Research of principle and site trial method for DC current transformer in the converter station

Recently, the development of electric power system in China has increased rapidly. A large number of of DC transmission projects are proposed, thus more and more OCTs are widely used in convert substations. In this paper, the principle and structure of OCT are introduced. And on-sit method of calibration for OCT is researched. Based on the practical field situation, multi-area synchronous measuring method is presented. Then this method is verified by field test and proven to be useful.