Research On ZVS And Parallel Pickups Characteristics For Inductive Power Transfer Systems

Inductive power transfer technology utilizes the principle of electromagnetic induction to couple energy through the magnetic field to the secondary side,which has the advantages of safety and convenience,low maintenance cost,etc.It is widely used in mobile logistics transportation,electric vehicles and electronic products and other fields.The LCC/S compensated inductive power transfer system has been widely used in applications where its insensitivity of output characteristics to loads variation.In this thesis,the main circuit of the LCC/S compensated IPT system is analyzed using fundamental harmonic approximation method,and the fundamental equivalent model of the IPT system is obtained.The characteristics of the compensation network are studied from the perspective of the two-port network.The resonant conditions of the LCC/S compensation network,the primary coil current characteristics,and the output characteristics of the system are analyzed.In the MATLAB/Simulink simulation software,the characteristics of the LCC/S compensation main circuit are simulated and analyzed,the simulation results verify the correctness of the main circuit characteristics analysis.For the efficiency of the power transmission of the LCC/S compensated IPT system,this thesis analyzes the main circuit modes in the phase-shift control mode,and proposes a method to realize the zero voltage switching condition of the full-bridge inverter circuit.For this reason,the time-domain analysis of the converter was studied to accurately analyze the input current of the LCC/S compensation network at the switching time,and the time domain expression of the input current of the compensation network in the phase shift control mode is obtained.The parameters of the system is optimized when ZVS is realized.At the same time,based on the consideration of improving the output power of IPT system,this thesis proposes a parallel method of the pickup module,and gives the analysis method of the current sharing control scheme based on current error feed-forward.The closed-loop small-signal model of the Buck converter is analyzed under the feed-forward error control scheme.Based on which,the design principles of the control loop of the voltage loop and the current-sharing loop are proposed.Finally,the LCC/S compensated IPT system was built.The experimental results are consistent with the results of theoretical analysis and simulation analysis.Experiment results were presented to verify the effectiveness of the proposed method.