Oil-filled power transformers are some of the most critical components in the distribution network. The grid upgrade cost along with congestion challenges associated with rapid increase in onshore wind energy integration in the distribution system can partly be resolved by dynamic loading of transformers. Distribution transformers can be dynamically rated if the temperatures, especially Top-Oil (TOT) and Hot-Spot (HST) temperatures, are accurately determined. This paper presents industry’s well-proven and established differential equations-based thermoelectric models for transformers. The models are validated, and the performances are compared with the measured temperatures for a 6.8 MVA wind turbine transformer. Moreover, the thermal lifetime utilization of the test transformer is calculated based on its loading and ambient conditions history for the year 2017, using the recommendations of international loading guides. The annual thermal variations and lifetime utilization of test distribution transformer are assessed for an increase in wind energy production in 2017. Based on this analysis, further wind energy integration is facilitated by deferring grid expansion costs related to transformers.
|Title of host publication||Proceedings of 25th International Conference on Electricity Distribution|
|Number of pages||5|
|Publication status||Published - 2019|
|Event||25th International Conference on Electricity Distribution - IFEMA North convention centre, Madrid, Spain|
Duration: 3 Jun 2019 → 6 Jun 2019
|Conference||25th International Conference on Electricity Distribution|
|Location||IFEMA North convention centre|
|Period||03/06/2019 → 06/06/2019|
Kazmi, S. H. H., Holbøll, J., Olesen, T. H., & Sørensen, T. S. (2019). Dynamic thermoelectric modelling of oil-filled transformers for optimized integration of wind power in distribution networks. In Proceedings of 25th International Conference on Electricity Distribution  Cired.