The Texas Interconnection is one of the three minor alternating current (AC)

Alternating current

In alternating current the movement of electric charge periodically reverses direction. In direct current , the flow of electric charge is only in one direction....

 power grids in North America. The other two minor interconnections are the Québec Interconnection

Québec Interconnection

The Québec Interconnection is one of the three minor alternating current power grids in North America. The other two minor interconnections are the Texas Interconnection and the Alaska Interconnection...

 and the Alaska Interconnection. The two major interconnections are the Eastern Interconnection

Eastern Interconnection

The Eastern Interconnection is one of the two major alternating current power grids in North America. The other major interconnection is the Western Interconnection...

 and the Western Interconnection

Western Interconnection

The Western Interconnection is one of the two major alternating current power grids in North America. The other major wide area synchronous grid is the Eastern Interconnection...

.

All of the electric utilities in the Texas Interconnection are electrically tied together during normal system conditions and operate at a synchronized frequency operating at an average of 60Hz. The Texas Interconnection covers most of the state of Texas

Texas

Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...

.

Interconnections can be tied to each other via high-voltage direct current

High-voltage direct current

A high-voltage, direct current electric power transmission system uses direct current for the bulk transmission of electrical power, in contrast with the more common alternating current systems. For long-distance transmission, HVDC systems may be less expensive and suffer lower electrical losses...

 power transmission lines (DC ties), or with variable frequency transformer

Variable frequency transformer

A variable frequency transformer is used to transmit electricity between two alternating current domains. The VFT is a relatively recent development...

s (VFTs), which permit a controlled flow of energy while also functionally isolating the independent AC frequencies of each side. The Texas Interconnection is tied to the Eastern Interconnection with two DC ties, and has a DC tie and a VFT to non-NERC systems in Mexico

Mexico

The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

.

On October 13, 2009, the Tres Amigas SuperStation was announced to connect the Eastern, Western and Texas Interconnections via three 5 GW superconductor

Superconductivity

Superconductivity is a phenomenon of exactly zero electrical resistance occurring in certain materials below a characteristic temperature. It was discovered by Heike Kamerlingh Onnes on April 8, 1911 in Leiden. Like ferromagnetism and atomic spectral lines, superconductivity is a quantum...

 links.

See also

• North American Electric Reliability Corporation (NERC)
• Electric Reliability Council of Texas (ERCOT)