Analysis of dynamic reactive power demand characteristics of inverter stations of multi-infeed HVDC

Dynamic reactive power demand in inverter stations concerns the stability of transient voltage in multi-infeed high voltage direct current (HVDC) receiving-end grids. In this paper, with PSCAD/EMTDC simulation platform, a doubly fed HVDC model is built by adopting the CIGRE HVDC benchmark system. And the demand rule for dynamic reactive power in HVDC transmission system is studied by using the control variable method, considering various control modes and stiffness of electric coupling between HVDC inverters. Some preliminary relation curves between reactive power demand and different factors are outlined. The simulation results show that under constant voltage control inverter would absorb much reactive power and a critical coupling distance exists which would distinguish the two trends of reactive power in inverter station.