Power Loss Analysis and Comparison of Segmented and Unsegmented Energy Coupling Coils for Wireless Energy Transfer

Area of Science:

• Electrical Engineering
• Electromagnetics
• Power Electronics

Background:

• Wireless energy transfer (WET) systems face power loss challenges.
• High operating voltages in WET can lead to significant intrawinding dielectric losses.
• Optimizing coil design is crucial for efficient power transfer.

Purpose of the Study:

• To investigate and compare power losses in unsegmented and segmented energy coupling coils for WET.
• To analyze the impact of coil parameters on winding conduction and intrawinding dielectric losses.
• To evaluate the effectiveness of coil segmentation in mitigating dielectric losses.

Main Methods:

• Development of four 30-cm energy coupling coils with varied winding separations, conductor areas, and turns.
• Testing coils in both unsegmented and segmented configurations.
• Evaluation of winding conduction and intrawinding dielectric losses using a lumped circuit model.

Main Results:

• Intrawinding dielectric loss can exceed winding conduction loss by up to seven times at 6.78 MHz in tightly wound, unsegmented coils.
• Increasing winding separation or reducing turns lowers dielectric loss but also reduces power transfer capability.
• Coil segmentation effectively eliminates intrawinding dielectric loss.

Conclusions:

• Coil segmentation is a viable strategy to mitigate dielectric losses in WET.
• The findings are applicable to various coil types (transmitting, receiving, resonant) in WET systems.
• This research provides insights for designing more efficient WET systems, particularly for medical implants.