American Superconductor has announced the successful operation and testing of its advanced prototype SuperVAR synchronous condenser, (see MPS, June 2004 for more details) generating 8 MVAR of reactive power on a continuous basis when synchronised with the FirstEnergy power transmission grid in Ohio in the USA.

This design is an upgrade of an earlier model that had been installed in January 2004 on the Tennessee Valley Authority’s grid. TVA has committed to purchasing five SuperVAR synchronous condensers, conditional on the successful operation and testing of this prototype.

Based on results from the TVA prototype, the design was improved to increase the robustness of the machine and to further reduce the cost of its manufacture. The new version has now been successfully tested on the power grid at Ideal Electric in Mansfield, Ohio. Ideal Electric, a subcontractor to American Superconductor, provided the conventional components for the machine.

Synchronous condensers act as reactive power “shock absorbers” for the grid, dynamically generating or absorbing reactive power depending on the voltage level of the transmission system. They are intended to respond quickly enough to protect the grid from voltage sags and surges.