Experimental Study on Transient Overvoltage Measurement Based on Capacitive Voltage Transformer

Abstract

Transient overvoltage of power grid threatens the high voltage insulation and safe operation of power equipment. At present, there is no effective measure of transient overvoltage. In this paper, a transient overvoltage optical monitoring method based on capacitor voltage transformer (CVT) is proposed. A capacitor C3for transient measuring is connected to the low voltage end of capacitive voltage divider of conventional CVT. Optical voltage sensor (OVS) is used to measure transient overvoltage. A CVT prototype with transient overvoltage measurement function is developed, and lightning impulse voltage tests are carried out. The test results show that the prototype can meet the requirements of transient overvoltage measurement, and the effectiveness of the proposed scheme is verified. The optical voltage measuring module is used to measure and analyze the transient voltage at the ground point caused by the transient ground potential rise found in the test process, which has certain guiding significance for the design and selection of grounding conductors at the ground points and electromagnetic compatibility design of secondary equipment connected with the primary equipment.