The increasing scale and complexity of power systems require high performance and high reliability of power system protection.Protective relaying based on directional comparison with power line carrier or microwave ch...The increasing scale and complexity of power systems require high performance and high reliability of power system protection.Protective relaying based on directional comparison with power line carrier or microwave channels is the most suitable protection scheme for long distance EHV transmission lines and is widely used in power systems.The key element of such protection is a directional relay used to discriminate the fault direction.In order to overcome the disadvantages of conventional directional relays,the authors of this paper put forward the directional comparison carrier protection based on the artificial neural network(ANN).The protection is extensively tested using electromagnetic transient program (EMTP) under various electric power system operating and fault conditions.It is proved that the directional comparison carrier protection based on ANN,which can recognize various fault patterns of the protected transmission line(such as fault direction,fault phases etc.)correctly in any kind of operating and fault conditions and the whole process,is satisfactory for EHV transmission line protection.展开更多
为了解决某甲醇双燃料汽车滚装船(Pure Car and Truck Carrier,PCTC)结构艉轴赛龙轴承所在铜合金框架厚度不足以容纳轴承温度、轴承间隙测量传感器等一系列监测装置的问题,并顺利取得“SCM”入级符号,在赛龙轴承合金框架外对艉轴管中各...为了解决某甲醇双燃料汽车滚装船(Pure Car and Truck Carrier,PCTC)结构艉轴赛龙轴承所在铜合金框架厚度不足以容纳轴承温度、轴承间隙测量传感器等一系列监测装置的问题,并顺利取得“SCM”入级符号,在赛龙轴承合金框架外对艉轴管中各传感器电缆使用特殊电缆管进行保护,以避免电缆受到海水腐蚀,提高监测系统使用寿命。电缆保护管设计布置须综合考量环氧理论厚度、各传感器电缆信息、保护管的路径及支架位置等多种因素,以确保船舶轴系工程精度的可控程度,同时克服船舶最大吃水深度下的艉轴管内部压力、涡流以及海水腐蚀等的影响,保证电缆保护设计的完整性。研究验证了赛龙轴承合金框架外进行布置的可行性,可为各类船舶螺旋桨轴状态监控的设计提供一定的参考。展开更多
文摘The increasing scale and complexity of power systems require high performance and high reliability of power system protection.Protective relaying based on directional comparison with power line carrier or microwave channels is the most suitable protection scheme for long distance EHV transmission lines and is widely used in power systems.The key element of such protection is a directional relay used to discriminate the fault direction.In order to overcome the disadvantages of conventional directional relays,the authors of this paper put forward the directional comparison carrier protection based on the artificial neural network(ANN).The protection is extensively tested using electromagnetic transient program (EMTP) under various electric power system operating and fault conditions.It is proved that the directional comparison carrier protection based on ANN,which can recognize various fault patterns of the protected transmission line(such as fault direction,fault phases etc.)correctly in any kind of operating and fault conditions and the whole process,is satisfactory for EHV transmission line protection.
文摘为了解决某甲醇双燃料汽车滚装船(Pure Car and Truck Carrier,PCTC)结构艉轴赛龙轴承所在铜合金框架厚度不足以容纳轴承温度、轴承间隙测量传感器等一系列监测装置的问题,并顺利取得“SCM”入级符号,在赛龙轴承合金框架外对艉轴管中各传感器电缆使用特殊电缆管进行保护,以避免电缆受到海水腐蚀,提高监测系统使用寿命。电缆保护管设计布置须综合考量环氧理论厚度、各传感器电缆信息、保护管的路径及支架位置等多种因素,以确保船舶轴系工程精度的可控程度,同时克服船舶最大吃水深度下的艉轴管内部压力、涡流以及海水腐蚀等的影响,保证电缆保护设计的完整性。研究验证了赛龙轴承合金框架外进行布置的可行性,可为各类船舶螺旋桨轴状态监控的设计提供一定的参考。
