Analysis of Modal Participation for Low Frequency Oscillation in Interconnected Power Systems

The analysis of low frequency oscillation in interconnected power systems can take the method of small disturbance stability. Usually, the problem is one of ensuring sufficient damping of system oscillations. In general, the stability of oscillatory modes can be analysed by considering the systems linearized about an equilibrium point represented by a steady state operating condition. The quantitative and qualitative information of stability can be accessed by eigenvalue calculations. Based on introducing the mathematic model of eigenvalue analysis, the participation degree calculation between the oscillatory modes and system state variables is proposed by calculating eigenvalues and eigenvectors. Finally, results of eigenvalue calculations for four machines two regions system validated the effectiveness of the analysis of low frequency oscillation relating the analysis method of modal participation degree. Furthermore, the method is available for the allocation of various controllers such as PSS in real power systems.