Calibration method of capacitive electronic voltage transformer in smart substation
In order to calibrate the capacitive electronic voltage transformer (EVT) in complex environment of smart substation, a comparative experiment research was done to improve the calibration precision. According to the field calibration problem of capacitive EVT in smart grid, the field calibration methods of capacitive EVT was proposed based on the comparative methods. The ratio error f and angle error δ of tested capacitive EVTs could be directly obtained from the electronic transformer calibrator, when the proposed field calibration method was used. Based on the voltage working principle of primary devices and the operation method of primary devices, the secondary basic principle and working mechanism of the proposed method is studied. Meanwhile the equivalent mathematical model of capacitive EVT's field calibration method is established. Finally the application results are not only demonstrate the effectiveness and accuracy of the proposed method, but also show that the tested capacitive EVTs can be used as 0.2 level power meter transformers. (5 pages)