Assessing the Contribution of Large Inverter-connected Power Sources on the Performance of Power System Stabilizers

Abstract

This article investigates the impacts of dominant electromechanical oscillations on power systems with the participation of large inverter-connected power source systems. From first principles, new formulas are derived to estimate the contribution of synchronizing and damping torques as functions of the current power system operating condition. An extended Heffron–Phillips model accounting for these effects is then proposed and further simplified to be used for designing damping controllers in power systems having a large inverter-connected power source. A clear interpretation of the influence of inverter-connected power source generators on the synchronizing and damping torque is provided. By using the developed system model, the performance degradation of a power system stabilizer damping controller is assessed for a wide range of operating conditions. The results of computational studies performed on a test system show that the damping torque is adversely affected as the level of active power generation of the large inverter-connected power source is increased. Furthermore, the simulation results obtained indicate that there is an increased potential for amplifying adverse interacting effects between power system stabilizer controllers and other control system devices responding in the frequency range of the dominant electromechanical modes.