THE INFLUENCE OF MOISTURE, AIR AND OIL-TYPE ON THE AGEING OF SOLID INSULATION IN TRANSFORMERS

Transcription

1 THE INFLUENCE OF MOISTURE, AIR AND OIL-TYPE ON THE AGEING OF SOLID INSULATION IN TRANSFORMERS Siemens AG, PTD T Höhlein / Heinzig IEEE Committee Meeting, Jackson (MS) March Foil 1

2 Ageing Factors & Ageing Mechanisms Primary Ageing Factors Feedback Air Moisture Ageing Products Acids + Temperature Oil + Paper Ageing Sludge + Electrical Stress Moisture Contamination Siemens AG, PTD T Höhlein / Heinzig IEEE Committee Meeting, Jackson (MS) March Foil 2

3 Ageing of Paper DP = 800 Power Transmission and Distribution DP = 200 Siemens AG, PTD T Höhlein / Heinzig IEEE Committee Meeting, Jackson (MS) March Foil 3

4 Ageing of Oil Oxidation processes lead to sludge formation with noninhibited oils at normal operating service temperatures GSU Transformer Manufacturing Year 1996, Picture 2002 Siemens AG, PTD T Höhlein / Heinzig IEEE Committee Meeting, Jackson (MS) March Foil 4

5 WHAT DO WE KNOW NOW? ROLE OF CHEMICAL ENVIRONMENT ON THE AGEING PROCESSES AT TRANSFORMER SERVICE TEMPERATURES ROLE OF MOISTURE Siemens AG, PTD T Höhlein / Heinzig IEEE Committee Meeting, Jackson (MS) March Foil 5

6 Role of Moisture Development of DP with time at different starting moisture contents at 95 C. 1,2 1 1% moisture DP/DPo 0,8 4% 0,6 moisture 0,4 10% 0,2 moisture 0 Additional moisture ingress Time (months) Siemens AG, PTD T Höhlein / Heinzig IEEE Committee Meeting, Jackson (MS) March Foil 6

7 WHAT DO WE KNOW NOW? ROLE OF CHEMICAL ENVIRONMENT ON THE AGEING PROCESSES AT TRANSFORMER SERVICE TEMPERATURES ROLE OF MOISTURE & AIR Siemens AG, PTD T Höhlein / Heinzig IEEE Committee Meeting, Jackson (MS) March Foil 7

8 Power Transmission and Distribution Ageing of Kraft Paper Influence of Air or/and Moisture Thermal Behaviour of Kraft Paper under the Influence of Air and Moisture at 115 C 1200 Moisture + Air Air, no Moisture 1000 Moisture, no Air no Moisture, no Air 800 DP Time (Months) Siemens AG, PTD T Höhlein / Heinzig IEEE Committee Meeting, Jackson (MS) March Foil 8

9 Ageing of Solid Transformer Ageing Insulation of Paper Comparison Thermally Stabilized Paper & Kraft Paper Thermal Behaviour of Kraft and Thermostabilized Paper under the Influence of Air and Moisture at 115 C Thermally Stabilized Paper DP Moisture + Air Air, no Moisture Moisture, no Air no Moisture, no Air Moisture + Air Air, no Moisture Moisture, no Air no Moisture, no Air Time (Months) Kraft Paper Siemens AG, PTD T Höhlein / Heinzig IEEE Committee Meeting, Jackson (MS) March Foil 9

10 Influence of the Insulation Fluid Development of DP with time at 115 C in Midel 7131 Power Transmission and Distribution Thermally Stabilized Paper Moisture + Air Air, no Moisture Moisture + Air Air, no Moisture DP Kraft Paper Time (months) Siemens AG, PTD T Höhlein / Heinzig IEEE Committee Meeting, Jackson (MS) March Foil 10

11 Influence of the Insulation Fluid 0,003 1/DP 0,0025 0,002 0,0015 0,001 0, Time (Months) Non inhibited oil, air Inhibited oil, air Non inhibited oil, absence of air Progress of Ageing (DP), Effect of Air, Inhibitor (85 C, 4% moisture in pressboard) Siemens AG, PTD T Höhlein / Heinzig IEEE Committee Meeting, Jackson (MS) March Foil 11

12 Summary Humidity in the solid material and contact of Oil to the Air accelerate the ageing process The primary moisture content determines the slope of aging especially in the first time Thermally Stabilized Paper shows a better aging behavior than Kraft Paper under the influence of Humidity and/or Air The influence of primary Humidity inside Paper is lower in Ester-Fluids than in Mineral oil due to the better moisture absorbing behavior of the Ester-Fluid Inhibited Oil shows lower ageing of the solid insulation under the influence of air than non-inhibited oil Further information see report of CIGRE Task-Force TF D Paper Ageing Paris Session 2004 Convener: Lars Lundgaard Siemens AG, PTD T Höhlein / Heinzig IEEE Committee Meeting, Jackson (MS) March Foil 12

13 Thank You For Your Attention Siemens AG, PTD T Höhlein / Heinzig IEEE Committee Meeting, Jackson (MS) March Foil 13