广域测量系统仿真子站实时通信问题

Real-time communication of WAMS simulation substation

介绍了广域测量系统(WAMS)仿真子站的基本功能,分析了在Windows平台下实现WAMS仿真子站的实时通信时存在的问题:Windows窗口定时器的定时精度无法达到要求,消息处理出现较大延时;当数据帧写入socket的发送缓冲区时,若数据帧的帧长较短,会出现数据帧积压,导致多包数据同时到达主站。基于Windows环境和网络通信的OSI 7层参考模型,在OSI应用层上采用多媒体定时器和多线程技术结合的方案,解决精确定时问题;针对WAMS主站和子站数据管道的数据传输特点,在OSI传输层上修改了TCP/IP协议栈的传输控制方法,关闭TCP的Nagle算法,解决数据积压问题。实验及调试结果验证了实现方法的有效性和可行性。

The basic functions of WAMS（Wide Area Measurement System） simulation substation are introduced. The problems in its real-time communication on Windows platform are analyzed： the precision of windows timer is low, causing big delay in message processing;the data frames are accumulated in the socket send -buffer if the frame length is not long, causing several data frames arrived at the main station at the same time. Based on Windows platform and the OSI reference model of network communication,solutions arc given：use multi-media timer and multi-thread technology in the application level of OSI to improve timer precision;modify the transmission control method of TCP/IP protocol stack on the transmission level of OSI by closing Nagle algorithm of TCP to avoid data overstock. Experimental and debugging results show the proposed solutions are effective and feasible.