Network

Large, spatially adjacent and electrically connected power grids , which include a large number of power plants and consumers, are referred to as interconnected networks . They represent the opposite pole to the spatially separated and smaller island networks .

An interconnected network has advantages such as:

• the local difference between the supply and demand of instantaneous power can be better balanced within the network; less control power has to be kept in relation to the total installed power
• the energy system becomes more stable because a certain control strategy is followed and over- and under-capacities can be absorbed or evened out
• By exchanging power, load fluctuations can be better compensated for in the short term than just by regulating the power plants and
• the reliability of the network is increased.

The disadvantage is the increased effort for the coordination and regulation of the entire network.

General

Electrical interconnections are with three-phase AC operated. These are characterized by the fact that all producers in the connected power grids are synchronized, i.e. H. work with identical mains frequency and defined phase position . This means that they can be connected together electrically directly. If the frequency were not exactly the same for all generators, there would be greater equalizing currents between the individual generators, the effects of which are comparable to electrical short circuits .

If power grids cannot be synchronized with one another, for example because the necessary control technology in the power plants and in the control level in the form of data networks is missing, the electrical energy exchange between these power grids can only be carried out to a small extent and with great effort, for example through power electronics such as high-voltage direct current transmission ( HVDC) or through HVDC short couplings . Further possibilities on a smaller scale are the use of converters or frequency converters , consisting of a mechanical combination of two rotating electrical machines .

In Germany, the north-south line built in the 1920s was one of the first steps towards an integrated network. During the Second World War , RWE began building high-voltage lines to Belgium, the Netherlands and France, thus creating the first parts for what would later become the European network .

Africa

• South-Western Mediterranean Block (SWMB): The power grids of Algeria, Morocco and Tunisia are part of the SWMB network. The SWMB since 1997 with the European grid system synchronized, as a first phase current - submarine cables (400 kV , 700 MW ) from Spain was transferred. Another submarine cable with the same output followed in 2006, so that the transmission capacity between Spain and Morocco is now 1,400 MW. (see also COMELEC )

• West African Power Pool (WAPP): The aim of the WAPP is to unite the power grids of the 15 countries in Western Africa that have come together in ECOWAS . As of June 2015, however, only the power grids of a few countries are linked. In addition to expanding electricity generation, the construction of transmission lines is therefore a high priority.

• Southern African Power Pool (SAPP): The network of the SAPP includes the power grids of 9 of the 12 countries of southern Africa that have come together in the SAPP.

America

Networks in North America

North America

There are four interconnected networks in the USA and Canada, all of which operate with the same network frequency of 60  Hz . They are not synchronized with each other, but connected to each other by HVDC.

• Eastern Interconnection
• Western interconnection
• Québec Interconnection , (see also Hydro-Québec )
• Texas Interconnection

In Mexico, the state-owned CFE operates a national network. Baja California Sur is currently (June 2015) disconnected from the rest of Mexico. There are connections to the Western Interconnection (synchronized) as well as to the Texas Interconnection (asynchronous). In addition, Mexico is connected to the Central American SIEPAC .

Middle and South America

In Central America there is SIEPAC , a network between 6 countries.

The countries of South America either operate national networks such as B. Brazil, or there are several unconnected power grids in one country such as B. in Chile:

• Brazil: The Sistema Interligado Nacional (SIN) is operated by the Operador Nacional do Sistema Elétrico (ONS). With the exception of some island networks in the Amazon region, the SIN covers all of Brazil.
• Chile: see Verbundnetz (Chile)

Asia

Interconnected networks in Japan

China

There are various interconnected networks in China. Operators are e.g. B. State Grid Corporation and China Southern Power Grid .

India

In India there is a nationwide interconnected network operated by the Power Grid Corporation of India under the motto One Nation, One Grid, One frequency . Originally there were five regional networks that were initially connected to each other by HVDC. Starting in the 1990s, the networks were then gradually synchronized. In December 2013, the last regional network was merged with the nationwide network.

Japan

In Japan there is a western and an eastern interconnected network. The special thing about Japan is that the eastern network works with 50  Hz and the western one with 60  Hz . The two interconnected networks are linked by HVDC transmission. There are ten electricity suppliers who are area monopoly - see Denki Jigyō Rengōkai .

middle East

• GCC Interconnection Authority (GCCIA): The six states of the GCC founded the GCCIA in 2001 to connect their national power grids. However, synchronization is not possible because the power grid in Saudi Arabia works with 60 Hz and the networks of the other countries with 50 Hz. For this reason, the first step in 2011 was to connect the networks of Bahrain, Qatar and Kuwait to the network in Saudi Arabia via HVDC. With a peak load of 93,781 MW, the installed capacity could be reduced from 105,781 MW to 100,726 MW. H. the reserve capacity to be kept was almost halved from 12,085 to 6,945 MW.

• South-Eastern Mediterranean Block (SEMB): The SEMB's interconnected grid includes the power grids of Egypt, Jordan, Lebanon, Libya and Syria.

Australia

In Australia there is the National Electricity Market (NEM) network and, due to the distance and low population density, numerous island networks. The NEM covers parts of the states of New South Wales , Queensland , South Australia , Tasmania and Victoria . In the state of Western Australia , the South West Interconnected Network (SWIN) is operated by Western Power .

Europe

→ Main article : European network system

Interconnected networks in Europe

In Europe there are the following interconnected networks, all of which work with 50 Hz:

• ATSOI , Verbundnetz in Ireland (see also EirGrid )
• European network system (EV) (see also UCTE and ENTSO-E )
• IPS / UPS , network in Russia and some neighboring countries
• NORDEL , network in Scandinavia
• UKTSOA , interconnected network in Great Britain

The following connections exist between these networks:

• NORDEL - IPS / UPS: HVDC close coupling Wyborg
• EV - NORDEL: several submarine cables, e.g. B. NorNed
• EV - UKTSOA: HVDC Cross-Channel and BritNed
• UKTSOA - ATSOI: East – West Interconnector

Indicators

The following table provides an overview of the most important key figures for some interconnected networks:

Network	Installed power (GW)	Peak load (GW)	Annual consumption (TWh)	population	Transmission system operator	countries
ATSOI / UKTSOA	85	66	400	65
IPS / UPS	337	215	1,285	280
NORDEL	92.8	66	402.6	24
SAPP	58.4					9
SEMB	35.3	29.2	142.6			5
SWMB	15.9	11.6	55.6			3
EV	587	405	2,611	450	33	23

swell

• European, CIS and Mediterranean Interconnection: State of Play 2006; 3rd SYSTINT report; Ref: 2007-030-0428. (PDF 1.34 MB) EURELECTRIC , January 2007, accessed on June 15, 2015 (English). 

Individual evidence

1. ↑ Chronicle 1931-1945. RWE , accessed on June 15, 2015 . 
2. ↑ ^{a b} EURELECTRIC, 2007, pp. 27-28
3. ↑ MedRing: Building an interconnected system across three continents. Global Transmission Report, March 2, 2009, accessed June 15, 2015 . 
4. ^ South Asia Regional Workshop on Competitive Electricity Markets Colombo, SriLanka: March 18, 2014. (PDF 5.8 MB, pp. 8, 17, 28–29, 36) www.usea.org, accessed June 22, 2015 ( English). 
5. ^ West Africa Power Pool. Global Energy Network Institute (GENI), accessed June 22, 2015 . 
6. ↑ Estiman integración de BCS al sistema eléctrico… en 2018. www.elfinanciero.com.mx, September 18, 2014, accessed on June 15, 2015 (Spanish). 
7. ↑ Transamerica Interconnections. tdworld.com, December 1, 2011, accessed June 15, 2015 . 
8. ^ O que é o SIN - Sistema Interligado Nacional. (No longer available online.) Operador Nacional do Sistema Elétrico (ONS), archived from the original on April 19, 2015 ; Retrieved June 15, 2015 (Portuguese). Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.   
9. ^ O ONS. (No longer available online.) ONS, archived from the original on June 27, 2015 ; Retrieved June 15, 2015 (Portuguese). Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.   
10. ^ Sketch map of national power networks. GENI, accessed June 15, 2015 . 
11. ^ One Nation-One Grid. Power Grid Corporation of India , accessed June 22, 2015 . 
12. ^ Power Grid Regions of India. www.mapsofindia.com, accessed June 22, 2015 . 
13. ^ Ten Electric Power Companies as Responsible Suppliers of Electricity. Denki Jigyō Rengōkai (FEPC), accessed June 15, 2015 . 
14. ^ Company Profile. (No longer available online.) GCCIA, archived from the original on May 21, 2015 ; accessed on June 15, 2015 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.   
15. ^ GCCIA Phase 1 Making interconnection in the Gulf a reality. (PDF 4.5 MB, p. 2) (No longer available online.) Alstom , archived from the original on January 28, 2015 ; accessed on June 15, 2015 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.   
16. ^ GCC interconnection grid. (No longer available online.) GCCIA, p. 14 , formerly in the original ; accessed on June 15, 2015 .  ( Page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.    
17. ↑ ^{a b} Eurelectric, 2007, pp. 26-27
18. ↑ About Us. (No longer available online.) Www.gridaustralia.com.au, archived from the original on December 17, 2014 ; accessed on June 15, 2015 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.   
19. ^ NEM: The National Electricity Market. www.originenergy.com.au, accessed June 15, 2015 (English). 
20. ↑ About us. Western Power, accessed June 15, 2015 . 
21. ↑ Eurelectric pp. 14-17
22. ↑ ANNUAL REPORT 2014. (PDF 33.6 MB, p. 4 (3), 40 (39), 73 (72)) (No longer available online.) SAPP, archived from the original on June 18, 2015 ; accessed on June 18, 2015 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.   
23. ↑ Eurelectric, 2007, pp. 11-13

Web links

• Map of interconnected networks from Open Infrastructure Map. Retrieved March 7, 2018 .