Application of transient line ratings for transmission circuits in a thermally constrained Tasmanian network

The Tasmanian transmission network is owned and operated by Transend Networks Pty Ltd and is connected to mainland Australia through the Basslink DC interconnector. Many of the 220 kV back bone transmission lines are thermally constrained especially when Tasmania is exporting power to the mainland. To mitigate the thermal limitations of the transmission lines, Transend employs short term transient ratings. This paper addresses the practical aspects involved in the application of short term transient ratings and the different schemes that are applied to implement these ratings. Moreover the operation of a scheme has been demonstrated through a network contingency event simulation. Also the paper discusses the field test that has been used to validate the simulation models.