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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. [ABSTRACT FROM AUTHOR]

Over the past few years, first generation (1G) high temperature superconductor (HTS) wires have been used to demonstrate large-scale prototype devices, including a 5 MW U. S. Navy motor and an 8 MW synchronous condenser. In addition, the fabrication and testing of larger devices (a 36.5 MW motor and a 12 MW synchronous condenser) are currently underway. Although 1G HTS wire will continue to be a workhorse for demonstrating this technology over the next few years, the lower cost potential of second-generation (2G) HTS wire is driving its rapid development and scale-up. In addition to reporting on key material properties of this wire for coil applications, this paper presents thermal cycling data on 2G racetrack coils, showing excellent robustness under conditions of significant thermal strain. A 2G solenoid coil with a 5 cm inner diameter has achieved 1.5 T at 64 K. These results are a major step in confirming the viability of 2G HTS wire in coil applications. [ABSTRACT FROM AUTHOR]

Of particular concern to designers of HTS machines are potential heating effects in the superconducting windings due to AC losses caused by load fluctuations encountered in real-life operating conditions. A 5 MW HTS synchronous prototype ship propulsion motor has been tested extensively under steady-state and dynamic load conditions in the Advanced Test Facility of the Center for Advanced Power Systems at Florida State University. This paper presents results from two tests of rotor heating effects, one employing single frequency torque oscillations and the other more realistic load modeling of sea-states by means of Hardware-in-the-Loop (HIL) real-time simulations. Temperature results from 4 different torque oscillation tests and 12 different sea-state tests provide rotor-heating information, obtained from multiple temperature sensor data within the HTS rotor, and are compared with data obtained from steady-state runs. [ABSTRACT FROM AUTHOR]