WPH goals: prepare the specifications for the main components of the deep-sea infrastructure: - Main electro-optical cable (MEOC); - Power transmission and distribution; DC/DC (Medium Voltage Converter, MVC) and/or AC/DC converters; sea return (short/long distances from shore: site dependent developments) - Deep-Sea operated electro-optical connectors: HV, hybrid low voltage, ….; - Junction Boxes: primary (PJB) (short/long distances from shore: site dependent developments), secondary (SJB); - ROV and/or AUV needed for the deep-sea handling infrastructure; manipulating tools to be mounted on the ROV set-up an engineering plan for construction of the deep-Sea handling infrastructure and tools (ROV, manipulators, …) Validation and long duration tests of some critical components going on: -DC/DC power converters -Connectors -ROV KM3NeT Seafloor network: WPH report Antonio Capone University “La Sapienza” and INFN - Roma KM3NeT WPH report to the general meeting, LNS, Catania, 22/02,2012 1

A deep-sea infrastructure for KM3NeT The KM3NeT-DS TDR described two possible solutions for the detector layout and indicated the first one as preferred. Star-like geometry for 1 “building block” “R ing” geometry Other aspects of the infrastructure were questioned (DC or AC; MEOC with sea return or two wires; MVC: where, penetrator or HV connector; the HV value: 10kV or less; …) KM3NeT WPH report to the general meeting, LNS, Catania, 22/02,2012 2

AC/DC versus DC/DC power transmission In the case of long cabled distances, the cable parameters plays a mayor role in an alternating current power grid regardless the power itself. Typical number for reactive losses are in the range of 3-5 kVAR/km for 10 kV, 2 wire, cross-linked PE-cable [2]. The DC losses in contrast are only related to I load 2 R cu. Due to the effects as skin effect (only AC) and proximity effect, R cu will be higher then just the calculated copper resistance. Moreover the isolation value of the cable depends on the peak value of the voltage and not on the rms voltage. This imply that with the same current a DC transfer can handle √2 more power. To convert AC to lower power levels often transformers are used, simple robust components. However, by the reactive behaviour of a long distance transfer a power factor corrector is needed to optimize the power transfer within the rules of the main supplier. This is done by extra inductors in the cable and an electronic device, to modulate the current, which is working by the same components as a DC to DC convertor. So in terms of losses (cable construction and cross section) and complex components subsea the direct current transfer will be preferred. [1] [2] E.Heine, H.Z.Peek, “Power distribution”, SJ B AC concept SJ B DC concept Comparison of a DC power transfer and a AC power transfer with the most important components Comparison of a DC power transfer and a AC power transfer for transmission with sea return. PFC E. Heine

What’s the intensity of the magnetic field due to DC/DC transmission with “sea return” ? [2] A DC-link will produce an electromagnetic field which will disturbs the local Earth Magnetic Field (EMF). Some marine life seems to use the EMF for their navigation during migration from living ground to reproducing grounds [1], although other reports are denying this effect [3]. The EMF intensity (or induction) is in the order of μT [2]. The absolute value and variation is shown in figure 1a,b. [1] Fig.1, Intensity and variation of the earth magnetic field To calculate the EMF intensity of a one conductor cable we use the Biot – Savart law for a very long cable; B=μI/2πr [T] B=induction, I=current [A], r=distance [m], μ=μ 0 μ r permeability μ 0 =4π.10 -7, μ r ≈1 for seawater For a load of 100kW 10kV) figure 2 shows the influence on the EMF. Although there are not found references to qualify the influence on life, the outcome on a small distance is a fraction of the earth magnetic field. So there is only some effect in shallow water. Fig.2, Influence of the cable on the EMF for an uni-polar and a bi-polar (2 wires on 5cm) transmission. [3] E. Heine

A. B C JB Floor plan for 1 Building Block with “star layout” VEOC IL HEOC MEOC Cable glossary DU E. Heine KM3NeT WPH report to the general meeting, LNS, Catania, 22/02, From now on we will discuss the deep sea infrastructure for one KM3NeT Building Block ~ 100 D.U.s

KM3NeT WPH report to the general meeting, LNS, Catania, 22/02, Star-like layout: main components

Star-like layout: cable specifications A monopolar cable with sea return (positive electrode on “wet ground”, on shore, and negative electrode in water ) provides the solution with lower power dissipation. KM3NeT WPH report to the general meeting, LNS, Catania, 22/02,2012 7

8 Star-like layout: power distribution system - 1 One KM3NeT Building block at 100km from the shore.

Star-like layout: power distribution system KM3NeT WPH report to the general meeting, LNS, Catania, 22/02,2012

The Medium Voltage Converter - 1 KM3NeT WPH report to the general meeting, LNS, Catania, 22/02, Two 10kV-400V DC/DC MVCs produced by by ALCATEL are owned by the KM3NeT community (NEMO): each one delivers 10kW. ALCATEL (Dec. 2010) confirmed no future production of other MVCs like the NEMO (2) / NEPTUNE (6) ones. Other possible suppliers: PBF, Heinzinger, CAEN, OceanWorks (Canada), L-3 MariPro have been contacted and showed great interest and competence. Specifications have been given.

The Medium Voltage Converter - 2 KM3NeT WPH report to the general meeting, LNS, Catania, 22/02, The ALCATEL MVC. Deployed since in Capo Passero site in December 2010 and operational since then (no load). Smooth operation, no problem reported so far.

Specifications for the OceanWorks MVC under study: Input range from -7kVDC to -10kVDC Output voltage of 375VDC at 10kW 10 kW modules telemetry system for output power and working parameters internal cooling no need for switching system at the HV input (soft start system) several (≥6) MVCs able to work in parallel dimensions (assumption): 20 inches x 36 inches Estimated (Oceanworks) time schedule: 8 months for the prototype unit 4 months for each additional unit The Medium Voltage Converter - 3 KM3NeT WPH report to the general meeting, LNS, Catania, 22/02,

Star-like layout: power budget and distribution KM3NeT WPH report to the general meeting, LNS, Catania, 22/02, It could be an over-estimate

Star Layout: the Primary Junction Box schematics KM3NeT WPH report to the general meeting, LNS, Catania, 22/02,

The Secondary Junction Box power system schematics KM3NeT WPH report to the general meeting, LNS, Catania, 22/02,

The PJB Power System Box KM3NeT WPH report to the general meeting, LNS, Catania, 22/02,

The SJB Power System Box KM3NeT WPH report to the general meeting, LNS, Catania, 22/02,

The Star-like layout Photonics scheme KM3NeT WPH report to the general meeting, LNS, Catania, 22/02,

The Marigold - MEUST scheme KM3NeT WPH report to the general meeting, LNS, Catania, 22/02,

The Marigold - MEUST scheme 20 KM3NeT WPH report to the general meeting, LNS, Catania, 22/02,2012

The MEUST – seabed power distribution system 21 KM3NeT WPH report to the general meeting, LNS, Catania, 22/02,2012

The MEUST – optical layout system 22 KM3NeT WPH report to the general meeting, LNS, Catania, 22/02,2012

The MEUST – controls and redundancies 23 KM3NeT WPH report to the general meeting, LNS, Catania, 22/02,2012

MARIGOLD Network components Sea return electrod e Manifol d Junctio n box Marigold nodes : Two main components : node = Junction box + manifolds KM3NeT WPH report to the general meeting, LNS, Catania, 22/02,

The MEUST – requirements for the MEOC 25 KM3NeT WPH report to the general meeting, LNS, Catania, 22/02,2012

The MEUST – elements of the seabed layout 26 KM3NeT WPH report to the general meeting, LNS, Catania, 22/02,2012

The MEUST – deploying the seabed layout 27 KM3NeT WPH report to the general meeting, LNS, Catania, 22/02,2012

The MEUST Node (JB) power system general scheme 28 KM3NeT WPH report to the general meeting, LNS, Catania, 22/02,2012

MEUST proposition for 90 DU layout 29 KM3NeT WPH report to the general meeting, LNS, Catania, 22/02,2012

Modular Connectorized Distribution Unit The PJB - APC hybrid wet mateable connector KM3NeT WPH report to the general meeting, LNS, Catania, 22/02,

The PJB H.V. connectors KM3NeT WPH report to the general meeting, LNS, Catania, 22/02,

KM3NeT WPH report to the general meeting, LNS, Catania, 22/02,

Development of new electro-optical connectors KM3NeT WPH report to the general meeting, LNS, Catania, 22/02,2012

Development of new electro-optical connectors KM3NeT WPH report to the general meeting, LNS, Catania, 22/02,2012

The Earth-Sea Science Sea-Floor: detectors positions 35 KM3NeT WPH report to the general meeting, LNS, Catania, 22/02,2012 KM3NET Safety Radius Benign Sensors only Active Sensors Acoustic Optic Sea Floor Real Estate -1 Safety distance

The Earth-Sea Science Sea-Floor: detectors position 36 KM3NeT WPH report to the general meeting, LNS, Catania, 22/02,2012 KM3NET Distributed junction boxes around the array Sea Floor Real Estate – 2 options

The Earth-Sea Science Sea-Floor: requests 37 KM3NeT WPH report to the general meeting, LNS, Catania, 22/02,2012 BANDWIDTH hdtv RAW 30FPS 1.5Gbit per second Compression Mpeg 50MBs 20MBs 10 cameras = 500 MBs Multibeam sonars Within capacity of one wavelength on fibre Conclude bandwidth is not a problem 2 Gbs capacity POWER 10kW total for ES science specified in TDR lights 500W each 1KW halogen Power can be reduced by LEDs What about sonars? Motors (inductive load) AUV docking Crawlers ( Wally), ROVs 10kW capacity at each JB but not used all the time

Summary Seafloor network for a KM3NeT building block has been defined. Cables specifications are set (MEOC, HEOC, ILC, VEOC). Contact with industries advanced (ALCATEL, NEXANS, DRAKA, …) Power and command/data routings (on cables, PJB, SJBs, DU) are described schematically. Connectors and penetrators for HV, LV, cables, fibers, hybrid, available, under tests, under development. Medium Voltage Converters for DC/DC power transmission available (ALCATEL) and/or under study (Oceanworks, L-3 MariPro). Detailed study and development of PJB and SJBs are going on. MEUST scheme for sea-floor network (and components) has been developed for Toulon area. KM3NeT WPH report to the general meeting, LNS, Catania, 22/02,