Evaluation, Verification and Operational Supervision of Corona Losses in Sweden

This paper presents the operational supervision of corona losses in the load dispatching system of Svenska Kraftnaumlt, the Swedish National Transmission System Operator. The aim of this supervision is to decrease the total active losses in the 220-400 kV national grid during the winter period, when the corona losses can be high. These losses are calculated from measured quantities on the inservice transmission lines and the voltage dependence of these losses are also taken into account during voltage optimization, when operational mitigation is planned against corona losses. The calculation method used has been verified by a year-long field measurement during 2003-2004. The evaluation of the measured data contains very interesting relations between the weather parameters and the corona losses. Both this measurement and the conclusions are also described in this paper