Study on relationship between inter-area oscillation damping and operating conditions in power systems

Inter-area oscillation problem is an important subject in power system stability and control research. This paper focuses on the influence of network operating conditions on inter-area oscillation damping. Since concerned study lacks enough theoretical analysis, the general rule has not been revealed. Using theoretical deduction, the relationship between electromechanical oscillation damping and rotor angle difference under general cases in two-generator interconnected power system is illuminated. Accordingly, the complex inter-area oscillation damping characteristics in real complex power system is theoretically explained. The moving trend of inter-area oscillation damping with the change of inter-area transfer power is determined by the comparison of damping per inertia of generators in equivalent two-generator interconnected system. Three illustrative examples are proposed to verify the validity of the theoretical analysis.