This paper investigates the design of a robust H ∞ output feedback controller for a capacitive power transfer (CPT) system. Firstly, a first harmonic model of the CPT system is derived based on first harmonic approximation (FHA). Secondly, by linearizing the first harmonic model at its operation point, a linearized state space model is obtained. Thirdly, variations of coupling capacitances and load in the CPT system are described as polytopic uncertainties in the linearized state space model.

more »

... en, we propose a novel robust H ∞ output feedback controller design technique for the linearized state space model with polytopic uncertainties. Finally, both simulation and experiment are carried out to verify the effectiveness of the proposed controller design. INDEX TERMS Robust H ∞ control, dynamic system modelling, capacitive power transfer, class-E inverter.