Reduced-Order Dynamical Models of Tuned Wireless Power Transfer Systems

Abstract

Dynamical models of wireless power transfer (WPT) systems are of primary importance for the dynamical behavior studies and controller design. However, the existing dynamical models usually suffer from high orders and complicated forms due to the complex nature of the coupled resonances and switched-mode power converters in WPT systems. This letter finds that a well-tuned WPT system can be accurately described by a much simpler dynamical model. Specifically, at the tuned condition, the existing dynamical model can be decomposed into two parts. One is controllable and the other one is uncontrollable. The former should be considered in the modeling while the latter can be ignored because it always exponentially converges to zero. For illustration, the recently proposed zero-voltage-switching full-bridge pulse-density modulation WPT system is modeled as an example since such a system can efficiently operate at the tuned condition with soft switching and control capabilities. The derived model was verified in experiments by time-domain and frequency-domain responses. 1Index Terms -Dynamical model, wireless power transfer.I.

Research on dynamic matching technology of Class EF high frequency inverter in wireless charging system

“…Reference [6] proposes a two-sided self-tuning LCC/S system based on parameter identification, which improves system efficiency through variable switching capacitance and control strategy. From the perspective of energy, a simplified dynamic model was proposed in literature [7] to optimize the system. In literature [8], by measuring the time difference between the rising edge of the drive signal and the zero crossing of the primary current, the input impedance phase Angle is obtained as a feedback parameter to control the switching frequency of the inverter, and the output power and efficiency are improved.…”