Auto Test System Of Arc Fault Detection Device

Arc fault detection devices(AFDD) is a novel kind of protection device,which was mainly used for preventing the fire caused by arc fault. The overcurrent protection device which was already installed in the circuit can not prevent the art fault fire effectively because that there is no causal relationship between the size of current and arc fault.However, If the AFDD is series with the circuit, the circuit would timely find fault arc and disconnect the circuit to avoid the occurrence of fire.There’re a various of experiments in the testing of AFDD. Every operation must be done according to testing standard and that’s not only a waste of time,but also often have wrong operations when it is done manually. The research and development of automatic testing system of AFDD discussed in this thesis can commendably solve the problems above.The hardware of the automatic testing system discussed in this thesis mainly consists of IPC(industrial personal computer), industrial control card and experimental circuit.The testing software of IPC will carry out each corresponding experimental step according the relevant requirements of AFDD through the control of automatically and sequentially opening or closing the relay in the experimental circuit by the industrial control card.During the test,the testing software will not stop collecting the current data of the experimental circuit until the AFDD breaks up the circuit. Then the oscilloscope will show the wave of the experimental circuit’current.the tester can decide whether the AFDD is qualified or not by observing the wave. The whole automatic testing system can perform the experiments fleetly,accurately and automatically,and make appraisal of the AFDD.Experimental circuit can imitate all kinds of loading and arc fault condition by varying the relay switches and the order of them.Therefore the arc fault characteristic data is significantly useful for the research of the arithmetic of the arc fault testing.If we collect and record these data,there will be abundant original data accumulated for the research of the arithmetic,which forms the arc database.Therefore,this article also designed the date collection terminal.Connecting the data collection terminal into the automatic testing system makes the automatic testing system designed in this thesis gets the function of collecting the arc fault characteristic data:the testing software of the IPC carries out each experiment through the control of experimental circuit relay and the order by the industrial control card,and the data collection terminal can transform the single current signal into multiple arc fault characteristic signal and collect it to construct the arc database used for the research of the arithmetic of the arc fault testing.The main components of the thesis:(1) Design the construction of the automatic testing system of AFDD,dividing it as the major subject of the automatic testing system and the data collection terminal.(2) Design the experimental circuit of the major subject of the automatic testing system,including the access of the load,the method used in common to realize the load,the design of the mutually exclusive switch and the choices of the equipments of experiment.(3) Design the testing software of the major subject of the automatic testing system,including the operating and showing surface,the control of the experimental circuit’ relays and wave showing of the circuit’current.(4) Design of the data collection terminal’s hardware and software. The data collection terminal transforms the single current signal into multichannel arc fault characteristic signal,then it performs collection of these channels at the same time and stores them into the SD card in form of binary streams in real time.The binary file data stored in the SD card can be translated into test files with certain structure by file-format conversion tools,facilitating the analysis of data and the read of arithmetic data.The real testing of the AFDD automatic testing system reflects that this system can accomplish the expected function of testing the AFDD and collecting the arc fault characteristic data.