Читать книгу Handbook of Large Hydro Generators - Geoff Klempner - Страница 4

1 Chapter 1Figure 1.1-1 Representation of two magnetic poles of opposite polarity, with...Figure 1.1-2 Representation of two north poles and the magnetic field betwee...Figure 1.1-3 Representation of a “permanent magnet” showing the north and so...Figure 1.1-4 Representation of a magnetic field created by the flow of curre...Figure 1.1-5 Representation of a magnetic field produced by the flow of elec...Figure 1.1-6 Representation of a magnetic field produced by the flow of elec...Figure 1.1-7 Representation of a magnetic field produced by the flow of elec...Figure 1.1-8 Electricity. (I) Ionic clouds of positive and negative currents...Figure 1.2-1 Electrical–mechanical equivalence.Figure 1.3-1 A phasor E that can represent the voltage impressed on a circui...Figure 1.3-2 Alternating circuits (resistive).Figure 1.3-3 Alternating circuits (resistive‐inductive‐capacitive).Figure 1.3-4 Definition of the “power triangle” in a reactive circuit.Figure 1.3-5 Schematic of a simple system in one‐line form.Figure 1.3-6 Case 1. The load is purely resistive in this example, and the s...Figure 1.3-7 Case 2. The load is resistive and inductive in this example, an...Figure 1.3-8 The effect on the voltage drop as the circuit goes from lagging...Figure 1.4-1 Three‐phase systems. Schematic depiction of a three‐phase circu...Figure 1.4-2 A “wye‐connected” source feeding a “delta‐connected” load.Figure 1.5-1 Both forms of Faraday's basic law of electromagnetic induction....Figure 1.5-2 The Ampere–Biot–Savart law of electromagnetic‐induced forces as...Figure 1.5-3 Lenz's law as it applies to electric rotating machines. Basic n...Figure 1.5-4 Principle of energy conversion as applicable to electric rotati...Figure 1.6-1 The hydroelectric generator from Lauffen, now in the Deutches M...Figure 1.6-2 “Growth” graph, depicting the overall increase in size over the...Figure 1.6-3 Synchronous machine construction.Figure 1.6-4 “Developed” view showing four‐poles, slots, and a section of th...Figure 1.6-5 Typical winding configurations.Figure 1.7-1 Production of stator rotating field.Figure 1.7-2 Phasor diagram of an unsaturated salient pole generator (laggin...Figure 1.7-3 Vector diagram of generator with a lagging power factor.Figure 1.7-4 Vector diagram of generator with a leading power factor.Figure 1.7-5 Steady‐state power angle characteristic of a salient pole synch...Figure 1.7-6 One‐line representation of the circuit shown in Figures 1.4-1 a...Figure 1.7-7 Steady‐state equivalent circuit of a synchronous machine.Figure 1.7-8 Steady‐state equivalent circuit and vector diagram. (a) Generat...

2 Chapter 2Figure 2.1-1 Cross section of core showing inter‐laminar damage and the eddy...Figure 2.1-2 Inter‐laminar insulation reduces eddy current losses in the ste...Figure 2.1-3 Laminated‐core eddy‐current loss as percentage of full‐block lo...Figure 2.1-4 Stator core segment described.Figure 2.1-5 Showing the U shaped or “hairpin” coil.Figure 2.1-6 Lamination stacking in the stator, also showing the conventiona...Figure 2.1-7 Heavy lamination segment with I‐shaped blocks (radial duct) – r...Figure 2.1-8 Shows double dovetail design that prevents core buckling.Figure 2.1-9 Core‐to‐keybar mounting arrangement in the stator frame. Shim l...Figure 2.1-10 Shows another arrangement for the core bolt.Figure 2.1-11 For demonstration purposes this figure shows an insulating bus...Figure 2.1-12 Showing the vent lamination with the hole to accommodate the b...Figure 2.1-13 Shows compression washer assembly.Figure 2.1-14 Shows keybar and core clamping bolt as one piece with threaded...Figure 2.1-15 76 MVA newly piled stator core showing the clamping finger ass...Figure 2.1-16 86 MVA newly piled stator core showing the first packet with s...Figure 2.1-17 Shows finger plate installation with adjustable fulcrum points...Figure 2.2-1 Shows outside part of stator frame showing the wrapper plate an...Figure 2.2-2 Typical soleplate positioned in the foundation awaiting final s...Figure 2.2-3 Shows another style of soleplate with double “J or T” hooks.Figure 2.3-1 Four pole generator flux pattern.Figure 2.3-2 Flux distribution and flux density at no load obtained by FE si...Figure 2.3-3 Flux distribution and flux density at rated load obtained by FE...Figure 2.3-4 Flux distribution and flux density during sudden short circuit ...Figure 2.3-5 Shows the flux distribution in the over‐excited mode with field...Figure 2.3-6 Shows the flux density in the over‐excited mode with field curr...Figure 2.3-7 Shows the flux distribution in the under excited mode with fiel...Figure 2.3-8 Shows the flux density in the under excited mode with field cur...Figure 2.7-1 Typical multi‐turn coil strand configurations.Figure 2.7-2 Typical single turn Roebel bar configuration.Figure 2.7-3 Cross section of stator bar in the stator slot.Figure 2.7-4 Cross section of a stator multi‐turn coil in the stator slot.Figure 2.7-5 Shows a two turn bar in the stator slot (teeth are adjacent to ...Figure 2.7-6 Stator endwinding showing reversing group jumper connection on ...Figure 2.7-7 Stator endwinding showing reversing group jumper connections on...Figure 2.7-8 Showing reduced eddy current losses with individual strands of ...Figure 2.7-9 Individual strand cross section to reduce losses from right to ...Figure 2.7-10 Looping of a coil with inverted turn.Figure 2.7-11 Roebel transposition 3D view.Figure 2.7-12 Roebel bar principle.Figure 2.7-13 Temperature profile of a double‐stack stator bar with separate...Figure 2.7-14 Cross Roebel transposition‐temperature profile of a double‐sta...Figure 2.7-15 Cross Roebel transposition – temperature profile of a double s...Figure 2.7-16 Shows a 3D representation of a typical water cooled stator bar...Figure 2.7-17 Direct cooled stator winding (rotor poles removed).Figure 2.7-18 Shows the black semiconducting material and the grey Silicon C...Figure 2.7-19 Flat side‐packing (top) and ripple spring (bottom) with semico...Figure 2.7-20 Shows stand up view of Figure 2.7-19 to illustrate the ripple ...Figure 2.8-1 Typical packing material and wedge assemblies.Figure 2.8-2 Various types of wedge assemblies.Figure 2.8-3 Shows core packet and fretting at the interface of wedge groove...Figure 2.8-4 Shows minimal damage to wedge groove after cleaning.Figure 2.9-1 Stator endwinding support system for a bar winding.Figure 2.9-2 Stator endwinding support system for a multi‐turn coil.Figure 2.10-1 Two parallel Y connected winding.Figure 2.10-2 Four parallel Y connected winding.Figure 2.10-3 Two parallel paths with long series jumpers.Figure 2.11-1 Generator main leads – new installation with tags to show test...Figure 2.11-2 Shows split phase CT's on main output leads.Figure 2.11-3 Generator neutral leads – new CT's tested and ready.Figure 2.12-1 Shows a modern day rotor.Figure 2.12-2 Shows rotor from 1925 without the field poles installed.Figure 2.12-3 The beginning of rim piling.Figure 2.12-4 Shows rim stack at an early stage of progression.Figure 2.12-5 Rim being piled showing the stacks of steel laminations and ri...Figure 2.12-6 Rim press operation during the piling process.Figure 2.12-7 Shows rotor rim donuts.Figure 2.12-8 Fully piled rim with no end plate – just steel segments on top...Figure 2.12-9 Shows another rim design with end plates.Figure 2.12-10 Rim key in final position.Figure 2.12-11 Tapered rim keys set in final position by hydraulic jack.Figure 2.12-12 Torque key installation in progress.Figure 2.13-1 Shows a cast and fabricated spider assembly.Figure 2.13-2 Shows spider drum design.Figure 2.13-3 Rotor drum support shelves.Figure 2.13-4 Rotor spider support shelf.Figure 2.14-1 Example flux distribution through pole body.Figure 2.14-2 Shows parts of field pole being assembled.Figure 2.14-3 Shows finished rotor pole end plate with the “L” shaped portio...Figure 2.14-4 Concept of interpolar wedge.Figure 2.14-5 Example of an interpolar wedge.Figure 2.15-1 Copper strap edge bent coils.Figure 2.15-2 Edge bend consequence of gaps between copper segments.Figure 2.15-3 Assembled copper pieces at the jigsaw (interlocking) joint sim...Figure 2.15-4 Brazed jig saw (interlocking) sections and uniform copper.Figure 2.15-5 Shows groundwall insulation, insulating collar, silicone seala...Figure 2.15-6 Shows wedges on pole body to secure copper coil.Figure 2.15-7 Finished field pole with red insulating varnish applied.Figure 2.16-1 Amortisseur bar visible through the pole punching.Figure 2.16-2 Pole under construction with the amortisseur shorting bar show...Figure 2.16-3 Flexible connection between amortisseur circuits on adjacent p...Figure 2.16-4 Shows solid amortisseur connection between adjacent poles.Figure 2.17-1 Brushless excitation.Figure 2.17-2 Traditional rotating brushless exciter with diodes.Figure 2.17-3 Shows modern style constant pressure spring.Figure 2.17-4 Slipring assembly with old style adjustable spring.Figure 2.18-1 Ventilation diagram for a rim ventilated machine.Figure 2.19-1 Rotor centrifugal fan.Figure 2.19-2 Rotor axial fan.Figure 2.20-1 Extra rim laminations at the bottom (colored in red).Figure 2.21-1 Shows a cross section of a conventional two guide bearing gene...Figure 2.21-2 Shows a cross section of an umbrella style generator with one ...Figure 2.21-3 Shows Babbitt bearing pie pieces or “shoes.”Figure 2.21-4 Shows Teflon^™ bearing pie pieces or “shoes.”Figure 2.21-5 Shows load cells supporting the thrust bearing shoes.Figure 2.21-6 Shows oil pressure distribution between runner plate and pivot...Figure 2.21-7 Sketch showing oil wedge principle for a pivoting shoe on jack...Figure 2.21-8 Oil pressure distribution between the runner plate for a sprin...Figure 2.21-9 Shows runner plate that sits on top of thrust bearing shoes....Figure 2.21-10 Shows spring assembly to support the shoes.Figure 2.21-11 Shows the bearing shoe installed.Figure 2.21-12 Shows the copper cooling coil at the bottom of the oil reserv...Figure 2.21-13 Shows thrust bearing cooler (extruded aluminum fin CuNi) tube...Figure 2.21-14 Demonstrates the principle of the hydrodynamic wedge in the g...Figure 2.21-15 Typical shaft guide bearing (sleeve type).Figure 2.21-16 Guide bearing shoe in the thrust/guide bearing combination as...Figure 2.21-17 Shows a Babbitt bearing wipe.Figure 2.21-18 Shows another bearing wipe.Figure 2.21-19 Shows what is left of a PTFE bearing when shoe removed and sp...Figure 2.21-20 Bearing shoe with surface abrasion.Figure 2.21-21 Bearing shoe with tin oxide damage.Figure 2.21-22 Bearing that exhibits overheating.Figure 2.21-23 Bearing shoe exhibiting thermal ratcheting.Figure 2.21-24 Bearing show exhibiting oil starvation.Figure 2.21-25 Show exhibiting outer edge Babbitt erosion.Figure 2.21-25 Bearing shows signs of electrical pitting.Figure 2.21-27 Edge load pivoted show showing Babbitt mechanical fatigue....Figure 2.21-28 Edge load journal shell with mechanical fatigue.Figure 2.21-29 Shoe segment showing fatigue.Figure 2.21-30 Shows result of cavitation erosion on the bearing surface....

3 Chapter 3Figure 3.1-1 Shows oil pot labyrinth seal at the top.Figure 3.1-2 Shows a typical high hat or chimney tube.Figure 3.2-1 Typical tube type surface air cooler.Figure 3.2-2 Shows typical water box on one side of surface air cooler.Figure 3.2-3 Cross section of a heat exchanger tube, showing the inner tube ...Figure 3.3-1 Thrust bearing cooling coil.Figure 3.3-2 Simple copper tubing used for cooling of the oil inside an oil ...Figure 3.4-1 Simplified Schematic of the pure water system piping.Figure 3.4-2 Relationship between conductivity and pH under ideal conditions...Figure 3.5-1 Shows pilot and main rotating exciters.Figure 3.5-2 Schematic of a shaft‐driven, rotating pilot and main excitation...Figure 3.5-3 Typical stator or stationary field.Figure 3.5-4 Typical rotating exciter armature.

4 Chapter 4Figure 4.1-1 Typical nameplate for a hydro generator.Figure 4.1-2 Schematic representation of a generator feeding a load through ...Figure 4.1-3 Typical capability curve for internal utility use.Figure 4.1-4 Typical saturation curve for transformers and generators.Figure 4.1-5 Hysteresis losses under normal and abnormal conditions.Figure 4.1-6 Manufacturer issued V/Hz curve.Figure 4.3-1 Open circuit and short circuit characteristics.Figure 4.3-2 Typical open circuit saturation characteristic.Figure 4.3-3 Typical short circuit characteristic.Figure 4.3-4 Typical capability curve from the manufacturer.Figure 4.3-5 Basic capability curve for internal utility use.Figure 4.3-6 Another manufacturer curve showing saliency circle and theoreti...Figure 4.3-7 Typical V‐curve from the manufacturer.Figure 4.5-1 Armature reaction.Figure 4.5-2 How the armature reaction affects the output voltage of a gener...Figure 4.5-3 Generator equivalent circuit.Figure 4.5-4 Vector representation of the fundamental circuit equation.Figure 4.5-5 Power transfer function applied to the power transferred betwee...Figure 4.5-6 Graphic representation of the fundamental circuit equation.Figure 4.5-7 Graphic solution for change of excitation from I_F1 to I_F2.Figure 4.5-8 Numerical example for Case 4.3.Figure 4.5-9 Continuation of Case 4.3 numerical example.Figure 4.5-10 Graphical representation of change in power.Figure 4.5-11 Numerical example for Case 4.4.Figure 4.5-12 Calculation of circulating current between two generators conn...Figure 4.5-13 Out‐of‐step mechanical conceptualization.Figure 4.5-14 Power system stability case with two lines and two busses befo...Figure 4.5-15 Simple case of generator stability from the generator perspect...Figure 4.6-1 Sets of balanced and unbalanced three‐phase phasors. (a) Balanc...Figure 4.6-2 An unbalanced set of three‐phase phasors and its symmetrical co...Figure 4.6-3 Symmetrical sequence components.Figure 4.6-4 Generator subjected to a phase‐to‐phase short circuit on its te...Figure 4.7-1 Typical life endurance of a shaft under periodic torsional stra...

5 Chapter 5Figure 5.3-1 Polar graph of instantaneous temperature magnitude for all hose...Figure 5.3-2 One hose‐outlet sensor indicating plugging as temperature in re...Figure 5.5-1 Embedded core thermocouple on lamination. Note that this figure...Figure 5.5-2 V/Hz curve.Figure 5.5-3 Core accelerometer placed on back of core between keybar and co...Figure 5.5-4 Limits for vibrational displacements [4].Figure 5.5-5 Illustration of a slot RTD installed in separator pad and locat...Figure 5.5-6 Fiber‐optic stator endwinding vibration transducer.Figure 5.5-7 Loose circuit ring vibrating and the white powder produced agai...Figure 5.5-8 Shows typical location of the partial discharge couplers on the...Figure 5.5-9 The Iris Power PDA‐IV^RP instrument.Figure 5.5-10 Slot discharge from loss of the semiconducting coating or coro...Figure 5.5-11 Internal and slot discharges.Figure 5.5-12 Shows stator core and parasitic currents.Figure 5.5-13 Shows the electrical arc as bar is vibrating and contact is lo...Figure 5.5-14 Shows the various locations for surface discharges in the endw...Figure 5.5-15 Damage at the semiconducting/stress control interface just out...Figure 5.5-16 Endwinding discharges where conductive debris is extending the...Figure 5.6-1 Radio‐frequency monitoring.Figure 5.7-1 A simple schematic for PD coupler locations on the generator wi...Figure 5.7-2 Typical partial discharge coupler installation.Figure 5.8-1 Plan view of the SSC installation.Figure 5.8-2 Stator slot coupler end view.Figure 5.8-3 Installed stator slot coupler.Figure 5.9-1 Shows a flux probe installation in progress on the stator core....Figure 5.9-2 Software output for flux probe data collected.Figure 5.9-3 Polar representation of flux probe data collected showing short...Figure 5.9-3 Shaft grounding brush.Figure 5.9-4 Airgap system architecture.

6 Chapter 6Figure 6.1-1 Single‐function protective relay.Figure 6.1-2 Schweitzer Engineering Laboratories SEL 300G multifunction rela...Figure 6.1-3 Beckwith Electric Co. Inc. M‐3425A multifunction relay.Figure 6.1-4 Beckwith M‐3425A multifunction generator protection outline (ty...Figure 6.3-1 High impedance ground protection and grounding transformer.Figure 6.3-2 Subharmonic voltage injection scheme.Figure 6.3-3 Protection using two loss of excitation relays.Figure 6.3-4 Example of a voltage balance relay circuit.Figure 6.3-5 Example of a generator with one PT feeding its protection and e...Figure 6.3-6 Functional diagram of a generator zone breaker failure scheme....Figure 6.3-7 Approximate equivalent circuit.Figure 6.3-8 Generator percentage differential relay slope characteristic.

7 Chapter 7Figure 7.1-1 Shows the effects of a metallic object on the surface of a stat...Figure 7.1-2 Foreign material caused serious core damage.Figure 7.2-1 Ground leads applied to the generator bus at the switchgear.Figure 7.5-1 Example set of inspection tools.Figure 7.5-2 Typical borescope with articulating head.Figure 7.5-3 Pocket knife used to spot check core tightness.

8 Chapter 8Figure 8.1-1 Shows bare soleplate on concrete foundation before encasing in ...Figure 8.1-2 Typical soleplate arrangement as seen under the stator frame.Figure 8.1-3 Shows solid rectangular key with grease fitting for lubrication...Figure 8.1-4 Shows original soleplate arrangement – Teflon^™ pucks not ...Figure 8.1-5 Shows soleplate with Teflon^™ puck inserts in a steel hous...Figure 8.1-6 Shows mating steel surfaces on stator frame.Figure 8.1-7 Shows completed soleplate arrangement from inside stator frame ...Figure 8.1-8 Shows outer blocks welded to the frame ring.Figure 8.1-9 Shows center block which aids radial freedom and prevents tange...Figure 8.1-10 Shows welded/integral soleplate.Figure 8.1-11 Showing soleplate nut and stator hold‐down bolt.Figure 8.1-12 Shows hold-down bolt individual components.Figure 8.1-13 Shows assembled hold down bolt without the stator in place.Figure 8.1-14 Shows soleplate arrangement that does not allow radial expansi...Figure 8.1-15 Shows removable dowel pins similar to the ones in Figure 8.1-1...Figure 8.1-16 Shows grout pocket cracking.Figure 8.1-17 Shows foundation cracking.Figure 8.2-1 Shows frame welds.Figure 8.2-1 Shows stator frame‐split complete with a dowel and bolted arran...Figure 8.2-3 Shows metal filings in a new generator.Figure 8.2-4 Shows a light coating of contamination on the shelves and core ...Figure 8.2-5 Shows a significant amount of oil from a bearing leak.Figure 8.3-1 Shows that the core flares a small amount around the I‐beam ass...Figure 8.3-2 Shows core is more uniform and does not droop around the I‐beam...Figure 8.3-3 Shows stator core air ducts choking off airflow.Figure 8.4-1 Shows laminar fretting and missing pieces of stator core on the...Figure 8.4-2 Shows laminations found at bottom of generator pit.Figure 8.4-3 Shows piece of lamination on rotor pole.Figure 8.4-4 Shows degradation of the stator laminations, core finger, and w...Figure 8.4-5 Shows excellent core‐to‐keybar interface with no broken laminat...Figure 8.4-6 Shows fretting and broken and missing lamination pieces.Figure 8.4-7 Shows lamination shift at the very top of the core under clampi...Figure 8.4-8 Shows knife penetration of laminations.Figure 8.4-9 Core‐to‐keybar fretting – subtle beginning.Figure 8.4-10 Shows split axial misalignment.Figure 8.4-11 Shows minor smearing after repairs.Figure 8.4-12 Shows split paper still in place.Figure 8.4-13 Shows split fretting (red‐orange dust).Figure 8.4-14 Shows split that has been repacked by the OEM.Figure 8.4-15 Shows chevroning of the core.Figure 8.4-16 Shows stator core step punching fretting.Figure 8.4-17 Shows weeping epoxy (red color) on the laminations to consolid...Figure 8.4-18 Shows severe stator core step punching fretting and subsequent...Figure 8.4-19 Shows clamping plate removed exposing the finger assembly.Figure 8.4-20 Shows the fingers/heavy lamination and clamping plate assembly...Figure 8.4-21 Shows welded fingers to the clamping plate.Figure 8.4-22 Shows a gap between the clamping finger and stator core lamina...Figure 8.4-23 Shows insulating repair wedge epoxied in place (red color is e...Figure 8.5-1 Shows a typical clamping plate and finger assembly.Figure 8.5-2 Shows clamping fingers welded to the heavy lamination.Figure 8.5-3 Shows assembled clamping plate and the fingers with heavy lamin...Figure 8.5-4 Shows two fingers into the airgap and one finger machining the ...Figure 8.5-5 Shows crooked clamping finger.Figure 8.5-6 Shows bare stator frame before piling of core with keybars and ...Figure 8.5-7 Shows insulated core clamping studs that go through the core as...Figure 8.5-8 Shows the core stud and keybar attachment to the frame.Figure 8.5-9 Shows the core keybar/stud attachment to the frame.Figure 8.5-10 Shows keybar support gusset weld crack.Figure 8.5-11 Shows the gusset cracked as well as the weld.Figure 8.5-12 Shows another example of weld cracking.Figure 8.6-1 Shows chunks of insulation missing.Figure 8.6-2 Shows tape separation as evidenced by the black area on the end...Figure 8.6-3 Shows girth cracking (necking) evidenced by the separation of g...Figure 8.6-4 Shows partial discharge (white powder) at the interface.Figure 8.6-5 Shows extreme deterioration of the semi‐con/grading interface....Figure 8.7-1 Shows bypassed stator bar.Figure 8.7-2 Shows resistor on bottom end of winding into bypassed bar.Figure 8.8-1 Shows normal wedge installation.Figure 8.8-2 Shows filler migration.Figure 8.8-3 Shows center filler migrating out the bottom of the winding.Figure 8.8-4 Shows the black packing strip (at bottom of slot) migrating out...Figure 8.8-5 Shows felt and lashing added to prevent wedge and filler migrat...Figure 8.8-6 Shows wedge fretting and evidence of greasing on core packet.Figure 8.8-7 Shows silicone applied to the endwinding with insufficient clea...Figure 8.8-8 Shows bull ring and bull ring support.Figure 8.8-9 Circuit rings sitting inside the red blocking and lashed.Figure 8.8-10 Shows another style of circuit ring arrangement.Figure 8.8-11 Shows a completed brazed connection.Figure 8.8-12 Shows completed taped and epoxy encapsulated brazed connection...Figure 8.8-13 Shows encapsulation or end caps for a bar winding.Figure 8.8-14 Shows jumper connections encapsulated.Figure 8.8-15 Shows open type series connection.Figure 8.8-16 Shows rivet fastener on copper clip.Figure 8.10-1 Shows a more modern encapsulated type of current transformer....Figure 8.10-2 Shows older style taped CT.

9 Chapter 9Figure 9.0-1 Example of a cast spider and rim arrangement.Figure 9.0-2 Shows larger cast spider with laminated shrunk rim.Figure 9.1-1 Shows spider arms and support shelves that support the mass of ...Figure 9.1-2 Shows enlarged side view of an undamaged spider support shelf....Figure 9.1-3 Shows enlarged side view of support shelf with greasing and dep...Figure 9.1-4 Shows underside of Figure 9.1-3 with greasing at interface.Figure 9.1-5 Shows support shelf sheared off from a fatigue failure.Figure 9.1-6 Normal view of the side of a support shelf – no fretting or gre...Figure 9.1-7 Shows normal underside view of support shelf – no fretting dust...Figure 9.1-8 Shows crack on support shelf.Figure 9.1-9 Shows newly installed support brace on one side (other side not...Figure 9.1-10 Shows up close view of new support brace on the rim ledge.Figure 9.1-11 Shows a typical spider (drum style) assembly.Figure 9.1-12 Shows drum from Figure 9.1-11 with rim lamination stacking in ...Figure 9.1-13 Shows rim support shelf on drum design with fretting dust pres...Figure 9.1-14 Shows crack on spider post where weld ends on torque block.Figure 9.1-15 Shows air vanes where cracks tend to initiate.Figure 9.1-16 Shows crack where spider arms meet at hub.Figure 9.1-17 Shows crack on spider arm near rotor field leads attachment po...Figure 9.1-18 Shows shaft coupling bolts.Figure 9.2-1 Shows a rim key on a shrunk rim in excellent condition.Figure 9.2-2 Shows another style of rim key that is clean and free from fret...Figure 9.2-3 Shows rim keys installed with no visual on sides.Figure 9.2-4 Shows clean fretting free key inside rotor.Figure 9.2-5 Shows rim key on rotor rim with no fretting.Figure 9.2-6 Shows minor signs of fretting on rim keys (rim key from Figure ...Figure 9.2-7 Shows fretting dust inside the keyway and collection on the rim...Figure 9.2-8 Shows rim keys with fretting dust as collected on the white rag...Figure 9.3-1 Shows amortisseur missing from field pole.Figure 9.3-2 Shows localized burning of the laminations in contact with the ...Figure 9.3-3 Pump generator pole shows amortisseur bars and brazed connectio...Figure 9.3-4 Shows cracked braze and shorting bar for amortisseur.Figure 9.3-5 Shows severe damage to amortisseur circuit assembly on a pump g...Figure 9.3-6 Shows severe pole lamination damage.Figure 9.3-7 Shows a field pole with missing amortisseur bars.Figure 9.3-8 Leaf spring assembly to compress and position the coil on the p...Figure 9.3-9 Illustration of how the leaf springs are installed on the rotor...Figure 9.3-10 Shows side view illustration of Figure 9.3-8 when installed.Figure 9.3-11 Sketch showing spring inside rim pushing against bottom collar...Figure 9.3-12 Illustrates position of spring on bottom collar from Figure 9....Figure 9.3-13 Shows a potted pole with no field collar.Figure 9.3-14 Shows “slip plane” material used in between collar and last tw...Figure 9.3-15 Shows inter‐polar wedge.Figure 9.3-16 Shows typical field pole inter‐connector.Figure 9.3-17 Shows severely damaged field winding.Figure 9.3-18 Shows rim damage when field winding melted.Figure 9.3-19 Shows new omega style flexible connector.Figure 9.3-20 Shows braided interpole flexible connector.Figure 9.3-21 Shows a copper laminated leaf type connector not yet assembled...Figure 9.3-22 Shows flexible braided amortisseur connectors.Figure 9.3-23 Shows a rigid amortisseur connection.Figure 9.3-24 Shows a double “T” style pole key arrangement.Figure 9.3-25 Shows a typical dovetail style key arrangement.Figure 9.3-26 Shows pole key keeper plate.Figure 9.3-27 Shows red marks where cracks could initiate on a dovetail asse...Figure 9.3-28 Shows red marks where cracks could initiate on a T‐style assem...Figure 9.3-29 Shows cracks in rim laminations in attachment area.Figure 9.3-30 Shows close‐up view of rim lamination cracks from Figure 9.3-2...Figure 9.3-31 Shows large crack in end plate.Figure 9.3-32 Shows crack on T‐head.Figure 9.3-33 Shows a portion of the T‐head missing on end plate and on lami...Figure 9.3-34 Shows field leads as they connect to the field poles.Figure 9.4-1 Shows typical brake assembly.Figure 9.4-2 Shows newly installed brake track segment.Figure 9.4-3 Shows an alternate style brake assembly with no springs and pro...

10 Chapter 10Figure 10.1-1 Shows older style field breaker.Figure 10.1-2 Shows a more modern DC field breaker.Figure 10.1-3 Shows an AC field breaker.Figure 10.1-4 Shows one style of shunt on the field bus inside field breaker...Figure 10.1-5 Shows schematic of excitation system with field discharge resi...Figure 10.1-6 Shows typical discharge resistor inside field breaker cubicle....Figure 10.1-7 Shows another typical field discharge resistor.Figure 10.3-1 Shows brushless exciter diode end.Figure 10.3-2 Shows brushless exciter bus end.Figure 10.5-1 Shows armature commutator, brush assembly, risers, dust, and o...Figure 10.5-2 Shows close up of exciter stator (stationary part).Figure 10.5-3 Shows armature coil connections before brazing or soldering.Figure 10.5-4 Shows brazed connections from armature coil to risers.Figure 10.5-5 Shows the stator winding in good visual condition.Figure 10.5-6 Shows a failed exciter stator winding.Figure 10.5-7 Shows exciter interpole winding.Figure 10.5-8 Shows exciter armature (rotating part) out of stator.Figure 10.5-9 Shows exciter mounting bolt for the commutator assembly.Figure 10.5-10 Shows commutator brush rigging that can be rotated circumfere...Figure 10.6-1 Shows metallic particles inside the slipring helical grooves....Figure 10.6-2 Shows same contamination from slipring on copper bus.Figure 10.6-3 Shows a good commutator surface film.Figure 10.6-4 Shows good clean split brush that is in good condition and pro...Figure 10.6-5 Shows brush that is not properly seated.Figure 10.6-6 Shows streaky commutator.Figure 10.6-7 Shows threading on the commutator.Figure 10.6-8 Shows example of a grooved commutator.Figure 10.6-9 Shows bar edge burning on the commutator.Figure 10.6-10 Shows slipring in good condition.Figure 10.6-11 Shows slipring burned after a failure and severe damage to th...Figure 10.6-12 Shows close up view of slipring damage where brush surface re...Figure 10.6-13 Shows typical slipring insulation configuration.Figure 10.6-14 Illustration showing the difference between a “U and V” shape...Figure 10.6-15 Shows commutator bevel on the copper bars.Figure 10.6-16 Shows typical slipring brush gear arrangement.Figure 10.6-17 Shows approximate relationship of safe brush operation.Figure 10.6-18 Shows broken strands on brush shunt.Figure 10.6-19 Shows old style commutator springs.Figure 10.6-20 Shows old style slipring springs.Figure 10.6-21 Shows modern style commutator springs.Figure 10.6-22 Shows modern style slipring springs (same spring as in Figure...Figure 10.7-1 Shows significant scale buildup restricting water flow.Figure 10.7-2 Shows the water box open on a surface air cooler.Figure 10.7-3 Shows cooler tubes that are damaged.Figure 10.8-1 Shows a heat activated device mounted above the water deluge r...Figure 10.9-1 Shows one style of shaft grounding brush.Figure 10.9-2 Shows missing bolts on frame member for upper covers.

11 Chapter 11Figure 11.1-1 Shows knife test at the back of the core.Figure 11.1-2 Shows radial and tangential measurement probe locations.Figure 11.2-1 Stator core fault current path.Figure 11.2-2 Shows a block diagram of the ELCID setup.Figure 11.2-3 Shows multiple loops of wire on the stator as part of the ELCI...Figure 11.2-4 Setup for ELCID testing.Figure 11.2-5 Shows the ELCID potentiometer basic circuit.Figure 11.2-6 Shows the Chattock Potentiometer on the stator core.Figure 11.2-7 Flux test cable forming the loop or rings wrapped around the s...Figure 11.2-8 Shows repaired core ready for the high energy flux test.Figure 11.2-9 Shows a thermal scan of Figure 11.2-8.Figure 11.3-1 Shows manual method of checking wedge tightness with a small b...Figure 11.3-2 Shows automated wedge tapper on the stator core.Figure 11.3-3 Shows the wedge map produced by the software.Figure 11.5-1 Shows a perfect semiconducting (black) and stress control (gre...Figure 11.5-2 Shows interface damage and resulting partial discharge activit...Figure 11.5-3 Shows interface with advanced severe deterioration.Figure 11.5-4 Shows another example of severe damage to the interface area....Figure 11.5-5 Shows the coil ready for the black semiconducting paint applic...Figure 11.5-6 Shows the black semiconductive paint applied to the coil and t...Figure 11.5-7 PD testing by capacitive coupling – offline.Figure 11.5-8 Shows PD summary values.Figure 11.5-9 Shows classic PD patterns.Figure 11.5-10 Shows TVA probe for use on the stator slots.Figure 11.5-11 Shows ultrasonic probe with headphones to detect PD.Figure 11.5-12 Equivalent circuit showing the four currents monitored during...Figure 11.5-13 Insulation resistance measurements at 5 kV for same machine b...Figure 11.5-14 Measured current for a generator with a strong influence of t...Figure 11.5-15 Types of currents for an epoxy‐mica insulation with a relativ...Figure 11.5-16 Temperature correction factors for “Thermoplastic” (asphalt) ...Figure 11.5-17 Polarization index curves for insulation resistance as a func...Figure 11.5-18 DC ramp test plot.Figure 11.6-1 Crack in spider arm support ledge clearly visible by the naked...Figure 11.6-2 Shows a magnetic particle indication of a crack.Figure 11.6-3 Shows phased array approach to crack detection.Figure 11.6-4 Shows FEA results outlining the pole attachment high stress ar...Figure 11.6-5 Shows FEA results outlining the rim attachment high stress are...Figure 11.6-6 Shows increased radius in the rim section to alleviate the str...Figure 11.6-7 Shows increased radius in the pole section to alleviate the st...Figure 11.6-8 Shows machining of the pole attachment area.Figure 11.6-9 Shows on‐site machining of the rim attachment area.Figure 11.6-10 Shows spider arm and welds to check with NDE.Figure 11.6-11 Shows spider hub and which welds to check with NDE.Figure 11.6-12 Shows shelf crack and where UT should be positioned.Figure 11.6-13 Shows one style of rotor fan for NDE of welds.Figure 11.6-14 Shows another style of rotor fan for NDE.Figure 11.6-15 Shows drum assembly with disks and vanes.Figure 11.7-1 Shows horseshoe style field coil interpole connectors.Figure 11.7-2 Shows rotor leads fastened to the rotor structure.Figure 11.7-3 Shows schematic setup for a impedance (VIW) test.Figure 11.7-4 Shows examples of a tested pole with no shorts.

12 Chapter 12Figure 12.5-1 Shows two capability curves – original in red and uprated in b...Figure 12.5-2 Shows uprated capability with new higher power factor.Figure 12.6-1 Schematic of the static pilot and rotating exciters.Figure 12.6-2 Shows architecture of a rotating brushless exciter with diode ...Figure 12.6-3 The original exciter stator void of all old poles and interpol...Figure 12.6-4 Newly manufactured field poles on the original stator exciter ...Figure 12.6-5 Shows completed exciter stator.Figure 12.6-6 Shows the original armature with the commutator removed and a ...Figure 12.6-7 The exciter armature in final phases of winding assembly and d...Figure 12.6-8 Shows the completed exciter armature.Figure 12.6-9 Shows thyristor arrangement in the architecture of the exciter...Figure 12.6-10 Shows new brushless exciter with thysristor technology.Figure 12.6-11 3D model of the exciter stator in Figure 12.6-10.Figure 12.6-12 Sectional view of the rotor assembly.Figure 12.6-13 Shows difference in response times for diode vs thyristor/sta...Figure 12.6-14 Shows de‐excitation rate between diode, static, and thyristor...Figure 12.6-15 Shows transceivers inside exciter housing.Figure 12.6-16 Shows the conversion schematically from thyristor to diode mo...Figure 12.6-17 Typical static exciter schematic.Figure 12.6-18 Shows a simplified diagram of the static excitation system....Figure 12.6-19 Typical static exciter on the right and exciter transformer o...