Current Ripple Mechanism with Quantization in Digital LLC Converters for Battery Charging Applications
| Autor: | Qianhong Chen, Zhiliang Zhang, Ya-Qi Wu, Dong-Jie Gu |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Engineering
business.industry 020209 energy Quantization (signal processing) 020208 electrical & electronic engineering Ripple 02 engineering and technology Converters Battery charger Control theory 0202 electrical engineering electronic engineering information engineering Electronic engineering Output impedance Dither Electrical and Electronic Engineering business Frequency modulation Voltage |
| Zdroj: | IEEE Transactions on Power Electronics. 33:1303-1312 |
| ISSN: | 1941-0107 0885-8993 |
| DOI: | 10.1109/tpel.2017.2683798 |
| Popis: | The mechanism of current ripple propagation in a digital controlled LLC converter is investigated from three aspects: battery load, quantization error, and double line frequency perturbation at the input. With conventional frequency modulation (FM), every modulation step is accompanied by quantization error due to limited resolution of digital controllers. Large current ripple is propagated to the output due to poor FM and extremely low internal impedance of batteries, which hurts battery health seriously. The analytical model of output current oscillation is proposed considering the quantization effects and double line frequency input voltage perturbation. The synchronous frequency dither (FD) is proposed to improve quantization resolution and reduce current ripple further. A 2-kW Li-ion battery charger was built to verify the proposed current oscillation model and effectiveness of synchronous FD control. Good agreement is verified between analytical derivations and experimental results. The quantization current ripple is significantly attenuated by around 45% over entire charging range. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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