Abstract
This paper proposes a method to control a soft-switching gallium-nitride (GaN) based half-bridge with a delta-sigma (ΔΣ) modulator at multi-megahertz switching frequencies. A GaN-based High Electron Mobility Transistor (HEMT) can be operated at very high switching frequencies. However operating at these switching frequencies can be challenging as pulse-width modulators have several drawbacks when requiring zero-voltage switching with a variable switching frequency. Therefore a ΔΣ-modulator is extended to support zero-voltage switching operation for the entire output range. Also a compensation scheme is implemented that reduces the output voltage distortion due to blanking time. As a result of the proposed ΔΣ modulation scheme, the switching frequency automatically varies to minimize the inductor current ripple. The proposed method is validated in simulation including system non-idealities. Additionally the converter switching frequency range and zero-voltage switching behavior of the half-bridge is analyzed. Results show an improvement up to 14dB in output voltage distortion compared to the same PWM modulated converter with a constant switching frequency. Besides, the PWM modulated converter is not continuously soft-switching and has unnecessarily large inductor current ripple especially at small modulation indices.
Original language | English |
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Title of host publication | 2021 IEEE 12th Energy Conversion Congress & Exposition - Asia (ECCE-Asia) |
Publisher | Institute of Electrical and Electronics Engineers |
Pages | 1638-1643 |
Number of pages | 6 |
ISBN (Electronic) | 9781728163444 |
DOIs | |
Publication status | Published - 13 Jul 2021 |
Event | 12th Annual Energy Conversion Congress and Exposition, ECCE-Asia 2021 - Virtual, Singapore, Singapore Duration: 24 May 2021 → 27 May 2021 Conference number: 12 https://ecceasia2021.com/ |
Conference
Conference | 12th Annual Energy Conversion Congress and Exposition, ECCE-Asia 2021 |
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Abbreviated title | ECCE 2021 |
Country/Territory | Singapore |
City | Singapore |
Period | 24/05/21 → 27/05/21 |
Internet address |
Keywords
- Blanking Time Distortion
- Delta-Sigma Modulation
- Gallium Nitride (GaN)
- High Frequency Power Converter
- Zero-Voltage Switching