Stabilization Control of Output Voltage for Segmented Dynamic Capacitive Power Transfer System Based on Partial Power Processing

In the operation of dynamic capacitive power transfer (DCPT) systems, time-varying parameters can significantly impact the stability of the system’s output voltage. Closed-loop controller becomes important for achieving precise regulation of the system output. This article proposes a control method for DCPT systems based on the partial power processing (PPP) technique. It achieves output voltage stability under various disturbances by processing only a fraction of the power. First, this article outlines the architecture of the PPP-based DCPT system and conducts system modeling. Based on the model, the influence of varying input voltage, coupling parameters, and load resistance on the open-loop output characteristics of the system is analyzed. Furthermore, the relationship between the duty cycle of the Boost converter, the power ratio of the main/auxiliary channels, and the output voltage are investigated after the controller’s intervention. A 1.3 kW DCPT experimental prototype is established, demonstrating stable control of the system’s output voltage at 200 V despite disturbances such as load variations within the range of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$30\sim 100~\Omega $ </tex-math></inline-formula>, movement of the receiver between adjacent transmitting segments, and input voltage fluctuations of ±10%. When compared to a DCPT system with a cascaded dc-dc converter, the system’s efficiency is also improved by 0.83%~2.60% under different load conditions.