Surge 1.2/50µs Test Automation for DIN-Rail Residual Current CB

The thesis project entitled "Surge 1.2/50 µs test automation for DIN-Rail Residual Current CB", carried out at the ABB S.p.A company based in Vittuone (MI), starting from the study of residual current circuit breakers was the protagonist of the development of the automation of a test carried out daily within the laboratory that deals with the electromagnetic compatibility verification of products. The task of the surge test is to verify that the devices are sufficiently immune to such disturbances by meeting the functional and safety requirements of the relevant product standards. Residual current circuit breakers during the test may trip as a result of applied over-voltages. The operator must then reset the part and mark the test conditions under which the trip occurred. The purpose of this thesis was to eliminate the presence of an operator during surge testing on differential circuit breakers din-rail, replacing his action with an ABB motor drive and appropriate control logic. In this regard, it is possible to use graphical programming environment to work on such as Labview. As mentioned earlier for the automation of the test, it is necessary to replace the current operator action with a motor control, for which the choice could be the new MOD device under development in the company, which is coupled with the COMM WIFI communication module, also under development. To monitor the progress of the above test, one must include measurement instrumentation such as an oscilloscope, which can analyze voltages and currents related to each surge pulse. After addressing this aspect, since each instrument used has to be networked, it is necessary to introduce the serial communication of the machine used for carrying out the Surge test. COM ports are therefore employed, managed in such a way that they can be used simultaneously by more than one software, since it is necessary that both Labview and the Surge machine’s own sotfware can have read and write access to them. To remotely drive the MOD device through the COMM Wifi communication module the Modbus TCP protocol must be validated and implemented. Going through all these steps, it is necessary to create a report file in which are listed the test parameters for each case history, the voltage and current values for each surge pulse and any voltage and current waveforms in cases where a trip or over-current occurs. It is important for the program to consider two possible types of tests: the normal sequence and the random angle sequence; these in fact employ different test structures that impact the data handling by the Labview program created. Finally, it is necessary to create a user interface, through which the latter can manage and monitor the status of the test through visual and audible signals, entering test parameters of numeric or string type, and being able to intervene by starting or stopping the test through appropriate buttons.