M. Candas, O. S. Meric
2. Development of the UHV Transmission System in the World
The studies related to UHV transmission technologies began in Russia, Japan, the United States of America
(USA), Italy, Canada, and Brazil in 1960s and 1970s. In addition, China started UHVAC transmission projects
in 1986. China, India and South Africa have been still studying on UHVDC transmission.
The first UHV studies in Russia (The Former USSR) were appeared in 1970s. At the beginning of the 1990s,
1150 kV AC transmission lines (2362 km) were established but later voltage level was decreased to 500 kV. In
addition 1090 km and ±750 kV DC transmission lines were built in the beginning of 1980s.
In Japan the studies about UHV transmission technology started in 1973 [6]. Tokyo Electric Power Company
(TEPCO) constructed to 1100 kV transmission lines which aim to connect power station to crowded coun-
tries/regions in 1993 and also in 1999 power sources on the Pacific Ocean were connected with the transmission
lines. In 2000s those routes were operated at 550 kV although they were constructed at 1100 kV which could
provide 3 to 4 times greater capacity [7].
UHV transmission studies started in 1967 in the USA. Transmitting bulk power, developing system stability
and reducing environment impacts were aimed by using new transmission systems. The facilities which per-
formed UHV studies were General Electric Company (GE), the Electric Power Research Institute (EPRI), the
American Electric Power Company (AEP), and the Bonneville Power Administration (BPA). In recent years, it
could be said that the U.S. has little activity on UHV transmission technologies as compared with China [5].
The CU Powerline and Square Butte Projects which were included North American grid HVDC projects were
studied for delivering the power among the cities such as From North Dakota to Minneapolis, Minnesota and
Duluth, Minnesota, respectively.
Two projects called Neptune and Trans Bay Cable were constructed by Siemens Company. Neptune project
proposed to link Long Island and New Jersey transfers 660 MW over 65 miles. The second project, a 53 miles
400 MW Trans Bay Cable carries bulk power into San Francisco Bay. HV DC and AC transmission projects are
Illinois River Project, Rock Island Clean Line LLC Project and the other transmission line projects are The
Plains and Eastern Clean Line Transmission Project, The Centennial West Clean Transmission Line Project and
The Grain Belt Express Clean Line Transmission Project which are planned to be done [8].
In Italy, UHV studies were done in the laboratories and testing stations that A 700 kV generator was used in
1970s.
In Canada, at the HV laboratory of Hydro-Que’bec Institute of Research (IREQ) studies related to voltages up
to 1500 kV were performed. Test studies such as Corona, electric field and ion current performance were re-
searched in the range of ±600 kV to 1200 kV DC and 1500 kV AC. Also at Magdalen Islands, test line was built
vibration performance test of 6 and 12 conductor bundles and development of spacer dampers [6]. The Project,
550 miles and 3.8 GW of capacity, called The Nelson River in Canada links to hydroelectric sources which are
located in Northern Manitoba to population centers in Southern Manitoba. Between 1990 and 1992, The Que-
bec-New England Project, have over 930 miles and 2 GW of capacity, was instructed from Hudson Bay (in
Quebec) to Massachusetts (near Boston) [8].
FACTS, a technology that enforces the weak AC grids and stabilizes AC transmission to longer distances, is
the world’s biggest project in India (at Purnea and Gorakhpur). Hydropower from Bhutan over long distances
are achieved by this Project [9]. India is establishing lines with ultrahigh voltages of ±800 kV. Nowadays India
has still been studying on the world’s the first ultrahigh voltage power transmission lines at 1200 kV with par-
ticipants such as Bharat Heavy Electricals Ltd, Vijai Electricals Ltd, Crompton Greaves, Larsen & Toubro, Sie-
mens, Alstom India, KEC International, Supreme & Co [10].
In Brazil, transmitting the bulk power from Amazon Basin to the load centers at far distances was required
using transmission lines above 1000 kV. Since 1984, Brazil has used to the world’s highest voltage and capacity
system called The Itaipu transmission line at ±600 kV [6]. In 2014, 2400 km HVDC link was instructed in Bra-
zil. It is the world’s longest link for carrying 3150 MW of power in the northwest to Sao Paulo [11]. In 2014, a
consortium led by SGCC won a 30-year concession to build and operate a 2000-km (1240-mile), 800 kV UHV
line in Brazil. The transmission system will carry power from the Belo Monte dam in northern Brazil to the ma-
jor consumption centers in the southeast [12].
China is a leader developing country for UHV technologies in the World. The largest number of HVDC links
are available in China. Because of faster developing industries, demand of power generation and power trans-
mission is increasing. Due to prevent high energy losses, 800 kV - 1100 kV UHDC and 1000 kV UHVAC vol-
