Analysis and comparison of secondary series- and parallel-compensated IPT systems

Secondary series and parallel compensations are widely used in inductive power transfer (IPT) system for different circuit requirements. The compensations are often studied for some isolated constrains of maximum power transfer, optimal efficiency at a particular loading condition, etc., leaving little information for engineers in selecting between the two compensation techniques to be used as a voltage converter with optimal efficiency at various loading conditions. This paper studies the characteristics of the IPT system at different frequencies of operations utilizing the two compensation techniques to work as a voltage converter. The frequencies that can provide optimal efficiency of operation, load-independent voltage-transfer ratio are of interested. Theoretical operating frequencies for maximal efficiency of operation and load-independent voltage-transfer ratio are explored, looking for some practical power-conversion-efficient and load-independent operating frequencies. The frequencies interested for the two compensation techniques are found and compared to facilitate the design of voltage converter with efficient power conversion and load-independent frequency of operation. The analysis is supported with experimental results.