A 70W and 90% GaN-based class-E wireless-power-transfer system with automatic-matching-point-search control for zero-voltage switching and zero-voltage-derivative switching
| Autor: | Kuo-Chi Liu, Yen-Ting Lin, Ke-Horng Chen, Che-Hao Yeh, Chao-Jen Huang, Cheng-Yu Xie, Ying-Hsi Lin, Wen-Hau Yang, Shen-Fu Lu, Chun-Chieh Kuo |
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| Rok vydání: | 2018 |
| Předmět: |
Materials science
business.industry Capacitive sensing 020208 electrical & electronic engineering Electrical engineering Impedance matching 02 engineering and technology Power factor Compensation (engineering) law.invention Capacitor law 0202 electrical engineering electronic engineering information engineering Wireless power transfer business Electrical efficiency Voltage |
| Zdroj: | ISSCC |
| DOI: | 10.1109/isscc.2018.8310222 |
| Popis: | High-power (>50W) and high-efficiency (>90%) wireless-power-transfer (WPT) systems are becoming in demand for portable electronic applications. In Fig. 8.2.1, power efficiency and/or output power specifications in prior-art designs are much below the expected requirements [1-5]. Frequency tuning in [1,2] is simple, but the switching frequency (f SW ) deviates from 6.78MHz. Capacitor tuning [3,5] is the most intuitive approach, but the capacitor matrix occupies a large area, and the dynamically tuned compensation capacitor bank is limited by the digital-control resolution and compensation accuracy. In addition, the duty-cycle control in [4] leads to an unregulated output voltage at the RX side. Existing impedance-matching techniques for reducing power loss are not applicable to high-power impedance matching of a GaN-based WPT system in the case of timevariable charging distance, loading, operation voltage, and temperature variations that induce a wide range of inductive or capacitive loading effects. Inductive loading degrades the efficiency by 51% in a GaN power switch and induces serious coupling effects to the gate of the GaN device due to the hard-switching (HS) power loss. Likewise, capacitive loading results in the efficiency degradation of 14% due to the body-diode conduction (BDC) power loss. Such large dissipation easily breakdowns a GaN device and even seriously damages the wPt system, especially when transmitting high-power. Therefore, simultaneously achieving both (1) the minimized HS and BDC power loss by efficient impedance matching and (2) highly reliable operation of a GaN device over a wide range of loading effects is in urgent demand for high-power and high-efficiency WPT systems. |
| Databáze: | OpenAIRE |
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