LAUSR

In inductive power transfer systems, load and coupling fluctuations may cause significant reactive power. In this article, a dual shunt inductor compensation topology (named as L-S/S-L) with parallel inductors at both ports of the series/series compensation is proposed to maintain nearly unity power factor and implement a wide load range with considering misalignment. With the balanced parameter configuration, L-S/S-L compensation can keep a constant zero phase angle. This feature maintains nearly unity power factor under load, coupling, and frequency variations. A monotonically rising power versus frequency characteristic can be designed by setting the scale factors of L-S/S-L. Based on the designed characteristic, frequency control is implemented to adjust the output power over a wide range. Furthermore, zero voltage switching is achieved within the selected operating frequency range by slightly adjusting the primary shunt inductance in the design stage. A 2.1 kW prototype is built to demonstrate the validity of the proposed method. Experimental results show that the power factor is close to unity under various working conditions. Within the coupling coefficient range from 0.35 to 0.16, the maximum efficiency changes little from 95.6% to 94.7%.