A Generic Coupled and/or Decoupled Integrated Inductors Optimization for WPT Applications

Using integrated inductors in a wireless power transfer (WPT) system offers various advantages, e.g., reduced ferrite material usage, cost, converter size, and increased power density. This paper presents an optimization method for the integrated inductors in WPT systems, which can be applied to not only DC-DC converters requiring complete decoupling, but also compensation inductors where power is directed to desired coils while decoupled from other coils. A modified lumped loop model is proposed to accelerate the optimization process to enable simultaneous design of multiple decoupled and/or coupled integrated inductors for diverse WPT applications. Using a double-sided LCC configuration as a case study, the optimized design can achieve a 26% and 24% self-inductance reduction for additional integrated inductors on transmitter side and receiver side, respectively. Moreover, it significantly reduces undesired cross-coupling and its fluctuation, while maximizing the desired cross-coupling. Additionally, a simple capacitor tuning is introduced to avoid notch phenomena in the inverter. The proposed method is validated in an experimental test setup, achieving a maximum DC-DC efficiency of 96.5%.