The most important performance merits of inductive wireless power transfer links (IWPTL) operating at load-independent-voltage-output (LIVO) frequency are efficiency and output characteristics. It was recently demonstrated that none-series (NS) compensated IWPTL operating at LIVO frequency outperforms its series-series (SS) and series-none (SN) compensated counterparts in terms of efficiency. In order to complete the comparison, this paper presents output characteristics modeling and analysis (namely, relation between output voltage and load power) of a practical NS-compensated IWPTL operated at LIVO frequency. It is demonstrated that even though the system is operated at LIVO regime, its output voltage remains load-dependent due to practical issues. The lower bound of the output voltage range corresponds to operation under rated loading and is derived using phasor domain equivalent circuit, assuming continuous conduction mode (CCM) of the receiving-side diode rectifier without neglecting equivalent series resistances. On the other hand, upper bound of the output voltage range corresponds to operation under zero loading (inevitably imposing discontinuous conduction mode (DCM) of the receiving-side diode rectifier) and is obtained using time-domain solution of corresponding differential equations system due to the fact that classical phasor analysis fails to accurately describe DCM operating NS-compensated IWPTL. The proposed method is applied to a 1 kW, 400 V NS-compensated IWPTL operated at LIVO frequency and is well-verified by simulations and experiments. Comparison with output voltage characteristics of SS and SN-compensated IWPTLs assert the advantage of NS-compensated topology.
- Load independent voltage output
- None-series compensation
- Resonant inductive wireless power transfer
ASJC Scopus subject areas
- Modeling and Simulation
- Hardware and Architecture