High Voltage Safety Marine Synchronous Generator W. Maes - - PowerPoint PPT Presentation

▶
high voltage safety
SMART_READER_LITE
LIVE PREVIEW

High Voltage Safety Marine Synchronous Generator W. Maes - - PowerPoint PPT Presentation

Jun 02, 2023 214 likes •763 views

High Voltage Safety Marine Synchronous Generator W. Maes Department of Marine Engineering Antwerp Maritime Academy HV, 2016 Willem Maes High Voltage Safety 6.6KV Marine Synchronous Generator Willem Maes High Voltage Safety Principle of

slide-1
SLIDE 1

High Voltage Safety

Marine Synchronous Generator

  • W. Maes

Department of Marine Engineering Antwerp Maritime Academy

HV, 2016

Willem Maes High Voltage Safety

slide-2
SLIDE 2

6.6KV Marine Synchronous Generator

Willem Maes High Voltage Safety

slide-3
SLIDE 3

Principle of operation

Willem Maes High Voltage Safety

slide-4
SLIDE 4

Number of poles

f = p.n 120 f = frequency p = number of poles on the rotor n = speed of the generator

Willem Maes High Voltage Safety

slide-5
SLIDE 5

Stator

Willem Maes High Voltage Safety

slide-6
SLIDE 6

Main features of the Stator

The winding is always connected in wye. The phase voltage is only 58% of the line voltage. Line to neutral 3th harmonics cancel each other out in star but add up in delta.

Willem Maes High Voltage Safety

slide-7
SLIDE 7

Main features of the Stator

Willem Maes High Voltage Safety

slide-8
SLIDE 8

Salient Pole Rotor

Willem Maes High Voltage Safety

slide-9
SLIDE 9

Main features of the Rotor

1

Salient pole rotors

Salient poles are mounted on a steel frame. The Damper winding is a squirrel cage winding for smoothing sudden load changes.

2

Cylindrical rotors

High speed generators 2 to for poles. Long solid steel cylinder with slots milled out to accommodate the windings.

Willem Maes High Voltage Safety

slide-10
SLIDE 10

Field Excitation and Exciters

Figure : brushed excitation

Willem Maes High Voltage Safety

slide-11
SLIDE 11

Field Excitation and Exciters

Figure : brushless excitation

Willem Maes High Voltage Safety

slide-12
SLIDE 12

No Load Saturation Curve

Willem Maes High Voltage Safety

slide-13
SLIDE 13

No Load Saturation Curve

Willem Maes High Voltage Safety

slide-14
SLIDE 14

Synchronous reactance and equivalent circuit of an AC generator

Willem Maes High Voltage Safety

slide-15
SLIDE 15

Synchronous reactance and equivalent circuit of an AC generator

Willem Maes High Voltage Safety

slide-16
SLIDE 16

Synchronous reactance and equivalent circuit of an AC generator

Xs = 2.π.f.L Xs = synchronous reactance per phase (Ω) f = generator frequency (Hz) L = apparent induction of the stator winding, per phase (H)

Willem Maes High Voltage Safety

slide-17
SLIDE 17

Equivalent circuit of a generator showing one phase

Willem Maes High Voltage Safety

slide-18
SLIDE 18

Synchronous Generator under Load

Willem Maes High Voltage Safety

slide-19
SLIDE 19

Type of Loads

Isolated loads (single generator). The infinite bus.

Willem Maes High Voltage Safety

slide-20
SLIDE 20

Isolated Load lagging power factor

Willem Maes High Voltage Safety

slide-21
SLIDE 21

Isolated Load lagging power factor

Ix creates the flux Φ. Voltage E0 is generated by flux Φ. Current I lags behind terminal voltage E by an angle ϕ. cosϕ is the power factor of the load Voltage Ex across the synchronous reactance leads current I bij 90deg E0 equals the phasor sum of E and Ex Both E0 and Ex are voltages that exist inside the stator windings and cannot be measured directly.

Willem Maes High Voltage Safety

slide-22
SLIDE 22

Isolated Load leading power factor

Willem Maes High Voltage Safety

slide-23
SLIDE 23

Synchronization of a generator

Willem Maes High Voltage Safety

slide-24
SLIDE 24

Synchronization of a generator

A generator is said to be synchronized when it meets the following conditions: The generator frequency is equal to the system frequency. The generator voltage is equal to the system voltage. The generator voltage is in phase with the system voltage. The phase sequence of the generator is the same as that

  • f the system.

Willem Maes High Voltage Safety

slide-25
SLIDE 25

Synchronization of a generator

Willem Maes High Voltage Safety

slide-26
SLIDE 26

Synchronization of a generator

Willem Maes High Voltage Safety

slide-27
SLIDE 27

Synchronization of a generator

Willem Maes High Voltage Safety

slide-28
SLIDE 28

Synchronization of a generator

Willem Maes High Voltage Safety

slide-29
SLIDE 29

Synchronous generator on the Infinite Bus

An infinite bus is so powerful it imposes its own Voltage and Frequency upon all apparatus connected to its terminals. On

  • ur machine we can only change:

1

The exciting current Ix.

2

The mechanical torque exerted by the driving engine.

Willem Maes High Voltage Safety

slide-30
SLIDE 30

Infinite Bus, effect of varying the Exciting Current

Figure : Generator floating on an infinite bus

Willem Maes High Voltage Safety

slide-31
SLIDE 31

Infinite Bus, effect of varying the Exciting Current

Figure : Generator floating on an infinite bus

Willem Maes High Voltage Safety

slide-32
SLIDE 32

Infinite Bus, effect of varying the Exciting Current

Figure : Over Excited generator on infinite bus

Willem Maes High Voltage Safety

slide-33
SLIDE 33

Infinite Bus, effect of varying the Exciting Current

Figure : Over Excited generator on infinite bus

Willem Maes High Voltage Safety

slide-34
SLIDE 34

Infinite Bus, effect of varying the Exciting Current

Figure : Under Excited generator on infinite bus

Willem Maes High Voltage Safety

slide-35
SLIDE 35

Infinite Bus, effect of varying the Exciting Current

Figure : Under Excited generator on infinite bus

Willem Maes High Voltage Safety

slide-36
SLIDE 36

Infinite Bus, effect of varying the Exciting Current

If we over excite a synchronous generator connected to the infinite bus we will deliver reactive power to the bus. If we under excite a synchronous generator to the infinite bus we will draw reactive power from the bus. If our generator floats on the infinite bus we deliver or draw nothing.

Willem Maes High Voltage Safety

slide-37
SLIDE 37

Infinite Bus, effect of varying the Mechanical Torque

Figure : Varying mechanical torque

Willem Maes High Voltage Safety

slide-38
SLIDE 38

Infinite Bus, effect of varying the Mechanical Torque

Figure : phasor diagram varying torque

Willem Maes High Voltage Safety

slide-39
SLIDE 39

Infinite Bus, effect of varying the Mechanical Torque

Figure : Physical interpretation of alternator behavior

Willem Maes High Voltage Safety

slide-40
SLIDE 40

Infinite Bus, effect of varying the Mechanical Torque

Figure : The N poles of the rotor are ahead of the S poles of the stator

Willem Maes High Voltage Safety

slide-41
SLIDE 41

Speeddroop

Figure : Speeddroop of the engines regulator enables equal active load sharing

Willem Maes High Voltage Safety

slide-42
SLIDE 42

Speeddroop

Figure : Voltage droop of the alternators AVR enables equal reactive load sharing

Willem Maes High Voltage Safety

slide-43
SLIDE 43

AVR Automatic Voltage Regulator

Figure : Automatic Voltage Regulator

Willem Maes High Voltage Safety

slide-44
SLIDE 44

AVR Automatic Voltage Regulator

Is a device that continuously monitors the voltage at the voltage regulating point of the system and maintains the terminal voltage of the generator. The AVR also controls that the synchronous generator

  • perates within preset limits.

An auxiliary winding supplies the excitation power under the control of the AVR.

Willem Maes High Voltage Safety

slide-45
SLIDE 45

AVR Automatic Voltage Regulator

Is a device that continuously monitors the voltage at the voltage regulating point of the system and maintains the terminal voltage of the generator. The AVR also controls that the synchronous generator

  • perates within preset limits.

An auxiliary winding supplies the excitation power under the control of the AVR.

Willem Maes High Voltage Safety

slide-46
SLIDE 46

AVR Automatic Voltage Regulator

Is a device that continuously monitors the voltage at the voltage regulating point of the system and maintains the terminal voltage of the generator. The AVR also controls that the synchronous generator

  • perates within preset limits.

An auxiliary winding supplies the excitation power under the control of the AVR.

Willem Maes High Voltage Safety

slide-47
SLIDE 47

AVR Automatic Voltage Regulator

A voltage feedback is supplied by the voltage transformer and a current feedback is provided by the current transformer. The transformers are installed in the generator. Operational limits, such as over and under excitation, machine voltage and Volts/Hz, are implemented in the AVR. Static reactive power compensation in parallel operation and several other software functions are also available.

Willem Maes High Voltage Safety

slide-48
SLIDE 48

AVR Automatic Voltage Regulator

A voltage feedback is supplied by the voltage transformer and a current feedback is provided by the current transformer. The transformers are installed in the generator. Operational limits, such as over and under excitation, machine voltage and Volts/Hz, are implemented in the AVR. Static reactive power compensation in parallel operation and several other software functions are also available.

Willem Maes High Voltage Safety

slide-49
SLIDE 49

AVR Automatic Voltage Regulator

A voltage feedback is supplied by the voltage transformer and a current feedback is provided by the current transformer. The transformers are installed in the generator. Operational limits, such as over and under excitation, machine voltage and Volts/Hz, are implemented in the AVR. Static reactive power compensation in parallel operation and several other software functions are also available.

Willem Maes High Voltage Safety

slide-50
SLIDE 50

AVR Automatic Voltage Regulator

A voltage feedback is supplied by the voltage transformer and a current feedback is provided by the current transformer. The transformers are installed in the generator. Operational limits, such as over and under excitation, machine voltage and Volts/Hz, are implemented in the AVR. Static reactive power compensation in parallel operation and several other software functions are also available.

Willem Maes High Voltage Safety

slide-51
SLIDE 51

Marine generators have an adapted AVR to generate a sustained short-circuit current of 350 % of the nominal current. This short circuit is required to allow the circuit breakers to trip in a selective way. The ability of ships generators to generate a short circuit current high enough for selectivity or discrimination is essential and above industrial (shore) standards.

Willem Maes High Voltage Safety

slide-52
SLIDE 52

Marine generators have an adapted AVR to generate a sustained short-circuit current of 350 % of the nominal current. This short circuit is required to allow the circuit breakers to trip in a selective way. The ability of ships generators to generate a short circuit current high enough for selectivity or discrimination is essential and above industrial (shore) standards.

Willem Maes High Voltage Safety

slide-53
SLIDE 53

Marine generators have an adapted AVR to generate a sustained short-circuit current of 350 % of the nominal current. This short circuit is required to allow the circuit breakers to trip in a selective way. The ability of ships generators to generate a short circuit current high enough for selectivity or discrimination is essential and above industrial (shore) standards.

Willem Maes High Voltage Safety