Mathieu Guertin Director Europe, Russia and Africa Morgan Schaffer Inc. Canada A cost effective strategy for smart grid technology adoption
Why protecting assets? Cost of fault: $52 MILLIONS!!! Easy ROI calculations for transformer dissolved gas monitoring http://www.cbc.ca/money/story/2010/07/07/alcan-explosion.html http://ca.news.finance.yahoo.com/s/14102010/2/biz-finance-quebec-aluminumsmelter-explosion-cost-rio-tinto-alcan.html
Combustible Gas Generation rates 3 key learnings
DGA Understanding process and operations jar Sampling point syringe Sampling techniques & location Packaging & handling Transportation Sample preparation Gas extraction Gas separation and measurement Multiple and varied steps Hard to control variables Multiples operators along the complet analysis process
Your DGA results: Accurate or not? Every Laboratory should be able to demonstrate their precision and accuracy, if this is not possible or by any reason unknown, the below chart is recommended to use as a guide of IEC/CIGRE laboratories, from roundrobin tests using DGA standards. Medium gas concentrations Low gas concentrations Best lab ±3% ±22% Average ±15% ±30% Worst Lab ±65% ±64% IEEE August 2005, M. Duval, J. Dukarm, Improving the reliability of transformer in gas-in-oil diagnosis
Your DGA results: Accurate or not? Diagnostic reliability is affected by the accuracy of the DGA measurement results CIGRE result for Round Robin Test (RRT) at low concentration levels.. Results of individual laboratories x prepared DGA standard value () IEEE August 2005, M. Duval, J. Dukarm, Improving the reliability of transformer in gas-in-oil diagnosis +/- 15% variation limit of absolute values
DGA as a tool From Information to Action
Diagnosing transformer condition A good rule is: Never make a decision based only on a ratio if either of the two gases used in a ratio is less than 10 times the amount the gas chromatograph can detect FIST 03-30, USA Bureau of reclamation
Diagnosing transformer condition TDG (Total Dissolved Gases) expressed in % to 1.000.000ppm, i.e. in the picture TRN1 we see 7%, meaning there is a total of 70.000 ppm of gases (all the gases) TDCG (Total Dissolved Combustible Gases) all the gases except N2, O2 and CO2, also in % to 1.000.000ppm, that s why we see 0% (less than 1ppm, as almost all the gases are N2, O2 and CO2) THCG (Total Headspace Combustible Gases) are the gases on the headspace at the transformers (especially in sealed transformers with N2 blanket) as the gases dissolved in the oil are in equilibrium with the headspace, we calculate, based on the Ostwald coefficient, each gas at the headspace level.
Diagnosing transformer condition 1 The Duval Triangle method, like any other DGA diagnostic method, should be applied only when there is some suspicion of a fault, based on an increase in combustible gas or some other suspicious symptom. The diagnostic method itself is not a means of fault detection. Because of the relative inaccuracy of gas-in-oil concentration measurements at low concentrations, DGA diagnostic methods, including the Duval Triangle, should not be applied unless the gas concentrations are well above the detection limit. If reasonably stable concentrations of the gases were present before the onset of the suspected fault, it is advisable to subtract out the background concentrations, provided that the differences are large enough for interpretation. The diagnosis should be based on recently-formed gas if possible, and including pre-fault gas in the diagnostic calculations can lead to misleading results 2. 1 PPMreport, Morgan Schaffer Myrkos s operating system 2 http://www.deltaxresearch.com/triangle.htm
Diagnosing transformer condition Rogers used these relationships and determined that if a certain ratio existed, then a specific temperature had been reached. By comparing a large number of transformers with similar gas ratios and data found when the transformers were examined, Rogers could then say that certain faults were present. Like the Key Gas Analysis above, this method is not a sure thing and is only an additional tool to use in analyzing transformer problems. FIST 03-30, USA Bureau of reclamation
Summary of gases used by the diagnostics tools IEEE test: Duval test: Rogers test: Doerneburg CO2/CO H2 CH4 C2H2 C2H4 C2H6 CO CO2 CH4 C2H2 C2H4 H2 CH4 C2H2 C2H4 C2H6 H2 CH4 C2H2 C2H4 C2H6 CO CO2 Standards tests support the decision making process 1) What is the current situation of the transformer? 2) What is the nature and severity of the fault?
Operationalizing and integrating And being SMART about it
Transformers monitoring: 3 key values Value no.1 Ability to Detect a change in condition In ALL cases = Protection Value. Value no.2 Ability to Monitor the Evolution of the Condition = Monitoring Value. Value no.3 Ability to Diagnose the nature of the bad condition = Diagnostic Value.
Defining the needs 1) Review current resources & operations Diagnostic value Diagnostic 2) Defining Asset Criticality 3) Review needs 4) Plan & budget Detect Monitor 5) Implement, deploy, and integrate # of Gases analyzed
Transformer Condition evolution economical costs $$$$ Worst Case $ Best Case Time
Transformer: Electrical network $ The Global Picture Significant savings occur when a large number of transformers are being monitored Failures will happen it s a matter of probability!! Time
Monetizing Online monitoring What you actually pay for Diagnostic Diagnostic Value : Value Approx. : 0 30 000 Monitoring Monitoring Value : Value Approx. 0 : 0$ 10 000 Detection Value : Approx. 10 000 10 Years If no problem arises during the life of the transformer, only the Detection value of the instrument is of benefit.
Monetizing Online monitoring Condition change Condition : better change allocation of budget Diagnostic Value 30 000 0 Monitoring Value Detection Value 10 000 0 10 000 10 Years When a condition change occurs, Diagnostics capabilities are important, but otherwise only Detection and/or Monitoring
Deploying online monitors Maximizing coverage of electrical assets New Detect Monitor Diagnose Sub-station So when a transformer s condition changes abnormally Critical 1 Critical 2
Deploying online monitors Alarm New Detect Monitor Diagnose Sub-station Evolving fault triggers a signal to substation for action 1 Critical 1 Critical 2
Deploying online monitors Alarm triggers on-site inspection and Myrkos DGA New Detect Monitor Diagnose Sub-station Field team quickly addresses the alert On-site AND channels the DGA results. Communicate with Asset Manager for DGA-based action plan Critical 1 1 2 <<<< 1 day to provide results for diagnostics by Asset manager or Lab DGA Critical 2
Deploying online monitors Multigas can be used effectively to closely monitor transformer New Detect Monitor Diagnose After condition assessment and decision taken on faulty transformer Sub-station 1 ASTM D3612 IEC 60567 Critical 1 2 On-site Condition assessment Critical 2 3 When needed : on-line multigas monitor for problematic/concerning fault gases evolution (temp/perm)
Deploying online monitors Budget allocation efficiency Detect Detect New Monitor New Monitor Diagnose A Sub-station 1x 3-4X B Critical 1 Critical 1 Critical 2 Critical 2 Diagnose
A Deploying online monitors @ equal budget B Detect A B Detect New Monitor Equal budget New Monitor Diagnose Sub-station Sub-station - Extended coverage - Diagnostics - Easier data management Critical 1 Critical 1 Critical 2 Critical 2 Diagnose
Interchangeability concept: key pointers Maximizing coverage of electrical assets Aiming for minimal downtime Leveraging the current infrastructure Maximizing monitoring value while maintaining Detect Monitor Critical 1 Diagnose Critical 2
Balancing values: interchangeability concept in action
Interchangeability concept in action: from a detection monitor alarm, to multigas diagnostics Details : Normal operation **Change in condition This case study is about 18.4/23 MVA power transformer, 19/6.3 kv, Dyn1, manufactured in 2010. Early in 2013, the Calisto 2 monitor installed on the transformer detected an increase on the H 2 values. The Calisto 2 was replaced with a Calisto 9 for further investigation (interchangeable units) Interchangeability concept From Detection To Diagnostics
Interchangeability concept in action: from a detection monitor alarm, to multigas diagnostics Details : The Calisto 9 measured high values were recorded for H2, C2H4, C2H6 and most importantly for C2H2. The measurements were double checked by the customer: Samples were sent to ABB Sweden for DGA and all measurements were confirmed. Electrical measurements were performed locally and the winding resistance measurements (static and dynamic) showed a loose contact of one winding with the OLTC selector.
Interchangeability concept in action: from a detection monitor alarm, to multigas diagnostics
Interchangeability concept in action: from a detection monitor alarm, to multigas diagnostics Duval Triangle 1) Adjusted for the actual oil type used in the transformer 2) 2 nd level analysis with Triangle no.4 and no.5 3) Only triggered when proper gas alarm limits have been reached, reducing false positive
Interchangeability concept in action: from a detection monitor alarm, to multigas diagnostics Additional diagnostics 1) Rate of change (Day, Week, Month, Year) 2) Rogers ratios 3) IEC 60599 4) Doernenburg 5) Key gas method 6) IEEE
Interchangeability concept in action: from a detection monitor alarm, to multigas diagnostics The loose contacts were one of the connecting points of the transformer windings with the OLTC tap positions. These contacts are located inside the transformer tank, not the OLTC tank Details : The transformer was opened, the oil was removed and the loose contacts were indeed found and fixed. Measurements from the Calisto 9 shown on the previous slide demonstrate the situation has stabilized after the problem had been fixed. The customers expressed their satisfaction regarding the early warning they received from the Calisto 2 that allowed them to fix the problem at no practical cost.
mguertin@morganschaffer.com AUW booth C4 Questions? Thank you!
Process excellence: empowering the field On-site Dissolved Gas Analysis Speed of reaction to particular event: field DGA Unstable H 2 condition? Alert On-site visit / visual inspection X X X T on-site/sampling T packing/shipping/customs T lab analysis T results/condition assessment/decision 1-10 Hours 1-10 Hours 1-5 days 1-5 days Critical early detection in H 2 change Elimination of time consuming and wasteful steps
Process excellence: empowering the field On-site Dissolved Gas Analysis Up to 98% * reduction in Cycle time = faster results = more up time Unstable H 2 condition? Critical early detection in H 2 change Alert On-site visit / visual inspection T on-site/sampling T on-site DGA/ immediate result T lab analysis 1-10 Hours 0.1 Hours 1-5 days PLUS with MYRKOS you tremendously increase your Diagnose * When normal cycle takes 2.5 months