Design of WPT coils to minimize AC resistance and capacitor stress applied to SS-topology

The only loss in the lumped circuit model of a wireless power transfer system comes from the parasitic resistances, which usually becomes more problematic at higher frequencies. Resonant currents and voltages can also exert a large stress on the system. This paper presents a simple coil design procedure that minimizes the AC resistance and the stress of the compensating capacitors. It results in the lightest coil designs that can be chosen from commercially available Litz wires. Test setup using SS-topology achieved 98.6 % coil-to-coil efficiency with 18 cm air-gap and 0.6 kg coils.

[1]  Grant Covic,et al.  Power transfer capability and bifurcation phenomena of loosely coupled inductive power transfer systems , 2004, IEEE Transactions on Industrial Electronics.

[2]  J. W. Kolar,et al.  Optimization of Transcutaneous Energy Transfer coils for high power medical applications , 2014, 2014 IEEE 15th Workshop on Control and Modeling for Power Electronics (COMPEL).

[3]  Grant Covic,et al.  A Bipolar Pad in a 10-kHz 300-W Distributed IPT System for AGV Applications , 2014, IEEE Transactions on Industrial Electronics.

[4]  J. Burdío,et al.  Simple resistance calculation in litz-wire planar windings for induction cooking appliances , 2005, IEEE Transactions on Magnetics.

[5]  Ivica Stevanovic,et al.  Modeling and $\eta $ - $\alpha $ -Pareto Optimization of Inductive Power Transfer Coils for Electric Vehicles , 2015, IEEE Journal of Emerging and Selected Topics in Power Electronics.

[6]  H. Takanashi,et al.  A large air gap 3 kW wireless power transfer system for electric vehicles , 2012, 2012 IEEE Energy Conversion Congress and Exposition (ECCE).

[7]  Shahriar Mirabbasi,et al.  Design and Optimization of Resonance-Based Efficient Wireless Power Delivery Systems for Biomedical Implants , 2011, IEEE Transactions on Biomedical Circuits and Systems.

[8]  Diego Puyal,et al.  Frequency-dependent resistance in Litz-wire planar windings for domestic induction heating appliances , 2006, IEEE Transactions on Power Electronics.

[9]  H. H. Wu,et al.  A review on inductive charging for electric vehicles , 2011, 2011 IEEE International Electric Machines & Drives Conference (IEMDC).

[10]  Zhi Yang,et al.  Inductor Modeling in Wireless Links for Implantable Electronics , 2007, IEEE Transactions on Magnetics.

[11]  Stephen P. Boyd,et al.  Simple accurate expressions for planar spiral inductances , 1999, IEEE J. Solid State Circuits.

[12]  José Francisco Sanz Osorio,et al.  Optimal Design of ICPT Systems Applied to Electric Vehicle Battery Charge , 2009, IEEE Transactions on Industrial Electronics.

[13]  Jih-Sheng Lai,et al.  Analysis and parameters optimization of a contactless IPT system for EV charger , 2014, 2014 IEEE Applied Power Electronics Conference and Exposition - APEC 2014.

[14]  C.M. Zierhofer,et al.  Geometric approach for coupling enhancement of magnetically coupled coils , 1996, IEEE Transactions on Biomedical Engineering.