Comments on "Analysis, Design, and Optimization of LC/S Compensation Topology With Excellent Load-Independent Voltage Output for Inductive Power Transfer"

In the article "Analysis, design, and optimization of LC/S compensation topology with excellent load-independent voltage output for inductive power transfer," by Yao et al., a novel LC/S (primary series-inductor parallel-capacitor/secondary series-capacitor) compensation topology was proposed. A single set of three-compensating-elements was derived, allowing to simultaneously attain LIVO and zero-voltage switching (ZVS). However, the inverter was not able to operate at a zero-phase angle (ZPA), minimizing its volt-ampere rating, with the proposed compensating element set. Since the proposed topology is extremely promising, the purpose of this note is to complement the presented analysis by pointing out the following: 1) A group of infinite three-compensating-elements sets exists (to which the set derived in the article belongs to), allowing to simultaneously achieve LIVO and ZVS; and 2) A unique three-compensating-elements set exists, allowing to simultaneously achieve LIVO and ZPA.