scholarly journals A CMOS Active Rectifier with Efficiency-Improving and Digitally Adaptive Delay Compensation for Wireless Power Transfer Systems

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8089
Author(s):  
Yichen Zhang ◽  
Junye Ma ◽  
Xian Tang
Keyword(s):  
Power Efficiency ◽  
Reverse Current ◽  
Cmos Process ◽  
Efficiency Improvement ◽  
Wireless Power ◽  
Delay Compensation ◽  
Power Transistors ◽  
Compensation Control ◽  
Turn On ◽  
Active Rectifier

A CMOS active rectifier with digitally adaptive delay compensation for power efficiency improvement is presented in this work. The power transistors are turned on and turned off in advance under the control of the regenerated compensation signals, which are generated by the proposed compensation control circuit; therefore, the reverse current is eliminated, and the efficiency is increased. Simulation results in a standard 0.18 μm CMOS process show that the turn-on and turn-off delay of the rectifier is effectively compensated. The power efficiency is up to 90.6% when the proposed rectifier works at the operation frequency of 13.56 MHz.

scholarly journals A CMOS Active Rectifier with Time Domain Technique to Enhance PCE

Electronics ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1450
Author(s):  
Shao-Ku Kao
Keyword(s):  
Time Domain ◽  
Power Efficiency ◽  
Input Voltage ◽  
Maximum Efficiency ◽  
Cmos Process ◽  
Delay Compensation ◽  
Compensation Circuit ◽  
Voltage Range ◽  
Active Rectifier ◽  
Off Time

This paper presents a CMOS active rectifier with a time-domain technique to enhance power efficiency. A delay compensation circuit was designed using a time-domain technique. It converts the delay buffer’s delay time to a voltage value. The voltage is able to control on/off time in the comparator for variable input voltage. This circuit is designed in 0.18 m CMOS process. The input voltage range is from 2 V to 3.8 V with the output voltage from 1.8 V to 3.6 V. The efficiency can be maintained at more than 83% when the load is from 100 Ω to 1300 Ω for 3.3 V input voltage. The maximum efficiency is 90.3% at output power to be 109 mW for 3.3 V input voltage.

scholarly journals Simulation of 2-Coil and 4-Coil Magnetic Resonance Wearable WPT Systems

Proceedings ◽  
2021 ◽  
Vol 68 (1) ◽  
pp. 13
Author(s):  
Yixuan Sun ◽  
Stephen Beeby
Keyword(s):  
Power Efficiency ◽  
Power Transmission ◽  
Rotation Angle ◽  
Wireless Power ◽  
Peak Efficiency ◽  
Frequency Splitting ◽  
At Resonance ◽  
Higher Power ◽  
The Impact ◽  
Proper Frequency

This paper presents the COMSOL simulations of magnetically coupled resonant wireless power transfer (WPT), using simplified coil models for embroidered planar two-coil and four-coil systems. The power transmission of both systems is studied and compared by varying the separation, rotation angle and misalignment distance at resonance (5 MHz). The frequency splitting occurs at short separations from both the two-coil and four-coil systems, resulting in lower power transmission. Therefore, the systems are driven from 4 MHz to 6 MHz to analyze the impact of frequency splitting at close separations. The results show that both systems had a peak efficiency over 90% after tuning to the proper frequency to overcome the frequency splitting phenomenon at close separations below 10 cm. The four-coil design achieved higher power efficiency at separations over 10 cm. The power efficiency of both systems decreased linearly when the axial misalignment was over 4 cm or the misalignment angle between receiver and transmitter was over 45 degrees.

scholarly journals High Step-Up Converter Based on Non-Series Energy Transfer Structure for Renewable Power Applications

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 689
Author(s):  
Luis Humberto Diaz-Saldierna ◽  
Jesus Leyva-Ramos
Keyword(s):  
Power Efficiency ◽  
Common Ground ◽  
Linear Models ◽  
Efficiency Improvement ◽  
Boost Converters ◽  
Renewable Power ◽  
Current Design ◽  
Alternative Sources ◽  
Transfer Structure ◽  
Laboratory Prototype

In this paper, a high step-up boost converter with a non-isolated configuration is proposed. This configuration has a quadratic voltage gain, suitable for processing energy from alternative sources. It consists of two boost converters, including a transfer capacitor connected in a non-series power transfer structure between input and output. High power efficiencies are achieved with this arrangement. Additionally, the converter has a common ground and non-pulsating input current. Design conditions and power efficiency analysis are developed. Bilinear and linear models are derived for control purposes. Experimental verification with a laboratory prototype of 500 W is provided. The proposed configuration and similar quadratic configurations are compared experimentally using the same number of components to demonstrate the power efficiency improvement. The resulting power efficiency of the prototype was above 95% at nominal load.

A Design of a Wireless Power Receiving Unit With a High-Efficiency 6.78-MHz Active Rectifier Using Shared DLLs for Magnetic-Resonant A4 WP Applications

2016 ◽  
Vol 31 (6) ◽  
pp. 4484-4498 ◽  
Author(s):  
Hyung-Gu Park ◽  
Jae-Hyeong Jang ◽  
Hong-Jin Kim ◽  
Young-Jun Park ◽  
SeongJin Oh ◽  
...  
Keyword(s):  
High Efficiency ◽  
Wireless Power ◽  
Active Rectifier
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