Determination of total transformer losses resulting from semirotating flux excitation

Theoretical and experimental studies have shown that hysteresis losses in a magnetic material subject to an applied rotating field decreases considerably as the field amplitude drives the magnetization into saturation. Recently, low core loss transformers operating with semirotating flux excitation have been proposed. The purpose of this paper is to present an analytical investigation of the overall iron and copper losses of such transformers. In this analysis, core magnetic properties are accurately represented and simulated using vector Preisach models. A sample design for a 110 V, 165 VA single-phase transformer with semirotating flux excitation is given and quantitative analytical results are used as a guide to determine its optimum operating conditions.