Online dissolved gas analysis sensor

Transcription

1 GAS Guard 8 Online dissolved gas analysis sensor Answers for energy.

2 Dissolved Gas Analysis (DGA) Dissolved gas analysis is the single-most comprehensive tool for transformer condition assessment. The current environment of higher loading on aging transformers, deferred capital expenditures on new equipment and increased service reliability requirements have driven the industry to investigate the use of innovative transformer condition assessment and management tools. Based on the historical installation rates of generator step-up, transmission and large distribution transformers, the average transformer age is 40 years. However, age itself is not a cause of failure. As transformers age, they endure various stresses that can contribute to a variety of failure mechanisms. Appropriate online DGA monitoring and diagnostic tools can help utilities avoid unplanned failures, lower maintenance costs and extend transformer useful life. Transformer GVA addition per year 2

3 Many transformer failures can be prevented through analysis of DGA data in support of the diagnosis of developing abnormal conditions. Gas chromatography (GC) has long been the accepted standard for the measurement of dissolved gas levels in transformer oil. The GAS-Guard 8 provides accurate and repeatable measurement of the eight critical fault gases as well as other significant parameters. The GAS-Guard 8 brings the DGA laboratory to your transformer with its rugged, closedloop gas chromatograph. The GAS-Guard 8 packs this science into a compact package designed to be mounted on or near the subject transformer. Key benefits include: Field-based fully automated DGA requires no manual oil sampling or remote lab testing Accurate and timely DGA results improve ability to protect transformer against fault damage Data generated by the GAS-Guard 8 can be used to support condition-based maintenance programs Time-date stamped test results allow correlation between real events and measured conditions. The Siemens GAS Guard 8 sensor provides a complete online dissolved gas analysis. 3

4 The Siemens GAS-Guard 8 provides accurate and repeatable measurement of eight (8) critical fault gases Graphical representation of GAS-Guard 8 connected to the transformer tank. DGA tolerances of the GAS-Guard 8 Gas Accuracy 1 Repeatability 2 Range 3 Hydrogen H 2 +/- 5% or +/- 2 ppm <2% 2-3,000 ppm Oxygen O 2 +/- 5% or +30 / - 0 ppm <1% 30-5,000 ppm Methane CH 4 +/- 5% or +/- 10 ppm <1% 10-5,000 ppm Carbon Monoxide CO +/- 5% or +/- 3 ppm <1% 3-10,000 ppm Carbon Dioxide CO 2 +/- 5% or +/- 5 ppm <1% 5-30,000 ppm Ethylene C 2 H 4 +/- 5% or +/- 3 ppm <1% 3-5,000 ppm Ethane C 2 H 6 +/- 5% or +/- 5 ppm <1% 5-5,000 ppm Through chromatography, the GAS-Guard 8 generates individual measurements of eight critical fault gases found in transformer oil. Accuracy is commensurate with traditional lab results. The sensor continually collects oil samples as often as every two hours. The GAS-Guard 8 can also measure moisture in the oil, oil temperature and ambient temperature. DGA results and other measurement data are date/time stamped and can thus be correlated to transformer load. Acetylene C 2 H 2 +/- 5% or +/- 1 ppm <2% 1-3,000 ppm NOTES: All specifications are independent of oil temperature and gas pressure level. 1 Percent of ppm - whichever is greater 2 At gas calibration level 3 Gas-in-oil 4

5 Comprehensive data requires powerful analytical tools The software package included with the GAS-Guard 8 sensor allows the user to graphically display continuous gas evolution for each of the eight critical fault gases as well as moisture, load and ambient temperature. Online diagnostic tools The software package also allows the user to trace changes in fault severity over time through dynamic plots created using the Duval Triangle and Rogers Ratios analysis tools. The Duval Triangle (IEC ) provides a diagnostic outcome for combinations of three fault gases. Online DGA data populating diagnostic tools deliver new insights. This displays Rogers Ratios (IEEE PC D11d) and basic gas ratios (IEC ). 5

6 Published by and copyright 2009: Siemens AG Energy Sector Freyeslebenstrasse Erlangen, Germany Siemens Energy, Inc Siemens Road Wendell, NC For more information, please contact: Telephone: +1 (919) Toll-free: +1 (800) Siemens Canada Limited 1550 Appleby Line Burlington, Ontario, Canada L7L 6X7 +1 (905) Order No. E50001-F730-A110-X-4A00 Printed in USA TD F BR All rights reserved. Trademarks mentioned in this document are the property of Siemens AG, its affiliates, or their respective owners. Subject to change without prior notice. The information in this document contains general descriptions of the technical options available, which may not apply in all cases. The required technical options should therefore be specified in the contract.