Operations

The Basslink HVDC Interconnector connects the 220kV Tasmanian transmission network at George Town Substation with the 500kV Victorian Transmission network at Loy Yang Substation.

The total transmission length between the two substations is 374.7km.

The HVDC Interconnector consists of a monopole with metallic return with a continuous rating of 500MW

Due to the minimum hold on current characteristic of the thyristor based converters the Interconnector has a minimum power flow threshold of 40 MW and the submarine cable requires a 2 minute deionisation time when reversing power flow.

The Interconnector target MW transfer is dispatched from NEMDE via Transmission Network Service Providers every 5 minutes, as well as following power target the Interconnector limits AC system frequency excursions by altering the MW transfer.

The Basslink control system is one of the most advanced control systems for HVDC in the world. It incorporates automatic control and system limitation software that monitors the surrounding ambient temperature for the Basslink equipment to ensure that the equipment works within its safe operating limits. For example, if the ambient temperature exceeds 43˚C in Loy Yang or 33˚C in George Town, the Basslink control system will automatically limit flows on the interconnector in order to protect the link against excessive temperature rise. Once the ambient temperature decreases the Basslink control system will automatically increase flows.