Multi-circuit HVDC system emergency DC power support with reactive control

Insufficient reactive power in DC converter stations may deteriorate the whole system operating conditions. In this paper, the ratio between reactive power consumption and active power transmission as a HVDC system provides Emergency DC Power Support (EDCPS) is analyzed and derived. Then multicircuit HVDC system EDCPS Strategies with reactive power controls, such as emergency reactive power compensation, converter station reactive power control and DC active power support's quantity adjustment are proposed to improve voltage stability. Simulation results on practical power systems validate the effectiveness of the control strategies. Finally an EDCPS implementation framework with reactive power coordinated control for large-scale power systems is introduced.