Research On High-power Driving Power Supply Of Platform Screen Door Based On ZVZCS Phase-shifting Technology

Platform edge doors are the key equipment in rail transit system.When doors are operated under the same order,the DC power supply system is required to provide a large power output instantaneously,while the output voltage should keep a small voltage derivation.Based on the door machine drive power supply as the research object,a class of high-power DC power supply module is designed.The control procedure consists of the selection of the DC power supply topology,theoretical analysis and mathematical modeling of the system,which is carried out by the STM32 ARM and UC3875 resonant control chip.selection,Moreover,simulation and hardware experiments are also introduced in this dissertation.The details are described as the following:First of all,this dissertation describes the load characteristics of subway shielding door and its technical requirements for DC power supply.ZVZCS soft switch circuit,which is composed of the primary side of the capacitor in series and the blocking diode,is selected as the main circuit topology of the DC power supply.The basic working principle and key technologies are analyzed and studied theoretically.Aiming at the defect that the voltage peak of the secondary side is too large during the commutation,the calculation formula of diode oscillation frequency and voltage peak is derived,and then the RCD+RC composite suppression network is adopted to suppress the voltage peak,which effectively reduces the voltage grade of the device.Secondly,the concept of effective duty ratio of transformer side is introduced,and the state space average method is used to establish the AC small signal equivalent model of DC power supply under the condition of ZVZCS.The open-loop transfer function of the system is derived.A type-II compensation controller is designed based on the frequency domain correction method,which improves the steady-state accuracy and dynamic response speed of the system.The control block diagram of the closed-loop system is given.Thirdly,according to the requirements,the parameters for the power module and power device are calculated in detail,which are used for the PCB circuit diagram and the experimental prototype.At the same time,a monitoring system based on STM32 ARM MCU is designed to meet the requirement of real-time monitoring of the working state of DC power supply.For the problem of system heat loss,the losspower of main power devices is calculated,and then the appropriate radiator is selected.The droop control strategy is adopted to meet the requirement of redundant configuration of power supply module.Finally,by PSIM simulation software simulated operation of the DC drive power,two sets of the experimental prototype with were developed,with the rated power of 2.2kw and instantaneous power of 3.3kw.Furthermore,the experimental results of a single module and multiple modules are presented.The simulation and experimental results show that the correctness and validity of the DC power supply.