Gas Pressure Calculations for Sealed Transformers under Varying Load Conditions

Wang

2022

The 35kV nitrogen sealed transformers are widely used due to its excellent explosion-proof performance. But for higher voltage transformers, the nitrogen solubility under different temperatures and pressures is unknown, which restricts the design of nitrogen layer volume. In this paper, a nitrogen solubility test platform is built. And the nitrogen solubility in insulating oil under different oil temperatures and nitrogen pressures is obtained. Besides, the relationship between pressure, temperature and nitrogen solubility is established, which provides an important basis for transformer design.

Section: Nitrogen Solubility Measurement Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Nitrogen solubility test under different pressures and temperatures for nitrogen-sealed transformers

Wang

2022

“…For the nitrogen blanket transformer, experts and scholars have carried out much research work in the aspects of nitrogen solubility [1][2] , nitrogen layer design [3][4][5] , dissolved gas analysis in oil [6] , and the internal arc fault analysis [7][8] . And the relevant research results have been applied to 35 kV and 66 kV transformers.…”

Section: Introductionmentioning

confidence: 99%

Insulation Test of the Nitrogen Blanket Transformer under Sudden Temperature Drop

et al. 2022

During the transformer operation, it is a common condition that the oil temperature decreases due to sudden rainstorms. Because the nitrogen layer is set to contact the transformer oil in the nitrogen blanket transformer directly, the influence of nitrogen dissolution and precipitation on the insulation characteristics is very important. In this paper, the effect of nitrogen is analyzed. First, the electrical field under the nitrogen bubble effect is simulated. Second, the sudden temperature drop situation is developed based on the reformed transformer. Last, the insulation changes are analyzed by partial discharge data. According to the analysis, the sudden temperature drop won’t influence the transformer operation.

“…For the nitrogen blanket transformer, experts and scholars have carried out much research work in the aspects of nitrogen solubility [1][2] , nitrogen layer design [3][4][5] , dissolved gas analysis in oil [6] , etc. Moreover, the relevant research results have been applied to 35 kV and 66 kV transformers.…”

Section: Introductionmentioning

confidence: 99%

Pressure changes of nitrogen blanket transformers under internal short circuit faults

et al. 2022

The root cause of the transformer fire is an oil tank crack caused by an internal short circuit fault. The gas layer of the nitrogen blanket transformer helps buffer the pressure change caused by the internal short-circuit fault. Moreover, the pressure change simulation is the basis for the configuration of non-electrical protection. This paper analyzes the relationship between the energy and pressure source of the internal short-circuit fault. Based on finite element simulation, the internal pressure transfer model of the transformer is built, and the pressure of the oil tank is obtained. By comparing with the pressure of conventional transformer, the excellent explosion-proof performance of nitrogen blanket transformer is verified.