Effects of series impedance on power system load dynamics

This paper analyzes the effects of series impedance, existing between an ob servation point and a load, on the active and reactive power dynamics of po wer system loads. First, the changes of dynamics expressed in the form of t ransfer functions are provided as the effects of series impedance. Next, a simulation shows that the change is small enough to allow approximation of the transfer function at the original order. The result also explains the e mpirical fact that the dynamics of most aggregated loads can be modeled by first-order transfer functions to obtain a good approximation, even though the order becomes higher as the effects of series impedance, insofar as the dominant load components are well approximated at the first order.