Topology Design of Pulse Energy Injection Inverters for Inductive Power Transfer Systems

For most of the inductive power transfer systems, due to the requirement of the resonance current with a certain frequency, the working frequency of inverters needs to be equal to the resonant frequency. However, a high-frequency and high-Q resonant tank may increase the switching loss of inverters, which may cause the decrease of power transfer efficiency for the whole system. This paper proposes a pulse energy injection inverter for inductive power transfer systems, which enables the working frequency of inverter much lower than the resonant frequency. Moreover, the proposed inverter also decouples the energy injection with the working frequency, the resonant tank, and the load to realize the discrete energy injection. Based on the proposed inverter, this paper offers the working modes and a differential equation model to describe the system states. Then some key principles for parameter tuning of this inverter are provided. Through simulations and experiments, it is proved that the proposed inverter is available and effective for inductive power transfer systems.