Increasing Power Density of Single-phase Power Converter by Reduced Passive Components Volume for Short-time Operation

This paper proposes a design concept of short-time rated ripple current for electrolytic capacitors and the concept method of inductors that accepts a magnetic saturation in order to reduce the volume of passive components. The short-time rated ripple current for DC-link capacitors is determined by the operation time of power converters and the transient temperature rise characteristic of the electrolytic capacitors with the ripple current exceeding the rated current. The relation between the operation time of the power converters and the current value of the electrolytic capacitors is derived by the thermal characteristics of the electrolytic capacitors. The thermal characteristics are obtained by the experiment for the temperature measurement of the element of the electrolytic capacitors. Besides, this paper provides the design concept of the grid-connected inductor from the magnetization characteristic of magnetic materials in order to reduce the size. The effect of the reducing inductor volume by 15% is demonstrated by the calculation with the experimental results.