Progress in the Knowledge, Application and Influence of Extremely Low Frequency Signals

Grid Frequency Measurement through a PLHR Analysis Obtained from an ELF Magnetometer

The stability of the power grid’s frequency is crucial for industrial, commercial, and domestic applications. The standard frequency in Europe’s grid is 50 Hz and it must be as stable as possible; therefore, reliable measurement is essential to ensure that the frequency is within the limits defined in the standard EN 50160:2010. In this article, a method has been introduced for the measurement of the grid frequency through a power line harmonics radiation analysis. An extremely low-frequency magnetometer was developed with the specific purpose of monitoring, in real time, the electromagnetic field produced by electrical installations in the range from 0 to 2.2 kHz. Zero-crossing and Fast Fourier transform algorithms were applied to the output signal to calculate the grid frequency as a non-invasive method. As a final step, data for a complete month (May 2021) were compared with a commercial power quality analyzer connected to the main line to validate the results. The zero-crossing algorithm gave the best result on 3 May 2021, with a coefficient of determination (R²) of 0.9801. Therefore, the indirect measurement of the grid frequency obtained through this analysis satisfactorily fits the grid frequency.

Advances in Solar Energy towards Efficient and Sustainable Energy

Conventional energy resources are not climate sustainable. Currently, engineers and scientists are looking for sustainable energy solutions influenced by climate change. A wide variety of sustainable natural energy resources are available, but they require technical solutions for their implementation. The general trend in energy research is based on renewable resources, amongst which solar energy stands out, being the most mature and widely accepted. In this paper, the current state of the sustainable energy system has been analysed. The main purpose is to provide additional context to assess future scenarios. The study of past contributions allows sustainability planning and increasing the welfare of future society. The aim is to highlight global trends in research on sustainable solar energy from 1995 to 2020 through a bibliometric analysis of 4260 publications. According to their linkages, the analysed articles are distributed in nine clusters: Sustainability assessment, Sustainable energy solutions, Environmental payback time analysis, Sustainability of solar energy in different scenarios, Environmental sustainability, Solar energy applications, Sustainable energy optimisation, Energy transition and Energy and sustainable scenarios. The most repeated keywords are Sustainability, Renewable energy, and Solar energy. Energy research and the exploration of new renewable solar resources are still necessary to meet sustainable energy’s future challenges.

Assessment of Possible Health Risks Potential of Electromagnetic Fields from High Voltage Power Transmission Lines in Akure, Nigeria

The primary objective of this paper is to assess and predict the health risk potential of extremely low-frequency electromagnetic fields (ELF-EMFs) emitted from high voltage power transmission lines (HVPTLs) in Akure metropolis, Nigeria. The assessment was conducted using BENETECH GM3120 Electromagnetic Radiation Tester to measure both the electric field strength and magnetic flux density emitted from 33 kV, 132 kV, 132/330 kV and 330 kV power transmission lines within the metropolis. The data collected were analysed and compared with limiting tolerable values by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines for both occupational and the general public. The comparative result shows that the maximum measured electric field strength and magnetic flux density in this study are lower than 40% of the limiting tolerable values in ICNIRP guidelines. Thus, the result of this study has shown clearly that the emitted ELF-EMFs from HVPTLs is not strong enough to cause any adverse effect health on human. In addition, analysis of the measured data also shows that the emitted ELF-EMFs from the HVPTLs vanish completely at about 60 m radius from the transmission lines, which implies that 60 m radius from transmission lines is an ideal experimental shortest possible distance residential building and people should be from HVPTLs in order to reduce the exposure level of people to EMFs radiations from HVPTLs.