Study on Optimal Structure of Three-Loop Simplified Scaling Model for Dry-Type Air-Core Reactors

In order to predict the spatial magnetic field distribution (SMFD) of dry-type air-core reactors (DARs), the optimal structure of the three-loop simplified scaling model with adjustable ring position and turn number for DARs was investigated. First, the formulas for calculating the SMFD of the original model and the three-loop simplified model were derived according to Biot–Savart law and superposition theorem. Then, the optimal structure of the three-loop simplified model which is the closest to the original model was obtained based on the least squares method after calculating the magnetic induction intensity in six typical directions. In the typical directions, the prediction error of the optimal simplified model was less than 5.5%. Furthermore, the corresponding laws of the optimal simplified model structure in accordance with the original model structures were obtained. The results based on the magnetic field measurement platform indicate that the optimal structure of the three-loop simplified model with frequency 50 Hz is 37.5% relative height, which is very close to the structure, calculated by the corresponding law with 36.15% relative height.