基于RBF-PID的互感器校验主从时钟误差修正算法

Error correction algorithm of master-slave clock for transformer calibration based on RBF-PID

电子式互感器作为智能变电站的主要信息来源,需对其进行定期校验,而保证时间同步是互感器校验过程中最为关键的环节。本文在之前所设计的互感器边云协同实时监测系统基础上,构建多互感器异地校验系统,标准互感器及被校验互感器均与监测系统融合,构成互感器边云协同测量单元,各测量单元实时异地传输互感器采集数据至云端存储,再统一导出至边缘计算侧进行互感器校验计算。分析各测量单元之间存在的理论时钟误差和数据上传云端的链路延时误差,建立互感器校验主从时钟误差模型,并提出基于卡尔曼滤波(Kalman filter,KF)和神经网络自适应控制(RBF-PID)的互感器校验主从时钟误差修正算法,以保证互感器校验过程的时间同步。通过仿真对此算法进行验证,在面对不同初始条件时,修正后主从时钟误差均小于200 ns,且收敛时间约在0.4 s。最后通过实验验证了此算法的可行性与实用性,经过主从时钟误差修正的互感器校验结果更为精确,相位误差约为0.45″,幅值误差约为0.00358%,满足0.1准确级的要求。

As the main information source of intelligent substation,electronic transformer needs to be checked regularly,and ensuring time synchronization is the most critical link in the process of transformer calibration.Based on the previously designed real-time collaborative monitoring system for CT side cloud,this paper constructs a multi-CT side cloud collaborative measurement system.Both standard CT and verified CT are integrated with the monitoring system to form a CT side cloud collaborative measurement unit.Each measurement unit transmits the data collected by CT remotely in real time to the cloud storage,then uniformly exported to the edge computing side for CT verification calculation.Theoretical clock errors and link delay errors of data uploading to the cloud between each measurement unit are analyzed,and a master/slave clock error model of CT calibration is established.A master/slave clock error correction algorithm based on KF and RBF-PID is proposed for CT calibration to ensure time synchronization during CT calibration.The proposed algorithm is verified by simulation.Under different initial conditions,the corrected errors of master and slave clocks are all less than 200 ns,and the convergence time is about 0.4 s.Finally,the feasibility and practicability of the proposed algorithm are verified by experiments.The calibration results of the CT corrected by the error of the master and slave clock are more accurate,with the phase error of about 0.45″and the amplitude error of about 0.00358%,meeting the requirement of 0.1 accuracy level.