On the Evolution of Electric Power Networks

Fig. 1.1: One–line diagram of a typical electric power network.

A typical Electric Power Network (EPN) can be divided into three main parts, namely: generation, transmission and distribution, Fig. 1.1. These have had many improvements since their emergence in 1880s (see Fig. 1.2). The first complete electric network (developed in 1882) was based on the DC theory. However, since electrical energy losses are dependent on the value of  R*(I^2) (the resistance times the square of the current), the voltage level has to be high to minimise losses. DC technology had not developed enough to transmit electric power over long distances at that time. The emergence of AC theory (mainly the AC transformer) allowed the transmission of electric energy over long distances, and as a consequence, the use of DC systems was gradually reduced, and for a long time more attention was paid to the developments of AC equipment [Kundur, 1994]. However, advances in power electronics and state solid technology gave the basis for the rise of DC equipment from the 1950’s onward, initially, for high power applications [Kundur, 1994; Li et al., 2010], Fig. 1.2.

Fig. 1.2: The electric power networks evolution (with information from [Moore, 1935; Burns, 1988; Kundur, 1994; Drury, 2009; Li et al, 2010; Lasseter, 2011; Siemens, 2011]).

The Present and Future of Electric Power Networks

At present, large parts of electric power networks are based on AC current and their infrastructure is largely based on the same principles as the first power systems constructed 120 years ago [Peretto, 2010; Palensky and Dietrich, 2011]. However, in Europe and North America, many power transmission systems are reaching their operational limits and older generation plant is nearing the end of its usable life and will need replacing, leaving room for the interconnection of renewable energy. In Asia, Africa, and Central and South America power networks are expanding rapidly [OECD/IEA, 2010].

Additionally, with the introduction of computer systems in the 80’s, loads requiring “Digital Quality” (critical computers systems, data systems, etc.) have increased as well [DTI, 2006]. It is expected that by 2030, electric energy consumption in the world could increase by about 50% [Peretto, 2010]. Other sources forecast that global electricity demand will rise by 65 % from 2014 to 2040. About 85% of the electricity rise will be due to developing economies. Fig. 1.3 outlines the worldwide forecast of electricity demand by sector and by region for 2040 [ExxonMobil, 2016].

Fig. 1.3: a) Worldwide forecast of electricity demand by sector and b) Forecast Electricity Demand by Region (Adapted from [ExxonMobil, 2016]).

References:

Main source: J. Carmona Sanchez. “A Smart Adaptive Load for Power-Frequency Support Applications”. PhD Thesis, Power Conversion Group, The University of Manchester, UK, December 2015. Available at: https://www.escholar.manchester.ac.uk/uk-ac-man-scw:300748

[Burns, 1988] R. W. Burns. “Book Reviews: An Early History of Electricity Supply — The Story of the Electric Light in Victorian Leeds”. Proceedings A of the IEE – Physical Science, Measurement and Instrumentation, Management and Education – Reviews, Vol. 135, No. 6, pp. 362, July 1988.

[DTI, 2006] Department of Trade and Industry  (DTI). “Electrical Energy Storage Systems – A mission to the USA”. Report of a DTI GLOBAL WATCH MISSION, December 2006.

[Drury, 2009] Bill Drury. “Control Techniques Drives and Controls Handbook”. 2nd Edition. Institution of Engineering and Technology (IET): Power and Energy Series 57, 2009.

[ExxonMobil, 2016] Exxon Mobil. "The Outlook for Energy: A View to 2040".  Exxon Mobil Corporation, 2016.

[Kundur, 1994] P. Kundur. “Power System Stability and Control”. First Edition, McGraw–Hill: EPRl Power System Engineering Series, 1994.

[Lasseter, 2011] R.H. Lasseter. “Smart Distribution: Coupled Microgrids,” Proceedings of the IEEE, Vol. 99, No. 6, pp. 1074–1082, June, 2011.

[Li et al., 2010] Fangxing Li; Wei Qiao, Hongbin Sun, Hui Wan, Jianhui Wang, Yan Xia, Zhao Xu, and Pei Zhang. “Smart Transmission Grid: Vision and Framework”. IEEE Transactions on Smart Grid, Vol. 1, No. 2, pp. 168 – 177, September, 2010.

[Moore, 1935] A. E. Moore. “The History and Development of the Integrating Electricity Meter”. Journals of the IEE, Vol. 77, No. 468, pp. 851–859, December 1935.

[OECD/IEA, 2010] © OECD/IEA (Organisation for Economic Co–operation and Development)/( International Energy Agency). “Energy Technology Perspectives 2010: Scenarios and Strategies to 2050”. IEA Publications, July 2010.

[Palensky and Dietrich, 2011] Peter Palensky and Dietmar Dietrich. “Demand Side Management: Demand Response, Intelligent Energy Systems, and Smart Loads”. IEEE CS Transactions on Industrial Informatics, Vol. 7, No. 3, pp. 381–388, August 2011.

[Peretto, 2010] Lorenzo Peretto. “The Role of Measurements in the Smart Grid Era”. IEEE IMS Instrumentation & Measurement Magazine, Vol. 13, No. 3, pp. 22–25, June 2010.

[Siemens, 2011] Siemens. "Siemens Debuts HVDC PLUS with San Francisco’s Trans Bay Cable". Living Energy, The Magazine for International Energy Leadership, Issue 5, July 2011.