A New Method to Recognize the Status of Sic Surge Arresters in Substations

SiC lightning arresters are a kind of lightning arresters that nowadays are substituted with new type such as ZnO lightning arrester. Nonetheless, many SiC lightning arresters in Iran's electricity networks are operating. For instance, all the medium voltage network lightning arresters of Bakhtar Regional Electrical Company (BREC) are SiC type. The company wants to exchange these lightning arresters, but due to high cost and numbers of these lightning arresters, it is decided to put them in suitable ranks up to a due time. Since all suggested tests for recognition of lightning arresters deficiency are laboratory tests and must be done in lab, it isn't possible for the company to transfer all lightning arresters from substation to lab. Therefore, it has been decided to carry out that in the substation. Accordingly, a project has been suggested and carried out by the writers of this paper and the present paper is the result of this project. Different theories in this paper are surveyed. DC test is introduced as a suitable way for correct recognition deficiency of lightning arresters. The acquired results of DC test on some samples of lightning arresters are in coordination with the standard tests that have been carried out in Pars High Voltage Lab. Finally, three groups of arresters are defined according to their operating condition which includes acting good, delayed acting and not operating arresters. According to this classification, BREC is capable to exchange the arresters with respect to condition of the related arrester and with an appropriate priority which is obtained from its condition.