Hybrid control of capacitive power transfer system for coupling capacitance variation

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.