Presentation DG Sets

Diesel Generators
M. Nageswar Rao,
Sr.Mgr.(EMD),
NTPC-Simhadri
Date: 08.06.2016
Contents
Need for DG sets
Principle & Operation
DG set parts
DG sets starting
Auto start
Remote start
Local Starting
Voltage/speed bias
Protections & Alarms
2
Need for DG sets

DG sets are the backbone of the emergency supply
equipment of the power plant.

Safe isolation/ shutdown of the Unit in case of
AC failure
Grid failure
11kV unit bus fault
DC failure
Unit 220V dc failure.
Switchyard 220V dc failure
Station C&I 24V dc failure (Stage#2)
Emergency equipment (EOP, DC SOP, DC JOP, DC scanner
air fans) will start with battery back up.

For long time operation, DG sets to be started to charge
Emergency bus.
3
Principle &
Operation
DG sets Working Principle

Diesel engine is the prime mover, which
drives an alternator to produce electrical

energy.
chemical
DIESEL
DIESEL
ENGINE
ENGINE
mechanical
ALTERNATOR
ALTERNATOR
electrical
LOAD
LOAD
DG set system
Parts of DG set
Diesel Engine
Alternator
PCC (power command)
Local control Panel
Battery & Battery charger
Day tank
Radiator
Stack
Pros & Cons

Advantages
Disadvantages
Low operating costs

Easily available in the
market
Portable
Least inflammable
Maintenance is easy
Sound (However, one can
even buy silent

generators)
Produces higher smoke
8
DG set Rating
Prime Power Rating
(PRP)
Stand by Power
Rating (ESP)
Applicable for supplying in lieu of commercially installations served

electric power
purchased power.
by a reliable utility
source.
Power availability at
variable load for
unlimited number of
hours.
the duration of
power outage
Overload capacity at
intermittent periods.
10%
Nil
DG sets in NTPCSimhadri
10
DG sets in Simhadri
Stage#1
Stage#2
11
DG sets in SMPP
Stage#1
Stage#2
DG set Supplier
Powerica
Jaksons
Prime Power
Rating
415V, 1500kVA,
415V, 1250kVA,
Diesel Engine
Cummins
Alternator
Stamford-New Age,
U.K.
Stamford, India
Control
PLC based
Microprocessor based
Power Command
Enclosure
Open type
Accoustic enclosure
Diesel Engine specs

Stage#1
Make
Model
Stage#2
Cummins
KTA-50-G8
KTA-50-G3
No. of cylinders
16 Vee
Aspiration
Turbocharged-Aftercooled
Method of cooling of Engine &

lubrication oil
Displacement
Radiator cooled, Water cooled

50.3 ltrs (3067 cub.inch)
Output - Prime
1735 bhp (1294

kWm)
1470 bhp (1097

kWm)
Fuel consumption @100%

load
301.7 ltr/hr
251.8 ltr/hr
Oil consumption @100% load
0.35 ltr/hr
0.3 ltr/hr
Governor / Class
Electronic / A1
Lubricating oil system capacity
177 ltrs
Coolant capacity (engine +

radiator)
510 ltrs
440 ltrs
Alternator specs
Rating
Voltage, p.f.
Stator current
Stage#1
Stage#2
1500 kVA
1250 kVA
3-ph ,415V, 0.8 pf lag

2086 A
1739 A
Rated overload capacity
110% for 1 Hr. in every 12 Hrs Operation.
Stator winding
2/3 pitch, Double Layer Lap
Class of insulation
Class H
Temperature rise over 50 degC at rated

current
Class H
Make
Stamford-New Age, U.K.
Stamford, India
Frame size / Model No.
HC-74G
PI-734C2
0.5%
Voltage regulation
Winding
Alternator standard
Enclosure
Max. permissible unbalance electrical
loading
Star 12 winding
Star- 6 winding
IS 4722, IEC 60034-1
IP 22
IP 23
25% unbalance in electrical loading is allowed provided

none of the phases exceeds the rated current
Bearing
DE (BALL. 6228 C3)

NDE(BALL. 6319 C3)
Weight
4022 kg
Parts of DG set
15
DG set parts
16
Diesel Engine
In the diesel engine, air is
drawn into the cylinder and

is compressed to a high
ratio (14:1 to 25:1).
During this compression,
the air is heated to a
temperature of 700900C.
A metered quantity of
diesel fuel is then injected
into the cylinder, which
ignites spontaneously
because of the high
temperature. Hence, the
diesel engine is also known
as compression ignition (CI)
17
Alternator
Synchronous
generator
brushless with
rotating magnetic
field
18
Alternator naming
19
Exciter
Alternator is separately excited by the
PMG.
This is a shaft mounted, high frequency,
pilot exciter which provides a constant
supply of clean power via the Automatic
Voltage Regulator (AVR) to the main
exciter.
The main exciter output is fed to the
main rotor, through a full wave bridge
rectifier, protected by surge
suppression.
Stage
#1
Stage#2
Type
Brushless
Ratin
g
10.3 kVA, 3.6A,

0.8pf
20
Genset control
AVR Control
PCC control
21
ECP
The ECP controls the engine
speed at the set reference

speed (for e.g. 1500 RPM)
from No load to full load
(Isochronous operation).
22
AVR- MX321
3 phase rms sensed with a voltage regulation of 0.5% rms
(see the note on regulation).

The UFRO circuit has adjustable slope and dwell for
controlled recovery from step loads.
An over voltage protection circuit will shutdown the output
device of the AVR, it can also trip an optional excitation
circuit breaker if required.
Generator mounted current transformer to provide
quadrature droop characteristics for load sharing during
parallel operation.
Provision is also made for the connection of the STAMFORD
power factor controller, for embedded applications, and a
remote voltage trimmer.
23
PCC
PCC is a
microprocessor
based generator
set
monitoring,
metering, and
control system
designed to mount
directly on the
generator set.
24
Turbo charger
25
After cooler
Large capacity
integral aftercoolers
are supplied with
cooling water
separate from the
engine jacket.
This provides cooler,
denser intake air for
more complete
combustion and
reduced engine
stresses for longer
26
Radiator
A two pump, two
loop system must be

employed; i.e.
the engine jacket is
cooled by one
radiator or heat
exchanger and
the aftercoolers are
cooled by a separate
radiator or heat
exchanger.
27
Fuel filter
Dual spin on paper
element fuel filters

with standard water
separator
28
Fuel supply control

Fuel pump
Actuator
Fuel shut off valve
29
Lub-oil filter
Lub oil filter
Super bypass lub-oil

filter
30
Starter motor
31
Battery charging
alternator
32
Air filter
33
Lub-oil priming pump
34
Alternator terminals
Phase side
Neutral side
35
DG set starting
36
DG set starting
Remote starting
37
DG starting (St#1)
EMCC normally fed from USS Section#1.
In case of failure of incoming supply from 1DA/2DA bus,
on sensing of under voltage, tie breaker gets opened
Main DG takes auto-start & DG incomer auto-closes.
If Main DG fails to start, start S/B DG manually.
38
DG starting (St#2)
Both the sections of EMCC are fed from USS respective sections.
Main DG is on Sec#1 and S/B DG is on Sec#2
In case of failure of incoming supply from USS bus (1 section),
Bus coupler comes in auto.
In case of both sections fail
Auto start command goes to both Main DG & S/B DG.

After 13 seconds, Incomer of Main DG auto-closes.
In case of failure of Main DG comes in service in auto, Stand by DG set has to be started manually and board
has to be charged from ECP.
Bus coupler will close in auto on charging of any DG breaker.
39
Synch scheme
40
DG set starting in case of

both AC & DC failure of
UES
As per COS-Elec IOM,
2013, it was decided

to provide a self
powered (from VT
supply) Static U/V
relay (Minilec) with
the same setting that
of U/V relay in the VT
panel of UES may be
mounted with a
parallel contact for
DG set starting
41
DG set starting
Local starting
42
Starting of St#1DG sets

Electronic Instrument Panel
Local Control Panel
Remote command
43
St#1 DG Local start

Start the switch in Electronic
Control Panel
Keep Local/Remote switch in

Local
Press the Start Push button in
Local control Panel
44
St#2 DG Local start

Keep Local/Remote switch in
Local
Press the Local Start Push
button in Local control Panel
Keep O/Manual/Auto Switch in

Manual position
Press the Manual Run/Stop
button
45
Bias Voltage &

Speed
46
Bias- Stage#1 DG
Voltage bias through Motorized POT
Speed bias through Solid state POT
47
Bias- Stage#2 DG
Voltage/Speed bias through Digital POT
Aux 101 card enables PCC to accept
Voltage bias &
Speed bias
48
Aux. supplies
1-ph 415V ac supply (from UES),
Stage#1
which further steps down to 220V ac

Stage#2
to feed
Priming pump
Heaters (space heaters, lube oil
heater, water heater)
Lighting (canopy lights, panel
lamps, plug & socket)
Power source
24V dc battery charger to further
feed
1-ph 415V ac supply (from
UES),
24v dc (from DCDB), to feed
PLC
24V batteries
Engine protections (5kA, 6kA, 7kA)
Power command controls
220v dc (from DCDB), to feed

All protections
Annunciation panel
49
Protections & Alarms

Stage#1
Stage#2
Alarms
Protections
Alarms
Protections
Differential 87
Earth fault 51N
Over current
Overvoltage
Under voltage
High water temp.
Low lube oil pressure
Neutral displacement
Removed
Removed
Over speed
Under/Over frequency
Winding/ Bearing temp. high
Fuel oil level very low
50
Thank you all
51
Step timing control (STC) injectors

Premium STC injectors with ceremic
components have more durability and provide
high injection pressure for better fuel economy.
STCs variable fuel injection timing
Improves startability
Reduces part load fuel consumption, and
Minimizes white smoke at idle during cold start up.
Outer Base Circle (OBC). Injector
52

Presentation DG Sets

Uploaded by

Copyright:

Available Formats

Presentation DG Sets

Uploaded by

Document Information

Original Description:

Copyright

Available Formats

Share this document

Share or Embed Document

Sharing Options

Did you find this document useful?

Is this content inappropriate?

Copyright:

Available Formats

Presentation DG Sets

Uploaded by

Copyright:

Available Formats

Diesel Generators

Need for DG sets

equipment of the power plant.

Emergency equipment (EOP, DC SOP, DC JOP, DC scanner

air fans) will start with battery back up.

DG sets Working Principle

drives an alternator to produce electrical

Pros & Cons

Low operating costs

Sound (However, one can

even buy silent

Applicable for supplying in lieu of commercially installations served

Diesel Engine specs

Method of cooling of Engine &

Radiator cooled, Water cooled

1735 bhp (1294

1470 bhp (1097

Fuel consumption @100%

Oil consumption @100% load

Lubricating oil system capacity

Coolant capacity (engine +

3-ph ,415V, 0.8 pf lag

Rated overload capacity

110% for 1 Hr. in every 12 Hrs Operation.

2/3 pitch, Double Layer Lap

Temperature rise over 50 degC at rated

Stamford-New Age, U.K.

Frame size / Model No.

IS 4722, IEC 60034-1

25% unbalance in electrical loading is allowed provided

DE (BALL. 6228 C3)

drawn into the cylinder and

10.3 kVA, 3.6A,

speed at the set reference

(see the note on regulation).

loop system must be

element fuel filters

Fuel supply control

Super bypass lub-oil

Lub-oil priming pump

Auto start command goes to both Main DG & S/B DG.

DG set starting in case of

2013, it was decided

Starting of St#1DG sets

St#1 DG Local start

Keep Local/Remote switch in

St#2 DG Local start

Keep O/Manual/Auto Switch in

Bias Voltage &

1-ph 415V ac supply (from UES),

which further steps down to 220V ac

1-ph 415V ac supply (from

220v dc (from DCDB), to feed

Protections & Alarms

Earth fault 51N

Low lube oil pressure

Thank you all

Step timing control (STC) injectors

Outer Base Circle (OBC). Injector