Development of molded-core-type gapped iron-core reactor

The adhesive-coated nonoriented electromagnetic steel sheet is well known to be effective in realizing high-efficiency, high-power motors with compact size, low noise, and low vibration, as shown in Kaido et al. The authors developed newly adhesive-coated grain-oriented electromagnetic steel sheets. We developed the gapped iron-core-type reactor having a new iron-core structure using this material. By adapting the adhesive-coated grain-oriented electromagnetic steel sheets to the leg of the reactor, the fastening studs of the laminated electromagnetic steel sheets, which are required in a conventional reactor, and the through hole for the fastening studs could be omitted. This enabled us to simplify the structure and reduce the core diameter. On the other hand, we examined the magnetic flux distributions and local loss distributions in the yoke by a detailed magnetic-field analysis to use the oriented electromagnetic steel sheet with boltless construction, and realized the reduction of dimensions and weights due to the increase of magnetic flux density. The reactor developed has such features as smaller size, lighter weight, lower noise level, and low loss.