Power line harmonic radiation observed by the DEMETER spacecraft at 50/60 Hz and low harmonics

Abstract

We present a low‐altitude satellite survey of Power Line Harmonic Radiation (PLHR), i.e., electromagnetic waves radiated by electric power systems on the ground. We focus on frequencies corresponding to the first few harmonics of the base power system frequencies (50 Hz or 60 Hz, depending on the region). It is shown that the intensities of electromagnetic waves detected at these frequencies at an altitude of about 700 km are significantly enhanced above industrialized areas. The frequencies at which the wave intensities are increased are in excellent agreement with base power system frequencies just below the satellite location. We also investigate a possible presence of the weekend effect, i.e., if the situation is different during the weekends when the power consumption is lower than during the weekdays. Such an effect might be possibly present in the European region, but it is very weak. PLHR effects are less often detected in the summer, as the ionospheric absorption increases, and also, the radiation is obscured by lightning generated emissions. This difference is smaller in the U.S. region, in agreement with the monthly variations of the power consumption. The analysis of the measured frequency spectra reveals that although intensity increases at low odd harmonics of base power system frequencies are routinely detected, low even harmonics are generally absent. Finally, we verify the relation of PLHR intensities to the geomagnetically induced currents (GICs) proxy. It is shown that the PLHR intensity is increased at the times of higher GIC proxy values during the night.

Modeling ELF Electromagnetic Field in the Upper Ionosphere From Power Transmission Lines

“…The geographic maps of the occurrence rates of 50/60 Hz emissions recorded by DEMETER satellite showed remarkable agreement with the world map of power consumption and the base power system frequency (Nemec et al., 2015). This demonstrated that above industrialized areas the PLE intensity is significantly enhanced above normal levels.…”

“…Only odd harmonics are generated upon bipolar saturation regime, that is, the saturation of magnet core upon both positive and negative magnetic induction. The observations of PLE at DEMETER satellite indeed routinely detected intensity increases at odd harmonics of base power system frequencies, whereas even harmonics were generally absent (Nemec et al., 2015). The saturation of the magnet core of a power transformer and magnetization current may become unipolar, which occurs only for induction of one particular sign.…”

Systematic investigation of power line harmonic radiation in near‐Earth space above China based on observed satellite data

“…Such seasonal difference of more PLHR events in winter than in summer is similar to that in Němec et al [2015], while it is not in accordance with power consumption. In China, the power consumption in summer is generally larger than in winter.…”

Whistler Influence on the Overall Very Low Frequency Wave Intensity in the Upper Ionosphere

“…These waves can then propagate downward to the Earth (Chum & Santolík, ; Santolík & Parrot, , , ; Santolík, Chum, et al, ; Santolík et al, ). Alternatively, they may be of an artificial origin, such as electromagnetic signals from VLF transmitters (Cohen & Inan, ; Starks et al, ;) or power line harmonic radiation (e.g., Dudkin et al, ; Němec et al, , ). Finally, they may also be generated by lightning discharges.…”