Impact of harmonics on the electrical power supply system in an energetic, economic and ecological perspective

Abstract:
A fundamental target for the energy system is to transmit and distribute renewable electrical energy as efficiently as possible [1, 2]. This target is supported by regulatory requirements, among other things, and also reflects the importance of the efficient use of more environmentally friendly technologies. However, at the same time, there are no adequate incentives to improve efficiency in the transmission and distribution of electrical energy in order to reduce energy losses on the way from the supply to the consumer of electrical energy. In particular, more attention needs to be paid to the influence of voltage quality on efficiency and compliance with regulatory requirements [3]. This article takes a closer look at the relevance of harmonics for the energy efficiency of the transmission and distribution of electrical energy. Previous articles have already shown that the avoidance and compensation of harmonics and the resulting reduction in energy losses can be very useful. [4–6] In addition to the lack of incentives to reduce these losses, the missing knowledge about the amount of active power losses caused by harmonics is also a factor. In a previous article, a simulation was used to describe how high the expected additional energy losses would be if a purely sinusoidal supply voltage with a frequency of 50 hertz were used instead of a purely sine-shaped supply voltage [7]. It has not yet been possible to verify these results with real measurements, as it is essential to realize defined different frequencies and heights of the harmonics. After I was able to access a supply system that fulfils the requirements, the previously simulated results could be tested and verified with measurements. The following article presents the measurement and its results, which use a medium-voltage cable route to show how high energy losses due to harmonics are in a similar cable route. These results allow conclusions to be drawn about the relevance of harmonic compensation and the avoidance of energy losses due to harmonics for the energy system. These measurements show that the correlation determined by simulation and presented in previous publications is fundamentally valid. The following article shows that it can be assumed that in Germany, even if the current normative limits for voltage quality are adhered to, active power losses due to harmonics of over 10 GWh occur every year. These active power losses are strongly dependent on the amount and frequency of the harmonics. The following article presents these relationships in more detail and thus contributes to increasing the efficiency of the supply, transmission and distribution of electrical energy by specifically influencing the relevant parameters to avoid active power losses due to harmonics and which economic and ecological impacts are to be expected.