Directlink is a high voltage direct current transmission line between Mullumbimby and Bungalora in Australia. Directlink is a 59-km bipolar HVDC cable route, implemented for environmental protection reasons as underground cables. The system has three static inverters at each terminal, and three pairs of bipolar transmission cables. Each pair of cables operates at +/- 80 kV and transmits 60 MW, so the total rating of the project is 180 MW. HVDC was chosen for this project for reasons of low environmental impact of the transmission line, and the ability of the IGBT transistor converter stations at each end to accuractely control both real and reactive power. Individual water-cooled IGBT modules are rated at 2.5 kV and 500 A, with multiple units connected in series to achieve the required voltage rating. HVDC or high-voltage, direct current electric power transmission systems contrast with the more common alternating-current systems as a means for the bulk transmission of electrical power. ... The biggest little town in Australia, Mullumbimby, population 5000, is situated in the far north coast region of New South Wales, Australia. ... A static inverter station is the terminal equipment for a high voltage direct current transmission line, in which direct current is converted to three-phase alternating current, and, usually, the reverse. ... The Insulated Gate Bipolar Transistor combines the simple gate drive characteristics of the MOSFET with the high current and low saturation voltage capability of bipolar transistors by combining an isolated gate FET for the control input, and a bipolar power transistor as a switch, in a single device. ...

External Link

ABB Directlink Information Page (http://www.abb.com/GLOBAL/GAD/GAD02181.NSF/viewUNID/C1256D71001E0037C1256A14003FAAB1!OpenDocument)