直流-直流変換器に存在する無負荷損失の解明と電磁結合による低減

抄録

To improve the technology for loss estimation and the efficiency of DC-DC converters, this paper focuses on air-core reactors. First, the author tests a reactor for the increase in temperature by changing the waveforms and frequencies under the same cooling and RMS current conditions. These conditions enable separation of the DC and AC losses. The results for the increase in temperature are different and demonstrate the existence of AC loss in the air-core reactor. It is determined that the AC loss is the eddy current loss by a finite element analysis. Next, this paper calculates the eddy current loss in the DC-DC converter. The ripple current in the DC-DC converter causes no-load loss, which consists of DC and AC losses. The former is the Joule loss due to the ripple current, and the latter is the eddy current loss due to the ripple current. The eddy current loss accounts for more than 90% of the no-load loss. Finally, this paper discusses the reduction of the no-load loss. Electromagnetic coupling is an effective way to reduce the no-load loss. The no-load loss decreases to 23% by electromagnetic coupling.