Residual Voltage Tests in Zinc Oxide (ZnO) Surge Arrester of 69kV

Equipment such as surge arresters are subject to various setbacks due to their exposure to adverse weather conditions. As a consequence of these setbacks, leaks of currents towards the ground can occur and cause accidents. In this way, high voltage tests are important to ensure the reliability of the equipment in the electrical system. As a benchmark for testing, IEC 60099-4 establishes the minimum reliability criteria for the operation of the surge arrester. In this context, the objective of this work is to perform Residual Voltage Tests in Zinc Oxide (ZnO) Surge Arrester of 69 kV and to compare the results with the data provided by the manufacturer which are based on the minimum criteria of IEC 60099-4. The methodology to obtain the results consisted in the measurement of residual voltage in the ZnO surge arrester the 69 kV for a current discharge of 5 kA and 10 kA using a Current Impulse Generator based on a Voltage Atmospheric Voltage Generator model SGD and reference data supplied by the manufacturer as well as the IEC 60099-4 standard. The measured residual voltage values were higher than the values guaranteed by the manufacturer according to the reference data. According to IEC 60099-4, the surge arrester can not be considered reliable and therefore is not capable of operating.