| Author: | Zhang, Xichen |
| Title: | Advanced segmented-vector pulse frequency modulation for three-level converter based wireless power transfer system |
| Advisors: | Liu, Wei (EEE) |
| Degree: | M.Sc. |
| Year: | 2026 |
| Department: | Department of Electrical and Electronic Engineering |
| Pages: | v, 33 pages : color illustrations |
| Language: | English |
| Abstract: | Three-level converters controlled by an advanced segmented-vector pulse frequency modulation (A-SVPFM) strategy are promising for high-power wireless power transfer (WPT). This dissertation proposes an A-SVPFM method and a dedicated digital modulator for a half-bridge flying-capacitor three-level converter. The modulator maps a continuous normalized voltage ratio into adjacent whole-wave pulses and preserves a zero-switching angle at the resonant frequency across the control range, enabling zero-voltage switching (ZVS) with wide-range A switching-state selection scheme that uses only voltage sampling is further introduced to regulate the flying-capacitor voltage, avoiding current sensors while maintaining small ripple around the reference. On the analysis side, the Fourier series of the system output-voltage is formulated and the harmonic structure induced by the finite modulation period is clarified; discrete Fourier transform (DFT) is then employed to compare A-SVPFM with pulse frequency modulation (PFM), showing a markedly lower transmitter-current total harmonic distortion (THD) under the band-pass input impedance of the WPT link. Moreover, a closed-form ZVS condition is derived that links the required transmitter-capacitance offset, dead time, and load, providing practical design guidance. The effectiveness of the proposed scheme is validated by software simulations and hardware experiments on a three-level WPT prototype. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| 8885.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 2.17 MB | Adobe PDF | View/Open |
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