Compensation Capacitors Sizing for Achieving Arbitrary Load-Independent Voltage Gain in Series-Series Inductive WPT Link Operating at Fixed Frequency

The letter reveals that for a given operating frequency, infinite amount of compensation capacitor pairs exists, yielding load independent voltage gain of a typical series-series compensated resonant inductive wireless power transfer link (WPTL). Closed-form analytical expression is derived, linking the values of compensating capacitors with the desired load independent voltage gain based on given coil inductances, coupling coefficient and operating frequency. Feasible range of achievable voltage gains is shown to be bounded by the value of coupling coefficient based on a novel 4-parameter generalized loosely coupled transformer model. Experimental results are given to validate the presented findings.