Measurement of Background Noise Levels Conducted Over Low Voltage Power Lines in Urban and Rural Areas

Specifying Power Filter Insertion Loss Values in Terms of Electromagnetic Safety of IT Equipment

“…More recent data on the level of conducted disturbances in low-voltage power supply lines for urbanised and rural areas located on the territory of Poland are provided in ref. [5], which was published by one of the authors of this article. This data is presented in Figure 4 for the urban (Figure 4a) and rural areas (Figure 4b), respectively.…”

“…In these figures, black straight lines were used to represent the approximate minimum, maximum and average values for the voltage levels of background noise conducted in frequency subrange from 150 kHz to 30 MHz. The analytical form for the approximating functions is described using the relationship below [5].…”

“…On the basis of comparative analysis of receiver specifications declared by the manufacturers, presented in ref. [5], which could be used for electromagnetic infiltration thanks to their parameters; it should be stated that the lowest noise factor values are offered by the IZ27B receiver manufactured by INTRIPLE company (Horní Počernice, Czech Republic) [7]. Therefore, to estimate additional insertion loss T introduced by the protective mains filter, above which electromagnetic infiltration is significantly hampered, the noise factor of the IZ27B, which is 4 dB for the frequency range 150 kHz to 30 MHz, should be taken into account.…”

“…This article identifies and estimates the values of parameters influencing the required insertion loss value for a mains filter. The analysis of the aforementioned parameters was performed using data available in technical literature [1-13], as well as data obtained through our own research [5], which was carried out for the purposes of this study (e.g., the results of environmental noise levels measurements conducted in low-voltage power supply lines).…”

“…We were motivated to write this article partly due to the fact that available examples of analysis of IT equipment mains filter parameter value requirements, which would minimize the risk of electromagnetic leakage of information, are rare in the international literature [5,6,[9][10][11][12][13][14][15] and the works available contain few important details regarding the technical solutions used.…”