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This paper proposes a novel capacitive power transfer (CPT) system with switchable compensation for achieving constant current (CC) or constant voltage (CV) output against load and coupling capacitance variations. Meanwhile, a parameter design method is proposed to ensure a low input impedance angle at constant operation modes. Mathematical models of voltage and current gains are established, which are used to analyze the CC and CV operation modes of the proposed CPT system. Two relays are adopted in receiver to reconfigure the compensation network to switch the CC mode and CV mode. The communication between the transmitter and receiver is not needed, and complex control is not required either for changing two operation modes. An experimental setup with 2A output current in CC mode and 96 V output voltage in CV mode is constructed. Experimental results show that the maximum variation of the output current is 4.0% in CC mode, and the maximum variation of the output voltage is 5.0% in CV mode, when the load resistance and coupling capacitance vary from 24 to 72 ohms, and 500 to 1000 pF, respectively. Experimental results verify the CC/CV output and the effectiveness of the proposed parameter design method.

Focusing on the output voltage reduction caused by variation of the equivalent coupling capacitance in capacitive power transfer (CPT) system, this paper proposes a hybrid control strategy to achieve constant output voltage with the variation. The hybrid automata model is introduced for the cascaded CPT system considering the characteristics of higher order, nonlinear, multi-mode, continuous time and discrete states. The control process of the system is transformed into a selection of boundary transition conditions, which simplify the controller design and implementation. Then, a hybrid automata model of the system is established based on the theory of hybrid system, and the boundary transition of each mode of the system is given. The simulation and experimental results show that the proposed hybrid control strategy can keep the output voltage constant when the coupling capacitance of CPT system varies in a certain range.

This paper proposes an LCL-L compensated capacitive power transfer (CPT) system with a four-plate compact capacitive coupler to achieve load adaptation. The coupling principle of four plates is explained, and the formulas between the cross-coupling capacitances and port capacitances are deduced by establishing a two-port capacitive network model of the coupler. The resonant frequency is designed to be unchanged whether the pick-up is removed or moved back to simplify system control. The model of the coupler and AC impedance model of CPT system are established, and the parameter design method is given. Finally, the feasibility and effectiveness of the proposed topology and its parameter design method are verified by simulation and experimental results.

Based on an analysis of the continuity of discrete transition functions, this paper presents a new approach for characterizing piecewise affine (PWA) systems’ regions of attraction (RoAs). First, the RoA boundary is proven to consist of the points where the discrete transition function is discontinuous and of the specific parts of switching surfaces. Then, the formulas and numerical algorithm for computing states with discontinuous discrete transition functions are developed. The proposed approach enables the characterization of the entire RoA for both equilibrium points and limit cycles. Finally, the proposed method is used to analyze multiple examples. For clarity, the results of a third-order inductor-capacitor-inductor resonant inverter are provided in a video. Although we focus on PWA systems, the key concept behind continuity and stability also applies to other hybrid dynamical systems, enabling the broader application of the proposed RoA computing method.