Sizing Transformer Considering Transformer Thermal Limits and Wind Farm Wake Effect

• Compared to the wind farm itself, wind farm transformers are often oversized with regard to their capacity and lifetime. One of the reasons is that power transformers are normally sized at planning stage according to their rated power limits instead of their thermal limits. The thermal limits are usually considered only in operation. In this paper, a new method is proposed to take thermal limits into account and size the wind farm transformer at planning stage based on the expected life of the transformer insulation. An analytical model of wind turbine wakes loss is combined with the transformer thermal model to calculate the expected lifetime of the transformer insulation more accurately. Different from the previous approaches, the proposed method considers both the wake effect and the time-varying ambient temperature. Results show that compared to using the constant temperature and predicted power output without wake loss consideration, the expected lifetime of transformer insulation evaluated after involving these two factors is closer to the result evaluated based on the measured wind power.

Subject headings

NATURVETENSKAP  -- Data- och informationsvetenskap -- Programvaruteknik (hsv//swe)

NATURAL SCIENCES  -- Computer and Information Sciences -- Software Engineering (hsv//eng)

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik -- Annan elektroteknik och elektronik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering -- Other Electrical Engineering, Electronic Engineering, Information Engineering (hsv//eng)

Keyword

ambient temperature

transformer size

wake effect

wind power

Electric power system interconnection

Electric utilities

Power transformers

Temperature

Thermal insulation

Wakes

Expected lifetime

Planning stages

Power limit

Thermal limits

Thermal winds

Transformer insulation

Wake loss

Wind farm

Publication and Content Type

ref (subject category)

kon (subject category)