Design And Experimental Study Of Distributed Switching Power Supply Monitoring System

With the advances in electronic technology and develpment of communications and power industry,more and more increasingly high requirements are required in switching power supply.Monitoring technology in switching power supply,making the maintenance and management of the power from the human duty of maintenance management model to conversion of centralized monitoring and management model based on computer.In this way,not only improves the maintenance and management of the device of the power level,but also provides power quality,so that the power supply has higher reliability and economy with a reducing maintenance costs.Power monitoring system is actually a combination of monitoring software and microcontroller to control power runs and associated data acquisition,the object to be measured by various physical quantities corresponding to the sensing element can be converted into an appropriate electrical signal,through signal conditioning,sampling quantization.coding and transmission,and finally is send to the computer for data processing and memory recording process.When one or more of a power failure happen in the system,it can narrow the scope ofthe failure and exactly point out the failure alarm information to improve the power efficiency of the maintenance staff.Therefore,the study of the distributed switching power supply monitoring system in this paper is of great significance.Firstly,this paper start from the monitored object,in regard to the issue of the same of different output voltage level of switching power supply is not casy to monitor,this paper proposed a system scheme of LabVIEW-based real-time monitoring of multiple switching power supply,which has been achieved centralized monitoring.One sing power module adopts two levels of typical structure.The former stage adopts power factor correction,and the later stage adopts zero voltage switch phase-shifted full bridge converters.The lower monitoring part take the joint control scheme of microcontroller and UCC3895.Then,designing the communication protocols and using the RS485 serial commuication bus for thenetworking of distributed power supplies.Realizing the operation of switching on and off of a single or multiple powers,setting the inputting over voltage or under voltage protection values,the output voltage values,the current limited values,and the values of the internal temperature protection;in order to be convenient to record,print and manage relevant monitoring information,adopting the method of accessing to database of Microsoft Access under the background of Lab VIEW in the upper monitoring software.In order to verify the feasibility of the monitoring system,two monitoring prototype were developed,two distributed power switching power supply in a certain area are centralized monitoring.Finally,the experimental results show that the monitoring system is stable,reliable,and can give the accurate information of a fault in a power supply.