Fig. 1. Cumulative number of power transformers andDGA sampling
Fig. 2. Distribution of DGA results
Fig. 3. Distribution of transformer with DGA results
Fig. 4. DGA alarm rate related to the age of powertransformers
Fig. 5. Weibull distribution of power transformers
Fig. 6. Failure rate of power transformers
Fig. 7. Alarm rate of H2 & C2H2 due to the aging oftransformers
Fig. 8. Alarm rate of C2H4 & CH4 due to the aging oftransformers
Fig. 9. Alarm rate of C2H6 & TCG due to the aging oftransformers
Fig. 10. Transformers with the GOST type oil preservationsystem
Fig. 11. DGA alarm as oil conservation systems
Fig. 12. DGA alarm gases of transformers with the GOSTtype oil preservation system
Fig. 13. Alarm rate of CO & CO2 due to the aging oftransformers
Table 1. DP in paper from three aged and four failed transformers
References
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