Strongly-coupled high-voltage-gain inductive wireless power transfer link employing identical coils for feedback-less energy delivery into enclosed compartment

The paper presents theoretical analysis and practical design of 150W, 48V_DC-to-200V_DC strongly-coupled inductive wireless power transfer link (IWPTL) for a through-glass AC power delivery system into existing wireless-ready sealed industrial glove box. One of the wireless-ready glove box walls comprises pre-installed dual-side identical transmitting and receiving coils (to assure direction-insensitive installation and confusion-proof repair). The load residing within the enclosed compartment requires a 120V, 60Hz AC voltage supply, created by an off-the-shelf buck-topology inverter powered by the proposed IWPTL operating in load-independent output voltage (LIVO) mode without any feedback. It is shown that due to adoption of symmetrical coils and operation under high coupling coefficient, it is impossible to attain the required voltage gain employing classical series (capacitor) – series (capacitor) compensation. Consequently, the recently revealed series (capacitor) – series (inductor) compensation is adopted in order to attain the required voltage gain value. It is further shown that the output voltage of a practical capacitor-inductor compensated IWPTL remains load-dependent even under LIVO frequency operation, yet residing within a certain range defined in the paper. Expression for coil-to-coil efficiency of the proposed arrangement is also established in this work. Functional feasibility of the proposed system is accurately supported by simulations and experiments.