Thermal Simulation

Analytical lumped models suffice for early feasibility, but industrial wireless charging products require simulation that captures spatial hotspots: FET die under gate driver shadow, ferrite center-leg temperature rise, and PCB trace heating on multi-oz copper carrying 100 A secondary current. SiCore uses thermal simulation to lock mechanical stack-ups before tooled dock plates and receiver enclosures commit to production.

Simulation inputs come from electrical design: switching loss vs load tables from double-pulse tests, coil AC resistance vs frequency and temperature, and duty-cycle profiles derived from fleet telemetry — not continuous rated power alone.

01Model construction

• FEA steady-state and transient for conduction-dominant paths: FET-to-heatsink, ferrite-to-plate.
• CFD for enclosure airflow, dock pit geometry, and receiver chassis vent configurations.
• Loss maps: spatially distributed W/cm² on FET tops, ferrite volumes, and DC bus shunt zones.
• Material properties: temperature-dependent ferrite and copper resistivity, anisotropic PCB effective conductivity.
• Boundary conditions: warehouse ambient, concrete thermal mass for floor-mounted docks, solar load for outdoor pilot sites.

02WPT-specific simulation focus

Coil assemblies are modeled with split losses: copper I²R in windings, core Steinmetz or measured loss density at operating flux, and adjacent metal eddy heating from fringing fields. Misalignment scenarios increase secondary voltage and receiver rectifier loss — SiCore runs parametric sweeps at nominal and worst-case gap before signing thermal derating curves.

Dock designs with multiple coils simulate thermal crosstalk: an idle adjacent pad still warm from prior session heats shared enclosure air and raises baseline for the next vehicle. Transient simulation over back-to-back charge cycles validates fan hysteresis and firmware derating onset timing.

03Correlation and sign-off

Simulation correlates to hardware within agreed tolerance — typically ±5 °C on FET case and ±8 °C on ferrite bulk at rated power after 60-minute soak. Thermocouples attach at defined points matching model probes; IR images identify convection errors where emissivity assumptions were wrong. Correlation reports gate release of thermal derating tables embedded in firmware and fleet commissioning limits.