Copper losses in low voltage distribution circuits are a significant proportion of total energy losses and contribute to higher customer costs and carbon emissions. These losses can be evaluated using network models with customer demand data. This paper considers the under-estimation of copper losses when the spiky characteristics of real customer demands are smoothed by arithmetic mean averaging. This is investigated through simulation and by analysis of measured data. The mean losses in cables and equipment supplying a single dwelling estimated from half-hourly data were found to have significant errors of 40%, compared to calculations using high resolution data. Similar errors were found in estimates of peak thermal loading over a half-hour period, with significant variation between results for each customer. The errors reduce as the demand is aggregated, with mean losses for a group of 22 dwellings under-estimated by 7% using half-hourly data. This paper investigates the relationship between the demand data time resolution and errors in the estimated losses. Recommendations are then provided for the time resolution to be used in future measurements and simulation studies. A linear extrapolation technique is also presented whereby errors due to the use of averaged demand data can be reduced.
Funding
This work was supported by the Engineering and Physical Sciences Research Council (EPSRC), UK [grant number: EP/I031707/1] and voucher 11220756) and by E.ON Technologies (Ratcliffe) Limited, U.K.
History
School
Mechanical, Electrical and Manufacturing Engineering
Research Unit
Centre for Renewable Energy Systems Technology (CREST)
Published in
IEEE Transactions on Power Systems
Volume
30
Issue
3
Pages
1483 - 1491
Citation
URQUHART, A.J. and THOMSON, M., 2014. Impacts of demand data time resolution on estimates of distribution system energy losses. IEEE Transactions on Power Systems, 30 (3), pp. 1483-1491.
This work is made available according to the conditions of the Creative Commons Attribution 3.0 Unported (CC BY 3.0) licence. Full details of this licence are available at: http://creativecommons.org/licenses/by/3.0/
Publication date
2014-09-01
Copyright date
2015
Notes
This work is licensed under a Creative Commons Attribution 3.0 License. For more information, see http://creativecommons.org/licenses/by/3.0/