Analysis of the influence of optical fiber layout on the internal electric field of power transformer

Many information technologies such as intelligent sensing, online monitoring and artificial intelligence are integrated in the intelligent power transformer to further improving its reliability and safety. Due to the strong electromagnetic environment in the transformer, optical fiber sensing technology has become a hot spot in the transformer sensor research field because of its good insulation and anti-electromagnetic interference performance. In this paper, the typical layout of optical fiber in the transformer was investigated, and five typical optical fiber sensing arrangement methods were summarized. Taking the optical fiber as the object, the simulation model of five different layout models of optical fiber which near the inner winding of transformer was established to explore the influence of fiber layout on the internal electric field of transformer under AC and DC conditions. The results show that under the condition of AC electric field, different arrangements of optical fiber does not cause severe electric field distortion in transformer, and the relative permittivity of the sheath material has an effect on the maximum electric field strength near the fiber optic. While in DC condition, the influence of the optical fiber on electric field is greater compared with that under AC condition, and the electric field distortion is serious when there is a narrow gap.