Design and performance analysis of class-e double sided lc compensation topology for CPT system efficiency improvement

• Main Author: Cheok, Yan Qi
• Format: Thesis
• Language: English; English
• Published: 2023
• Subjects: T Technology (General); TK Electrical engineering. Electronics Nuclear engineering
• Online Access: http://eprints.utem.edu.my/id/eprint/27694/; https://plh.utem.edu.my/cgi-bin/koha/opac-detail.pl?biblionumber=123705

Nowadays, Capacitive Power Transfer (CPT) is becoming an increasingly popular technology in the wireless charging field thus attracting the attention of many researchers. Although various research has been conducted with the aim of improving the performance of the system, there is still room for improvement to be made to further optimize the efficiency of the CPT system transmission. It is well known that the CPT system’s efficiency and output power are limited when the transfer distance or gap distance between metal electrodes increases due to any misalignment of capacitive coupling plates or changes in load resistance. Therefore, this thesis proposed the development of a CPT system with high efficiency for low power contactless charging applications. Initially, the thesis begins by designing a Class-E resonant inverter that can provide high-frequency switching capability to increase the power of the system. The Class-E resonant inverter satisfies the soft-switching condition through parameter design thus improving the system’s efficiency. Next, the output performance is analyzed by observing the zero-voltage switching (ZVS) condition, output power and efficiency of the system. Due to the characteristics of the Class-E resonant inverter which is sensitive to the circuit parameters variation, the π1b impedance matching circuit is included in the design to enable the power transfer efficiently between transmitter and receiver. In this part, the mathematical analysis of the sensitivity of the system’s output power with respect to the load variation was introduced. In order to have a wider range of load variations, Class-E combined with double-sided LC matching circuits such as LCCL circuit and LCLC circuit were incorporated into the proposed approach. By switching the position of inductor and capacitor in LC matching at the receiver side of Class-E LCCL circuit, Class-E LCLC circuit was formed. The output performances of both circuits were analyzed and compared based on load variations, duty cycle variations and gap distance variations. MATLAB Simulink was used in this work to design and simulate all the aforementioned circuits. The design with the best output performance was selected to construct the CPT system. A 10W prototype was constructed which is operated at 1mm air gap with an efficiency of more than 84.6%. In conclusion, the research outcomes demonstrate the potential of CPT as an emerging wireless power transfer solution, as well as the theoretical and practical design methods to establish a solid foundation for future CPT research and development.