Quantitative investigation into the use of resonant magneto‐inductive links for efficient wireless power transfer

Abstract

The use of resonant magneto‐inductive links is an efficient technique to transfer power over midranges in the field of wireless power transfer (WPT). Power transfer efficiency (PTE) and power delivered to the load (PDL) are two important indicators of power transmission for a WPT system. A predetermined amount of PDL need be generated at maximum PTE for practical application in a WPT system; thus, the authors focus on maximising PTE and a predetermined amount of PDL for transfer in this study. First, load‐matching conditions are presented for maximum PTE transfer though circuit theory‐based analyses. Then, a new tuning method is proposed to transfer a predetermined amount of PDL which can be controlled by source‐matching distance at maximum PTE. The relations between the loss of a load‐matching resonator and the PTE (or PDL) of a correspondingly unmatched system are derived though analyses as well. Finally, the calculated results of the design examples are verified through electromagnetic simulations and experimental measurements.

Analysis and Optimization of Three-Resonator Wireless Power Transfer System for Predetermined-Goals Wireless Power Transmission

“…The angle vector, θ = [θ TX , θ RX ] shown in Figures 1b and 9a, is tuned to achieve the optimal k for the three predetermined-goals WPT. According to the measured S-parameters based on port impedance z 0 = 50 Ω of the network analyzer, the PDL (or I RX ) and PTE of the WPT network with arbitrary R S and R L values can be determined by transforming calculation method [22,26], and the block diagram for the procedures is presented in Figure 9b. with the aid of the two-port VNA, as shown in Figure 9a. Figure 9b.…”

“…However, it is effective using the proposed optimal method to achieve the preset constant PDLs at maximum PTEs starting from D TR = 0.4 m and 0.5 m for PDL C = 0.5 W and 1 W respectively, for the maximum offsets below PDL C = 0.5 W at D TR = 0.4 m and PDL C = 1 W at D TR = 0.5 m are 12.9% and 9.21% respectively. The effects of cross coupling on energy transfer can be addressed through power flow analysis [22]. The power flow from TX and IX to Rx can be calculated by P TR " Re`´jωM TR I TX IR X˘a nd P IR " Re`´jωM IR I IX IR X˘, respectively.…”

“…However, the optimized coils with the proper size, turns and conductor width for the maximizing PTE in these references were only effective for a certain transfer distance. A constant amount of PDL need to be transferred at maximum PTE for practical application in a WPT system [20][21][22]. However, on-chip frequency-tracking oscillation class-D PA in [20] and additional compensation capacitors in [21] have increased the cost and volume of WPT system.…”

Enhanced Power Transmission for on-Road Agv Wireless Charging Systems Using a Current-Optimized Technique

“…The early structure of a magnetic coupling WPT system was composed of four elements: source loop, transmitting coil (TX), receiving coil (RX), and load loop [2][3][4]. In order to heighten transmission distance with power delivered to the load (PDL), multi-repeater WPT systems have been proposed [5][6][7][8].…”

Efficiency Analysis of Multiple-Transmitter Wireless Power Transfer Systems

“…The research of magnetic-resonance coupling is particularly prized in the areas of wireless power transfer (WPT) since this research was published in the US journal Science in 2007 [1]. Many interesting fields on magnetic-resonance WPT have been studied in just the last 10 years alone [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19].…”