电子式互感器接入的光纤差动保护数据同步方法

Data Synchronization Method of Optical Fiber Differential Protection Connected with Electronic Transformers

指出了电子式互感器(ET)接入的线路光纤差动保护在数据同步方面遇到的主要困难,分析了全球定位系统(GPS)同步方法与传统数据同步方法的局限,提出了利用改进插值法进行数据同步的新方法。该方法不依赖于任何外部设备,可靠性高;不调整采样时刻,适应于IEC 60044-8标准规定的合并单元功能结构条件,并能灵活适用于线路一侧为ET一侧为传统互感器的情况。数据同步的目标始终是要保证参加差动运算的电压电流量追溯到一次侧是同一时刻的,为此,各侧ET二次变送延时的影响必须被计及到保护装置的数据同步过程之中。对保护装置而言,补偿两侧ET二次变送延时的时间差是数据同步的核心内容。对需要配置光纤差动保护的线路,ET的合并单元最好能够提供符合IEC 60044-8标准的数据输出接口。

The major difficulties encountered during the data synchronization process of optical fiber differential protection connected with electronic transformers （ET） are pointed out, and the shortcomings of GPS and traditional data synchronization methods are analyzed. In addition, a new data synchronization method employed with improved inserting is proposed. The method depends not on any peripheral equipment and has high reliability. It doesn＇ t need to adiust the sampling time in compliance with the function and frame condition of merged unit （MU） specified in standard IEC 60044 8, and it can be applied flexibly to the ease that one side connected with ET and other side with traditional transformer. This paper shows that the target of data synchronization is to ensure that voltage and current value in the differential calculation are simultaneously traced back to primary side. Therefore, the secondary transform delay of ET at every side must be accounted in protection data synchronization process. As for the protection, compensation of time difference of the secondary transform delay at two sides of ET is the core content of data synchronization. For the line, which needs to use optical fiber differential protection, the MU of the ET may provide better data output interface according with standard IEC 60044 8.