变电站过程CAN总线时延特性分析

过程总线替代二次电缆连接是变电站自动化技术未来发展的重要趋势.采用过程总线首先需定量分析信息在网络上传输的端对端时延,判断其能否满足变电站自动化功能对信息传输提出的实时性要求.文中分析了变电站过程总线数据流特征和控制器局域网(CAN)总线网络行为,综合考虑了网络传输时延和端系统处理时延对信息端对端时延的影响,建立了变电站过程CAN总线实时性能分析模型;借鉴实时调度的基本理论和分析方法,提出了任务和信息联合调度的方法,推导出了过程层CAN总线端对端时延的解析表达式,为定量分析系统性能提供了理论依据.

Study on the Delay of CAN Bus at the Process Level of Substation

A new method for testing real-time performance of controller area network (CAN) at the process level of substations is presented. This method takes into consideration both the delay in transmitting a message in communication media and that in processing the message in end systems. The analytic model for studying real-time performance of process bus is presented, which is composed of communication network model, software design model and delay model. Then, a method for integrated scheduling of task and message is put forward to calculate the end-to-end (ETE) delay of process bus in substations. Finally, the formulation of ETE delay of CAN bus at the process level is derived.