A power flow control method on primary side for a CPT system

This paper presents a power flow control method for contactless power transfer systems. The proposed method is to control the magnitude of the primary track current based on the concept of energy injection and regeneration. The stored energy and resonant current is controlled to vary on the primary side. As a result, the induced current on the secondary side varies. For such a reason, the power flow to the secondary side is controlled. A controller is developed by monitoring primary track current and the output voltage of the secondary power pickup. Switching losses and EMI (Electromagnetic Interference) are reduced due to the ZCS (Zero Current Switching) operation of the converter. Simulation and experimental results show that the magnitudes of the primary current and the output voltage of a secondary power pickup are both fully controllable against load variations.