Murraylink is an Australian high voltage direct current electricity transmission link between Berri in South Australia and Red Cliffs in Victoria, connecting the two state electricity grids. The Murraylink consists of two 180-kilometre (110 mi) long bipolar HVDC cables, which for environmental protection reasons are underground, with an operating voltage of 150 kV and a transmission capacity of 220 megawatts. The link operates an "HVDC Light" voltage-sourced converter system, utilising insulated-gate bipolar transistors (IGBT), to convert electricity between alternating current and direct current.
This is believed to be the worlds longest underground transmission system and cost more than 177 million Australian dollars. It was built by TransEnergie Australia, a subsidiary of Hydro-Québec. It was sold to the Australian Pipeline Trust in March 2006 for A$153 million.