High-power series-compensated WPT systems achieve efficiency via zero-voltage switching (ZVS), relying on dead time to discharge parasitic capacitances. Capacitor aging reduces compensation capacitance, narrowing the dead time window and risking ZVS loss, voltage notches, and efficiency drops. This paper analytically and experimentally studies aging effects on a 2 kW WPT prototype, showing even 3% degradation shifts ZVS limits. A practical design method is proposed to select compensation capacitance and dead time, ensuring robust ZVS and sustained efficiency over the system’s lifespan, validated under varying loads and air gaps.
