摘要
CAN总线在电力系统过程网络取得广泛应用,总线的实时性是衡量网络性能的重要指标。对CAN总线传输时延进行分析,指出影响CAN总线端到端时延的主要因素。根据CAN总线非破坏逐位仲裁的特点,基于OPNET软件使用队列模型对CAN总线数据传输进行建模仿真,以一个电站过程网络为对象,得到了考虑位填充和不同网络速率情况下数据帧的最大时延和网络平均负载流量,验证了模型的正确性。针对CAN总线强制优先级导致低优先级数据传输时延过大的缺点,使用分类动态优先级方法,在保证不同类别数据实时传输的同时,保证同一类别数据传输的公平性,提高网络的利用率。结果表明,该仿真模型基本反映了CAN传输时延特点。
CAN（Controller Area Network） bus is widely used in process network of electric power system and its real-time performance is an important index.The transmission delay of CAN bus is analyzed and the main factors affecting its end-to-end delay are pointed out.According to the non-destructive bitwise arbitration of CAN bus,its data transmission is modeled and simulated with queuing model based on OPNET software.A process network of power station is taken as a research object to get the maximum delay of data frame and the network average traffic load with the consideration of bit stuffing for different network speeds,which verifies the correctness of model.To avoid the excessive transmission delay caused by CAN＇s priority arbitration,the dynamic classified priority method is applied to ensure the real-time transmission of different data types and the fairness of data transmission in same category for improving the network utilization.Results show that the simulation model reflects the basic features of CAN＇s transmission delay.
出处
《电力自动化设备》
EI
CSCD
北大核心
2011年第11期103-107,共5页
Electric Power Automation Equipment
