Research On Key Technologies Of Massage Chair Based On Half-Bridge LLC Resonant Power Supply

As a health care and massage tool,massage chair is welcomed by more and more people.And the performance of power supply in massage chair is very important to the whole massage chair system.In this thesis,the half-bridge LLC resonant power supply is selected to replace the traditional flyback switching power supply as the power supply of massage chair because of its soft-switching technology,which is deeply studied from the aspects of principle,modeling,main circuit design,simulation and experimental verification.Aiming at the influence of motor interference source on the control system of massage chair,this thesis also makes some analysis and research on the electromagnetic interference of motor on massage chair.Firstly,the topology of half-bridge LLC resonant converter is given in the thesis,and the working principle of half-bridge LLC resonant converter is analyzed and explained from two aspects of working frequency and ideal working state.The steady-state model of half-bridge LLC resonant converter is established by using the fundamental wave analysis(FHA).Combining the DC gain formula,DC gain curve and equivalent model,the resonant converter is set in the range of capacitive and inductive switching,which can realize zero-voltage switching-on(ZVS)of primary MOS and zero-current switching-off(ZCS)of secondary rectifier diode.Secondly,the hardware circuit of the power supply on the massage chair is designed from three parts: the former input electromagnetic interference(EMI)filter circuit,the Boost-based active power factor correction(APFC)circuit and the half-bridge LLC resonant converter.According to the experimental prototype,the experimental platform of the system is built.And the correctness of theoretical analysis of half-bridge LLC resonant converter is verified by simulation and experiment.Finally,the electromagnetic interference of the motor on the massage chair to the control system is analyzed.The transmission line model of conductive interference on motor winding of massage chair is established.And based on the modeling and Simulation of conductive interference on motor,the existence of conductive interference is confirmed.At the same time,the anti-interference measures are put forward from the hardware point of view,and the anti-interference experiments are carried out pertinently.