提出了一种适合就地化变压器保护的有主分布式环形网络及其同步方案,按断路器配置保护子机,变压器本体子机兼作保护主机,直接采用常规采样、常规跳闸模式,对外连接全部采用预制的航空插头。主变本体子机利用IEEE 1588网络对时协议实现...提出了一种适合就地化变压器保护的有主分布式环形网络及其同步方案,按断路器配置保护子机,变压器本体子机兼作保护主机,直接采用常规采样、常规跳闸模式,对外连接全部采用预制的航空插头。主变本体子机利用IEEE 1588网络对时协议实现各侧子机模拟量的同步采集,各侧子机采样数据发送到主变本体子机,由主变本体子机完成全部保护及MMS通信等功能。保护动作后,主变本体子机发出GOOSE跳闸命令,各侧子机收到GOOSE命令后跳开本侧开关。此方案可以使110 k V及以上电压等级变电站所有保护装置满足就地化安装的要求,取消保护小室,减少新建变电站占地面积。展开更多
Chinese railway has entered the ＂HSR era＂, while the structure of ＂four vertical and four horizontal＂ railways for transit passengers is almost completed. Taking the Beijing-Shanghai High-Speed Rail （hereinafter ...Chinese railway has entered the ＂HSR era＂, while the structure of ＂four vertical and four horizontal＂ railways for transit passengers is almost completed. Taking the Beijing-Shanghai High-Speed Rail （hereinafter referred to as HSR） as an example, this paper first explores HSR＇s effects on the spatial structure of regional tourist flows using the social network analysis. Next, it notes changes in the accessibility of regional transportation. After analyzing the factors including initial endowment of regional tourism resources, hospitality facilities, the density of the regional tourism transportation network, and locations, the paper discusses the mechanisms through which HSR affects regional tourist flows. The study shows the following： （1） HSR＇s effects on the spatial structure of regional tourist flows are manifested through the Matthew effect, the filtering effect, the diffusion effect and the overlying effect, and （2） the Matthew effect of HSR is manifested under an obvious interaction of the location, the initial endowment of tourism resources, hospitality capacity, tourist transportation network density and ＂time-space compression＂. The filtering effect of HSR is manifested for those tourism nodes without favorable location conditions, endowment of tourism resources, hospitality capacity, or tourist transportation network density and without obvious benefits from ＂time-space compression＂. Those tourism nodes that boast advantages in terms of lo- cation condition, endowment of tourism resources, hospitality capacity, tourist transportation network density and obvious ＂time-space compression＂ will become sources for the diffusion effect. HSR will strengthen the aggregation effects of tourist flow in these diffusion sources, which will thereafter diffuse to peripheral tourist areas, manifesting ＂aggregation-diffusion＂. HSR has overlapped tourists＇ spatial traveling range over large-scale spaces. However, the overlying effect is only generated in those tourism nodes w展开更多
文摘提出了一种适合就地化变压器保护的有主分布式环形网络及其同步方案,按断路器配置保护子机,变压器本体子机兼作保护主机,直接采用常规采样、常规跳闸模式,对外连接全部采用预制的航空插头。主变本体子机利用IEEE 1588网络对时协议实现各侧子机模拟量的同步采集,各侧子机采样数据发送到主变本体子机,由主变本体子机完成全部保护及MMS通信等功能。保护动作后,主变本体子机发出GOOSE跳闸命令,各侧子机收到GOOSE命令后跳开本侧开关。此方案可以使110 k V及以上电压等级变电站所有保护装置满足就地化安装的要求,取消保护小室,减少新建变电站占地面积。
基金Key Project of National Natural Science Foundation of China,No.41230631National Natural Science Foundation of China,No.41271134
文摘Chinese railway has entered the ＂HSR era＂, while the structure of ＂four vertical and four horizontal＂ railways for transit passengers is almost completed. Taking the Beijing-Shanghai High-Speed Rail （hereinafter referred to as HSR） as an example, this paper first explores HSR＇s effects on the spatial structure of regional tourist flows using the social network analysis. Next, it notes changes in the accessibility of regional transportation. After analyzing the factors including initial endowment of regional tourism resources, hospitality facilities, the density of the regional tourism transportation network, and locations, the paper discusses the mechanisms through which HSR affects regional tourist flows. The study shows the following： （1） HSR＇s effects on the spatial structure of regional tourist flows are manifested through the Matthew effect, the filtering effect, the diffusion effect and the overlying effect, and （2） the Matthew effect of HSR is manifested under an obvious interaction of the location, the initial endowment of tourism resources, hospitality capacity, tourist transportation network density and ＂time-space compression＂. The filtering effect of HSR is manifested for those tourism nodes without favorable location conditions, endowment of tourism resources, hospitality capacity, or tourist transportation network density and without obvious benefits from ＂time-space compression＂. Those tourism nodes that boast advantages in terms of lo- cation condition, endowment of tourism resources, hospitality capacity, tourist transportation network density and obvious ＂time-space compression＂ will become sources for the diffusion effect. HSR will strengthen the aggregation effects of tourist flow in these diffusion sources, which will thereafter diffuse to peripheral tourist areas, manifesting ＂aggregation-diffusion＂. HSR has overlapped tourists＇ spatial traveling range over large-scale spaces. However, the overlying effect is only generated in those tourism nodes w
