智能变电站组网传输采样值光纤差动保护同步方案研究

Research of the sample synchronization scheme for optical differential protection based on sampled value transmit by network in smart substation

阐述智能变电站中组网传输采样值系统结构,分析了基于组网方式传输采样值的电子式互感器采样时序及站内采样同步的关键技术,在此基础上提出一种基于组网传输采样值的纵联光纤差动保护同步方案。该方案将纵联光纤差动采样同步下放至合并单元中完成,根据计算出的两侧采样时刻偏差和本侧重采样时刻对对侧采样数据进行重采样,最终在合并单元中完成两侧采样数据的同步,并将同步之后的对侧数据以IEC61850-9-2方式发送至过程层网络。通过理论分析和仿真验证可知,该采样同步方案不依赖同步时钟源、同步精度高、运算量小、易于实现、并具备工程应用灵活及兼容性强的优点,有着广泛推广的现实意义。

This paper expounds the system structure of the sampled value transmit by network in smart substation, analyses time sequence of electronic instrument transformer sampled value transmit by network and key technologies of sample synchronization, based on this, puts forward a kind of longitudinal optical differential synchronization scheme based on the sampled value transmit by network. Using this scheme the optical differential sample synchronization is completed in merge unit, the opposite data based on calculated sampling time deviation of two sides and the time resample stamp of this side are resampled, finally sample synchronization is finished in the merge unit, and then the synchronous sampled value is sent to the network by IEC61850-9-2. Theoretical analysis and simulation results prove that the sample synchronization scheme does not rely on the source synchronous clock, and has advantages of high precision, small burden, being easy to carry out, and the flexible engineering application and strong compatibility, so it has widely practical significance.