Steady-state error calibration technology for electronic instrument transformer

The steady-state error is the most important parameter for the calibration system of electronic instrument transformer. It is ensure to practice in power system. Firstly, this paper describes the working principle and communication features of electronic instrument transformer. It has the advantage of insulating performance, cubage, weight, intelligence and etc compared with conventional electromagnetic instrument transformer in the EHV and UHV transmission system. Then explains the superiority communication style that is meeting the latest IEC61850 standard, and it can be suitable for smart grid construction. Secondly, analysis the electromagnetic instrument transformer characteristics and completed of calibration system modeling. According to the secondary output difference between current transformer and voltage transformer, this paper researches the comparison of the analog output and digital output steady-state error calibration circuits. The calibration system includes of standard device, merge unit and electronic instrument transformer steady-state error calibrator. The calibrator contains synchronization signal generator and multi-channel collector. Calibration system adopts the new designed and implements ratio error, phase displacement, time parameter calibration with difference output style test-objects. Thirdly, to ensure the objectivity and accuracy of test, the calibration system error of measurement source are analyzed. According to the above source of error, calibration system uncertainty analysis was accomplished. And then the testing system performance was obtained. The calibration system has achieved the request in the fields of measurement and operation stability.