| Abstract: | An immittance converter has fine performance in many power electronics applications. Its function is to convert voltage sources into current sources and current sources into voltage sources. The immittance converter has an input impedance that is proportional to the admittance of loads 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. When an immittance converter operates at a resonant frequency and is inserted to high-frequency link systems, voltage source outputs turn into current source outputs and current source outputs turn into voltage source outputs. Some power electronics applications of this converter are photovoltaic inverters and dc-dc converters with constant current outputs. It is well known that a quarter-wavelength transmission line shows immittance conversion characteristics. However, it has a very long line length for its switching frequency (e.g., 20 kHz), and is not suitable for power electronics applications. Therefore we propose five immittance converters that consist of lumped L and C elements and show the immittance conversion characteristics at a resonant frequency. These immittance converters are much smaller and lighter than the transmission line. Their principles, basic circuits, and basic characteristics are described in this paper. We also evaluate their application to high-frequency link systems of power electronics. © 1998 Scripta Technica, Electr Eng Jpn, 124(2): 53–62, 1998 |
