Rosanna Cocimano for the NEMO collaboration VLV T08, Toulon, France April 2008 Rosanna Cocimano for the NEMO Collaboration A comparison of AC and DC power feeding systems based on the NEMO experiences International Workshop on a Very Large Volume Neutrino Telescope for the Mediterranean Sea April 2008, Toulon Palais Neptune Conference Centre

Rosanna Cocimano for the NEMO collaboration VLV T08, Toulon, France April 2008  NEMO PHASE 1 ELECTRICAL POWER SYSTEM - AC THREE- PHASE  NEMO PHASE 1 POWER CONTROL SYSTEM  NEMO PHASE 2 ELECTRICAL POWER SYSTEM – DC  PRESSURE TEST ON ELECTRIC AND ELECTRONIC COMPONENTS AGENDA

Rosanna Cocimano for the NEMO collaboration VLV T08, Toulon, France April 2008 POWER SUPPLY ON SHORE KVA 0  1200 V 4 7 KVA 660 V / 400 V 4 25 km 4 X 4 mm 2 FLOOR 4 40 W 4 FLOOR 3 40 W 4 FLOOR 2 40 W 4  ~ - FLOOR 1 40 W 4  ~ MINITOWER JUNCTION BOX 300 m 4 X 4 mm 2 40 m 100 m 40 m TOWER BASE OFF SHORE AC THREE PHASE SHORE STATION NEMO PHASE 1 - ELECTRICAL POWER SYSTEM ~ -  ~ -  ~ -

Rosanna Cocimano for the NEMO collaboration VLV T08, Toulon, France April 2008 INPUT 660 V AC OUTPUT V AC NEMO PHASE 1 – THE JUNCTION BOX OUTPUT V AC OUTPUT V AC OUTPUT V AC In the Junction Box there is 1 input line and 4 output lines. It is present a step- down transformer of 7 kVA. The input voltage is 660 V (line-to-line) while the output one is 400 V (line-to-line). In each line there is:  a breaker that can be switched on and off from the on-shore control panel,  voltage and current measurements, that can be monitored from the on-shore control panel. At the input a power control supply system is connected, it is realized by a NORMAL linear power supply and a REDUNDANT one. For them a suitable protection system is used.

Rosanna Cocimano for the NEMO collaboration VLV T08, Toulon, France April 2008 INPUT 400 V AC DC OUTPUTS 12 V DC 5,5 V DC 3,5 V DC FLOOR POWER MODULE NEMO PHASE 1 – THE FLOOR POWER MODULE In each floor is present a FLOOR POWER MODULE that hosts the AC/DC linear converters and the floor control system. The load power supply contain a a six-pulse rectifier. The input voltage is 400 V AC (line-to-line) and the output voltage are: 12 V,3.5V, 5.5V DC. In the module is present a breaker and current and voltage measurements.

Rosanna Cocimano for the NEMO collaboration VLV T08, Toulon, France April 2008  NEMO PHASE 1 ELECTRICAL POWER SYSTEM - AC THREE- PHASE  NEMO PHASE 1 POWER CONTROL SYSTEM  NEMO PHASE 2 ELECTRICAL POWER SYSTEM – DC  PRESSURE TEST ON ELECTRIC AND ELECTRONIC COMPONENTS AGENDA

Rosanna Cocimano for the NEMO collaboration VLV T08, Toulon, France April 2008 THE POWER CONTROL SYSTEM IS ABLE TO: NEMO PHASE 1 - POWER CONTROL SYSTEM  acquire physics parameters such us temperature, humidity and pressure inside the boxes and acquire the values of current and voltage in each line  switch the power on and off to each feeding line under ordinary conditions and reveal the electric fault and remotely control the breakers in order to isolate the portion interested by the fault, set the breaker threshold from remote. DURING DESIGN WAS IMPORTANT:  foresee the storage of as much as possible devices in an oil and high pressure environment, to reduce the pressure vessel dimensions  use, where it is possible, commercial devices already tested and used,  minimize the failure points to maximize reliability,  foresee the right redundancies. Both the power supply and all boards and sensors of the power control system are redundant, so there is a NORMAL power control system and a REDUNDANT one.

Rosanna Cocimano for the NEMO collaboration VLV T08, Toulon, France April 2008 MAIN BOARD (SC13 BOARD) MODEM RS 485 MEDIA CONVERTER ACQUISITION BOARDS RS 485 SENSORS BREAKERS CONTROL BOARDS MODEM JUNCTION BOX FLOOR MEDIA CONVERTER ON SHORE The JB MAIN BOARD houses a SC13 microcrocontroller that manages:  an ethernet interface that allows the communication with the shore station on optic fibres thanks to a media converter,  a serial comunication channel (RS 485) allows the communication with the local acquisition board,  a communication channel that uses a conveyed wave modem that allows communication with the floor board. The FLOOR BOARD houses a PIC 16F876 microcontroller : a communication channel allows the communication with the JBP MAIN BOARD by means of a conveyed waves modem SENSORS BREAKER SENSORS BREAKERS NEMO PHASE 1 - POWER CONTROL SYSTEM ON-SHORE there is a USER INTERFACE that allows to supervise and control the system and store the data acquired. OPTICAL FIBERS CONVEYED WAVES

Rosanna Cocimano for the NEMO collaboration VLV T08, Toulon, France April 2008 JUNCTION BOX INPUT FLOOR POWER MODULE NEMO PHASE 1 - POWER CONTROL SYSTEM USERS INTERFACE - RESULTS ON-SHORE TOTAL POWER CONSUMPTION (LOSSES INCLUDED) 800 VA JUNCTION BOX OUTPUT JB & FLOOR TEMPERATURE 20 °C TRANSFORMER TEMPERATURE 38°C

Rosanna Cocimano for the NEMO collaboration VLV T08, Toulon, France April 2008 The START UP of NEMO PHASE 1 successfully took place the 12 th of December 2006 at 12:00 pm. The START UP of NEMO PHASE 1 successfully took place the 12 th of December 2006 at 12:00 pm.  Even though some problems occurs during deployment and connections, thanks to redundancies in the control system, the system didn’t lose any functionality.  The voltages and currents temperatures values monitored were in line with the expected ones.  The off-shore system was monitored from remote (LNS – HOME)  The voltages and currents of the on-shore UPS and Power Supply were monitored from remote too. NEMO PHASE 1 - CONCLUSIONS

Rosanna Cocimano for the NEMO collaboration VLV T08, Toulon, France April 2008  NEMO PHASE 1 ELECTRICAL POWER SYSTEM - AC THREE- PHASE  NEMO PHASE 1 POWER CONTROL SYSTEM  NEMO PHASE 2 ELECTRICAL POWER SYSTEM – DC  PRESSURE TEST ON ELECTRIC AND ELECTRONIC COMPONENTS AGENDA

Rosanna Cocimano for the NEMO collaboration VLV T08, Toulon, France April 2008 In NEMO PHASE 2 the system will be feeded in DC insted of AC THREE-PHASE so the power system has been modified from the PHASE 1 one. Following the experience acquired :  in NEMO F1 a conveyed wave system was utilized to communicate. This choice allows a complete INDEPENDENCE of the power control system from the data transmission system and from the optical fibers. In NEMO F2 we decided to have the same INDIPENDENCE from the data transmission system => don’t use optical fibers but twisted pairs.  Increase the sensors to monitor the tower cinematic and mechanical behavior both during the furling operation and in steady state.  Maintain the same redundancies NEMO PHASE 2 - PREFECE

Rosanna Cocimano for the NEMO collaboration VLV T08, Toulon, France April 2008 In NEMO PHASE 2 The TOWER BASE has replaced the NEMO PHASE 1 Junction Box and so it will be able to :  Monitor the output voltage of the ALCATEL DC/DC  Monitor the voltage applied to the tower backbone and the current consumption of the 16 floors  Allows the tower backbone switch on and off  House the media converter that allows the fiber optic/ twisted pair conversion necessary for the communication with the on-shore control system. A Goal of the new system was to reduce power consumption and to have space-saving. NEMO PHASE 2 - PREFECE

Rosanna Cocimano for the NEMO collaboration VLV T08, Toulon, France April 2008 NEMO PHASE 2 – MAIN ELEMENTS Power Feeding Equipment : P out 10 kW V out 10 kV DC a dummy load allows operational testing Electro-optical cable: V max 10 kV R 1.5 Ohm/km 20 optical fibers Medium Voltage converter: P 10 kW Vin 10 kV DC Vout 400 V DC Estimated Efficency > 90% at full load SHORE POWER FEEDING EQUIPMENT AC/DC 10 kW – 10 kV ALCATEL DC/DC 10KV / 400 V 10 kW ALCATEL Electro-Optical CABLE 100 km NEMO TOWER Frame ODI Wet- mateable connector

Rosanna Cocimano for the NEMO collaboration VLV T08, Toulon, France April 2008 NEMO PHASE 2 – NEMO TOWER CONTROL SYSTEM LOAD 20 W LOAD 35 W B t B 1B16 TOWER BASE FLOOR 1 FLOOR 16 DC-DC B 0 CONTROL SYSTEM LOAD 20 W DC-DC CONTROL SYSTEM LOAD 35 W DC-DC B t TOWER BASE B 0 ……… DC-DC CONTROL SYSTEM LOAD 35 W FLOOR 1 FLOOR 3 FLOOR 2 FLOOR 4 ……… FLOOR 13 FLOOR 15 FLOOR 14 FLOOR 16 TOWER BACKBONE 1 TWISTED PAIR to supply the ODD FLOORS 1 TWISTED PAIR to supply the EVEN FLOORS

Rosanna Cocimano for the NEMO collaboration VLV T08, Toulon, France April NEMO PHASE 2 – TOWER CABLING SPI & 5.5VDC Twisted Pair A-RS485 Redundancy Twisted Pair B-RS485 Normal Twisted Pair C-400VDC Odd Floor Twisted Pair D-400VDC Even Floor Redundant Control System PCS Redundant Control System PCS Power Module & Control system Power Module & Control system TOWER BASE TOWER FLOOR TOWER BACKBONE PCS = POWER CONTROL SYSTEM FPMS = FLOOR POWER MODULE SYSTEM Power Module FPMS Power Module FPMS SPI & 5.5 VDC 12V 5.5V 4.2V Normal Control System PCS Normal Control System PCS

Rosanna Cocimano for the NEMO collaboration VLV T08, Toulon, France April 2008 NEMO PHASE 2 – TOWER BASE 400 V DC-DC for the CONTROL SYSTEM A V Media Converter ETHERNET2SPI 5 V 400 V FROM THE ALCATEL DC/DC CONVERTER OPTICAL FIBERS RS485 NORMAL RS485 REDUNDANT TO THE ODD FLOORS TO THE EVEN FLOORS BASE TOWER CONTROL SYSTEM PCS BLOCK DIAGRAM

Rosanna Cocimano for the NEMO collaboration VLV T08, Toulon, France April 2008 NEMO PHASE 2 – FLOOR POWER MODULE BLOCK DIAGRAM

Rosanna Cocimano for the NEMO collaboration VLV T08, Toulon, France April 2008 MAIN CHARACTERISTICS :  Soft Start system  Overvoltage protection  Opt-isolated high voltage sensor  DC/DC 400V/5.5V 50W  Input and output filters  Output current and low voltage sensors  breaker to switch on and off the output low voltage line NEMO PHASE 2 – FLOOR POWER MODULE 100mm 160mm

Rosanna Cocimano for the NEMO collaboration VLV T08, Toulon, France April 2008 NEMO PHASE 2 – FLOOR DC/DC CONVERTER

Rosanna Cocimano for the NEMO collaboration VLV T08, Toulon, France April 2008 The power control system is able to:  acquire voltages, currents, temperatures and pressure,  switch on and off the power to the backbone (high voltage) and to each floor (low voltage),  it is possible to set the breakers threshold from shore,  the system host a tri-axial magnetometer and an accelerometer to give the exact position of the floor.  the control system is redundant NEMO PHASE 2 –POWER CONTROL MODULE 130mm 55mm

Rosanna Cocimano for the NEMO collaboration VLV T08, Toulon, France April 2008 NEMO PHASE 2 – CONCLUSIONS THE TOWER POWER AND CONTROL SYSTEM HAVE BEEN REALIZED AND TESTED The goals of the power consumption reduction and of the space-saving have been successfully reached NOW WE ARE READY FOR INTEGRATION AND TEST OF THE ENTIRE SYSTEM WITH DUMMY LOADS

Rosanna Cocimano for the NEMO collaboration VLV T08, Toulon, France April 2008  NEMO PHASE 1 ELECTRICAL POWER SYSTEM - AC THREE- PHASE  NEMO PHASE 1 POWER CONTROL SYSTEM  NEMO PHASE 2 ELECTRICAL POWER SYSTEM – DC  PRESSURE TEST ON ELECTRIC AND ELECTRONIC COMPONENTS AGENDA

Rosanna Cocimano for the NEMO collaboration VLV T08, Toulon, France April 2008 WHY WE DO PRESSURE TESTS:  The storage of as much as possible devices in pressure and oil environment is important for the containers design. In this way the steel pressure vessel houses only the electronic devices that cannot stay under pressure.  This solution will improve on reliability due to the reduced number of sealed connection that represent failure points.  It will improve on costs due to the reduction of its dimensions and to the use of low cost materials rather than expensive alloy such as standard titanium. OUR GOAL HAS BEEN TO TEST AND CHARACTERIZE THE MAXIMUM NUMBER OF ELECTRIC AND ELECTRONIC DEVICES UNDER PRESSURE IN AN OIL ENVIRONMENT PRESSURE TEST ON ELECTRIC AND ELECTRONIC COMPONENTS

Rosanna Cocimano for the NEMO collaboration VLV T08, Toulon, France April 2008 Tests have been curried out on: Transformers, contactors, Solid state relay, Vicor dc/dc converter, current and voltage hall effect trasducers, temperature sensor, quarts crystals, capacitors, microcontrollers, integrated circuits, various electronic components. Tests have been done for over two years in different iperbaric chambers at INFN- LNS (Catania),.), NURC- Nato Undersea Research Center (La Spezia). PRESSURE TEST ON ELECTRIC AND ELECTRONIC COMPONENTS ALL THE COMPONENTS OF THE NEMO PHASE 1 POWER AND CONTROL SYSTEM WORKED UNDER PRESSURE, NOW WE ARE WORKING TO HAVE THE SAME RESULTS FOR NEMO PHASE 2. No failure have been detected in the majority of the components tested.