On the Immunity of Data Acquisition Systems Used in Power Systems

Abstract

The paper deals with some tests regarding the immunity for radiated emissions and compliance with international standards for electromagnetic compatibility (EMC) measurements for an industrial data acquisition system (DAS) used in power systems. The behavior of the DAS, when functioning near electromagnetic disturbance sources, is studied. The goal is to test its robustness in similar conditions as those encountered in its normal environment. It is known that multiple factors may affect the accuracy of data acquired by DAS. The Equipment Under Test (EUT), witch in this case is represented by DAS is tested for immunity in a specialized enclosure (GTEM Cell). The immunity based on the analysis of the influences of an electric field with constant magnitude and variable frequency in the range of 80 MHz…1 GHz is studied. After analyzing the initial tests results, partial and, afterwards, full shielding of the EUT’s case is performed in order to remove the EM influence. The tests’ results drive to the conclusion that it is necessary to design and build an enclosure from conductive material for the DAS. After the implementation of the measures, the EUT passed the tests concerning the immunity. The GTEM Cell construction, GTEM model, generation and distribution of electric and magnetic field inside the GTEM Cell, equipment under test (EUT), radiated emission measurement scheme, EMC standards for GTEM Cell, are exposed. images