With the highly-extensive integration of distributed renewable energy resources(DER)into the grid,the power distribution system has changed greatly in the structure,function and operating characteristics.On this groun...With the highly-extensive integration of distributed renewable energy resources(DER)into the grid,the power distribution system has changed greatly in the structure,function and operating characteristics.On this ground,An AC-DC hybrid DER system becomes necessary for effective management and control over DER.This paper first summarizes the physical characteristics and morphological evolution of AC-DC hybrid DER system.The impact of these new features on system configuration planning is analyzed with respect to its flexible networking,rich operation control modes,and tight sourcenetwork-load-storage coupling.Then,based on a review of the existing research,problems and technical difficulties are figured out in terms of converter modeling,steady-state analysis,power flow calculation,operating scenarios management,and optimization model solution.In light of the problems and difficulties,a framework for the configuration optimization of AC-DC hybrid DER systems is proposed.At last,the paper provides a prospect of key technologies from six aspects including morphology forecasting,coupling interaction analysis,uncertainty modeling,operation simulation,optimization model solving algorithm and comprehensive scheme evaluation.展开更多
基于模块化多电平换流器的背靠背柔性直流输电系统(back to back modular multilevel converter based high voltage directcurrent,Back-to-BackMMC-HVDC)可实现区域电网的异步互联,提高电网可靠性。为更好地研究背靠背MMCHVDC接入后...基于模块化多电平换流器的背靠背柔性直流输电系统(back to back modular multilevel converter based high voltage directcurrent,Back-to-BackMMC-HVDC)可实现区域电网的异步互联,提高电网可靠性。为更好地研究背靠背MMCHVDC接入后的交直流系统互耦特性,需建立兼顾区域电网仿真效率与精确模拟MMC-HVDC系统动态特性的交直流混合模型。研究了MMC-HVDC运行原理与控制策略,基于电力系统全数字仿真装置(advanceddigitalpowersystem simulator,ADPSS)搭建含背靠背MMC-HVDC系统的交直流电网机电-电磁混合模型。通过仿真对比,验证了上述MMC-HVDC电磁暂态模型及其控制系统的正确性;基于混合模型进行了交直流电网机电-电磁混合仿真研究,并与对交流大电网进行等值简化后的纯电磁模型进行对比分析。结果表明,与将交流电网等效为理想电压源加等值阻抗的纯电磁暂态模型相比,混合仿真模型可更好地体现交流系统特性,更贴近实际工程,为研究交直流互联电网提供了较好的参考。展开更多
采用PSCAD/EMTDC建立了±800 k V/500 k V交直流混联输电线路反击耐雷水平仿真模型,讨论了杆塔接地电阻、绝缘子片数、雷电流波形、杆塔高度、避雷器变化对耐雷水平的影响,着重从分流系数的角度分析了接地电阻影响反击耐雷水平的原...采用PSCAD/EMTDC建立了±800 k V/500 k V交直流混联输电线路反击耐雷水平仿真模型,讨论了杆塔接地电阻、绝缘子片数、雷电流波形、杆塔高度、避雷器变化对耐雷水平的影响,着重从分流系数的角度分析了接地电阻影响反击耐雷水平的原因,比较了±800 k V/500 k V交直流混联输电线路和500 k V同塔双回线路、±800 k V直流线路的反击耐雷水平。理论分析表明:在交直流混联线路中,±800 k V线路的反击耐雷水平是其交流500 k V线路的2倍以上;反击耐雷水平在接地电阻为某一定值时急剧降低;交直流混联线路中,交流线路和直流线路的反击耐雷水平分别大于单独500 k V同塔双回线路、±800 k V直流线路。展开更多
基金This work was supported by the National Key R&D Program of China(2017YFB0903300).
文摘With the highly-extensive integration of distributed renewable energy resources(DER)into the grid,the power distribution system has changed greatly in the structure,function and operating characteristics.On this ground,An AC-DC hybrid DER system becomes necessary for effective management and control over DER.This paper first summarizes the physical characteristics and morphological evolution of AC-DC hybrid DER system.The impact of these new features on system configuration planning is analyzed with respect to its flexible networking,rich operation control modes,and tight sourcenetwork-load-storage coupling.Then,based on a review of the existing research,problems and technical difficulties are figured out in terms of converter modeling,steady-state analysis,power flow calculation,operating scenarios management,and optimization model solution.In light of the problems and difficulties,a framework for the configuration optimization of AC-DC hybrid DER systems is proposed.At last,the paper provides a prospect of key technologies from six aspects including morphology forecasting,coupling interaction analysis,uncertainty modeling,operation simulation,optimization model solving algorithm and comprehensive scheme evaluation.
文摘基于模块化多电平换流器的背靠背柔性直流输电系统(back to back modular multilevel converter based high voltage directcurrent,Back-to-BackMMC-HVDC)可实现区域电网的异步互联,提高电网可靠性。为更好地研究背靠背MMCHVDC接入后的交直流系统互耦特性,需建立兼顾区域电网仿真效率与精确模拟MMC-HVDC系统动态特性的交直流混合模型。研究了MMC-HVDC运行原理与控制策略,基于电力系统全数字仿真装置(advanceddigitalpowersystem simulator,ADPSS)搭建含背靠背MMC-HVDC系统的交直流电网机电-电磁混合模型。通过仿真对比,验证了上述MMC-HVDC电磁暂态模型及其控制系统的正确性;基于混合模型进行了交直流电网机电-电磁混合仿真研究,并与对交流大电网进行等值简化后的纯电磁模型进行对比分析。结果表明,与将交流电网等效为理想电压源加等值阻抗的纯电磁暂态模型相比,混合仿真模型可更好地体现交流系统特性,更贴近实际工程,为研究交直流互联电网提供了较好的参考。
文摘采用PSCAD/EMTDC建立了±800 k V/500 k V交直流混联输电线路反击耐雷水平仿真模型,讨论了杆塔接地电阻、绝缘子片数、雷电流波形、杆塔高度、避雷器变化对耐雷水平的影响,着重从分流系数的角度分析了接地电阻影响反击耐雷水平的原因,比较了±800 k V/500 k V交直流混联输电线路和500 k V同塔双回线路、±800 k V直流线路的反击耐雷水平。理论分析表明:在交直流混联线路中,±800 k V线路的反击耐雷水平是其交流500 k V线路的2倍以上;反击耐雷水平在接地电阻为某一定值时急剧降低;交直流混联线路中,交流线路和直流线路的反击耐雷水平分别大于单独500 k V同塔双回线路、±800 k V直流线路。
