Component design procedure for LCC-S wireless power transfer systems based on genetic algorithms and sensitivity analysis

This paper introduces a novel approach for designing a Wireless Power Transfer (WPT) system with LCC-S compensation. Since WPT systems operate under resonant conditions, even small deviations of the components from the nominal values can result in a significant reduction of the power transferred to the load, and in an increment of the circulating currents, reducing the system efficiency. The design techniques available today in the literature provide a unique combination of passive components capable of transferring a certain power to the load. This is a limitation, because, in practice, there are several combinations that allow reaching the desired output power, but they are usually neglected because they are extremely difficult to compute analytically. For this reason, in this paper, the authors present an innovative design procedure that enables, through a Genetic Algorithm, the identification of multiple feasible combinations of the LCC-S components capable of achieving the desired output power. Moreover, the authors evaluate the effects of the component tolerances on the output power to determine which combinations are more robust to component variations. This task is performed by calculating the probability that a particular combination yields the desired output power, once the tolerances have been considered, following a Monte Carlo approach. This information is utilized to decide whether it is possible to reduce the component quality (worsening the tolerance) without affecting the performance. Finally, an optimal solution granting both low-cost and robustness against component tolerances can be individuated. The proposed design procedure is applied to a case study and validated experimentally.