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Design and Optimization of a 3-Coil Inductive Link for Efficient Wireless Power Transmission
Mehdi Kiani1, Uei-Ming Jow, Maysam Ghovanloo
1GT Bionics lab, School of Electrical and Computer Engineering at the Georgia Institute of Technology, Atlanta, GA 30308, USA.
IEEE Transactions on Biomedical Circuits and Systems
|September 17, 2011
Summary
A new 3-coil inductive power transfer link offers high power delivered to the load (PDL) at large distances, surpassing 2- and 4-coil designs. This advancement optimizes wireless power for implantable devices and energy harvesting systems.
Area of Science:
- Electrical Engineering
- Wireless Power Transfer
- Biomedical Engineering
Background:
- Inductive power transmission is crucial for energizing implantable microelectronic devices (IMDs), recharging batteries, and powering energy harvesters.
- Power transfer efficiency (PTE) and power delivered to the load (PDL) are critical parameters influencing wireless link performance, affecting power source needs, heat, range, and interference.
Purpose of the Study:
- To analyze and compare the performance of 2-, 3-, and 4-coil inductive power transfer links.
- To propose and validate an optimized 3-coil inductive link design for improved power delivery at larger distances.
Main Methods:
- Comprehensive circuit-based analysis to guide design and optimization of inductive links.
- Development of an iterative design methodology for optimal coil geometries in 3-coil systems.
- Optimization for a 13.56 MHz carrier frequency and 12 cm coupling distance, verified by simulations and measurements.
Main Results:
- The proposed 3-coil inductive link achieves a 37% PTE at 12 cm, comparable to the 4-coil link (35% PTE) but with significantly higher PDL.
- At 12 cm, the 3-coil link's PDL is 1.5 times higher than the 2-coil link (15% PTE) and 59 times higher than the 4-coil link.
- Optimal coil configurations vary with distance: 2-coil for high PDL at short distances, 4-coil for large driver resistance or low power needs, and 3-coil for high PDL at larger distances.
Conclusions:
- The 3-coil inductive power transfer link presents a superior solution for applications requiring high power delivery at extended coupling distances.
- The study provides a validated design methodology and performance comparison, guiding the selection of optimal inductive link topologies based on specific application requirements.
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