Hybrid-type immittance converter

The immittance converter has an input impedance that is proportional to the admittance of a load connected across output terminals. Therefore, in this converter, the output current is proportional to the input voltage and the input current is proportional to the output voltage. Consequently, it converts a constant-voltage source into a constant-current source and a constant-current source into a constant-voltage source. It is well know that the quarter-wavelength transmission line shows immittance conversion characteristics. However, it has a very long line length for the switching frequency of converters and is not suitable for power electronics application. Thus, we proposed five types of immittance converters that consist of lumped elements L and C and showed improved immittance conversion characteristics at a resonant frequency. The output characteristics and efficiency characteristics of an immittance converter are the most important parameter when it is used in practical applications in a high-frequency link, In this paper, we show voltage-current transformation characteristics, current-voltage transformation characteristics, and efficiency characteristics of a hybrid-type immittance converter which consist of L and C elements with losses. The excellent characteristics were confirmed analytically and experimentally. (C) 2001 Scripta Technica.