Discussion of Test Results of a Superconductor Synchronous Condenser on a Utility Grid

An 8 MVAR, 13.8 kV superconducting dynamic synchronous condenser (SDSC) prototype was tested on the Tennessee valley authority (TVA) grid for about a year. It shared a bus with an arc furnace. The SDSC was subjected to transient currents and harmonics created by the arc furnace, which consisted of up to 50% negative sequence and 20% zero sequence components. The SDSC operated successfully in the presence of such high transient/harmonic currents. It provided cycle by cycle correction of voltage during operation. The benefits of voltage correction were observed both at the local bus and at the generator bus of a power generation station several miles away. Currently two commercial units rated 12 MVAR, 13.8 kV, are on order by TVA and are scheduled for delivery in December 2006 and March 2007. These units will be skid-mounted for easy installation on site. This paper discusses test results of the prototype unit operation on the grid and describes its potential applications for voltage support in wind farms.