Design Of Power Supply Module For Power Monitoring System

With development of society and city urbanization,the requirement of electric power resources is needed much more.The scale of China’s power grid continues to expand and the smart grid is emerging.The design of power supplies and distribution is more important than ever before.At the same time online monitoring of power supplies and distribution network need improvement as well.As the distribution line of power transmission has large dispersion,long distance and complex surroundings,the remote monitoring of power transmission has become an inevitable trend.This has put forward higher requirements of power supply designs of the monitoring terminal.It is required to develop a modular power supply product,which is suitable for power monitoring system operating conditions and is small in size,has high reliability with reasonable cost.In view of this,this paper will introduce how to research and develop a DC/DC isolation module power supply which has new technology and new processes.The Flyback converter as the basic topology,based on the optimization of peripheral circuits and the planar transformer,crossover interconnection packaging structure and components surface coating technology,can operate with high efficiency and high reliability in high temperature,high humidity and high levels of pollution.The main research work and innovation points of this paper are as follows:Firstly,the operating principle and mode of Flyback converter are analyzed.Based on the theory of above,the module is designed to realize the super wide high voltage range(88VDC-400VDC)input as well as the stable low ripple output.At the same time,the state space equation is established to analyze the stability and reliability of the Flyback converter system.The PI controller is designed to analyze amplitude,phase and frequency.Secondly,the power loss of the circuit is analyzed,mainly including both of the switching devices and magnetic devices.Conversion efficiency is further improved by improvement of planar transformer,synchronous rectifier and soft-switch technique.Power density is further improved by using the industry’s leading technology of the crossover interconnection packaging structure.Finally,optimize the design of control loop and increase the protection circuit to realize varied protection functions,including input over voltage and under voltage,output over voltage and over current,and module over temperature,to improve product stability.The new heat conductor was selected and the heat sink assembly process was optimized to meet the thermal performance requirements of operating at 100oC.Selecting the new insulation material and using the element surface coating protection technology makes the module have the ability to work in high levels of pollution and achieve high voltage insulation performance,meanwhile improve the reliability of the products.