Electrical strength in air core reactors

The evaluation of transient voltage distributions in windings of electrical equipment is important for electrical insulation sizing and design optimization. This paper presents an accurate model for the evaluation of transient voltage distributions in single-layer air core reactors. The numerical solution of the proposed equivalent electric circuit and the calculation of its parameters are presented. The technique used to expand the model so as to represent a grounded shielding cylinder surrounding the reactor is presented in detail. In order to validate the proposed model, an air core reactor and a shielding were built and several computational simulations and experimental tests were carried out. Some details of the experimental setup are given. The computer simulation results are presented and compared with the experimental ones, showing good agreement for both cases: with and without the shielding cylinder