Research On Capacitance Coupling Wireless Power Supply Technologyfor Medium And Low Speed Maglev Train

The medium and low speed maglev train has gradually entered the public view in recent years because of its small noise,more stable operation and faster speed.However,the traditional sliding power supply for low and medium speed maglev train can cause problems such as device wear,noise and poor contact formation of electric sparks,resulting in higher system maintenance costs and reduced safety.Capacitively coupled power supply technology is capable of transmitting radio energy through capacitive pole plates,which has the advantages of low cost and light weight,and solves the problems caused by sliding power supply.The purpose of this paper is to propose a capacitively coupled wireless power supply system for low and medium speed maglev train and to study it feasibility.Firstly,this paper proposes a capacitively coupled wireless energy transfer circuit to address the problems caused by sliding power supply.By studying the topology,a full-bridge topology circuit is designed to realize the bi-directional flow of energy.By studying the impedance matching circuit,it proposes an LCL-LC impedance matching topology circuit.The topology circuit improves the transmission efficiency of the circuit and realizes that the output voltage remains basically constant when the load generates changes.The transmission capability of the energy transfer mechanism is analyzed,and the CPT topology is designed to meet the power supply requirements of the maglev train.This paper designs a ground energy storage system with a DC-DC bidirectional converter as the energy conversion device,a double closed-loop control system as the central control system,and a battery as the energy storage mechanism,and calculates the energy storage capacity for the problem of voltage increase at the supply side caused by train braking.Secondly,this paper characterizes the mutual capacity model and edge effect of the energy transfer mechanism and determines the specific parameters of the energy transfer mechanism.The impedance matching circuit was characterized to verify the principle of voltage regulation at the output and to determine the inductor and capacitor related parameters in the circuit.By analyzing and comparing the voltage and current double closed-loop control system and the voltage single closed-loop system,it is concluded that the double closed-loop control system is more stable and faster response.By characterizing the DC-DC bidirectional converter,it is proved that the converter can achieve the requirement of stabilizing the voltage at the supply side.The deflection characteristics of the energy transfer mechanism are analyzed,and it is proved that the bilateral vertical mounted energy transfer mechanism has good deflection resistance.Finally,this paper builds a simulation and experimental platform for wireless energy transfer circuit and ground energy storage system,realizes capacitive coupled two-way wireless energy transfer,achieves stable supply-side voltage of ground energy storage system,and verifies constant voltage supply at the vehicle end and good offset resistance of bilateral vertical mounted energy transfer mechanism.The experimental results verify the reliability and effectiveness of the system.