Implementation of Constant Current or Constant Voltage Output Based on Switching Circuit for Battery Charging Applications

The charging technology based on wireless power transmission technology has a good application prospect. Due to the real-time change of the battery equivalent load and the relative position of the charging coils on both sides, the output current and voltage of the wireless charging system will change, which can not meet the requirements of the constant current or constant voltage charging for the lithium battery. The compensation topology on both sides of the wireless charging system has a decisive impact on the constant current or constant voltage output of the system, but the existing compensation topology has some problems, such as the constant current or constant voltage output and the zero phase of the input impedance can not be realized at the same time, and the constant current or constant voltage output parameters change with the mutual inductance of the coupling coils; In this paper, a hybrid compensation topology based on switching circuit is proposed. Through the topology switching on the secondary side, the constant current or constant voltage output can be realized when the load changes, the zero phase input impedance can be realized in both working modes, and the parameters of the two working modes are independent of the mutual inductance of the coupling coils; The constant current or constant voltage output of wireless charging system can also be realized by phase-shifting control on the primary side when the mutual inductance changes. The simulation results show that the proposed hybrid compensation topology can meet the design requirements.