Individual Output Voltage Regulation Method of Multifrequency Multireceiver Simultaneous WPT Systems With a Single Inverter

Individual output voltage regulation is an important issue in the multireceiver simultaneous wireless power transfer system. To solve this issue, a novel output voltage regulation method based on a multifrequency modulator and multiple proportional-integral (PI) controllers has been proposed. The proposed modulator combines the improved selected harmonic elimination pulsewidth modulation (SHEPWM) technique and delta-sigma modulation (DSM) technique, which has much less number of switching actions in comparison with the existing multifrequency modulation methods. A continuous-time small-signal model of the system is derived to close the voltage loop. With the proposed method, the output voltages of the system can be regulated individually, continuously, and accurately just using a single inverter and standard receivers. Moreover, the proposed method can be easily extended to the system with more receivers. Finally, the effectiveness of the proposed method is verified experimentally.