Dissolved Gas Analysis Method

FINAL YEAR PROJECT 1 PROGRESS REPORT 1 AUTHOR’S NAME:Ruban s/o Paramasivam STUDENT ID:EP083765 REPORTING PERIOD:18TH JUNE 2012 - 15TH JULY 2012 SUPERVISOR’S:Mr. John Steven NAME PROJECT TITLE:Dissolved Gas Resolution in determining Transformer Faults SUBMISSION DATE:16TH JULY 2012 1. 0 Background of Studies Oil sampling resolution is a conducive, ominous, defence dupe for determining transformer soundness. DGA is verified as one of the satisfactory habit of oil sampling in evaluating transformer soundness. The subduedown of electrical insulating representative internally the transformer breeds gases among the transformer. The convertibility of gases entity breedd is conducive in any destructive habit defence program. DGA habit involves oil sampling habit and testing the case to compute the disembodiment of the wild gases. The two regular leading object of gas construction among an exempt transformer are electrical restlessness and zealous resolution. All transformers breed gasses to some degree at ordinary exempt latitude. Insulating azoic oils for transformer are mixtures of frequent unanalogous hydrocarbons and the resolution system for these hydrocarbons are frequent-sided. During this system, locomotive hydrogen atoms and hydrocarbons litter are createed. These litter can add delay each other to create gasses such as Hydrogen (H2), Methane (CH4), Acetylene (C2H2), Ethylene (C2H4), Ethane (C2H6) and frequent prefer. The gasses listed are regarded combustible. The reprove at which each gas are productd depends on the latitude. Therefore, the disembodiment of the indivisible wild gasses set in transformer insulating oil may be used straightly to evaluate the transformer and hint any drawbacks among the transformer. After cases bear been enslaved and analysed, the original march in evaluating DGA issue is to regard the disembodiment plane of each gasses. Basically, any ardent growth of the key gasses revulgar balance betrays unopen whole among the transformer. The likeness of drawbacks which the key gasses can product conquer be prefer discussed in the consider. Attainment Resurvey 2. 0 Dissolved Gas Resolution Capacity Transformers are industrious delay oil which acts as a dielectric medium and to-boot as a force assign substitute too entity an insulator to the transformer. The insulated oil is made up of saturated hydrocarbons. These molecules are conjoined simultaneously to create a security common habit by carbon and hydrogen. [1] Consultation 1: Chemical building of insulating oil and drawback gases During ordinary use, there is a slack suspension of azoic oil which products gases that dissipate in the oil, but when there is a electrical drawback, the oil starts to relegate and latitude rises. Unanalogous patterns of gases are breedd due to unanalogous intensities of disembodiment wild according to the likeness of drawbacks. This happens beobject of the meek security of the chemical building of the insulating oil. Therefore, the meek security conquer create its own chemical building which is known as hydrocarbon gases or to-boot known as drawback gases. It can be disjoined into 3 categories which is Zealous forceing, Corona and Arching, The most exact force of disembodiment evacuation occurs delay arching, followed by zealous forceing and the lowest exact is Corona. Figure 1 illustrates the system of subdueing security among the insulating oil chemical building of the drawback arcing, zealous forceing, and corona. Figure 1: Breaking security system of drawback arcing, corona, zealous forceing and pyrolysis of cellulose Gases which are productd by the suspension of oil beobject of the growth of latitude may be objectd by contrariant factors: [2] * exact balanceloading * lighting * switching transients * habitual flaws * chemical resolution of oil or insulation * balanceheated areas of the windings * bad connections which bear a exalted touch opposition The likeness of gases bestow in an oil case makes it likely to asundoubtful the likeness of drawback that occurs in the transformer. This is effected by evaluating the disembodiment of gases bestow in the oil during defence. The likeness of drawback and its characteristics are as adown [3]: * Arcing Arcing is the most exact of all drawback systemes. Large sum of hydrogen and acetylene are productd, delay junior quantities of methane and ethylene. Arcing occurs in exalted vulgar and exalted latitude stipulations. Carbon dioxide and carbon monoxide may to-boot be createed if the drawback complicated cellulose. In some instances, the oil may befit carbonized. * Zealous forceing Resolution products embody ethylene and methane, simultaneously delay meaner quantities of hydrogen and ethane. Traces of acetylene may be createed if the drawback is exact or involves electrical touchs. * Corona Corona is a low-disembodiment electrical drawback. Low-disembodiment electrical acquits product hydrogen and methane, delay mean quantities of ethane and ethylene. Compartalented sums of carbon monoxide and dioxide may issue from acquit in cellulose. 2. 1 How DGA Works DGA habit embodys sampling of oil internally the transformer at unanalogous locations. Chromatographic resolution conquer be effected on the oil case to asundoubtful the disembodiment of wild gas. The gases are then separated, verified and quantitatively decided such that the DGA habit can then be applied in direct to allure legitimate idiosyncrasy [6]. The extracted gases meant for resolution object are Hydrogen (H2), Methane (CH4), Ethane (CH6), Ethylene (C2H4), Acetylene (C2H2), Carbon Monoxide (CO), Carbon Dioxide (CO2), Nitrogen (N2) and Oxygen (O2). These drawback gases can be classified into 3 groups which are shown in Consultation 2. Group| Hydrocarbons & Hydrogen| Carbon Oxides| Non-drawback gases| Gases| CH4,H2,CH6, C2H4,C2H2| CO, CO2| N2, O2| Consultation 2 :Fault Gases Group Depending on the disembodiment of the wild gases, stipulation of the transformer can be evaluated. This is achievtalented beobject each likeness of drawback burns the oil in a unanalogous way where it breeds unanalogous likeness of gases. Therefore, it is self-possessed to explore the drawback disesteemed on the gas released and its disembodiment plane. Consultation 3 : Affinity between Drawback likeness and Drawback gases 2. 2 DGA Sign Methods Insulating oil subduedowns to mean sum of gases due to balance electrical or zealous emphasis. Thus, the compromise of these gases plays a role in determining likeness of drawback. Through DGA sign habits, it is likely to asundoubtful drawbacks as discussed antecedent. There are frequent habits in DGA and 5 habits conquer be thoughtful in this attainment resurvey part. 2. 2. 1 Rogers Connection Habit The Roger’s habit utilizes indecent gases connections: CH4/H2, C2H6/CH4, C2H4/C2H6 and C2H2/C2H6. Idiosyncrasy if drawbacks are obliging via a absolute coding intrigue disesteemedd on files of the connection as shown in consultations adown [4]. Consultation 4: Gas Connection Codes [4] Consultation 5: Roger’s Connection Rule [4] The association of the coding gives 12 unanalogous likenesss of transformer drawbacks. The likeness of drawbacks disesteemedd on the rule is shown in consultation 6 adown: [4] Ttalented 6 : Classification disesteemedd on Roger’s Connection Codes 2. 2. 2 IEC Connection Habit This habit originated from the Roger’s Connection habit, ate that the connection C2H6 /CH4 was dropped past it singly implied a scant latitude file of resolution [3]. Here, the cherishing three gas connections bear unanalogous files of rule as compared to the Roger’s connection habit and they are shown in consultation 7. The drawbacks are disjoined into nine unanalogous likenesss as listed in consultation 8. [4] Consultation 7: IEC Connection Codes [4] Consultation 8: Classification disesteemedd on IEC Connection Codes 2. 2. 3 Doenenbury Connection Method This habit utilizes the gas disembodiment from connection of CH4/H2, C2H2/CH4, C2H4/C2H6 and C2H2/ C2H4. The compute of the gases at original must abound the disembodiment L1 to as undoubtful whether there is indeed a whole delay the item and then whether there is satisfactory progeny of each gas for the connection resolution to be convenient [5]. Consultation 9 shows the key gases and their disembodiment L1 [5], and consultation 10 shows drawback likeness of specific connections. Consultation 9: Disembodiment of L1 for Doernenburg Connection Consultation 10: Drawback idiosyncrasy for Doernenburg Connection Habit 2. 2. 4 Duval Triangle Habit M. Duval open this habit in the 1960s. To designate whether a whole insists at lowest one of the hydrocarbon gases or hydrogen must be at L1 plane or balance and the gas progeny reprove is at lowest at G2. [6] The L1 plane and the gas progeny reprove for this habit are shown in consultation 11. Consultation 11: L1 limits and gas progeny reprove for Duval Triangle Methode Once a whole has been decided to insist, to allure idiosyncrasy, number the entirety accumulated sum of the three Duval Triangle gases (CH4, C2H2, C2H4) and separate each gas by the entirety to asundoubtful the percentage of each gas of the entirety. Plot the percentages of the entirety on the triangle (Figure2) to enter at the idiosyncrasy [6] Figure 2: Duval Triangle Transformer Drawback Idiosyncrasy 2. 2. 5 Key Gas Habit Figure 3 : Key Gases Idiosyncrasy The doctrine of the Key Gas habit is disesteemedd on the sum of drawback gases released from the insulating oil when a drawback occurs which in alter growth the latitude in the capacity transformer. The nearness of the drawback gases depends on the latitude or disembodiment that conquer subdue the integrate or affinity of the insulating oil chemical building. This habit uses the indivisible gas rather than the investigation of gas connections for detecting drawback. The momentous and relation of the gases are designated “key gases”. Figure 3 betray these “key gases” and not-absolute relations for the indecent public drawback likenesss [5]. 3. 0 Scheduled Work Task| Start Date| Duration (days)| Remarks| Progress| Scheme Epithet Selection| 28. 05. 2012| 12| Proposed own scheme epithet and submitted it on 4th June 2012| Completed| Inquiry for Scheme Proposal| 08. 06. 2012| 10| Journals and doctrines were browsed through in IEEE, Science Direct, Scopus| Completed| Scheme Proposal| 14. 6. 2012| 3| Scheme Proposal was effected disesteemedd on the journals and doctrines set. | Completed | Inquiry for Attainment Review| 19. 06. 2012| unrecognized| Journals and doctrines were searched for the attainment resurvey| Ongoing| Proficiency Report 1| 01. 07. 2012| 15| Each proficiency towards the collection of Final Year Scheme 1| Completed| Inquiry / Vocal Endowment Preparation| 17. 07. 2012| 24| Complete the attainment resurvey and getting opportune for the vocal bestowation suitableness doing inquiry for the scheme| Incomplete| Vocal Presentation| 10. 08. 2012 / 29. 08. 012| -| Endowment of all the ascertainings and inquiry and logbook to be submitted| Incomplete| Proficiency Report 2| 10. 08. 2012| 3| Each proficiency towards the collection of Final Year Scheme 1| Incomplete| 4. 0 Conclusion In the end of this consider, I’ll be talented to designate the pros and cons of all the unanalogous likenesss of DGA signs habits and be talented to designate transformer drawbacks out of the sign habits which are very induced to thwart transformer detriment. Suggestions and recommendations conquer be abandoned to prefer ameliorate the willingness of those availtalented sign habits . 0 Reference 1. Church, J. O. , Haupert, T. J. and Jakob, Fredi (1987). “Analyze Incipient Faults delay Dissolved-gas Nomograph. ” Elecrical World. Oct. Pgs. 40-44. 2. DiGiorgio, Joseph B. (1997). “Dissolved Gas Resolution of Azoic Oil Insulating Fluids. ” California: Northern Technology & Testing 3. Domun, M. K. (1996). “Condition Monitoring of Capacity Transformers by Oil Resolution Techniques. ” Proc. of the 11th Conference on Electric Capacity Supply Industry (CEPSI). Kuala Lumpur, Malaysia 4. Siva Sarma, D. V. S. S. and G. N. S. Kalyani, ANN Approach for Stipulation Monitoring of Capacity Transformers using DGA. 2004 IEEE Region 10 Conference, TENCON 2004. , 2004. C: p. 444-447. 5. C57. 104. 1991, I. , IEEE Guide for Interpretation of Gases Generated in Oil-Immersed Transformer, I. The Institute of Electrical and Electronic Engineers, Editor. 1992, The Institute of Electrical and Electronic Engineers, Inc p. 27 6. FIST3-31, Facilities Instructions, Standards and Techniques Volume 3-31 Transformer Diagnostics. 2003, Bureu of Reclamation Hydroelectric Inquiry and Technical Services Group Denver. p. 5-13.