Sensitivity Investigation and Mitigation on Power and Efficiency to Resonant Parameters in an LCC Network for Inductive Power Transfer

In an inductive power transfer (IPT) system, the variations of passive parameters affect the system performance. This paper investigates the impact of the variation of resonant parameters on the system power and efficiency in a 5.7 kW LCC compensated IPT system for electric vehicle (EV) charging application. For the single-parameter variation, the sensitivity of power and efficiency to each parameter is investigated by LTspice simulation. For multi-parameter variations, exhaustive analysis and Monte-Carlo methods are applied to quantify the sensitivity issue. It indicates that with random multi-parameter variations within ±10%, the 5.7kW IPT system only has a 73.87% probability to satisfy a 10% power fluctuation of [5.13kW, 6.27kW] with efficiency above 92%. To mitigate the sensitivity issue, the cascade Monte-Carlo method is used to optimize the central values of parameters at the design stage, which can increase the yield rate in mass production from 73.87% to 82%. Furthermore, a frequency tuning method is proposed to regulate power and efficiency. Finally, a 5.7kW full-power prototype is implemented. Experiments are performed using three special parameter combinations, which validated the sensitivity concern and the feasibility of the proposed frequency tuning method.