scholarly journals Adaptive Impedance Matching Scheme for Magnetic MIMO Wireless Power Transfer System

Electronics ◽  
2021 ◽  
Vol 10 (22) ◽  
pp. 2788
Author(s):  
Ziyang Lu ◽  
Yubin Zhao ◽  
Dunge Liu

In coupled magnetic resonance (CMR) wireless energy transfer systems, the energy transfer power is low and the power transfer efficiency changes with the coil position. One reason for this reduction in power and efficiency is the impedance mismatching (IM) between the Tx and Rx coils; achieving impedance matching for multiple-input multiple-output (MIMO) CMR IM wireless power transmission (WPT) is quite complex due to the uncertainty in the number of coils and the interaction between coils. In this paper, we provide an analytical model of MIMO CMR which fully formulates the complex relationship between multiple Tx and Rx channels. Then, we design an impedance matching network (IMN) for MIMO CMR and derive an optimal IM solution. Base on this solution, we also develop an adaptive impedance matching scheme to control IMN, based on an automatic analysis of MIMO CMR system; the resulting control scheme achieves optimal values for transmission power and efficiency through IMN and coil selection. The simulation results indicate that the scheme is able to automatically adjust the impedance matching network according to the changes of the relative positions between Tx and Rx coils to achieve high energy transfer power and efficiency.

Author(s):  
Anurag Saxena ◽  
Paras Raizada ◽  
Lok Prakash Gautam ◽  
Bharat Bhushan Khare

Wireless power transmission is the transmission of electrical energy without using any conductor or wire. It is useful to transfer electrical energy to those places where it is hard to transmit energy using conventional wires. In this chapter, the authors designed and implemented a wireless power transfer system using the basics of radio frequency energy harvesting. Numerical data are presented for power transfer efficiency of rectenna. From the simulated results, it is clear that the anticipated antenna has single band having resonant frequency 2.1 GHz. The anticipated antenna has impedance bandwidth of 62.29% for single band. The rectenna has maximum efficiency of 60% at 2.1 GHz. The maximum voltage obtained by DC-DC converter is 4V at resonant frequency.


Signals ◽  
2020 ◽  
Vol 1 (2) ◽  
pp. 209-229
Author(s):  
Mohammad Haerinia ◽  
Reem Shadid

Wireless power transmission (WPT) is a critical technology that provides an alternative for wireless power and communication with implantable medical devices (IMDs). This article provides a study concentrating on popular WPT techniques for IMDs including inductive coupling, microwave, ultrasound, and hybrid wireless power transmission (HWPT) systems. Moreover, an overview of the major works is analyzed with a comparison of the symmetric and asymmetric design elements, operating frequency, distance, efficiency, and harvested power. In general, with respect to the operating frequency, it is concluded that the ultrasound-based and inductive-based WPTs have a low operating frequency of less than 50 MHz, whereas the microwave-based WPT works at a higher frequency. Moreover, it can be seen that most of the implanted receiver’s dimension is less than 30 mm for all the WPT-based methods. Furthermore, the HWPT system has a larger receiver size compared to the other methods used. In terms of efficiency, the maximum power transfer efficiency is conducted via inductive-based WPT at 95%, compared to the achievable frequencies of 78%, 50%, and 17% for microwave-based, ultrasound-based, and hybrid WPT, respectively. In general, the inductive coupling tactic is mostly employed for transmission of energy to neuro-stimulators, and the ultrasonic method is used for deep-seated implants.


Author(s):  
Sayed Amir Hoseini ◽  
Jahan Hassan ◽  
Ayub Bokani ◽  
Salil S. Kanhere

The Unmanned Aerial Vehicles (UAVs), used in civilian applications such as emergency medical deliveries, precision agriculture, wireless communication provisioning, etc., face the challenge of limited flight time due to their reliance on the on-board battery. Therefore, developing efficient mechanisms for in-situ power transfer to recharge UAV batteries hold potential in extending their mission time. In this paper, we study the use of far-field wireless power transfer (WPT) technique from specialized, transmitter UAVs (tUAVs) carrying Multiple Input Multiple Output (MIMO) antennas for transferring wireless power to receiver UAVs (rUAVs) in a mission. The tUAVs can fly and adjust their distance to the rUAVs to maximize energy transfer. The use of MIMO antennas further boost the energy reception by narrowing the energy beam toward the rUAVs. The complexity of their dynamic operating environment increases with the growing number of tUAVs, and rUAVs with varying levels of energy consumption and residual power. We propose an intelligent trajectory selection algorithm for the tUAVs based on a deep reinforcement learning model called Proximal Policy Optimization (PPO) to optimize the energy transfer gain. Simulation results demonstrate that with the use of PPO, the system achieves a tenfold flight time extension compared to no wireless recharging. Further, PPO outperforms the benchmark movement strategies of ’Traveling Salesman Problem’ and ’Low Battery First’ when used by the tUAVs.


Drones ◽  
2021 ◽  
Vol 5 (3) ◽  
pp. 89
Author(s):  
Sayed Amir Hoseini ◽  
Jahan Hassan ◽  
Ayub Bokani ◽  
Salil S. Kanhere

Unmanned Aerial Vehicles (UAVs), used in civilian applications such as emergency medical deliveries, precision agriculture, wireless communication provisioning, etc., face the challenge of limited flight time due to their reliance on the on-board battery. Therefore, developing efficient mechanisms for in situ power transfer to recharge UAV batteries holds potential to extend their mission time. In this paper, we study the use of the far-field wireless power transfer (WPT) technique from specialized, transmitter UAVs (tUAVs) carrying Multiple Input Multiple Output (MIMO) antennas for transferring wireless power to receiver UAVs (rUAVs) in a mission. The tUAVs can fly and adjust their distance to the rUAVs to maximize energy transfer gain. The use of MIMO antennas further boosts the energy reception by narrowing the energy beam toward the rUAVs. The complexity of their dynamic operating environment increases with the growing number of tUAVs and rUAVs with varying levels of energy consumption and residual power. We propose an intelligent trajectory selection algorithm for the tUAVs based on a deep reinforcement learning model called Proximal Policy Optimization (PPO) to optimize the energy transfer gain. The simulation results demonstrate that the PPO-based system achieves about a tenfold increase in flight time for a set of realistic transmit power, distance, sub-band number and antenna numbers. Further, PPO outperforms the benchmark movement strategies of “Traveling Salesman Problem” and “Low Battery First” when used by the tUAVs.


2019 ◽  
Vol 16 (11) ◽  
pp. 20190156-20190156 ◽  
Author(s):  
Hiroya Andoh ◽  
Keita Tsuzuki ◽  
Dai Oikawa ◽  
Toko Sugiura ◽  
Takehiko Tsukamoto ◽  
...  

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1348
Author(s):  
Yingqin Zeng ◽  
Conghui Lu ◽  
Cancan Rong ◽  
Xiong Tao ◽  
Xiaobo Liu ◽  
...  

In a wireless power transfer (WPT) system, the power transfer efficiency (PTE) decreases sharply with the increase in transfer distance. Metamaterials (MMs) have shown great potential to enhance PTE in mid-range WPT systems. In this paper, we propose two MM slabs of a 3 × 3 array to enhance the magnetic coupling. The MM unit cell was designed by using square spiral patterns on a thin printed circuit board (PCB). Moreover, the asymmetric four-coil WPT system was designed and built based on the practical application scenario of wireless charging for unmanned devices. The simulation and experimental results show that two MM slabs can enhance power transmission capability better than one MM slab. By optimizing the position and spacing of two MM slabs, the PTE was significantly improved at a mid-range distance. The measured PTEs of a system with two MM slabs can reach 72.05%, 64.33% and 49.63% at transfer distances of 80, 100 and 120 cm. When the transfer distance is 100 cm, the PTE of a system with MMs is 33.83% higher than that without MMs. Furthermore, the receiving and load coils were integrated, and the effect of coil offset on PTE was studied.


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