Overview

The theoretical documentation provides a slightly more in-depth review of the workings of the thermal transformer model. On the following pages more information can be found:

• Transformer definition: General introduction to transformers.
• Model description: introduction to the thermal modelling of transformers and the equations used in the package.
• Thermal limits: definitions of thermal limits as prescribed by the loading guide.
• Model input: Detailed descriptions of all the transformer specifications needed for thermal modelling.
• Hot-spot factor calibration: method for determining the hot-spot factor when unknown.
• Potential model improvements: Ideas for increasing model accuracy that have not yet been implemented.

Relevant standards:

• IEC 60076-1: Power transformers - General;
• IEC 60076-2: Power transformers - Temperature rise for liquid-immersed transformers;
• IEC 60076-7: Power transformers - Loading guide for mineral-oil-immersed power transformers;
• IEC 60214: On-load tap-changers;
• IEC 60137: Insulated bushings for alternating voltages above 1000 V.