| Author: | Shang, Zhenyu |
| Title: | Multilevel inverter based wireless power transfer |
| Advisors: | Chau, K. T. (EEE) |
| Degree: | M.Sc. |
| Year: | 2026 |
| Department: | Department of Electrical and Electronic Engineering |
| Pages: | x, 66 pages : color illustrations |
| Language: | English |
| Abstract: | In high-power wireless charging systems for electric vehicles, flying capacitor multilevel inverters (FCMLIs) offer promising performance but suffer from critical stability issues when relying on closed-loop control based on ADC sampling. Sampling failure or noise can cause capacitor voltage imbalance, leading to circuit-level instability and potential topological collapse. To address this challenge, this paper proposes a five-level FCMLI topology featuring wide-range output voltage control under Pulse Magnitude Modulation (PMM), derived from Delta-Sigma principles. A topology-level passive capacitor voltage self-balancing mechanism is implemented using a hybrid clamping circuit and open-loop modulation strategy, eliminating the dependence on real-time feedback. Furthermore, it is identified that PMM may cause limit-cycle oscillations, which further induce capacitor imbalance. To mitigate this, a dithering method adapted from communication systems is introduced to suppress limit cycles and enhance system stability. The proposed system is validated through theoretical analysis, simulation, and experimental tests at 200V, demonstrating enhanced modulation stability, robust voltage balancing, and high output controllability without reliance on closed-loop ADC feedback. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| 8883.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 6.16 MB | Adobe PDF | View/Open |
Copyright Undertaking
As a bona fide Library user, I declare that:
- I will abide by the rules and legal ordinances governing copyright regarding the use of the Database.
- I will use the Database for the purpose of my research or private study only and not for circulation or further reproduction or any other purpose.
- I agree to indemnify and hold the University harmless from and against any loss, damage, cost, liability or expenses arising from copyright infringement or unauthorized usage.
By downloading any item(s) listed above, you acknowledge that you have read and understood the copyright undertaking as stated above, and agree to be bound by all of its terms.
Please use this identifier to cite or link to this item:
https://theses.lib.polyu.edu.hk/handle/200/14454