The Electric Field Simulation Of Optical Voltage Transformers

With the capacity of the power system increasing and the voltage level rising, many challenges for the manufacture of the power equipments have been propsed. In the high voltage power system, the production of the customer voltage transformer is not only difficult, but also high price. The optical voltage transformer based on Pockels effect, has the merits which are compatible with the development of the power system and is an ideal alternative for the customer voltage transformer.The optical voltage transformers, developed rectently, are mainly based on electric-optic effect. By the detection of the electric field, we could know the voltage. Knowing the distribution of the electric field in the transformer is important for the design of the optical voltage sensor, the reliability of the insulation of the transformer, the measurement accuracy and the anti-interference of transformer. Therefore it is necessary to simulate the electric field of the transfomer.In this article, after introducing the principle of the optical voltage transformer, the electric field distribution of the two kind of chosen transfomers was simulated. By using the finite element software ANSYS, the electric field distribution of the optical voltage transformer with single optical voltage sensor and the optical voltage transformer with more optical voltage sensors was given in the related partials. From the results, we know that the transformer insulation is reasonable, moreover, the single sensor transformer has good linear property.In this article, the stray field effects on the electric field distribution of the optical voltage transformers was also presented. The grounded conductor and the neighboring transformer were seen as the intereferences. As the existence of the disturbances, the electric field deviation in the more-sensor transformer was 1.3% and 14%, separately. By using the quardrature method, the error became 0.05% and 0.02%. Comparatively, the electric field deviation in the single sensor voltage transformer was 3.2% and 0.12%.The electric field distribution of the optical voltage transformer could give us some references on the design of the optical voltage transformer.