Analysis of Core Loss Characteristics of Linear Phase-Shifting Transformer

Abstract

Linear phase-shifting transformer, as a new type of phase-shifting transformer, has the advantages of shifting phase at any angle, good expansibility, and easy modularization compared with the traditional core column phase-shifting transformer. To calculate the output performance such as the efficiency of linear phase-shifting transformer, the loss of linear phase-shifting transformer should be studied. The loss of linear phase-shifting transformer includes copper loss and core loss. Among them, the core loss has an important impact on linear phase-shifting transformer performance parameters such as efficiency and temperature rise, but there is a lack of relevant research at present. In this paper, based on the traditional separation model of ferromagnetic materials, a calculation method for linear phase-shifting transformer core loss is proposed. In this method, the loss coefficient of the linear phase-shifting transformer iron loss model is calculated by the least square method based on the calculation and analysis of the magnetic field law of the core by the time-step finite element method, and the loss coefficient is further modified by considering the influence of local hysteresis loop, non-sinusoidal magnetic field, and harmonic magnetic field. The linear phase-shifting transformer model based on finite element field-road coupling simulation is established, a low-power experimental prototype is designed, and a multi-stack inverter system platform is built. The theoretical calculation is verified by simulation and experiment. Simulation and experimental results demonstrate the accuracy of the core loss calculation method presented in this paper.