Dealing with Uncertainty for Dissolved Gas Analysis
This chapter presents three approaches to tackling uncertainties occurring in transformer condition assessment, including the ER approach, the hybrid FL and ER approach and the BN approach. Firstly, the methodology of transferring a transformer condition assessment problem into an MADM solution under an ER framework is presented. Three examples for performing transformer condition assessment, using the ER approach, are then illustrated highlighting the potential of the ER approach. The second part of this chapter employs a hybrid approach to the analysis of DGA data based upon several traditional DGA methods. Ideas adapted from the FL theory are applied to soften fault decision boundaries used by the traditional DGA methods. These diagnoses are then considered as pieces of evidence ascertaining to conditions of transformers, which are aggregated using an ER algorithm. The third part is concerned with a BN approach to processing dissolved gases. The methodology of mapping the knowledge in the DGA domain into a BN is described. Finally, an applicable solution to tackle the cases which are not identifiable by the IEEE and IEC code scheme is discussed using the BN approach.
KeywordsFault Diagnosis Fault Type Preference Degree Basic Probability Assignment Transformer Fault
- 1.Mollmann A, Pahlavanpour B (1999) New guidelines for interpretation of dissolved gas analysis in oil-filled transformers. Electra, CIGRE France 186:30–51Google Scholar
- 2.International Electrotechnical Commission (1993) IEC600762-power transformers—part 2: temperature rise. International Electrotechnical Commission Standard, GenevaGoogle Scholar
- 3.International Electrotechnical Commission (1978) IEC60559: interpretation of the analysis of gases in transformers and other oil-filled electrical equipment in service. International Electrotechnical Commission Standard, GenevaGoogle Scholar
- 4.The Institute of Electrical and Electronics Engineers (1994) Transformers Committee of the IEEE Power Engineering Society, IEEE guide for the interpretation of gases generated in oil immersed transformers, IEEE Std. C57.104-1991. The Institute of Electrical and Electronics Engineers, Inc., New YorkGoogle Scholar
- 5.Saaty TL, Vargas LG (1988) The analytic hierarchy process, RWS Publications, Pittsburgh, pp 1–24Google Scholar