Load Matching in Single-Stage Constant Power Series-Parallel Compensated Inductive Charging with High Voltage Gain

Inductive charging can alleaviate the drawbacks of the traditional conductive charging methods. It is well known that a inductive charger achieves optimal efficiency at optimal load conditions. However, during charging the load varies substantially which degrades the efficiency. Thus, load matching is required to achieve optimal efficiency. Further, a constant power (CP) has a better performance than the constant current (CC) charging stage due to its faster charging speed and reduced thermal design in comparison to CC. Within a CP charging, a high voltage gain is required for applications such as EV charging where charging voltage levels are considerably high. In this paper, a single-stage CP inductive charger is presented. The proposed charger adopts a current controlled semi active rectifier to achieve load matching and CP output simultaneously at higher values of voltage gain. The proposed charger is based on fixed frequency operation and control is entirely done on the secondary side thereby eliminating the wireless feedback communication. The simulation results are included to show the effectiveness of the proposed charger.