Parameter Design for Power Maximization in Inductive Wireless Power Transfer Systems with Consideration of Frequency Splitting

Wireless Power Transfer (WPT) is expected to have a significant positive impact on both industry and daily lives. However, the maximal load power is prone to be reduced due to excessive coupling coefficient, which results in frequency splitting phenomenon. This paper provides design guidelines for WPT systems to ensure the maximal output power operation. From the point of view of the load power, this paper establishes the mathematical model of the frequency splitting phenomenon first, creating the connection between frequency splitting and extreme points of load power. Then we deduce the relationship between the coupling coefficient and frequency splitting, a discriminant is proposed to check whether there is frequency splitting. Analytical solutions of splitting frequencies are derived by solving zero points in the derivative of the load power over the operation angular frequency. Finally, the maximal load power under different coupling coefficient is attained. The theoretical analysis is validated by simulation.