[James_H._Harlow]_Electric_Power_Transformer_Engin(BookSee.org)

Recommendations

Info

Wang, C., Dong, X., Wang, Z., Jing, W., Jin, X., and Cheng, T.C., On-line Partial Discharge Monitoring System for Power Transformers, in Proc. 10th ISH, Montréal, 1997, p. 379. Wenzel, D., Borsi, H., and Glockenbach, E., Pulse Shaped Noise Reduction and Partial Discharge Localisation on Transformers Using the Karhunen-Loéve-Transform, Paper 5627, in Proc. 9th ISH, Graz, 1995. Wenzel, D., Schichler, U., Borsi, H., and Glockenbach, E., Recognition of Partial Discharges on Power Units by Directional Coupling, Paper 5626, in Proc. 9th ISH, Graz, 1995. Zaretsky, M.C. et al., Moisture sensing in transformer oil using thin-film microdielectrometry, IEEE Trans. Electrical Insulation, 24, 1989. 3.14 U.S. Power Transformer Equipment Standards and Processes Philip J. Hopkinson This section 4 describes the power transformer equipment standards approval processes and lists the standards that are in place in the U.S. in 2002. The subsection on accredited standards approval processes (Section 3.14.1) provides an abbreviated description of the methods that are employed in the U.S. for gaining American National Standards Institute (ANSI) approval and recognition. Similarly, an approval process is also shown for International Electrotechnical Commission (IEC) documents. The U.S. uses a voluntary process for the development of nationally recognized power transformer equipment standards. This chapter describes the U.S. standards accreditation process and provides flow charts to show how accredited standards are approved. With the International Electrotechnical Committee (IEC) taking on increased importance, the interaction of U.S. technical experts with IEC is also described. Finally, relevant power transformer documents are listed for the key power transformer equipment standards that guide the U.S. industry. 3.14.1 Processes for Acceptance of American National Standards The acceptance of a standard as an American national standard (ANS) requires that it be processed through one of three methods: 1. Canvass list 2. Action of accredited standards committee 3. Action of accredited standards organization Table 3.14.1 lists the major standards organizations. All three methods share the common requirement that the process used has been accredited by the American National Standards Institute (ANSI), that the methodology incorporates due process, and that consensus among the interests is achieved. Inherent in that approval is presentation of accepted operational procedures and/or a balloting group that is balanced among users, manufacturers, and generalinterest groups. Other considerations include the following: • The document must be within the scope previously registered. • Identified conflicts must be resolved. • Known national standards must have been examined to Avoid duplication or conflict Verify that any appeal has been completed Verify that the ANSI patent policy is met 4 Many thanks are offered by the author for assistance rendered by representatives of the National Electrical Manufacturer’s Association, by American National Standards Institute, and by individuals from IEEE, IEC, EEI, EL&P, UL, and especially by Ms. Purefoy, who arranged and documented these contents. TABLE 3.14.1 Major Standards Organizations ANSI ASC C57 IEEE NEMA EL&P EEI AEIC UL IEC American National Standards Institute Accredited Standards Committee C57 for Power and Distribution Transformers (deactivated December 31, 2002, by mutual decision of IEEE, NEMA, and C57 Committee) Institute of Electrical and Electronics Engineers National Electrical Manufacturers Association Electric Light and Power Edison Electric Institute Association of Edison Illuminating Companies Underwriter’s Laboratory International Electrotechnical Commission While the three processes differ in their methods of gaining consensus, all three use common methods for document submittal to ANSI. An explanation of the ANSI submittal process, which involves the use of Board for Standard Revision form 8 (BSR-8) and Board for Standard Review form 9 (BSR-9), is available on-line at http://web.ansi.org/rooms/room_16/public/ans.html. The BSR-8 form (request to initiate public review of a proposed ANS) is used to submit draft candidate American national standards for public review in ANSI’s standards action. This form can be submitted multiple times for the same standard if multiple public reviews are required due to substantive changes in text. If the BSR-8 form is a resubmittal, this should be clearly marked on the form. This form is available via the ANSI reference library or via e-mail to psa@ansi.org. The BSR-9 form (request for formal approval of a standard as an ANS) is used to submit candidate American national standards for final approval. All of the information requested on the form must be provided. The form itself serves as a checklist for the evidence of consensus that the BSR and the ANSI procedures require. The certification section on the form is the developer’s acknowledgement that all items listed as part of the certification statement are true, e.g., all appeals have concluded. This form is available via the ANSI reference library or via e-mail to psa@ansi.org. An explanation of the accreditation process (accreditation of American National Standards Developers) is available at http://web.ansi.org/rooms/room_16/public/accredit.html. 3.14.1.1 Canvass List The canvass-list method provides procedures for seeking approval/acceptance of a document without the structure of a committee or an organization. Figure 3.14.1 shows a flow diagram of the ANSI canvasslist method. Under the canvass list, the originator of a standard seeking its acceptance as an American national standard (ANS) must assemble, to the extent possible, those who are directly and materially affected by the activity in question. The standards developer conducts a letter ballot or “canvass” of those interested to determine consensus on a document. Additional interest in participating on a canvass is sought through an announcement in ANSI’s publication entitled, “Standards Action.” Although canvass developers provide ANSI with internal procedures used in the development of the draft American national standard, the due process used to determine consensus begins after the draft standard has been developed. Standards developers using the canvass method must use the procedures provided in Annex B of the ANSI procedures. The balloting group, by the above methods, consists of a balance of interests and affected parties. To summarize, once the canvass list is approved and finalized, the document is circulated for voting. Simultaneously, the manager of the canvass list completes and submits the Board for Standard Revision 8 (BSR-8) form for public notification of the undertaking and providing opportunity for comment from persons outside the balloted group. Once the balloting period ends, a minimum of 45 days, and usually after 60 days for transformers, the manager completes Board for Standard Review 9 (BSR-9) to provide (1) validation that the proposal received consensus approval in the balloting and (2) a report on how each of the participants voted. The BSR-9 is forwarded to ANSI for action by the Board for Standard Review. Of particular concern is that the document review be completed under an open and fair procedure and that a consensus of the voting group approve its acceptance. Underwriter’s Laboratories (UL) uses the canvass-list method to obtain ANSI recognition of UL documents. © 2004 by CRC Press LLC © 2004 by CRC Press LLC
3.14.1.2 Accredited Standards Committee The accredited standards committee (ASC) is a second method for gaining “national” acceptance of a standard. Figure 3.14.2 shows a flow diagram of the ANSI committee method. The accredited standards committees are standing committees of directly and materially affected interests created for the purpose of developing a document and establishing consensus in support of this document for submittal to ANSI. The committee method is most often used when a standard affects a broad range of diverse interests or where multiple associations or societies with similar interests exist. The committee serves as a forum where many different interests, without a common membership in an organization or society, can be represented. Accredited standards committees are administered by a secretariat, an organization that takes the responsibility for providing administrative oversight of the committee’s activities and ensuring compliance with the pertinent operating procedures. An accredited standards committee may adopt the procedures provided in Annex A of the ANSI procedures, or it may develop its own operating procedures consistent with the requirements of Section 2.2 of these procedures. Under current procedures, ASCs are entities established through the coalescence of a balance of interest groups focused on a particular product area. The product area and the committee’s organization and organizational procedures are approved by ANSI. The ASC charter is subject to periodic review and reaffirmation but, generally, is unobstructed. The ASC has the option to develop and submit standards for acceptance as ANSs or to process documents that fall within their operational scope that originate in other bodies — trade associations, business groups, and the like. Documents submitted to ASCs are subjected to the same procedures for consideration as in the canvass-list method. A BSR-8 is issued upon receipt of a document for acceptance to initiate committee review and vote. The BSR-8 provides for public notification of the undertaking and for public comment. Once the balloting period is ended, the BSR-9 report is sent to ANSI confirming the voting and the consensus. ANSI reviews the report and provides appropriate approval. Until recently, IEEE and NEMA used the Accredited Standards Committee to gain ANSI C57 document approvals. ASC C57 was deactivated December 31, 2002, by actions of IEEE, NEMA, and the C57 Committee. The Electric Light and Power Delegation (EL & P) represents the Edison Electric Institute (EEI) and the Association of Edison Illuminating Companies (AEIC). EL & P, predominantly through EEI, is well represented in the IEEE Transformers Committee. EL & P is not currently a standards development organization, but it votes as a delegation on documents submitted to ANSI C57 for approval. 3.14.1.3 Accredited Standards Organization The third method for acceptance is the accredited standards organization. The organization method is often used by associations and societies that have, among other activities, an interest in developing standards. This is the method used by IEEE starting January 1, 2003. Figure 3.14.3 shows a flow diagram of the ANSI standards-organization method. Although participation on the consensus body is open to all interested parties, members of the consensus body often participate as members in the association or society. The organization method is the only method of consensus development in which the standards developer must develop its own operating procedures. These procedures must meet the general requirements of Section 2.2 of the ANSI procedures. This method provides flexibility, allowing the standards developer to utilize a system that accommodates its particular structure and practices. Under these procedures, an organization demonstrates the openness and balance of its voting groups and its operating procedures. The ASO’s purview or authority for processing documents for acceptance as an ANS may be restricted to particular products or a group of products, depending upon organizational interests and goals. The documents developed by the ASO and conforming to the interest-balance and openness procedures are submitted to ANSI utilizing the BSR-8 and BSR-9 reports, in appropriate sequence. The ANSI BSR evaluates the documentation and makes its decision using the criteria as in the other methodologies. FIGURE 3.14.1 ANSI standards canvass-list approval process. © 2004 by CRC Press LLC © 2004 by CRC Press LLC
Page 1 and 2:
ELECTRIC POWER TRANSFORMER ENGINEER
Page 3 and 4:
I wish to recognize the interest of
Page 5 and 6:
Contents 1 Theory and Principles Ch
Page 7 and 8:
1.3 Equivalent Circuit of an Iron-C
Page 9 and 10:
designer starts to make a design fo
Page 11 and 12:
• Transient voltages generated du
Page 13 and 14:
the transformer’s bushings and, m
Page 15 and 16:
% regulation = [(V NL - V FL )/V FL
Page 17 and 18:
In core-form transformers, the wind
Page 19 and 20:
FIGURE 2.1.14 Layer windings (singl
Page 21 and 22:
the transformer design, which may b
Page 23 and 24:
consumer’s service circuit is a d
Page 25 and 26:
FIGURE 2.2.3 Single-phase transform
Page 27 and 28:
is installed so that the tank never
Page 29 and 30:
above which persons might be burned
Page 31 and 32:
FIGURE 2.2.16 Two-bushing subway. (
Page 33 and 34:
carbon steel or the very expensive
Page 35 and 36:
FIGURE 2.2.31 Radial-style dead fro
Page 37 and 38:
FIGURE 2.2.36 Complete transformer
Page 39 and 40:
voltage in each winding simultaneou
Page 41 and 42:
mounted transformers can have arres
Page 43 and 44:
V S + V S I V L Z=R+jX a) V L V S V
Page 45 and 46:
Z = jX (2.3.19) 0.7 Then the curren
Page 47 and 48:
X1 L* X1 S =X1 L X2 L* X3 L* a) S L
Page 49 and 50:
150 V(%) 100 50 0 -50 40 80 T(s) 12
Page 51 and 52:
2.3.8.1.2 Series Connection • The
Page 53 and 54:
A six-pulse single-way transformer
Page 55 and 56:
The degree of coupling also influen
Page 57 and 58:
where I h = current for the hth har
Page 59 and 60:
In the case of liquid-filled transf
Page 61 and 62:
FIGURE 2.4.21 A 36-pulse system mad
Page 63 and 64:
Vacuum-pressure encaps ulated — T
Page 65 and 66:
FIGURE 2.6.1 Typical wiring and sin
Page 67 and 68:
a) H1 b) Ip X2 FLUX H2 LEAKAGE FLUX
Page 69 and 70:
and for CTs is TCF = RCF - (PA/2600
Page 71 and 72:
RCF x Bx Bt RCF t - RCF 0 co
Page 73 and 74:
2000 1000 5% Vex BANDWITH FROM NOMI
Page 75 and 76:
This may be more useful when operat
Page 77 and 78:
also some uncertainty in repeatabil
Page 79 and 80:
FIGURE 2.6.25 Standard two-element
Page 81 and 82:
2.7 Step-Voltage Regulators Craig A
Page 83 and 84:
Source Bypass Switch Source Bypass
Page 85 and 86:
2.7.4 Theory A step-voltage regulat
Page 87 and 88:
FIGURE 2.7.22 Equalizer winding inc
Page 89 and 90:
TABLE 2.7.4 Increase in Ampere Load
Page 91 and 92:
References IEEE, Standard Requireme
Page 93 and 94:
300% FIGURE 2.8.4 Schematic of a co
Page 95 and 96:
TABLE 2.8.1 Typical Sizing Workshee
Page 97 and 98:
Input with Interruption Ferro Outpu
Page 99 and 100:
FIGURE 2.8.20A Performance of a rid
Page 101 and 102:
• Input frequency or frequency ra
Page 103 and 104:
References 1. Sola/Hevi-Duty Corp.,
Page 105 and 106:
FIGURE 2.9.5 Typical phase-reactor
Page 107 and 108:
FIGURE 2.9.10 Two generator arrange
Page 109 and 110:
• Overloading of lines • Increa
Page 111 and 112:
FIGURE 2.9.23 34-kV, 25-MVAR (per p
Page 113 and 114:
V 90 ( X X ) s T (2.9.10a) where,
Page 115 and 116:
Therefore, Line reactive losses = (
Page 117 and 118:
ate of rise of transient-recovery v
Page 119 and 120:
the LLCR is provided in IEEE Std. C
Page 121 and 122:
aluminum shielding, i.e., an oil-im
Page 123 and 124:
Leo J. Savio ADAPT Corporation Ted
Page 125 and 126:
3.1.2.2.2 Heat Dissipation A second
Page 127 and 128:
FIGURE 3.2.1 Solid-type bushing. ma
Page 129 and 130:
1.6 cm. This means that most of the
Page 131 and 132:
where HS = steady-state bushing ho
Page 133 and 134:
the conductivity of the water-solub
Page 135 and 136:
of 178 ohm-m, and a test duration o
Page 137 and 138:
2. Easley, J.K. and Stockum, F.R.,
Page 139 and 140:
FIGURE 3.3.5 Reactance-type LTC, in
Page 141 and 142:
FIGURE 3.3.10 LTC with delta connec
Page 143 and 144:
3.3.5 Selection of Load Tap Changer
Page 145 and 146:
FIGURE 3.3.19 Effect of the leakage
Page 147 and 148:
References Goosen, P.V. , Transform
Page 149 and 150:
If i 1 is the full-load current rat
Page 151 and 152:
TABLE 3.4.1 Loading Recommendations
Page 153 and 154:
3.5.4 Three-Phase Transformer Conne
Page 155 and 156:
FIGURE 3.5.4 Interconnected star-gr
Page 157 and 158:
3.6.1.1 Standards ANSI standards fo
Page 159 and 160:
ANSI standards. LTC control setting
Page 161 and 162:
FIGURE 3.6.7 Discharging the capaci
Page 163 and 164:
FIGURE 3.6.10 Standard switching-im
Page 165 and 166:
voltage of the excited winding, rea
Page 167 and 168:
FIGURE 3.6.18 Current, voltage, and
Page 169 and 170:
TABLE 3.6.3 Transformer Short-Circu
Page 171 and 172:
FIGURE 3.7.3 Control for voltage re
Page 173 and 174:
FIGURE 3.7.6A Feeder with power-fac
Page 175 and 176:
3. Circulating current (current bal
Page 177 and 178:
FIGURE 3.7.10 Control block diagram
Page 179 and 180: Primary Current (Amps) 60 40 20 0 -
Page 181 and 182: current transformer having two prim
Page 183 and 184: 87R1 87BL1 (A) Independent Harmonic
Page 185 and 186: Winding 1 Secondary Currents Data A
Page 187 and 188: Y Y 20 18 3 rd Harmonic CTR1=40 CTR
Page 189 and 190: 230 kV 3 180 MVA 138 kV 5 CTR1 = 2
Page 191 and 192: 29. Concordia, C. and Rothe, F.S.,
Page 193 and 194: FIGURE 3.9.1 Measurement of pressur
Page 195 and 196: H 2m 1. Vertical Forced Air 2. Prin
Page 197 and 198: Gade, S., Sound Intensity Instrumen
Page 199 and 200: nected. This steady-state voltage d
Page 201 and 202: where [A] = state matrix [B] = inpu
Page 203 and 204: where C = capacitance between the t
Page 205 and 206: L ijo = N i N j ijo (3.10.31) 1.4
Page 207 and 208: % VOLTAGE % VOLTAGE 100 BIL 90 50 3
Page 209 and 210: 29. Degeneff, R.C., Reducing Storag
Page 211 and 212: All connections should be cleaned a
Page 213 and 214: 6. Costs to set up and use a mobile
Page 215 and 216: Records of relay operation must be
Page 217 and 218: • Has heating occurred as the res
Page 219 and 220: a reference value) of the currents
Page 221 and 222: The next data-processing step is to
Page 223 and 224: temperature. As the transformer coo
Page 225 and 226: 3.13.3.2 Instrument Transformers Th
Page 227 and 228: FIGURE 3.13.5 Analysis of bushing s
Page 229: temperature. Under abnormal conditi
Page 233 and 234: FIGURE 3.14.4 IEC technical-committ
Page 235 and 236: TABLE 3.14.2 Relevant Documents for
Page 241: TABLE 3.14.13 Relevant Documents fo
show all

[James_H._Harlow]_Electric_Power_Transformer_Engin(BookSee.org)

Create successful ePaper yourself

Delete template?

Save as template?