Welsh HVDC Converter Station is an

HVDC A high-voltage direct current (HVDC) electric power transmission system (also called a power superhighway or an electrical superhighway) uses direct current (DC) for electric power transmission, in contrast with the more common alternating curren ...

back-to-back station connected between the

J. Robert Welsh Power Plant J. Robert Welsh Power Plant is a 1-gigawatt (1,056 MW), coal power plant located east of Pittsburg, Texas in Titus County, Texas. It is operated by SWEPCO, a subsidiary of AEP. The plant is named after J. Robert Welsh, a former President and B ...

and the

Oncor Electric Delivery Oncor Electric Delivery Company is the largest transmission and distribution electric utility in the state of Texas and the 5th largest utility company in the US. Their service territory includes east, west and north-central Texas, including Dall ...

substation at the

Monticello Steam Electric Station The Monticello Steam Electric Station was a 1.8-gigawatt (1,880 MW) coal-fired power plant located southwest of Mount Pleasant, Texas in Titus County, Texas. It operated from 1974 to 2018. History Monticello had three units. Unit 1 began operat ...

in Titus County, northeastern

Texas Texas (, ; Spanish language, Spanish: ''Texas'', ''Tejas'') is a state in the South Central United States, South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2 ...

. It went in service in 1995 and it can transfer a maximum power of 600 megawatts. It was built for AEP Southwestern Electric Power Company (SWEPCO) in 1995 by

Siemens Siemens AG ( ) is a German multinational conglomerate corporation and the largest industrial manufacturing company in Europe headquartered in Munich with branch offices abroad. The principal divisions of the corporation are ''Industry'', '' ...

and operates at 170 kV DC. It is tied to the 345 kV 60 Hz AC grids of the

ERCOT The Electric Reliability Council of Texas, Inc. (ERCOT) is an American organization that operates Texas's electrical grid, the Texas Interconnection, which supplies power to more than 25 million Texas customers and represents 90 percent of the sta ...

and SPP. ERCOT documents refer to this link as the "East DC Tie". It uses electrically triggered

thyristor A thyristor () is a solid-state semiconductor device with four layers of alternating P- and N-type materials used for high-power applications. It acts exclusively as a bistable switch (or a latch), conducting when the gate receives a current ...

s, each with a rating of 5.5 kV.

References

Energy infrastructure completed in 1998 Energy infrastructure in Texas {{Texas-struct-stub