Communication-free robust wireless power transfer with constant output power and stable frequency

A primary challenge in wireless power-transfer (WPT) systems is to achieve efficient and stable power transmission when load conditions change dynamically, which often requires the load-to-source communication to share the load-variation information for source control. Addressing this issue, we propose a third-order pseudo-Hermitian WPT system whose output characteristics exhibit a stable frequency and constant power. The frequency-selection mechanism and energy efficiency of the nonlinear WPT system based on pseudo-Hermitian under the coupling-mode theory approximation are analyzed. Theoretical analysis indicates that under certain coupling coefficients and load conditions, the proposed system can achieve frequency adaptation in a stable frequency mode without the need to change the circuit frequency. When the load changes dynamically, the stability of the power output is maintained using a proportionalintegral (PI) control strategy that only collects the voltage and current at the transmitting end, eliminating the need for wireless communication circuits with feedback from the receiving side. Experimental results demonstrate that the proposed design scheme can achieve constant power transmission when load conditions change, maintaining stable and relatively high transmission efficiency. The proposed scheme exhibits benefits in practical applications since no communication is required.