The High Order Harmonic Distortion Phenomenon in the Strongly Coupled IPT System and Its Reduction Method

摘要

This paper studies the strongly-coupled inductive power transfer (IPT) system, which reveals that the high order harmonic distortions in the input and output currents become significant when the coupling coefficient is relatively high. The common used series-series (SS) compensation circuit is analyzed in this paper. The theoretical model of the circuit is presented for different frequencies. The analysis results show that the transfer power in the system closely relates to the harmonic components. Specifically, the distortion problem becomes more severe with an increasing coupling coefficient. In addition, this digest introduces an effective method to design the circuit parameters in order to reduce the distortion. At last, a 1.8 kW prototype is designed and implemented, and the measurement shows a coupling coefficient as high as 0.75. Experimental results validate the relatively large high order harmonic distortion problem as proposed. Meanwhile, with proper parameter design, the maximum current distortion is limited within 37%, which is acceptable for the real application.