The dynamic characteristics of new generation synchronous condenser and static synchronous compensator (STATCOM) were compared in both frequency and time domains in this paper, based on which their applicability under different scenes was analyzed. Firstly, an effective reactive current gain index was proposed to realize the dynamic response evaluation, via which the characteristics of two devices were studied in the frequency domain. The analyses include their effectiveness and comparison of phase and amplitude frequency characteristics under voltage fluctuation of different frequencies. Based on the current and planning power systems, their dynamic characteristics were compared in the time domain, considering the application demands for frequency and steady-state overvoltage restraining in sending-end power systems, the decreasing the possibility of simultaneous commutation failure in multiple DC lines, and the increasing transient voltage stability of receiving-end power systems. Their technical advantages and applicability under different scenes were finally analyzed and compared, to provide technical support of dynamic reactive power compensator selection in planning power systems.
