Experimental investigation and evaluation of drying methods for solid insulation in transformers: A comparative analysis

Abstract

Drying of transformer winding insulation has a direct impact on the dependability and durability of the transformer. The extraction of moisture from paper insulation is a crucial need in the manufacturing process of transformers. Insulation efficiency in transformers can be reduced over time due to the detrimental effects of temperature, moisture, and air, often known as aging. Heat, oxygen, and residual moisture increase the deterioration of cellulose in transformer solid insulation. This might potentially result in premature failure of the transformer. The factory's insulation drying process should ensure that the residual moisture content of bulk solid insulation remains below 0.5 %. The primary aim is to maintain a high degree of polymerization, often ranging from 1000 to 800. This article investigates the factors contributing to the degradation of cellulose insulation and analyzes various techniques that are used in manufacturing plants in Kazakhstan. In addition, this study experimentally investigates the impact of vacuum on the process of moisture evaporation and partial discharge (PD) in analysis with other methods of drying transformers.

Keywords

• Cellulose insulation
• Distribution power system
• Drying methodologies
• Partial discharge
• Power transformers