This paper presents a capacitive power transfer (CPT) system design for low‐power rotary applications. The aim of a rotary CPT system is to be free of power cables so it can achieve 360 degrees of free rotation, while remaining simple and easy to clean. In this work, a class‐E high‐frequency inverter with second‐order LC compensation is proposed to drive the rotary CPT system. An LC compensation circuit is applied on both stationary and rotating sides in order to maximise the power transfer by increasing the voltage across the coupling plates. By implementing the proposed technique, the Class‐E LCCL rotary CPT system that is efficient and less sensitive to load variations can be achieved. A Boost converter is also proposed here to provide input impedance matching and tune the input power of the Class‐E LCCL rotary CPT system. A 10 W multiple plate rotary CPT prototype based on cascaded Boost‐ Class E LCCL is designed and implemented to demonstrate efficient wireless power transfer (WPT) across the rotating load. The results reveal >76% power transfer efficiency is successfully achieved at 1 MHz operating frequency and with 7.67 W output power.

This paper presents an alternative approach to power up unmanned aerial vehicle (UAV) system using inductive approach. The main issue of utilizing UAV in any application especially in precision agriculture is the lifetime of the battery. This limits the flight time of the UAV which makes the system is unable to be efficiently applied for precision agriculture purpose. Hence, this paper proposes a new approach of powering UAV system by using so called inductive power transfer (IPT) technology. Through this approach, the system can be powered up wirelessly with no physical link in between transmitter and receiver. To be specific, class E inverter circuit has been designed together with impedance matching circuit to ensure higher efficiency is obtained. Finally, a prototype of IPT system for powering up the UAV system was successfully developed, which is able to transmit 23.32 W of power at 1 MHz operating frequency from 12 V input supply. The system achieved up to 95.73% efficiency.

In this paper, the capacitive power transfer (CPT) technology is used as an alternative to inductive power transfer (IPT). CPT relies on electric fields that are not sensitive to the presence of any metals, utilizes metal electrodes for power transfer, and is less bulky compared to IPT. The proposed CPT system utilizes a Class-E resonant inverter with a double-sided inductor-capacitor (LC) matching circuit which operates at an optimum load, with a duty cycle, D=0.5 to gain an output power, W and efficiency, η=84.6%. The proposed CPT system enhances the system’s efficiency as compared to the past research while preserving the zero-voltage switching (ZVS) condition within a wider load range from 50 Ω to 1,316 Ω. This paper also shows that the proposed CPT system is less sensitive to load and coupling variations. Finally, the rate of power dissipated at varied load resistances, has been derived successfully to determine the sensitivity level of the proposed CPT systems toward load variations. These equations are then validated by plotting the efficiency graphs based on load and coupling variations.

Purpose: This paper aims to present a new wireless power transfer technique using capacitive coupling. The capacitive power transfer (CPT) system has been introduced as an attractive alternative to the traditional inductive coupling method. The CPT offers benefits such as simple topology, fewer components, better electromagnetic interference (EMI) performance and robustness to surrounding metallic elements. Design/methodology/approach: A class-E inverter together with and without inductor capacitor (LC) matching circuit has been utilised in this work because of its ability to perform the DC-to-AC inversion efficiently with significant reduction in switching losses. The validity of the proposed concept has been verified by conducting a laboratory experiment of the CPT system. Findings: The performances for both systems are analysed and evaluated. A 9.7 W output power is generated through a combined interface [printed circuit board (PCB) plate] capacitance of 2.82 nF at an operating frequency of 1 MHz, with 97 per cent efficiency for 0.25 mm coupling gap distance. Originality value: An efficient CPT system with class-E LC matching topology is proposed in this paper. With this topology, the zero-voltage switching can be achieved even if the load is different by properly designing the LC matching transformation circuit.

Nowadays, capacitive power transfer (CPT) is becoming increasingly popular technology in the wireless charging field due to its better mobility and higher durability. This paper proposed a CPT system by using Class-E inverter. This topology is selected due to its ability to achieve 100% efficiency theoretically. L-match impedance matching circuits are applied at both transmitter and receiver part to allow the load impedance to match with the source impedance to maximize the power transfer. The proposed CPT system is designed and simulated by using Simulink in MATLAB software. Its output performances are analyzed. Besides, the designed CPT system is used to investigate the factors that affect its output performance by varying the load, duty cycle and gap distance between coupling plates. From this work, the proposed CPT system produced up to 97.35% efficiency and output power of 10W.