Technical and Economic Evaluation of Class F and Class H Insulation in Dry-Type Transformers

Dry-type transformers are integral components in electrical distribution and power systems, providing reliable and efficient energy conversion in various applications. Different insulation classes significantly influence the performance of these transformers. This study compares the F and H insulation classes of dry-type transformers, commonly used in distribution and power systems. These insulation classes differ in terms of performance, cost, and operational characteristics. The analysis focuses on the advantages, economic efficiency, load losses, core losses, and temperature resistance of both classes. The findings show that F-class transformers, which can withstand temperatures up to 155 degrees C and have an average winding temperature rise of 100 degrees C, are cheaper to make and have lower load losses than H-class transformers. This makes F-class transformers particularly suitable for applications prioritizing cost efficiency and reduced energy losses. On the other hand, H-class transformers can handle higher temperatures. They have a maximum temperature resistance of 180 degrees C and an average winding temperature rise of 125 degrees C. This makes them perfect for applications that need to work with high loads for a long time in hot places. The findings indicate significant differences between the two classes in terms of both cost and performance, offering valuable insights for transformer designers to optimize the design.