Identifying power line harmonic radiation from an electrical network

Abstract

Abstract. It has been suggested that the space environment is being polluted by power line harmonic radiation (PLHR), generated from harmonics of the electrical power transmission frequency (50 or 60 Hz) and radiated into the ionosphere and magnetosphere by long power lines. While some insitu satellite measurements of PLHR have been reported, it has proved difficult to confirm the source and overall significance. The electricity network of the city of Dunedin, New Zealand, is tiny compared to the many large industrial zones found outside New Zealand. However, the 1050 Hz ripple control signal injected into the local electrical grid at regular intervals as a load-control mechanism provides an opportunity for identifying PLHR strengths radiated from a spatially well defined electrical network. In-situ observations by satellites should allow a greater understanding of PLHR and its significance as man-made pollution to nearEarth space. Calculations have been undertaken to estimate the strength of the radiation fields expected from the ripple control signal which is injected into the Dunedin city electrical network. We find that ground-based measurements will not be sensitive enough for detection of the ripple control radiation fields, even during the quietest winter night. While significant power penetrates the lower ionosphere, this is well below the reported threshold required for nonlinear triggering in the Van Allen radiation belts. Some radiated fields at satellite altitudes should be detectable, allowing insitu measurements. At the altitude of the DEMETER mission, the radiated electric fields will not be detectable under any ionospheric conditions. However, we find that the radiated magnetic fields may be detectable by the DEMETER satellite at certain times, although this will be very difficult. Nonetheless, there is the possibility for future experimental campaigns.

Long‐Lasting Geomagnetically Induced Currents and Harmonic Distortion Observed in New Zealand During the 7–8 September 2017 Disturbed Period

“…These represent harmonics generated by localized loads on the substation and include three intense pulses at ~1 kHz, which are most likely due to a 1,050‐Hz ripple injection system used to control domestic hot water heating systems in the Dunedin area (01:30, 11:00, and 11:15 UT on 8 September). Ripple control in Dunedin was previously described by Werner et al (). However, at 01:45 and 12:30 UT enhancements of harmonics up to 1.6 kHz are seen at HWB, and up to 1 kHz at Swampy Summit.…”

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

“…the characteristics of PLHR [Helliwell et al, 1980;Ando et al, 2002;Werner et al, 2005;Wu et al, 2014]. Many theoretical results, however, still do not match the observation data well.…”

Impact of Signal Radiation Leakage on Power Line Communication Systems

“…Differential mode on the other hand, ensures that current signals flow in opposite directions on the cable pair. Thus, a highly symmetrical line implies a large ratio of differential to common mode current flow, and by extension, very weak radiation, while a nonsymmetrical line results in common-mode current flow, inducing high radiation [10,21,22].…”