Optimal Output Power Tracking Method for MCR-WPT Based on DC/DC Converter

In this paper, a magnetically coupled resonant wireless power transmission system(MCR-WPT) output power tracking method is advanced to adress the challenge of decreasing output power of wireless power transmission systems due to the change of the distance. By first analyzing the output power of the system, an optimal reflection impedance is observed to maximize the output power. On this basis, a optimal output power tracking method is then proposed. This method performs the optimal matching of the reflected impedance by combining the adjustment of the DC/DC converter duty cycle and the proportion and integration (PI) control. It finally makes the magnetically resonant wireless power transmission system maintain the optimal output power even as the distance for transmission varies. Simulation, experiments are then conducted. The obtained results show that the maximum increase of the output power under simulation condition is almost 10.7% compared with the unregulated one when the transmission distance is in the range of 4–8 cm. Furthermore, the maximum increase in the output power under experimental conditions over unregulated is approximately 8.9%.