Study on Post-commutation-failure Active Power Characteristics of HVDC Converter and Its Influence on Sending-end AC System
Currently published studies on DC commutation failure have mainly focused on the inverter station and the re-ceiving-end AC system.This study discovered that the active power change of DC rectifier station caused by commutation failure might exceed the transmission power,thus causing huge power impact on the sending-end AC system.The work first clarified the equivalent model of LCC converter and the common DC control strategy in the current project.Then it established an electromagnetic transient simulation model of actual UHVDC project with detailed control and protection system explored the variation law of relevant electric parameters,and consequently analyzed the mechanism of post-com-mutation-failure active power variation exceeding normal transmission power,and the impacts of factors such as fault se-verity,power control mode,controller parameters,etc.,on rectifier-side active power.Finally it simulated the influence of receiving-end-fault-induced post-DC-commutation-failure strong active power fluctuation on stability of sending-end sys-tem with respect to practical AC/DC hybrid network.The conclusion of this study may contain useful information for op-eration and control of actual power system.
DC commutation failurerectifier stationactive power characteristiccurrent regulatorsending-end system stability