Power system low frequency oscillation center drift as affected by wind displacing synchronous generators

This paper investigates the transfer of power system low frequency oscillation center as affected by the reduced inertia due to wind displacing synchronous generators. The investigation focuses on the change of oscillation center when certain synchronous generators are displaced by wind turbine generators. Theoretical analysis is carried out on the basis of the continuum model of a power system, which is demonstrated and validated by simulation and computation of an example two-area multi-machine power system. It is found that the center of low-frequency power oscillations could drift as the result of the wind displacing synchronous generators. However, the position of the center seems irrelevant with the change of system steady-state load flow conditions. Those findings are useful in guiding the selection of the PMUs and frequency monitoring device when the wind generators are connected into power systems to displace synchronous generators.