LOAD MODELING IN STUDIES OF POWER-SYSTEM DAMPING

This paper considers the significance of load voltage dynamics in stud ies of power system damping. A generic model of dynamic loads is used to investigate the influence of active and reactive power dynamics on the damping of oscillations in a multimachine power system. The intera ction between the load and the power system is explored in terms of lo ad and system transfer functions. It is shown that the power system tr ansfer function is composed of a static part and a dynamic part. The s tatic part is derived from the power flow Jacobian. The investigations indicate that load voltage dynamics can significantly influence the d amping of modal oscillations. Static load models can give quite mislea ding predictions of damping when loads actually exhibit dynamic behavi our.