System modeling and control design for fast voltage regulation using STATCOMs

Fast voltage regulation using static compensators requires a dynamic system model that is valid on an instantaneous basis. This paper presents a general modeling strategy that allows design of fast voltage regulation controller while accounting for system parameters. The co-ordinate transform used to model the system facilitates extraction of linearized system dynamics with the help of circuit simulators. It is shown that the problem of voltage regulation using instantaneous reactive current is non-minimum phase for certain operating conditions, thereby limiting achievable dynamic response irrespective of the control design method. Simulation results with a controller designed using input output bode plots are presented to illustrate efficacy of the proposed method.