1 / 2019-01-21 16:48:51

Rotary Capacitive Power Transfer using Multiple Capacitive Coupler Approach

Capacitive Power Transfer, Class-E, Zero Voltage Switching, Power Conditioning

This paper explores the design and the development of a capacitive power transfer (CPT) system for supplying power across rotating machines wirelessly. This is important as the development of wireless power transfer (WPT) system for rotary applications has been an attraction in recent years, with the aim of substituting power cables due to constriction in angle of rotation and entanglement issues. Thus, a rotary CPT system with multiple capacitive coupler approach has been introduced in this work to generate a compact rotating capacitive coupler plates with the specified large amount of capacitance. Compared to the single plate approach, the multiple plates approach can significantly increase the coupling capacitance without the need of increasing electric field emission. The Class-E LCCL topology is used to resonate with the coupler and provide high voltage on the plates to transfer high power. Besides, a novel cascaded Boost-Class E is proposed here to provide simple output power tuning to the rotary CPT system. By implementing the proposed technique, the rotary CPT system that is efficient and less sensitive to load variations can be achieved. A 10W multiple plates rotary CPT system lab scale prototype is designed and implemented to demonstrate efficient wireless power transfer across the rotating load with 2mm air gap. The results reveal more than 76% power transfer efficiency is successfully achieved at 1MHz operating frequency and with 7.67W output power.