±800kV直流输电系统换流站直流电流互感器现场校准技术

On-site Calibration Technology of DC Current Measurement Device in Converter Station of ±800 kV UHVDC Transmission Project

国内直流输电用直流电流互感器投运后,由于缺乏试验设备,一般都不进行误差校准试验,这种现状已经成为直流输电系统安全稳定运行的隐患,并在一定程度上制约着直流输电系统控制、保护水平的提高。对换流站用直流电流互感器进行定期现场校准有助于及早发现设备隐患。为此研制了一套直流电流互感器现场校准系统,包括直流电流比例标准、便携5000A高稳定度直流电流源、GPS无线同步数据采集系统。采用该系统对向家坝-上海直流输电工程复龙换流站的极线光电流互感器在额定电流4000A下进行了现场校准试验。当试验电流>800A时,被校准直流电流互感器的测量误差<0.3%。依据试验结果对光电流互感器的性能进行了评估。建议将该技术在直流电流互感器交接试验和例行试验中进行推广。

The on-site calibrations of the DC current measurement devices in HVDC projects have not been carried out due to the lacking of the calibration equipments.This situation will potentially threaten the safe running of the DC transmission system and will restrict the promotion of the control and protect system to some extent,as the application of HVDC has become more and more widely in power system,it is necessary to involve the on-site calibration of the DC current measurement device as a routing test to prevent the system failure.An on-site calibration system for DC current measurement devices has been developed,consisting of a ratio standard of DC current measurement,a lightweight 5000 A current source of high output stability and a data collection system using the GPS wireless synchronization technology.Furthermore,the on-site calibration test of the pole optical current transducer（OCT） in Fulong convert station of Xiang-Shang ±800 kV UHVDC Transmission Project has been successfully carried out with testing current of 4000 A.The measurement errors of the OCTs were better than 0.3% with the testing current above 800 A.The performances of the OCTs under test were analyzed according to the experiment results.It is suggested to push the technique in the hand over inspections and routine tests of the DC current measurement device.