High‐frequency constant‐current power supply in noncontact energy transfer system using immittance converter

Noncontact energy transfer systems are used in various fields in the industry. A high-frequency constant current must be supplied to the feeder of noncontact energy transfer systems. This paper proposes a high-frequency constant power supply for a noncontact energy transfer system using an immittance converter. When there are two or more pick-up coils on the feeder, the output of one pick-up coil does not affect other pick-up coils on the feeder if the feeder current is constant. We proposed use of an immittance converter to transform the high-frequency constant-voltage source into a high-frequency constant-current source. “Immittance converter” is a combined form of “impedance-admittance converter.” The immittance converter has input impedance that is proportional to the admittance of the load connected across output terminals. 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. This paper contains descriptions of the configuration of the new high-frequency constant-current power supply for noncontact energy transfer system, output characteristics versus excessive reactance and small frequency deviations for different values of the duty factor. The experimental results are also described. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 158(3): 81–89, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20438