Electronic transformer is a key component of the new measurement system of smart grid

and the Rogowski coil based electronic current transformer attracts much attention in the research and application of electronic current transformers.The design of Rogowski coil directly determines the measurement accuracy of the transformer.This paper introduces the working principle of the Rogowski coil based electronic transformers and the design method of sensor head.According to the design theory

a sensor head was designed

and related experiments were conducted.The result indicates that its measuring precision achieves 0.2S level in the standard in the experimental condition.