分布式变电站远程视频监控系统的广域通信策略

Scheme of wide area communication in distributed remote video monitoring system for substations

高可靠、灵活性好的视频监控系统是变电站自动化系统的重要扩展.针对牵引供电系统的特殊情况,讨论了变电站远程视频监控系统的视频通信策略.设计了基于E1光纤信道的视频广域网,比较了基于轮询和复合包转发方式的通信方式,较好地解决了视频和报警信息的传输冲突难点.针对电铁专线监控的信道干扰及Internet等公用网监控的带宽动态变化的问题,提出了一种基于RTP/UDP/IP协议的视频传输体系结构.通过RTP协议的QoS反馈信息,可对视频源端的编码输出比特率进行动态调节,并给出了比特率调整的带宽控制算法.现场运行表明,基于该通信策略的视频监控系统具有可靠性好,通道利用率高,适应性强等优点.

Highly reliable and flexible video monitoring system is an important expansion for substation automatic system. In this paper, wide area video communication networks based on El fiber channel are designed according to practical situations of traction power system. Harmonious transmission of video and alarm data is realized by proposing two approaches, namely polling by control center and compound package transfer by substations. A video transmission architecture based on RTP/UDP/IP is put forward. With QoS feedback of RTCP, not only is the influence of electric interference in railway private line monitoring greatly reduced, but also dynamically changing bandwidth in Internet monitoring can be made full use of by adjusting the output bitrate of video encoder. Finally, bandwidth control algorithms of video source are discussed. It is proved by field running that system based on communication methods proposed in this paper is reliable, efficient in channel utilization and adaptive to various video monitoring environments.