An Online Calibration Method for Electronic Voltage Transformers Based on IEC 61850-9-2

摘要

Since electronic voltage transformers (EVTs) based on IEC 61850-9-2 are widely used in the substations, especially in the automating substations, their calibration becomes very important. Generally, the calibration of EVTs needs for the power to be interrupted and causes power outage, and also the faults of the running transformers cannot be found in time. For this reason, an online calibration system is proposed in this paper. By employing a specially designed remote-controlled hoisting unit and standard voltage transformer, the proposed system can calibrate EVTs without interrupting the power service and the power outage can be avoided. A two-order Hanning self-convolution window algorithm is adopted to suppress the influence of spectrum leakage caused by frequency fluctuation and harmonic interference. Tests have been performed in the China Electric Power Research Institute. The results show that the proposed system has good performance and it can reach the accuracy class of 0.05 in complicated electromagnetic fields.