Dynamic thermal rating and active control for improved distribution network utilisation

Currently, distribution network operators face a number of challenges such as load growth, the proliferation of distributed generation (DG) and ageing infrastructure. This is drawing attention to dynamic thermal rating and coordinated distributed generation output control techniques which will allow the increased utilisation of power system assets to be realised. The work described in this paper was carried out in the UK as part of a collaborative project aiming to realise the "Active control of distributed generators based on component thermal properties". In 2009 a prototype thermal control system was installed in open loop mode on a section of \´Scottish Power Energy Networks\´ distribution network. In this system electrical and environmental parameters are measured locally for components by a series of protection relays. This information is sent to a substation PC which hosts thermal state estimation and DG output control algorithms for wide area network power flow control. The protection relays also provide auxiliary functionality to calculate the dynamic thermal rating of local components and to trip DG in case power outputs are not reduced on command by the thermal control system.