[James_H._Harlow]_Electric_Power_Transformer_Engin(BookSee.org)

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TABLE 3.14.6 (continued) Relevant IEEE Documents IEEE C57.110-1998 IEEE C57.116-1989 (R1994) IEEE C57.117-1986 (R1992) IEEE C57.124-1991 (R1996) IEEE C57.134-2000 IEEE C57.138-1998 IEEE PC57.142 Recommended Practice for Establishing Transformer Capability when Supplying Nonsinusoidal Load Currents Guide for Transformers Directly Connected to Generators Guide for Reporting Failure Data for Power Transformers and Shunt Reactors on Electric Utility Power Systems Recommended Practice for the Detection of Partial Discharge and the Measurement of Apparent Charge in Dry-Type Transformers IEEE Guide for Determination of Hottest-Spot Temperature in Dry-Type Transformers Recommended Practice for Routine Impulse Test for Distribution Transformers A Guide to Describe the Occurrence and Mitigation of Switching Transients Induced by Transformer and Breaker Interaction TABLE 3.14.7 NEMA TP-1 Rating Range for Single-Phase and Three-Phase Dry-Type and Liquid-Filled Distribution Transformers Voltage Class: Primary Voltage = 34.5 kV and below Secondary Voltage = 600 V and below Transformer Type Number of Phases Rating Range Liquid rating Single phase 10–833 kVA Three phase 15–2500 kVA Dry rating Single phase 15–833 kVA Three phase 15–2500 kVA Note: Includes all products at 1.2 kV and below. 3.14.3.4.2.2 NEMA TP-2, Standard Test Method for Measuring the Energy Consumption of Distribution Transformers — This standard is intended for use as a basis for determining the energy-efficiency performance of the equipment covered and to assist in the proper selection of such equipment. This standard covers single-phase and three-phase dry-type and liquid-immersed distribution transformers (transformers for transferring electrical energy from a primary distribution circuit to a secondary distribution circuit or within a secondary distribution circuit) as defined in Table 3.14.8. This standard addresses the test procedures for determining the efficiency performance of the transformers covered in NEMA Publication TP-1 Products excepted from this standard include: Liquid-filled transformers below 10 kVA Dry-type transformers below 15 kVA Transformers connected to converter circuits All rectifier transformers and transformers designed for high harmonics Autotransformers Nondistribution transformers, such as UPS transformers Special impedance and harmonic transformers Regulating transformers Sealed and nonventilated transformers Retrofit transformers Machine-tool transformers Welding transformers Transformers with tap ranges greater than 15% Transformers with frequency other than 60 Hz Grounding transformers Testing transformers TABLE 3.14.8 NEMA TP-2 Rating Range for Single-Phase and Three-Phase Dry-Type and Liquid-Immersed Distribution Transformers Transformer Type Number of Phases Rating Range Liquid immersed Single phase 10–833 kVA Three phase 15–2500 kVA Dry type Single phase 15–833 kVA Three phase 15–2500 kVA Note: Includes all products at 1.2 kV and below. 3.14.3.4.3 ANSI/UL 1562, Standard for Safety for Transformers, Distribution, Dry-Type — over 600 V These requirements cover single-phase or three-phase, dry-type, distribution transformers. The transformers are provided with either ventilated or nonventilated enclosures and are rated for a primary or secondary voltage from 601 to 35,000 V and from 1 to 5,000 kVA. These transformers are intended for installation in accordance with the National Electrical Code. These requirements do not cover the following transformers: Instrument transformers Step-voltage and induction-voltage regulators Current regulators Arc-furnace transformers Rectifier transformers Specialty transformers (such as rectifier, ignition, gas-tube-sign transformers, and the like) Mining transformers Motor-starting reactors and transformers These requirements do not cover transformers under the exclusive control of electrical utilities utilized for communication, metering, generation, control, transformation, transmission, and distribution of electric energy, regardless of whether such transformers are located indoors (in buildings and rooms used exclusively by utilities for such purposes) or outdoors (on property owned, leased, established rights on private property, or on public rights of way [highways, streets, roads, and the like]). A product that contains features, characteristics, components, materials, or systems new or different from those in use when the standard was developed — and that involves a risk of fire, electric shock, or injury to persons — shall be evaluated using the appropriate additional component and end-product requirements as determined necessary to maintain the level of safety for the user of the product as originally anticipated by the intent of this standard. 3.14.3.4.4 IEC Technical Committee 14 Power Transformers The purpose of IEC Technical Committee 14 Power Transformers is to prepare international standards for power transformers, on-load tap changers, and reactors without limitation of voltage or power (not including instrument transformers, testing transformers, traction transformers mounted on rolling stock, and welding transformers). Relevant documents are listed in Table 3.14.9. 3.14.3.5 Liquid-Filled Transformers 3.14.3.5.1 IEEE Documents These standards provide a basis for establishing the performance, limited electrical and mechanical interchangeability, and safety requirements of the equipment described. They are also a basis for assistance in the proper selection of such equipment. These standards describe electrical, mechanical, and safety requirements of liquid-immersed distribution and power transformers as well as autotransformers and regulating transformers, single and polyphase, with voltages of 601 V or higher in the highest-voltage winding. These standards also cover instrument transformers and rectifier transformers. © 2004 by CRC Press LLC © 2004 by CRC Press LLC
TABLE 3.14.9 Relevant Documents for IEC Technical Committee 14 Power Transformers 60076-1 General requirements 60076-2 Temperature rise 60076-3 Insulation levels, dielectric tests, and external clearances in air 60076-4 Guide for lightning-impulse and switching-impulse testing 60076-5 Ability to withstand short circuit 60076-6 Reactors (IEC 289) 60076-8 Power transformers — application guide 60076-9 Terminal and tapping markings (IEC 616) 60076-10 Determination of transformer reactor sound levels 60076-11 Dry-type power transformers (IEC 726) 60076-12 Loading guide for dry-type power transformers (IEC 905) 60214-1 Tap changers for power transformers 60214-2 Application guide for on-load tap changers (IEC 542) 61378 Converter transformers 61378-1 Transformers for industrial applications 61378-3 Applications guide These standards apply to all liquid-immersed distribution, power, regulating, instrument, and rectifier transformers except as indicated below: Arc-furnace transformers Specialty transformers Grounding transformers Mobile transformers Mine transformers Relevant IEEE documents are listed in Table 3.14.10. 3.14.3.5.2 NEMA Documents 3.14.3.5.2.1 NEMA TP-1, Guide for Determining Energy Efficiency for Distribution Transformers — This standard is intended for use as a basis for determining the energy-efficiency performance of the equipment covered and to assist in the proper selection of such equipment. This standard covers singlephase and three-phase dry-type and liquid-filled distribution transformers as defined in Table 3.14.11. Products excepted from this standard include: Liquid-filled transformers below 10 kVA Dry-type transformers below 15 kVA Drives transformers, both ac and dc All rectifier transformers and transformers designed for high harmonics Autotransformers Nondistribution transformers, such as UPS transformers Special impedance and harmonic transformers Regulating transformers Sealed and nonventilated transformers Retrofit transformers Machine-tool transformers Welding transformers Transformers with tap ranges greater than 15% Transformers with frequency other than 60 Hz Grounding transformers Testing transformers TABLE 3.14.10 Relevant IEEE Documents IEEE 62-1995 Guide for Diagnostic Field Testing of Electric Power Apparatus — Part 1: Oil Filled Power Transformers, Regulators, and Reactors IEEE 259-1994 Standard Test Procedure for Evaluation of Systems of Insulation for Specialty Transformers (ANSI) IEEE 637-1985 Guide for the Reclamation of Insulating Oil and Criteria for Its Use (ANSI) IEEE 638-1992 Standard for Qualification of Class 1E Transformers for Nuclear Generating Stations IEEE 799-1987 Guide for Handling and Disposal of Transformer Grade Insulating Liquids Containing PCBs (ANSI) IEEE 1276-1997 Trial-Use Guide for the Application of High Temperature Insulation Materials in Liquid- Immersed Power Transformers ANSI C57.12.00-1993 Standard General Requirements for Liquid-Immersed Distribution, Power, and Regulating Transformers (ANSI) ANSI C57.12.10-1988 American National Standard for Transformers — 230 kV and below 833/958 through 8333/10 417 kVA, Single-Phase, and 750/862 through 60 000/80 000/100 000 kVA, Three-Phase without Load Tap Changing; and 3750/4687 through 60 000/80 000/100 000 kVA with Load Tap Changing — Safety Requirements ANSI C57.12.20-1997 American National Standard for Overhead Distribution Transformers, 500 kVA and Smaller: High Voltage, 34 500 V and below: Low Voltage 7970/13 800 Y V and below ANSI C57.12.22-1989 American National Standard for Transformers — Pad-Mounted, Compartmental-Type, Self-Cooled, Three-Phase Distribution Transformers with High-Voltage Bushings, 2500 kVA and Smaller: High Voltage, 34 500 GrdY/19 920 Volts and below; Low Voltage, 480 Volts and below IEEE C57.12.23-1992 Standard for Transformers — Underground-Type, Self-Cooled, Single-Phase Distribution Transformers With Separable, Insulated, High-Voltage Connectors; High Voltage (24 940 GrdY/14 400 V and below) and Low Voltage (240/120 V, 167 kVA and Smaller) ANSI C57.12.24-1994 American National Standard Requirements for Transformers — Underground-Type, Three-Phase Distribution Transformers, 2500 kVA and Smaller; High Voltage, 34 500 GrdY/19 920 Volts and below; Low Voltage, 480 Volts and below — Requirements ANSI C57.12.25-1990 American National Standard for Transformers — Pad-Mounted, Compartmental-Type, Self-Cooled, Single-Phase Distribution Transformers with Separable Insulated High- Voltage Connectors; High Voltage, 34 500 GrdY/19 920 Volts and below; Low Voltage, 240/120 Volts; 167 kVA and Smaller IEEE C57.12.26-1992 Standard for Pad-Mounted, Compartmental-Type, Self-Cooled, Three-Phase Distribution Transformers for Use with Separable Insulated High-Voltage Connectors (34 500 GrdY/19 920 Volts and below; 2500 kVA and Smaller) ANSI C57.12.29-1991 American National Standard Switchgear and Transformers-Pad-Mounted Equipment- Enclosure Integrity for Coastal Environments ANSI C57.12.31-1996 American National Standard for Pole-Mounted Equipment — Enclosure Integrity ANSI C57.12.32-1994 American National Standard for Submersible Equipment — Enclosure Integrity IEEE C57.12.35-1996 Standard for Bar Coding for Distribution Transformers ANSI C57.12.40-1994 American National Standard Requirements for Secondary Network Transformers — Subway and Vault Types (Liquid Immersed) IEEE C57.12.44-1994 Standard Requirements for Secondary Network Protectors ANSI C57.12.70-1978 (R1992) American National Standard Terminal Markings and Connections for Distribution and Power Transformers IEEE C57.12.80-1978 (R1992) Standard Terminology for Power and Distribution Transformers IEEE C57.12.90-1993 Standard Test Code for Liquid-Immersed Distribution, Power, and Regulating Transformers and Guide for Short Circuit Testing of Distribution and Power Transformers IEEE C57.13-1993 Standard Requirements for Instrument Transformers IEEE C57.13.1-1981 (R1992) Guide for Field Testing of Relaying Current Transformers IEEE C57.13.3-1983 (R1991) Guide for the Grounding of Instrument Transformer Secondary Circuits and Cases IEEE C57.15-1986 (R1992) Standard Requirements, Terminology, and Test Code for Step-Voltage and Induction- Voltage Regulators IEEE C57.16-1996 Standard Requirements, Terminology, and Test Code for Dry-Type Air-Core Series- Connected Reactors IEEE C57.18.10-1998 Standard Practices and Requirements for Semiconductor Power Rectifier Transformers —continued © 2004 by CRC Press LLC © 2004 by CRC Press LLC
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ELECTRIC POWER TRANSFORMER ENGINEER
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I wish to recognize the interest of
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Contents 1 Theory and Principles Ch
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1.3 Equivalent Circuit of an Iron-C
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designer starts to make a design fo
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• Transient voltages generated du
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the transformer’s bushings and, m
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% regulation = [(V NL - V FL )/V FL
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In core-form transformers, the wind
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FIGURE 2.1.14 Layer windings (singl
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the transformer design, which may b
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consumer’s service circuit is a d
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FIGURE 2.2.3 Single-phase transform
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is installed so that the tank never
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above which persons might be burned
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FIGURE 2.2.16 Two-bushing subway. (
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carbon steel or the very expensive
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FIGURE 2.2.31 Radial-style dead fro
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FIGURE 2.2.36 Complete transformer
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voltage in each winding simultaneou
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mounted transformers can have arres
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V S + V S I V L Z=R+jX a) V L V S V
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Z = jX (2.3.19) 0.7 Then the curren
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X1 L* X1 S =X1 L X2 L* X3 L* a) S L
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150 V(%) 100 50 0 -50 40 80 T(s) 12
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2.3.8.1.2 Series Connection • The
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A six-pulse single-way transformer
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The degree of coupling also influen
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where I h = current for the hth har
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In the case of liquid-filled transf
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FIGURE 2.4.21 A 36-pulse system mad
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Vacuum-pressure encaps ulated — T
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FIGURE 2.6.1 Typical wiring and sin
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a) H1 b) Ip X2 FLUX H2 LEAKAGE FLUX
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and for CTs is TCF = RCF - (PA/2600
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RCF x Bx Bt RCF t - RCF 0 co
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2000 1000 5% Vex BANDWITH FROM NOMI
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This may be more useful when operat
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also some uncertainty in repeatabil
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FIGURE 2.6.25 Standard two-element
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2.7 Step-Voltage Regulators Craig A
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Source Bypass Switch Source Bypass
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2.7.4 Theory A step-voltage regulat
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FIGURE 2.7.22 Equalizer winding inc
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TABLE 2.7.4 Increase in Ampere Load
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References IEEE, Standard Requireme
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300% FIGURE 2.8.4 Schematic of a co
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TABLE 2.8.1 Typical Sizing Workshee
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Input with Interruption Ferro Outpu
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FIGURE 2.8.20A Performance of a rid
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• Input frequency or frequency ra
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References 1. Sola/Hevi-Duty Corp.,
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FIGURE 2.9.5 Typical phase-reactor
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FIGURE 2.9.10 Two generator arrange
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• Overloading of lines • Increa
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FIGURE 2.9.23 34-kV, 25-MVAR (per p
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V 90 ( X X ) s T (2.9.10a) where,
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Therefore, Line reactive losses = (
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ate of rise of transient-recovery v
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the LLCR is provided in IEEE Std. C
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aluminum shielding, i.e., an oil-im
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Leo J. Savio ADAPT Corporation Ted
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3.1.2.2.2 Heat Dissipation A second
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FIGURE 3.2.1 Solid-type bushing. ma
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1.6 cm. This means that most of the
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where HS = steady-state bushing ho
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the conductivity of the water-solub
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of 178 ohm-m, and a test duration o
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2. Easley, J.K. and Stockum, F.R.,
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FIGURE 3.3.5 Reactance-type LTC, in
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FIGURE 3.3.10 LTC with delta connec
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3.3.5 Selection of Load Tap Changer
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FIGURE 3.3.19 Effect of the leakage
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References Goosen, P.V. , Transform
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If i 1 is the full-load current rat
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TABLE 3.4.1 Loading Recommendations
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3.5.4 Three-Phase Transformer Conne
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FIGURE 3.5.4 Interconnected star-gr
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3.6.1.1 Standards ANSI standards fo
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ANSI standards. LTC control setting
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FIGURE 3.6.7 Discharging the capaci
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FIGURE 3.6.10 Standard switching-im
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voltage of the excited winding, rea
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FIGURE 3.6.18 Current, voltage, and
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TABLE 3.6.3 Transformer Short-Circu
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FIGURE 3.7.3 Control for voltage re
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FIGURE 3.7.6A Feeder with power-fac
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3. Circulating current (current bal
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FIGURE 3.7.10 Control block diagram
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Primary Current (Amps) 60 40 20 0 -
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current transformer having two prim
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87R1 87BL1 (A) Independent Harmonic
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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
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Page 197 and 198: Gade, S., Sound Intensity Instrumen
Page 199 and 200: nected. This steady-state voltage d
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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
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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
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Page 231 and 232: 3.14.1.2 Accredited Standards Commi
Page 233 and 234: FIGURE 3.14.4 IEC technical-committ
Page 235 and 236: TABLE 3.14.2 Relevant Documents for
Page 237: TABLE 3.14.5 Relevant Documents for
Page 241: TABLE 3.14.13 Relevant Documents fo
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