부성 임피던스 변환기를 적용한 자기공명 방식 무선전력전송 시스템의 효율 개선

A wireless power transfer system with a negative impedance converter(NIC) was designed and tested. The system was investigated to identify the effects of ferrites and conductors. To improve the power transfer efficiency(PTE), the Q-factor of the transmitter was enhanced by the negative resistance generated by the NIC. The NIC was composed of an Op-Amp and resistors. The negative resistance was obtained with respect to a resistor connected in a feedback loop. The dimension of the Tx coil was 250 mm×250 mm×0.8 mm. The impedance and Q-factor were 31+j1874 Ω and 60, respectively. The negative resistance was selected to be 30 Ω, and the Q-factor was increased to 900 by reduction of the transmitter resistance, which was about 15 times higher than that of a conventional transmitter. The measured PTE was greatly improved in comparison to that of a conventional system. These results demonstrate that the PTE is enhanced by using the NIC. [ABSTRACT FROM AUTHOR]