Traveling wave differential protection has the ability,in theory,to entirely eliminate the effects of distributed capacitive current,but it cannot be applied on series-capacitor-compensated lines directly.In this pape...Traveling wave differential protection has the ability,in theory,to entirely eliminate the effects of distributed capacitive current,but it cannot be applied on series-capacitor-compensated lines directly.In this paper,unbalanced output of conventional forward and reverse traveling wave differential currents under normal operating conditions and external faults was analyzed.A new type of traveling wave differential current was defined by combining forward and reverse traveling wave differential currents.Expressions of the defined differential current when internal and external faults occur were deduced.On this basis,a new principle of traveling wave module differential protection on series-capacitor-compensated lines was proposed,and characteristics of module differential current under different faults were analyzed.The priniciple is immune to line distributed capacity,series capacitor positions,and presence or absence of MOV breakovers.The validity of this scheme was verified by PSACD simulations.展开更多
为检测电容器内部元件的损坏故障,高压直流输电(high voltage DC transmission,HVDC)工程中交直流滤波器的高压电容器通常采用H形接线或分支接线形式,进而配置电容器不平衡保护作为反映该类故障的主保护。然而一些HVDC工程中电容器不平...为检测电容器内部元件的损坏故障,高压直流输电(high voltage DC transmission,HVDC)工程中交直流滤波器的高压电容器通常采用H形接线或分支接线形式,进而配置电容器不平衡保护作为反映该类故障的主保护。然而一些HVDC工程中电容器不平衡保护仍存在隐患。为此分别针对上述2种接线形式的电容器,定量推导了单个支路电容器的故障发展过程中及2个支路电容器均有电容元件击穿时的不平衡电流及相应过电压倍数。分别对2种接线的电容器不平衡保护提出了实用的判据,并探讨了相应的整定计算原则及动作策略。展开更多
文摘Traveling wave differential protection has the ability,in theory,to entirely eliminate the effects of distributed capacitive current,but it cannot be applied on series-capacitor-compensated lines directly.In this paper,unbalanced output of conventional forward and reverse traveling wave differential currents under normal operating conditions and external faults was analyzed.A new type of traveling wave differential current was defined by combining forward and reverse traveling wave differential currents.Expressions of the defined differential current when internal and external faults occur were deduced.On this basis,a new principle of traveling wave module differential protection on series-capacitor-compensated lines was proposed,and characteristics of module differential current under different faults were analyzed.The priniciple is immune to line distributed capacity,series capacitor positions,and presence or absence of MOV breakovers.The validity of this scheme was verified by PSACD simulations.
文摘为检测电容器内部元件的损坏故障,高压直流输电(high voltage DC transmission,HVDC)工程中交直流滤波器的高压电容器通常采用H形接线或分支接线形式,进而配置电容器不平衡保护作为反映该类故障的主保护。然而一些HVDC工程中电容器不平衡保护仍存在隐患。为此分别针对上述2种接线形式的电容器,定量推导了单个支路电容器的故障发展过程中及2个支路电容器均有电容元件击穿时的不平衡电流及相应过电压倍数。分别对2种接线的电容器不平衡保护提出了实用的判据,并探讨了相应的整定计算原则及动作策略。