Electrifying tale
A NEW electronic device, called thyristor-controlled series compensator (TCSC), may "revolutionise the way electricity is delivered to customers globally". The first such system was recently dedicated in the US to the Bonneville Power Administration's (BPA) Slatt substation in Antral Oregon.
According to a report in (Power Engineering International, Vol 2, No 3) of US, the new equipment uses advanced solid state switches to expand the capacity of existing transmission lines, while improving power quality and systems security. The recent dedication marked the successful checkout of the device, which may ultimately save the US Utilities an estimated US $6 billion in construction costs for transmission line expansion. In addition, Utilities will be able to delay costly investments in power plants because the TCSC will accommodate trades of large blocks of power between regions, which was previously impossible.
Concept development for the US $19 million demonstration began in 1990. The project is being co-funded by the Electric Power Research Institute (EPRI), BPA, Portland GE, and General Electric, which designed and manufactured TCSC under license from EPRI.
The Slatt substation was selected as the test site because of its high continuous current (2900A) and high short-circuit current (22,000A) ratings. Staged tests will examine the TCSC's reaction to a range of challenging conditions and results will be monitored to ensure that all aspects of the controller's response are as planned.
BPA executives expect that the cost of the new device will be two to three times that of a conventional series capacitor, which reduces line impedence but does not control subsynchronous resonance or damp system oscillations.