Wiki article · Collection 04

Conduction Loss

Engineering reference on Conduction Loss for wireless power system design, integration, and deployment.

6 minArticle 12/50Power Electronics

Conduction Loss — educational diagram — Fig.: Educational diagram for “Conduction Loss”.

Conduction loss is the predictable dissipation when current flows through resistive elements — MOSFET RDS(on), winding AC and DC resistance, connector contact resistance, and cable copper. In high-power AGV wireless charging at moderate frequency, conduction loss often exceeds switching loss once the link is well tuned.

Every milliohm in the coil-to-battery path matters at 50 A and above.

01Major contributors

inverter and SR MOSFET on-resistance at hot junction temperature.
Coil Litz or copper AC resistance including proximity and skin effect.
Bus bars, fuse holders, and charging contacts in the dock-vehicle interface.
Rectifier or SR channel loss when diodes remain in the path.

Conduction Loss — supporting diagram — Fig.: Supporting illustration for “Conduction Loss”.

02Reduction approaches

Parallel FETs or larger die when switching budget allows. Optimize coil conductor packing and ferrite geometry before adding power. Use four-point Kelvin sensing to find hidden resistance in assemblies. Specify maintenance for contact oxidation on mating surfaces in dirty industrial floors.

03Measurement

Thermography under sustained charge at fleet-representative current.
Compare calculated I²R sum to input-output efficiency gap.
Track conduction loss drift as contacts wear over docking cycles.