CAPACITIVE SENSOR CALIBRATION SYSTEM FOR MEASURING FAST TRANSIENT OVER-VOLTAGES

摘要

A capacitive sensor calibration system for measuring fast transient over-voltages is provided. The system includes: a high voltage steep pulse generator (201), a conical transmission tube (202), a capacitive sensor (203), a resistive voltage divider (204), coaxial cables (205-1, 205-2), a first oscilloscope (206) and a second oscilloscope (207). The high voltage steep pulse generator (201) is arranged to generate a high voltage steep pulse. The high voltage steep pulse is transmitted to the capacitive sensor (203) and the resistive voltage divider (204), which are installed on a Gas Insulation metal closed Switchgear (GIS) through the conical transmission tube (202). The conical transmission tube (202) is connected with the GIS coaxially. The resistive voltage divider (204) transmits a resistive voltage dividing signal to the first oscilloscope (206) through the coaxial cable (205-1). The capacitive sensor (203) transmits a capacitive voltage dividing signal to the second oscilloscope (207) through the coaxial cable (205-2). The calibration system utilizes the high voltage steep pulse generator (201) as the signal resource, so as to accord with a real wave shape of a Very Fast Transient Over-voltage (VFTO). The capacitive sensor (203) and the resistive voltage divider (204) are installed on the GIS tube, so as to calibrate the capacitive sensor (203) under the state approaching to the real installing condition.