EPG&D Flashcards
Purpose
The purpose of the EPG&D system is to produce stable NATO standard electrical power from the ship’s generators or shore power and distribute it to the ship’s systems and services requiring electrical power.
DG’s
Caterpillar C32 Diesel Generator
Powered by a 12 cylinder, four-stroke, turbo-charged diesel engine.
Generate NATO standard power for the ship’s switchboards.
Inside raft mounted acoustic enclosures.
1800 rpm.
830 kW
Started by HP air in dedicated flasks, one in FER and one in AER.
Cooled by a plate type heat exchanger which uses ASWC.
DGs can be controlled from MEC or DG LCP.
DG 1 & 2 located in FAMR
DG 3 and 4 located in AAMR
AVRs
Automatic Voltage Regulators
Each DG has 2 AVRs.
Automatic control of DC exciter voltage which regulates generator output voltage.
One is active, one on standby.
Will automatically change over to standby if primary fails.
Switchboards
2 switchboards distribute power from DGs or shore to various users.
5 ACB’s
55 MCCBs
Can be operated in Split operation (bus ties open) or Parallel (one or both bus ties closed.
Located in Fwd and Aft Switchboard Rooms
Switchboard Modes (List)
Automatic
Manual Permissive
Manual
Automatic (SWBD Mode)
DGs started and paralleled automatically.
Manual Permissive (SWBD Mode)
Parallelling done manually using the synchroscope.
Safeties protect the plant if paralleling is done incorrectly.
Manual (SWBD Mode)
Paralleling is done manually using the snychroscope.
No safeties are in place.
What is paralleling?
Synonym with “Synchronizing”
Adjusting the voltage, frequency, and phase of the DG to match with the other DGs.
EPCS
Electrical Power Control System
Responsible for monitoring and controlling the EPG&D system.
ESCs are in RTU 10 and 11 and communicate with eachother via IPMS LAN.
IF ESCs cannot communicate, they open bus ties and operate independantly.
CONSOLE CONTROL: Switchboard operated via IPMS.
SWITCHBOARD CONTROL: Switchboard controlled locally at the switchboard itself.
List ESC Functions
Load Sharing
Load Sheding
Preference Tripping
ACB Interlock
Blockout Sequence
Voltage Adjust
Automatic Synchronization
Load Sharing
Automatically adjusting the frequency of online DGs so that each DG shares an equal amount of load.
Load Shedding
When a sudden electrical load >110% rated load for the number of online generators, load shed breakers are tripped.
Preference Tripping
Same as load shedding but only when 1 DG is running and demand >150%.
Helps ensure we do not black out by allowing higher percentage before breakers trip.
ACB Interlock
Ensures only designed bus tie configurations occur.
1 DGs: 0,1,2
2 DGs: 0,1,2
3 DGs: 0,1
4 DGs: 0
Blackout Sequence
Ensures power to switchboards is quickly re-established if it is lost.
<22 volts sensed at bus bars of both switchboards:
All bus ties open
All DG ACBs open
All DGs start
First DG online will be loaded
All other DGs synch to that one
Voltage Adjust
Automatically synchronizes DGs with shore power.
If shore power >465 V, must be done manually.
Automatic Synchronization
Automatically allows sources to be tied together while ensuring synchronization.
Explain Generation Theory
3 Stators (stationary wire coils)
Rotor driven by diesel engine
2 magnetic pole pairs mounted on the rotor.
Excitation field strength of rotor pole pairs controls voltage.
Stator coils are 120 degrees apart for 3 phase power.
Shaft rotates at 1800 rpm for 60Hz (with 2 magnetic pole pairs)
Vital Loads
Yellow
Equipment that aids the ship with main propulsion and navigation.
Connected through ACOSs.
MLO pumps
Steering pumps
Gyros
Navigation Lighting
Semi-Vital Loads
Black
Communications and weapons equipment
Connected to switchboards via MCOSs
Direct Feed Non-Vital Loads
Red
Large equipment
115 Ton Chillers
Connected to swtichboards via MCCBs.
Load Shed Loads
Blue and White
Allow automatic load shedding.
Domestic lighting, bulkhead power outlets, galley equipment.
ACOS
Automatic Change Over Switch
Change over automatically.
MCOS
Require operator to change over.
Change over performed from IPMS console or locally at MCOS.
Secondary Power
Produced from NATO Standard Power using transformers, rectifiers, inverters, phase converters, and SFCs
120 V, 60 Hz, 1 phase
120 V, 400 Hz, 3 phase
28 V DC
UPS
120V, 60 Hz, 1 Phase
Domestic services such as lighting and bulkhead power outlets
120 V, 400 Hz, 3 Phase
Derived from SFCs
Helo Start Pack
57mm Gun
CEROS
SG-180
SMART-S
28 V DC
Derived from Static Rectifier Units
Sonar
Missiles
Torpedos
SRUs broken down into:
6x 100 W
4x 500 W
4x 700 W
UPS
33 UPSs
Supplied with NATO Standard Power
Provide 15 minutes of power
Casualty Power
Cable connections are run around damaged power distribution lines to supply Vital and Semi-Vital loads.
400 A Cables are red, white, and black and have tailored connection points so crossing of phases does not occur.
100 A cables also exist.
Cables are pre-cut lengths.
Cables connect to bulkhead and deckhead jumper stations.
Cables are run from load to source and must be authorized by Command to energize.
Modes of Operation (List)
Harbour State:
Home Port
Foreign Port
Normal Peacetime Cruising
Action State
Abnormal State
Harbour State: Home Port
DGs ON: 0
DGs Standby: 1
Bus Ties: 1,2
Mode: Manual Permissive
Harbour State: Foreign Port
DGs ON: 1
DGs Standby: 1
Bus Ties: 1,2
Mode: Auto Synch
Normal Peacetime Cruising
DGs ON: 2
DGs Standby: 1
Bus Ties: 2
Mode: Auto Synch
Action State
Maximum Suriviability
DGs ON: 4
DGs Standby: 0
Bus Ties: 0
Mode: Auto Synch
Abnormal State
Any other configuration.
May occur due to power export to other ships.
System Interfaces
FOS
HP Air
ASWC
IPMS
Redundancy and Survivability
Only 2 DGs required to provide power
Geographically distributed fwd and aft
Switchboards can function in solation
Switchboards operated in REMOTE and SWITCHBOARD control
Vital, Semi-Vital, Non-Vital loads
ACOS, MCOS
UPS
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