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In wireless charging devices, different wireless charging standards have caused charging incompatibility, and the utilization rate of the DC voltage at the transmitter is not high, which brings challenges to the application of wireless charging. To solve these two problems, this paper proposes a multi-frequency multi-amplitude (MFMA) superimposition modulation method. This method superimposes multiple frequency signals, and then compares the synthesized signal with a high-frequency triangular carrier to output a square wave voltage signal containing information such as the frequency and amplitude of the pre-output signal. Furthermore, a phase-shifting optimization algorithm is proposed, i.e., based on the proposed MFMA superimposition modulation method, the utilization rate of the DC voltage of the system is improved by reasonably adjusting the initial phase of each frequency. Simulation and experimental results show that the proposed method can output at least four frequencies simultaneously by using a single inverter, effectively reducing the volume of the transmitter, and being compatible with the frequency range of several charging standards. The proposed phase-shifting optimization has a significant effect on improving the utilization of DC voltage with an increase of 44.88%.

With the development of power electronics, wireless power transfer (WPT) technology has been widely used in many fields because of its convenience and safety. In this paper, a multi-frequency wireless power and information transfer system with common inductive coils is proposed by using the multi-frequency programmed pulse width modulation (MFPWM) technology, which applies double modules to realize the power and data transmission with a single full-bridge inverter. The performances of the power and data transfer, as well as the principles of the control strategy are analyzed in detail. It shows that the power and data can share a pair of common couple coil and a single inverter. A simulation model is designed to verify the effectiveness of the proposed method and structure. The system demonstrates stability and feasibility under this control strategy.

In wireless charging devices, a transmitter that applies a single inverter to output dual-frequency can effectively solve the charging incompatibility problem caused by different wireless charging standards and reduce the equipment volume. However, it is very difficult to solve the switching angle of the modulated dual-frequency waveform, which involves non-linear high-dimensional multi-objective optimization with multiple constraints. In this paper, an improved differential evolution (DE) algorithm is proposed to solve the transcendental equations of switching angle trains of dual-frequency programmed harmonic modulation (PHM) waveform. The proposed algorithm maintains diversity while preserving the elites and improves the convergence speed of the solution. The advantage of the proposed algorithm was verified by comparing with non-dominated sorting genetic algorithm II (NSGA II) and multi-objective particle swarm optimization (MOPSO). The simulation and experimental results validate that the proposed method can output dual-frequency with a single inverter for wireless power transfer (WPT). Web of Science 13 9 art. no. 2209