The article focuses on investigating the influence of some appliances powered by non-harmonic low-frequency voltage on the formation of electromagnetic fields (EMF). Theoretical description of non-harmonic power supply and nonlinear load using fast Fourier transform (FFT) serves to verify and quantify the occurrence and values of the EMF source in a selected environment. In the Separated Extreme Low Voltage (SELV) electrical installation system with an operating voltage of up to 60V when powered by pulse width modulation (PWM) with a frequency of 1480Hz and a modulation depth of 20%, more than the 14th component in the order of harmonics. According to the method of implementation of real modern electrical installations in public transport vehicles and in the study room, power lines with a length of 5 to 25 m from the switchboard to the load and nonlinear loads are installed there. Experimental measurements with a 0.5 m long single-core test wire at a location of possible long-term exposure of the human body result in an induced voltage of more than 150 mV with a non-harmonic component. Findings indicating the occurrence of EMF in areas where people stay for a long time are the basis for assessing the possible consequences of electromagnetic induction on sensitive electronic devices such as pacemakers with implanted electrodes.
Tropp et al. (Thu,) studied this question.