Design Of Residual Current Type Electric Fire Monitoring System

With the rapid development of modern society and the promotion of craftsman's spirit,construction technology is becoming more and more attractive,functional and intelligent.With the improvement of people's living standards,electric energy has been widely used as clean energy,with the emergence of new things such as household appliances,emerging robots and new energy vehicles,the amount of electric energy used has increased and the electric load has continued to increase.Therefore,the complexity of the power lines and the concealment of the laying route have led to the hidden danger of electrical fires threatening the people all the time.The low-voltage power grid has the characteristics of long-term operation,and some weak faults that do not affect the operation of the system are often ignored.Over time,these weak fault points are aging and leakage causing fires.Therefore,it is particularly important to study the fire caused by electrical reasons and develop relevant detection equipment.Firstly,this paper analyzes various electrical faults that cause fires.Because electrical faults do not cause fires overnight,they often have a slow development process.In this process,high-voltage protection devices do not play a protective role.Through theoretical analysis,it is concluded that residual current can better reflect the line situation as a monitoring object.Secondly,the basic theory and algorithm of residual current are studied.In addition to sine waves,the residual current directly monitored in the line also contains interference signals such as higher harmonics and noise.The processing of current signals requires not only judgment and alarm,but also filtering to obtain clean signals.Therefore,this paper makes a comparative study of filtering algorithm and alarm algorithm,and concludes that Fourier transform and slope algorithm can maximize the engineering benefits.Thirdly,according to the design of the electrical fire monitoring system for residual current detection,the circuit design of monitoring equipment,electronic encoder,detector and other components is completed with the two-bus technology as the communication mode of the system.The electronic encoder has the functions of address coding and alarm value setting.The function of the monitoring equipment is to monitor the state of each detector.When the line goes out of line and gives an alarm,the equipment can also store and print the fault information.The switching function of the main and standby power supplies enables the equipment to continuously supply power in a short period.Finally,the residual current fire monitoring equipment designed in this paper has been applied to the Jianmenguan Station of Xicheng high-speed rail.The system is running welland functioning normally.It has passed the acceptance of the fire department and has very practical engineering value.