1. NEMOProject Phase 2

2. Autorizzazioni e permessi Cavo elettro-ottico Branching Units
Nemo Phase 2 Composizione
Stazione a terra
Survey
Autorizzazioni e permessi
Cavo elettro-ottico
Branching Units
Cable Terminations Assembly
Operazioni Marine
Operazioni a terra
Shore Power Feed Equipment
DC/DC Converter

3. Ingresso Cavo Elettro-Ottico
Nemo Phase 2 Shore Station
Ingresso Cavo Elettro-Ottico

4. Nemo Phase 2 Backbone Cable
Cable Outer Diameter
Conductor Diameter
DC Resistance
Weight Air/Water
Cable Breaking load
Operating Tension
Min. Dynamic Bending
Working Voltage
Drop Voltage
Current
Power
17 mm
Copper Shield
1.6 Ω/km
Kg/m
70 kN
30 kN
500LW/900DA mm
10 kV
1.600 V
10 A
100 kW

5. Nemo Phase 2 Power Budget
Storey power load (4 OM + storey electronics + additional sensors) 20 W
x 16 storeys W
+ additional power load at the tower base (electronics, sensors, …) 100 W
Total power load per tower 420 W
x 81 towers (5.184 OM) 34 kW
+ JB power load (electronics, sensors, …), 300 W per JB 3 kW
+ additional power load as spare or associate science 10 kW
Total power load ~50 kW

6. Interdisciplinary Activity Requests
Nemo Phase 2 Branching Unit
Interdisciplinary Activity Requests
Electro-Optics Characteristics Intermediate Branching Unit
• Depth m
Power 250 W DC
1 Fiber Optic ITU.T G.655
• Depth m
Power 500 W DC

7. Nemo Phase 2 System Layout
Passive BU
Passive BU
Active BU
20 Km
100 m
100 m
40 Km
100 m
100 m
80 Km
100 m
7 Km
PFE
Current Probe
Trunk End#1
Trunk End#2
Trunk End#3
DC/DC
12 Km
100 m Depth
2.000 m Depth
3.500 m Depth

8. Nemo Phase 2 Marine Operations
Project Management
Desk top study
Environmental Impact Assessment
Authorization and permitting service
Cable Route Survey
Marine Geophysical Survey
Topographic Landing Area Survey
Diver Survey
Reporting and Charting
Route Clearance
Pre Lay Grapnel Run
Marine installation
Cable loading
Cable main lay
Beach work and cable protection
Post Lay Works
Final Reporting and Charting

9. Nemo Phase 2 Survey Cable Route Survey Marine Geophysical Survey
Topographic Landing Area Survey
Diver Survey
Reporting and Charting
Catania
Sintesi dei risultati
Confronto tra la rotta contrattuale e la rotta finale
Rotta Contrattuale
Rotta Finale e Diagramma di Linea
Differenze tra la Rotta Contrattuale e la Rotta     Finale
Lista dei Contatti Sonar
Lista dei Cavi Incrociati
Datum orizzontale e verticale
Topografia dell’area di approdo di Capo Passero
Capo Passero
Risultati di dettaglio
Rotta percorsa durante il Survey
Descrizione degli allegati cartografici
Campionamenti del fondo marino
Attività di possibile interferenza con il collegamento
Fattori antropici
Attività di pesca
Servizi esistenti ed in progetto
Relitti ed impedimenti alla    navigazione
Dati sui danni subiti dai cavi sottomarini
nell’area interessata dal cavo

10. Nemo Phase 2 Configuration

11. CABLE TERMINATING SHELF
Nemo Phase 2 Power Feed Equipment Block Diagram
CONTROLLER SHELF
PU Controller
Power In
Converter
to line PU
Monitors
Common
Monitors
Cable
Termination
Cubicle
n…..
ALARM CONCENTRATOR
SHELF
Converter
system
earth PU
OPTICAL FIBER
DISTRIBUTION UNIT
Dummy
Load
routing
switch
CABLE TERMINATING SHELF
EARTH ISOLATION SHELF

12. Nemo Phase 2 BMH
Capo Passero
Approdo
Catania
Approdo

13. Nemo Phase 2 Passive BU Specifications: ･ Dimensions 2.0x0.5x2.0(m)
High power flying ROV receptacle assembly
Electro-Optical Flying ROV receptacle assembly
Specifications:
･ Dimensions 2.0x0.5x2.0(m)
･ Weight : 1200kg (in Air)
･ Pressure Resist : 4000m

14. Control and Power Distribution
Nemo Phase 2 Active Branching Unit
Control and Power Distribution

15. Nemo Phase 2 DFME Auto Latching Branching Unit
>BU Supervisory Functions
1>1.2 s
Recovery Driver
Command
Sequence
28.8 ms
3 X Current
3 X Apply Current
Sharing
Share Request
1>1.2 s
Main Driver
Command
Sequence
28.8 ms
3 X Confirm
3 X Configuration
Configuration Request
Request
Main Driver
Recovery Driver
Commands
Commands
Command
Sequence
Delay between s

16. Nemo Phase 2 Active Branching Unit
Fibres
Optics Tray
ReF
Recovery receiver
Main Smoothing Board
Recovery Zeners
Fibres
Recovery Chassis
D (Earth) C
Main Chassis A B
Blank Chassis
Main Driver
ReE
RLB
ReC
ReD
RLA
Pin Diodes
Main Zero Detect and Resistor Box
Main Bridge Rectifier
Splice Tray
Surge Coil
Main Zeners
Main Receiver

17. Nemo Phase 2 Cable Termination Assembly
Sea Hearth Connection
CTA

18. Nemo Phase 2 Cable Termination Assembly
To shore
Cable In
VDC 10 kV
Cable Out
DC/DC
5-10 kW
400 Vdc Out
Fibre Out
ROV connector
DC/DC
5-10 kW JB
DC/AC

19. Synchronous rectifier
Nemo Phase 2 DC/DC Converter 10kV/400V
Internal supply
Input filter
Output filter
200V
50V Tx
Current sense
Primary switching
Synchronous rectifier
Gate Drive
Sub Converter
Topology used in the Neptune Project by JPL NASA
Low stress design
600V transistors used to switch 200V
Devices capable of working at 100oC used at 36oC

20. Nemo Phase 2 DC/DC Design
10kV
400V
Control / start-up 1
Control / start-up 3
Control / start-up 4
Control / start-up 5
Control / start-up 6
Control / start-up 2
In the event of the FET failing Open circuit the diodes fail short circuit, typically 0.5 to 1 ohm
Output diodes allows Large large scale failure of sub converter output sections or control with only reduced output current
10kV
400V
Control / start-up 1
Control / start-up 3
Control / start-up 4
Control / start-up 5
Control / start-up 6
Control / start-up 2
X-Ray showing plate construction.
Without bond wires, rupture current
grater than 150A
Sub converters input sections fail short circuit allowing large to fail without loss of output

21. Physical Construction of First MARS Converter
Large diameter sea case is expensive and difficult to handle
PCBs are too large for most manufactures, limited number of suppliers
PCBs are too large for pick and place assembly machines, must be hand built

22. Nemo Phase 2 DC/DC Converter Project
Compact Physical Construction
Pressure compensation using bellows
Flourinert FC77 filled housing
PCBs perpendicular to pressure vessel
Ethylene Propylene O-Rings
External connections

23. Ground Return Circuit Nemo Phase 2 Ground Return Electrodes
•Single conductor cable necessitates ground return electrodes
•Similar applications include:
–Gas generation
–HVDC Power Distribution
–Trans-ocean telecom systems
–Impressed current cathodic protection
Ground Return Circuit I V
Node
Converters
Shore
Power
Supply
Cathode
Cathode Coating
Sea Water
Saturated Sand
Soil
Backfill
Anode Coating
Anode kV
10 A - +

24. Nemo Phase 2 Remote Earth Electrode
Ti grade 2 electrode structure
Insulated steel strength termination
Standard cable buffer
Earth conductor +redundancy
Mixed metal oxide coating
Elastomer bend limiter
Active surface of electrode
LW cable core passes through electrode. Outer armour wires terminated in a similar way to an armoured cable joint

25. (Floor Control Module) Electro-optical cable
Nemo Phase 2 Tower Power Distribution 400 VAC
Benthosphere ~ ~
Electric load
storey 16 -
Tower storeys
FCM
(Floor Control Module) ~ ~
Electric load
storey 3 - ~ ~
Electric load
storey 2 - ~ ~
Electric load
storey 1 -
Base Tower CONNECTION
Vin 400VAC
Second. JB - base tower
Electro-optical cable
Secondary JB

26. Nemo Phase 2 Diagramma Temporale