IEEE Power & Energy Magazine - March/April 2014 - 76

history

Deepak Tiku

dc power transmission
mercury-arc to thyristor HVdc valves

"FORTUNATELY, THE TECHNOLogy of employing thyristors for dc
transmission differs more in dimensions than in principles from that of
employing mercury-arc valves."
E.W. Kimbark

Introduction
Direct current (dc) power transmission first came into existence in France
through the contribution of Marcel
Deprez that was showcased in the Paris
Exposition in 1881. In 1882, Deprez
helped Oskar Von Miller (founder of
AEG in Germany) to design long-distance dc transmission to carry 15-kW
power at a voltage of 2,000 V over a
distance of 35 mi (56.3 km) from Miesbach, Germany, at the foothills of the
Alps to the Glaspalast in Munich. The
rise and fall in the use of dc power
transmission in the beginning of the
20th century followed by its reemergence in the early 1950s is quite interesting. Between 1900 and 1950, there
was not a moment when dc systems of
one type or another were not working
or under development. The dc option
for power transmission was never
abandoned, due to the tenacity of a few
men like René Thury, who felt that two
wires were better than three and reactance was an unnecessary burden.
DC was directly generated and
transmitted to load centers. To enhance
dc power transmission capability, Swiss

The "History" article in this issue of IEEE Power & Energy Magazine, authored by
Deepak Tiku, is particularly timely in that it continues the story told in the September/October and November/December 2013 columns. The earlier two-part article
covered the synchronous or rotary converter, an early electromechanical means
to convert alternating current (ac) power to direct current (dc) power for many
needed applications. The rotary converter was invented in the latter years of the
19th century and was widely used during the 20th century. However, beginning in
the 1930s, rotary converters were gradually supplanted by newer technology.
This article discusses that newer technology, beginning with the mercuryarc valve and converter, which was invented in 1901 and progressively improved
such that it enjoyed widespread use by the 1930s. The development of the highvoltage (HV), high-power, mercury-arc valve led to HVdc transmission projects
in a number of countries. The advent of solid-state electronics and the siliconcontrolled rectifier in the 1950s resulted in the development of the thyristor valve
converter that began replacing mercury-arc converters during the 1960s. Today,
the field belongs to the thyristor, and both rotary and mercury-arc converters
have become virtually extinct.
Deepak Tiku was born in Srinagar, India. He earned a B.E. degree in electrical engineering from Maulana Azad College of Technology, Bhopal, India, and
an M.Tech. degree from the Indian Institute of Technology Delhi. From 1984 to
1994, Deepak worked in HVDC Engineering (Power Systems Department) at
National Thermal Power Corporation Limited, now known as NTPC, New Delhi.
He was associated with the execution of the first long-distance HVdc transmission project (1,500 MW ±500 kV) in India. He has been a member/contributor to
various CIGRÉ task forces regarding HVdc thyristor valves. He has authored and
coauthored papers that have been presented or published in various forums. He
is member of the CIGRÉ National Study Committee Group B4 (HVdc Links and
Power Electronics). His interests include the power electronics systems (HVdc,
STATCOM, VSC, MMC) and grid integration of renewables. He is currently working in the NTPC Engineering Services Division, New Delhi.
We are pleased to welcome Deepak Tiku as our guest history author for this
issue of IEEE Power & Energy Magazine.
-Carl Sulzberger
Associate Editor, History

Digital Object Identifier 10.1109/MPE.2013.2293398
Date of publication: 19 February 2014

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