in compassion with single signals,combined signals ameliorate the overall damping of the power system better.Hopefully,researches on the design of power system controllers,including but not limited to PSS,will benefit from the findings in this thesis.