This paper introduces the working principle of HVDC control and protection system. And the paper summarizes the flexible HVDC technology features and application fields and describes the composition and software intel...This paper introduces the working principle of HVDC control and protection system. And the paper summarizes the flexible HVDC technology features and application fields and describes the composition and software intelligent flexible HVDC control and protection system configuration. Finally, the simulation results are also given, experimental results show： HVDC flexible intelligent control and protection has a good control effect in the steady state and transient process, suitable for practical engineering application.展开更多
To analyze the influence of _＋400 kV Q^nghai-Tibet HVDC transmission system on transmission- line protections in Qjnghai AG power system, a closed-loop simulation system was constructed by combing HyperSim system wit...To analyze the influence of _＋400 kV Q^nghai-Tibet HVDC transmission system on transmission- line protections in Qjnghai AG power system, a closed-loop simulation system was constructed by combing HyperSim system with HVDG control protection devices. Various faults on double-circuit 750 kV and multi- circuit 330 kV AC transmission lines in Qjnghai power system were simulated. The impedance characteristics and harmonic components at Qjnghai side of Qjng-Tibet DG transmission line were analyzed. The harmonic proportion in voltages and currents were studied for faults that took place at different locations near the DG system. The inflence of Qing-Tibet DG system on the directional components of protections, differential protections and distance protections of AC transmission lines was discussed and drew the conclusions that the DC sytem had little influence on differential protections, while had great inflence on directional components and distance protection. The conclusions can provide reference for studying the interaction between AC and DG systems.展开更多
文摘This paper introduces the working principle of HVDC control and protection system. And the paper summarizes the flexible HVDC technology features and application fields and describes the composition and software intelligent flexible HVDC control and protection system configuration. Finally, the simulation results are also given, experimental results show： HVDC flexible intelligent control and protection has a good control effect in the steady state and transient process, suitable for practical engineering application.
文摘To analyze the influence of _＋400 kV Q^nghai-Tibet HVDC transmission system on transmission- line protections in Qjnghai AG power system, a closed-loop simulation system was constructed by combing HyperSim system with HVDG control protection devices. Various faults on double-circuit 750 kV and multi- circuit 330 kV AC transmission lines in Qjnghai power system were simulated. The impedance characteristics and harmonic components at Qjnghai side of Qjng-Tibet DG transmission line were analyzed. The harmonic proportion in voltages and currents were studied for faults that took place at different locations near the DG system. The inflence of Qing-Tibet DG system on the directional components of protections, differential protections and distance protections of AC transmission lines was discussed and drew the conclusions that the DC sytem had little influence on differential protections, while had great inflence on directional components and distance protection. The conclusions can provide reference for studying the interaction between AC and DG systems.
