Electric Machinery and Apparatus

8/16/2019 Electric Machinery and Apparatus

1/78

ELECTRIC MACHINERY ANDAPPARATUS

JUNE 3, 2016MINH-QUAN DANG


2/78

Contents

Electrical apparatus1 SWITCHING DEVICES ....................................................................................................................................................... 6

1.1 Purposes .................................................................................................................................................................. 6

1.2 Classification ........................................................................................................................................................... 6

1.2.1 By rated voltage .............................................................................................................................................. 6

1.2.2 Type of current ................................................................................................................................................ 6

1.2.3 Place of installation ......................................................................................................................................... 6

1.2.4 Extinguishing medium ..................................................................................................................................... 6

1.3 Definition................................................................................................................................................................. 7

1.4 Disconnectors .......................................................................................................................................................... 7

1.5 Earthing Switches .................................................................................................................................................... 7

1.6 High-speed Earthing switches ................................................................................................................................. 7

1.7 Switches .................................................................................................................................................................. 7

1.8 Contactors ............................................................................................................................................................... 7

1.9 Fuses ....................................................................................................................................................................... 8

1.10 Spark Gaps............................................................................................................................................................... 8

1.11 Surge arresters ........................................................................................................................................................ 8

1.12 Fault current limiters .............................................................................................................................................. 8

1.13 Starters .................................................................................................................................................................... 8

1.14 Switching regulators ............................................................................................................................................... 8

1.15 Electrical relays ....................................................................................................................................................... 9

1.16 Circuit breakers ....................................................................................................................................................... 9

1.17 Disconnecting Circuit breakers ............................................................................................................................... 9

2 SF 6 Circuit Breakers ....................................................................................................................................................... 9

2.1 Property of SF6 ........................................................................................................................................................ 9

2.2 Arc-extinguishing in SF6 medium ............................................................................................................................ 9

2.3 Double-pressure systems ...................................................................................................................................... 10

2.4 Single-pressure systems ........................................................................................................................................ 102.4.1 Single-pressure HV systems .......................................................................................................................... 10

2.4.2 Single-pressure EHV systems ........................................................................................................................ 11

2.5 Encapsulated distribution substations .................................................................................................................. 12

2.5.1 characteristics ............................................................................................................................................... 12

2.5.2 Advantages .................................................................................................................................................... 12

3 Oil and air circuit breakers ............................................................................................................................................ 12

3.1 Working Principle .................................................................................................................................................. 12


3/78

3.2 Minimum Oil Circuit Breaker ................................................................................................................................ 13

4 Air blast circuit breakers ............................................................................................................................................... 14

5 Low voltage protecting apparatus ................................................................................................................................ 15

5.1 Fuses ..................................................................................................................................................................... 15

5.2 Circuit breaker ....................................................................................................................................................... 16

5.2.1 Residual current circuit breaker – RCCB ....................................................................................................... 16

6 Vacuum circuit breakers ............................................................................................................................................... 17

6.1 Characteristics ....................................................................................................................................................... 17

6.2 Application ............................................................................................................................................................ 17

6.2.1 Principles ....................................................................................................................................................... 17

6.2.2 Vacuum extinguishing chamber .................................................................................................................... 18

6.2.3 Characteristics of the SF6 and vacuum current interrupting technologies. ................................................. 18

Electrical Machinery1 Introduction .................................................................................................................................................................. 21

1.1 Electromagnetic Energy Conversion ..................................................................................................................... 21

1.2 Energy Efficiency ................................................................................................................................................... 21

1.3 Mechanical Loads .................................................................................................................................................. 21

1.4 Equation of Motion ............................................................................................................................................... 21

1.5 Maxwell Equations ................................................................................................................................................ 22

1.6 Magnetic Circuit .................................................................................................................................................... 22

1.6.1 Magnetic circuit with air gap ........................................................................................................................ 23

1.6.2 Analogy – Magnetic x Electric ....................................................................................................................... 23

1.7 Electromagnetic Induction .................................................................................................................................... 23

1.8 Lorentz Force ........................................................................................................................................................ 24

1.9 Magnetization curve ............................................................................................................................................. 24

1.10 Rotating Magnetic Field ........................................................................................................................................ 25

2 DC MACHINES ............................................................................................................................................................... 25

2.1 DC MACHINE MAIN PARTS .................................................................................................................................... 252.2 SCHEMATIC DRAWINGS ........................................................................................................................................ 26

2.3 THREE BASIC TYPES OF DC MACHINES .................................................................................................................. 26

2.4 PRINCIPLES OF OPERATION................................................................................................................................... 26

2.5 GENERATOR ACTION ............................................................................................................................................. 27

2.5.1 BASIC EQUATIONS OF DC GENERATORS ....................................................................................................... 27

2.5.2 SEPARATELY EXCITED GENERATOR ............................................................................................................... 28

2.5.3 VOLT-AMPERE (LOAD) CHARACTERISTICS .................................................................................................... 28


4/78

2.5.4 ARMATURE REACTION .................................................................................................................................. 28

2.5.5 COMMUTATION PROCES .............................................................................................................................. 29

2.5.6 AUXILIARY COMMUTATION POLES ............................................................................................................... 29

2.5.7 SHUNT GENERATOR ...................................................................................................................................... 29

2.5.8 EXCITATION OF SHUNT GENERATOR ............................................................................................................ 30

2.5.9 COMPARISON OF GENERATORS ................................................................................................................... 30

2.5.10 ENERGY BALANCE (POWER DIVISION) .......................................................................................................... 30

2.6 MOTOR ACTION .................................................................................................................................................... 31

2.6.1 BASIC EQUATIONS OF DC MOTORS .............................................................................................................. 31

2.6.2 DC Motor Basic Description .......................................................................................................................... 31

2.6.3 SEPARATELY EXCITED .................................................................................................................................... 32

2.6.4 SHUNT EXCITED ............................................................................................................................................. 35

2.6.5 SERIES EXCITED ............................................................................................................................................. 36

2.6.6 COMPARISON OF MOTORS ........................................................................................................................... 39

2.6.7 STARTING AND ROTATION REVERSAL ........................................................................................................... 39

3 Transformers ................................................................................................................................................................. 40

3.1 Principle of Function ............................................................................................................................................. 40

3.2 Single-Phase Transformer ..................................................................................................................................... 40

3.3 Fundamental Transformer Equation ..................................................................................................................... 40

3.4 Real Transformer with Sinusoidal Supply ............................................................................................................. 41

3.5 Electromotive Force Ui in Winding ..................................................................................................................... 41

3.6 Equivalent Circuit of Transformer ......................................................................................................................... 413.7 No-Load Operation ............................................................................................................................................... 42

3.7.1 Iron Losses ΔP Fe ........................................................................................................................................... 42

3.8 Short-circuit operation .......................................................................................................................................... 43

3.9 Losses and Efficiency ............................................................................................................................................. 44

3.10 Voltage Drop over Load ........................................................................................................................................ 45

3.11 Connection ............................................................................................................................................................ 45

3.11.1 Star ................................................................................................................................................................ 45

3.11.2 Triangle.......................................................................................................................................................... 453.11.3 Zigzag ............................................................................................................................................................. 46

3.12 Vector group (hour angle) ..................................................................................................................................... 46

3.13 Parallel operation of transformers ....................................................................................................................... 46

3.13.1 no-load .......................................................................................................................................................... 47

3.13.2 Loaded ........................................................................................................................................................... 47

3.14 Autotransformer ................................................................................................................................................... 47

3.15 Current Instrument Transformer .......................................................................................................................... 48


5/78

3.16 Voltage Instrument Transformer .......................................................................................................................... 49

3.17 Connection of Transformer in No-Load Operation to Grid ................................................................................... 49

3.18 Short Circuit of Transformer in Steady-State No-Load Operation ........................................................................ 50

3.18.1 Limitation of Short-Circuit Current ............................................................................................................... 51

3.18.2 Mechanical Stress of Transformers ............................................................................................................... 52

4 Induction machine ........................................................................................................................................................ 53

4.1 Applications ........................................................................................................................................................... 53

4.2 Construction .......................................................................................................................................................... 53

4.3 Principle ................................................................................................................................................................ 54

4.3.1 Rotating magnetic field ................................................................................................................................. 54

4.3.2 Magnetic field in air gap................................................................................................................................ 54

4.3.3 Stator winding ............................................................................................................................................... 55

4.3.4 Pitch factor .................................................................................................................................................... 55

4.3.5 Distribution factor ......................................................................................................................................... 55

4.3.6 Stator slots .................................................................................................................................................... 56

4.4 Main speed terms ................................................................................................................................................. 56

4.5 Park transformation .............................................................................................................................................. 56

4.6 Equivalent circuit................................................................................................................................................... 56

4.7 Equations .............................................................................................................................................................. 57

4.8 Torque-speed characteristic ................................................................................................................................. 57

4.9 Circle diagram ....................................................................................................................................................... 58

4.10 Efficiency ............................................................................................................................................................... 624.11 Starting .................................................................................................................................................................. 62

4.12 Breaking ................................................................................................................................................................ 64

4.13 Speed control ........................................................................................................................................................ 64

4.14 Single-phase IM ..................................................................................................................................................... 65

5 Synchronous Machines ................................................................................................................................................. 66

5.1 Construction .......................................................................................................................................................... 66

5.2 Fluxes and Reactance ............................................................................................................................................ 66

5.3 Synchronous Alternator with a Cylindrical Rotor ................................................................................................. 67

5.4 Voltage Equations ................................................................................................................................................. 67

5.5 Asynchronous Run-up of a Synchronous Motor ................................................................................................... 68

5.6 Loading of a Synchronous Motor .......................................................................................................................... 69

5.7 Loading of a Synchronous Generator – Alternator ............................................................................................... 69

5.8 Basic Equivalent Circuit of a Turbomachine.......................................................................................................... 69

5.9 Phasor Diagram of an Overexcited Turbomachine ............................................................................................... 71


6/78

5.10 Loading at a Constant Excitation while Connected to a Strong Grid .................................................................... 72

5.10.1 Torque of a Turbomachine............................................................................................................................ 72

5.10.2 Torque of a Salient Pole Synchronous Machine ........................................................................................... 73

5.10.3 Power (Torque) Overload Capacity ............................................................................................................... 73

5.10.4 Stand-alone Alternator ................................................................................................................................. 74

5.11 Synchronization of Generator (Connecting to the Grid) ....................................................................................... 74

5.12 Dimensions of Turbomachines ............................................................................................................................. 74

5.13 Excitation Systems of Synchronous Machines ...................................................................................................... 75

5.13.1 Excitation from rotary converters ................................................................................................................. 75

5.13.2 Excitation from alternate driver .................................................................................................................... 75

5.13.3 Excitation with carried rectifier..................................................................................................................... 75

5.13.4 Excitation from a system with a rotary transformer .................................................................................... 76

5.13.5 Excitation from a static converter ................................................................................................................. 76

5.13.6 Excitation with permanent magnets ............................................................................................................. 76

5.14 Brushless DC Motor .............................................................................................................................................. 77


7/78

Electrical apparatus

1 SWITCHING DEVICES

1.1 PURPOSES

1.2 CLASSIFICATION

1.2.1 By rated voltage- Low voltage < 1kV

- High voltage > 1kV

- Extra-high voltage 245 kV 800 kV

1.2.2 Type of current- DC

- AC

1.2.3 Place of installation- Indoor

- Outdoor

1.2.4 Extinguishing medium- Air

- Oil

- Compressed air

- Vacuum

- SF6

- sand


8/78

1.3 DEFINITION

1.4 DISCONNECTORS

1.5 EARTHINGSWITCHES

1.6 HIGH-SPEEDEARTHING SWITCHES

1.7 SWITCHES

1.8 CONTACTORS


9/78

1.9 FUSES

1.10 SPARKGAPS

1.11 SURGE ARRESTERS

1.12 FAULT CURRENT LIMITERS

1.13 STARTERS

1.14 SWITCHING REGULATORS


10/78


11/78


12/78

7. Pevný kontakt – fixed contact

8. Izolační táhlo – insulating pull rod

9. Ventil zabraňující explozi - anti-explosion valve

2.4.2 Single-pressure EHV systems1. Horní vodič proudu – upper terminal

2. Nepohyblivý opalovací kontakt fixed arcing contact

3. Pohyblivý opalovací kontakt -movable arcing contact

4. „Puffer“ prostor „Puffer“ volume

5. Dolní vodič proudu - lower current conductor

6. Tryska - Jet

7. Nepohyblivý hlavní kontakt- fixed main contact

8. Pohyblivý hlavní kontakt- movable main contact

9. „Puffer“ válec – „puffer“ cylindr

10. Plnící ventil – charging valve

11. Nepohyblivý píst – fixed piston


13/78

2.5 ENCAPSULATED DISTRIBUTION SUBSTATIONS

2.5.1 characteristicsVoltage from 50 up to 800 kV

1. Vypínač -Circuit breaker

2. Přípojnicový odpojovač - bus bar disconnecting switch

3. Odpojovač od země - grounding disconnecting switch

4. Odpojovač od země - grounding disconnecting switch

5. Transformátor proudu – current transformer

6. Transformátor napětí - voltage transformer

7. Izolátorová průchodka SF6 – vzduch- insulating bushing SF6-air

8. Hydraulický pohon- hydraulic drive

9. Ovládání odpojovačů - disconnecting switch control boxes

10. Ovláda cí skříň – control cabinet

2.5.2 Advantages1. Needs small area for installation

2. Possibility to install distribution substations in the city centre

3. Operational High safety level

4. Quick installation

5. Low cost maintenance

6. High operational reliability

7. More expensive

3 OIL AND AIR CIRCUIT BREAKERS

3.1 WORKINGPRINCIPLE


14/78

The ionized gas around the arc sweep away through upper vent and cold oil enters into the arcing chamber through thelower vent in axial direction as soon as the moving contact tip crosses the lower vent opening and final arc quenching inminimum oil circuit breaker occurs.

The cold oil occupies the gap between fixed contact and moving contact and the minimum oil circuit breaker finally comesinto open position.

Whereas in case of radial venting or cross blast, the gases (mostly Hydrogen) sweep the arc in radial or transversedirection. The axial venting generates high gas pressure and hence has high dielectric strength, so it is mainly used forinterrupting low current at high voltage. On the other hand radial venting produces relatively low gas pressure and hencelow dielectric strength so it can be used for low voltage and high current interruption. Many times the combination ofboth is used in minimum oil circuit breaker so that the chamber is equally efficient to interrupt low current as well as highcurrent. These types of circuit breaker are available up to 8000 MVA at 245 KV.

In oil circuit breakers, the arc is drawn in oil inside a special compartment of the interrupting chamber called the explosionpot. The intense heat of the arc decomposes the oil and produces gases, mainly composed of hydrogen, generating highpressure that produces a fluid flow through the arc and out of the explosion pot through vents situated on its walls. Thusextending the arc’s column and carrying its energy away until its total extension see Fig 3.

3.2 MINIMUM OILCIRCUITBREAKER


15/78

As the volume of the oil in bulk oil circuit breaker is huge, the chances of fire hazard in bulk oil system are more. Foravoiding unwanted fire hazard in the system, one important development in the design of oil circuit breaker has beenintroduced where use of oil in the circuit breaker is much less than that of bulk oil circuit breaker. It has been decided thatthe oil in the circuit breaker should be used only as arc quenching media not as an insulating media. Then the concept ofminimum oil circuit breaker comes. In this type of circuit breaker the arc interrupting device is enclosed in a tank ofinsulating material which as a whole is at live potential of system. This chamber is called arcing chamber or interruptingpot. The gas pressure developed in the arcing chamber depends upon the current to be interrupted. Higher the currentto be interrupted causes larger the gas pressure developed in side the chamber, hence better the arc quenching. But thisput a limit on the design of the arc chamber for mechanical stresses. With use of better insulating materials for the arcingchambers such as glass fiber, reinforced synthetic resin etc, the minimum oil circuit breaker are able to meet easily theincreased fault levels of the system.

4 AIR BLAST CIRCUIT BREAKERS This type of circuit breakers, is those kind of circuit breaker which operates in air at atmospheric pressure. Afterdevelopment of oil breaker, the medium voltage air circuit breaker (ACB) is replaced completely by oil circuit breaker indifferent countries. But in countries like France and Italy, ACBs are still preferable choice up to voltage 15 KV. It is alsogood choice to avoid the risk of oil fire, in case of oil circuit breaker. In America ACBs were exclusively used for the systemup to 15 KV until the development of new vacuum and SF6 circuit breakers.

In Axial Blast ACB the moving contact is in contact with fixed contact with the help of a spring pressure as shown in thefigure. There is a nozzle orifice in the fixed contact which is blocked by tip of the moving contact at normal closed conditionof the breaker. When fault occurs, the high pressure air is introduced into the arcing chamber. The air pressure will counterthe spring pressure and deforms the spring hence the moving contact is withdrawn from the fixed contact and nozzle hole

becomes open. At the same time the high pressure air starts flowing along the arc through the fixed contact nozzle orifice.This axial flow of air along the arc through the nozzle orifice will make the arc lengthen and colder hence arc voltagebecome much higher than system voltage that means system voltage is insufficient to sustain the arc consequently thearc is quenched.

http://www.electrical4u.com/electrical-switchgear/oil-circuit-breaker.phphttp://www.electrical4u.com/electrical-switchgear/oil-circuit-breaker.phphttp://www.electrical4u.com/electrical-switchgear/oil-circuit-breaker.phphttp://www.electrical4u.com/electrical-switchgear/oil-circuit-breaker.php


16/78

In this type of axial blast air circuit breaker, the moving contact is fitted over a piston supported over a spring. In order toopen the circuit breaker, the air is admitted into the arcing chamber when pressure reaches to a predetermined value, itpresses down the moving contact; an arc is drawn between the fixed and moving contacts. The air blast immediately

transfers the arc to the arcing electrode and is consequently quenched by the axial flow of air.

The working principle of Cross Blast Air Circuit Breaker is quite simple. In this system of air blast circuit breaker the blastpipe is fixed in perpendicular to the movement of moving contact in the arcing chamber and on the opposite side of thearcing chamber one exhaust chamber is also fitted at the same alignment of blast pipe, so that the air comes from blastpipe can straightly enter into exhaust chamber through the contact gap of the breaker. The exhaust chamber is spit with

arc splitters. When moving contact is withdrawn from fixed contact, an arc is established in between the contact, and atthe same time high pressure air coming from blast pipe will pass through the contact gap and will forcefully take the arcinto exhaust chamber where the arc is split with the help of arc splitters and ultimately arc is quenched.

5 LOW VOLTAGE PROTECTING APPARATUS

5.1 FUSES Melting characteristics


17/78

Dependence of melting time as a function of current passing through fuse

5.2 CIRCUIT BREAKER Time-current switching –off characteristics

Extuinguishing chamber Electromagnetic release

Bimetal release

5.2.1 Residual current circuit breaker – RCCB


18/78


19/78

To increase breaker disconnecting ability anode spot must be eliminated.

It is possible by means:

1. Contact material property

2. Contacts shape arrangement

3. By means of electro-dynamic forces rotate the arc bottom round the anode

4. Contact dimensions increasing

5. External magnetic field excitation

6. To restrict over-voltage at low inductive currents disconnecting, chopped current must be minimised.

7. Low arc voltage, short time of arc relates to minimum arc energy and small contacts erosion =>extinguishing system is maintenance free.

6.2.2 Vacuum extinguishing chamber

6.2.3 Characteristics of the SF6 and vacuum current interrupting technologies.SF6 Circuit Breakers Vacuum Circuit Breakers

Criteria Puffer Circuit Breaker Self-pressuring circuit-breaker Contact material-Chrome-Copper


20/78


21/78

No. of short-circuitoperation

10 —50 10 —50 30 —100

No. full loadoperation

5000 —10000 5000 —10000 10000 —20000

No. of mechanicaloperation

5000 —20000 5000 —20000 10000 —30000


22/78

Electrical Machinery

1 INTRODUCTION

1.1 ELECTROMAGNETICENERGYCONVERSION

1.2 ENERGYEFFICIENCY

1.3 MECHANICALLOADS

1.4 EQUATION OF MOTION


23/78

1.5 MAXWELLEQUATIONS

1.6 MAGNETICCIRCUIT


24/78

1.6.1 Magnetic circuit with air gap

1.6.2 Analogy – Magnetic x Electric

1.7 ELECTROMAGNETICINDUCTION


25/78

1.8 LORENTZFORCE

1.9 MAGNETIZATION CURVE


26/78

1.10 ROTATING MAGNETICFIELD

2 DC MACHINES

2.1 DC MACHINE MAIN PARTS


27/78


28/78


29/78


30/78

2.5.5 COMMUTATION PROCES

2.5.6 AUXILIARY COMMUTATION POLES

2.5.7 SHUNT GENERATOR


31/78

2.5.8 EXCITATION OF SHUNT GENERATOR

2.5.9 COMPARISON OF GENERATORS

2.5.10 ENERGY BALANCE POWER DIVISION)


32/78

2.6 MOTOR ACTION

2.6.1 BASIC EQUATIONS OF DC MOTORS

2.6.2 DC Motor Basic Description


33/78

2.6.3 SEPARATELY EXCITED

2.6.3.1 DC SEM Characteristics

2.6.3.2 DC SEM speed + mechanical curves

2.6.3.3 INFLUENCE OF Ra ON n=f T) CURVE


34/78

2.6.3.4 DC SEM Starting

2.6.3.5 DC SEM Braking


35/78

2.6.3.6 DC SEM Reversal

2.6.3.7 DC SEM Speed Change


36/78

2.6.4 SHUNT EXCITED

2.6.4.1 DC SHM Characteristics

2.6.4.2 DC SHM Behavior


37/78

2.6.5 SERIES EXCITED

2.6.5.1 DC SRM Characteristics

2.6.5.2 DC SRM speed + torque + mechanical curves


38/78

2.6.5.3 DC SRM Starting

2.6.5.4 DC SRM Braking

2.6.5.5 DC SRM Reversing


39/78

2.6.5.6 DC SRM Speed Change


40/78


41/78

3 TRANSFORMERS

3.1 PRINCIPLE OFFUNCTION

3.2 SINGLE-PHASETRANSFORMER

3.3

FUNDAMENTAL

TRANSFORMER

EQUATION


42/78

3.4 REALTRANSFORMER WITHSINUSOIDALSUPPLY

3.5 ELECTROMOTIVEFORCEUI IN WINDING

3.6 EQUIVALENTCIRCUIT OFTRANSFORMER


43/78


44/78


45/78

3.9 LOSSES ANDEFFICIENCY


46/78

3.10 VOLTAGE DROP OVERLOAD

3.11 CONNECTION

3.11.1 Star

3.11.2 Triangle


47/78


48/78

3.13.1 no-load

3.13.2 Loaded

3.14 AUTOTRANSFORMER


49/78

3.15 CURRENTINSTRUMENTTRANSFORMER


50/78

3.16 VOLTAGE INSTRUMENTTRANSFORMER

3.17 CONNECTION OF TRANSFORMER INNO-LOAD OPERATION TOGRID


51/78

3.18 SHORT CIRCUIT OFTRANSFORMER INSTEADY-STATE NO-LOAD OPERATION


52/78

3.18.1 Limitation of Short-Circuit Current


53/78

3.18.2 Mechanical Stress of Transformers


54/78

4 INDUCTION MACHINE

4.1 APPLICATIONS

4.2 CONSTRUCTION


55/78

4.3 PRINCIPLE

4.3.1 Rotating magnetic field

4.3.2 Magnetic field in air gap


56/78

4.3.3 Stator winding

4.3.4 Pitch factor

4.3.5 Distribution factor


57/78

4.3.6 Stator slots

4.4 MAIN SPEED TERMS

4.5 PARK TRANSFORMATION

4.6 EQUIVALENT CIRCUIT


58/78


59/78

4.9 CIRCLE DIAGRAM


60/78


61/78


62/78


63/78

4.10 EFFICIENCY

4.11 STARTING


64/78


65/78

4.12 BREAKING

4.13 SPEED CONTROL


66/78

4.14 SINGLE-PHASEIM


67/78

5 SYNCHRONOUSMACHINES

5.1 CONSTRUCTION

5.2 FLUXES ANDREACTANCE


68/78

5.3 SYNCHRONOUSALTERNATOR WITH ACYLINDRICALROTOR

5.4 VOLTAGE EQUATIONS


69/78

5.5 ASYNCHRONOUSRUN-UP OF A SYNCHRONOUSMOTOR


70/78

5.6 LOADING OF ASYNCHRONOUSMOTOR

5.7 LOADING OF ASYNCHRONOUSGENERATOR– ALTERNATOR

5.8 BASICEQUIVALENTCIRCUIT OF ATURBOMACHINE


71/78


72/78

5.9 PHASORDIAGRAM OF ANOVEREXCITEDTURBOMACHINE

Loading at a Constant Power while Connected to a Strong Grid


73/78

5.10 LOADING AT ACONSTANT EXCITATION WHILECONNECTED TO ASTRONG GRID

5.10.1 Torque of a Turbomachine


74/78

5.10.2 Torque of a Salient Pole Synchronous Machine

5.10.3 Power Torque) Overload Capacity


75/78

5.10.4 Stand-alone Alternator

5.11 SYNCHRONIZATION OFGENERATOR CONNECTING TO THEGRID)

5.12 DIMENSIONS OF TURBOMACHINES


76/78

5.13 EXCITATIONSYSTEMS OFSYNCHRONOUSMACHINES

5.13.1 Excitation from rotary converters

5.13.2 Excitation from alternate driver

5.13.3 Excitation with carried rectifier


77/78

5.13.4 Excitation from a system with a rotary transformer

5.13.5 Excitation from a static converter

5.13.6 Excitation with permanent magnets


78/78

Documents

Electric Machinery and Apparatus