Maximum Efficiency Tracking for Dynamic WPT System Based on Optimal Input Voltage Matching

Wireless power transfer (WPT) technology has drawn much attention due to its advantages such as safety, convenience, and non-contact. For some movable devices such as intelligent inspection robot, the constant output voltage is very important to ensure its normal operation. In order to improve the system efficiency and steadiness of output voltage, a maximum efficiency tracking and constant voltage charging method is proposed for the dynamic WPT system. In this method, the mutual inductance and optimal input voltage can be estimated accurately no matter the coupling coefficient and equivalent load change or not. The simulation and experimental results have shown that the WPT system realize maximum efficiency tracking and constant voltage charging when the resistance is changed from <inline-formula> <tex-math notation="LaTeX">$10\Omega $ </tex-math></inline-formula> to <inline-formula> <tex-math notation="LaTeX">$5\Omega $ </tex-math></inline-formula>, and the same result was achieved when the mutual inductance is altered from <inline-formula> <tex-math notation="LaTeX">$20~\mu \text{H}$ </tex-math></inline-formula> to <inline-formula> <tex-math notation="LaTeX">$10~\mu \text{H}$ </tex-math></inline-formula>.