Effects of geometrical parameters on the performance of Rogowski coil for current measuring

Current measuring is the core precondition for relay protection, energy metering and Rogowski coil is one of the most favorable transformers. In this paper, the effects of geometrical parameters of Rogowski coil on its performance are calculated and compared to provide a general overview of geometrical selection. The expressions of mutual inductance of rectangular, circular and oval winding coil are derived and calculated, and the reliabilities of each shape of the coil are compared by the simulation. The results show that in condition of equal section area, the mutual inductance of rectangular, circular and oval winding coil are in descending sequences and the relative error of oval winding coil is the smallest, which is helpful for obtaining accurate current values. The research provides important guidance for the rapid and reasonable geometrical selection of Rogowski coil in engineering applications.