The Lingbao I HVDC back-to-back station of 360 MW, located on the border between the provinces Henan and Shaanxi in central China, has been in operation since October 2005. The new Lingbao II extension project expands the original asynchronous interconnection by an additional 750 MW and thus increases the possibilities for power sharing between the two networks For this extension, ABB has delivered valves and control system components. The project uses six-inch thyristors rated at 4,500 A, which so far is the highest rating in the world. The control system equipment is ABB's MACH 2, the world's most commonly used control platform for HVDC and FACTS projects.