Research On Inductively Coupled High-Power Transfer Technology Based On Loosely Coupled Transforme

Inductively Coupled Power Transfer is simplified for ICPT. This technology can transfer energy from a power supply to a power consumer contactlessly by loosely coupled transformer with an air gas varying from several millimeters to centimeters. Such energy transfer plays a tremendous role in power supply systems for handheld mobile equipment, electric vehicle and device in special environment.This thesis researched the power transfer characteristic of loosely coupled transformer basing on its T-type equivalent circuit model, analyzed the principle of Series-Series resonant ICPT system, gave the design criteria for loosely coupled transformer and calculate formulas for system circuit parameters, designed the circuit for ICPT system which consisted of full-bridge phase-shift converter, rectifier, filter, voltage sampling and wireless feedback system which completed wireless closed-loop control by RF transceiver chip and DSP.The characteristic of open-loop ICPT system was further researched, which included output voltage characteristic when the working frequency was different from the resonant frequency, phase-shift angle's influence on system's output voltage, realization conditions for full-bridge phase shift converter to work at Zero Voltage Switch Mode, and power transfer characteristic for different air gap. When the system worked at Zero Voltage Switch mode and the input voltage was 290V, the prototype's maximum output power was 3.75kW, and the overall efficiency was 89%.The characteristic of closed-loop ICPT system was preliminary researched. By changing the phase-shift angle to obtain different output characteristic and testing the open-loop bode plot, the PI control parameters was determined. The output voltage could keep stable while the load varied by adjusting the phase-shift angle. When the input voltage was 290V, the output voltage was stable at 260V and the maximum output power was 2kW.