Features & Benefits

The VFT system is based on a combination of hydro generator and transformer technologies. It consists of a rotary transformer for continuously controllable phase shift, together with a drive system and control that adjust the angle and speed of the rotary transformer to regulate the power flow through the VFT.

VFT Function

The VFT system provides a means to control power between two grids. The grids need not be synchronous. A common situation is where two grids of the same nominal frequency cannot economically be directly connected with AC lines. The VFT allows controlled power exchange between the grids, while retaining many of the inherent virtues of an AC interconnection.

Low Complexity, Low Maintenance

The simple design of the VFT components, based on established and widely used rotating machinery, ensures its long-term maintainability.

Archives

• Oct 17, 2006 -- GE to auction electric transmission capacity for New York City from proposed New Jersey transmission project (48KB PDF)
• Aug 31, 2006 -- AEP Purchases VFT for US-Mexico grid intertie
• Aug 1, 2006 -- The VFT unit for AEP in Lardeo, TX, featured as a cover story in T&D World.
• Oct 1, 2004 -- World's first VFT Installation at Hydro-Quebec, featured in T&D World.

Detailed Information

• Download the VFT Fact Sheet (337KB PDF)
• VFT Paper presented at CIGRE 2006: "A 100 MW Variable Frequency Transformer (VFT) on the Hydro-Quebec Network - A new technology for connecting asynchronous networks." (285KB PDF)
• VFT Paper presented at PowerGen MiddleEast 2006: "Variable Frequency Transformer: Applications for Secure Inter-regional Power Exchange. (297KB PDF)
• VFT paper presented at the IPST 2005 Conference (244KB PDF)