Post on 07-Oct-2020
DEMO 3 UPGRADING OF MULTI-TERMINAL INTERCONNECTORS
“UPGRADING EUROPE’S GRID TO NEW HIGH-CAPACITY TECHNOLOGIES” BEST PATHS DISSEMINATION WORKSHOPBERLIN, 26 OCTOBER 2016
Diego Cirio
RSE
27 October 2016
1967: Sardinia-Mainland
1987: 50 MW tap station in
Corsica
Converters Submarine cables
Land cables
Overhead
lines /
insulation
Converters
TOSHIBA
EUROPE
Submarine cables
NEXANS
Land cables
NEXANS
Overhead
lines /
Insulation
DE ANGELI
RSE
TERNA
TERNA RSE
TERNA
System
DEMO 3: OVERVIEWSardinia – Corsica - mainland Italy (SACOI)
2
3-terminal interconnection, 300 MW, ± 200 kV monopolar with sea electrodes
Complete “rehabilitation” decided and included in the Italian national grid development plan and in ENTSOE TYNDP 2016
Good laboratory for demonstrating new HVDC technologies!
DEMO 3: ACTIVITIES
HVDC CONVERTERS
Toshiba Europe
3
Converter technology – Toshiba T&D EuropeFocus on DC fault on OHL section
SACOI-II
upgrade to
Bipolar
HVDC/VSC
Link
4
Converter technology – Toshiba T&D EuropeDEMO Work - Circuit-topology VSC-converter developed by Toshiba
A buffer-reactor free, half-bridge VSC converter with a special converter transformer:
• Small footprint
• Small leakage flux (low induction currents in nearby metallic structures, e.g., in offshore platforms)
• High reliability (applying state-of-art IGBT device (Toshiba IEGT) )
• full current, pro-rated voltage MMCs (real scale half-bridge modules and controls)
• MV scaled converter transformer
• equipment manufacturing, site installation and operational testing
5
Converter technology – Toshiba T&D Europe
DEMO Work - Circuit-topology VSC-converter developed by Toshiba
6
DC power of the full DC Current
12 MW, +10 kVdc, 1200 Adc
Converter technology – Toshiba T&D EuropeDEMO Work - Circuit-topology VSC-converter developed by Toshiba
7
DEMO 3: ACTIVITIES
HVDC CABLES
Land & Submarine
Nexans
8
Test loop energized June 2016
9
HVDC XLPE Submarine Cable
• 400 kV• 1600 mm2 Cu • Compact conductorto minimize overalldimensions
• Minimized weightto allow deep seainstallation with reduced axial tension
Successfully produced a prototype length
Successfully tested water penetration100 Bars (1000 m depth)
• water penetration 2.4 m -- > Test Passed
Test loop energized April 2016
10
HVDC XLPE Land Cable
• Successfully produced a prototype length• 2500 mm2 Al Conductor (Milliken)• 21 mm XLPE Insulation• Metallic screen, Al laminated• Outer protective jacket,
HDPE/HFFR + SC skin
HVDC Extruded Repair Joint Cutaway
Design is identical to Land Field Joint
Additional features: external Steel case to withstand deep sea Laying tension
Bend stiffeners to avoid excessive bending (exactly like in phone charger)
The Mechanical Preconditioning for 500m depth
DEMO 3: ACTIVITIES
CONDUCTORS for HVDC overhead lines
De Angeli Prodotti
RSE
TERNA 13
ACFR Conductor
Kevlar® Fibres Core
Aramid fibre core
Rated Tensile Stength
Kevlar RopeStructural Applications
Aberfeldy’s bridge,Scotland
Built in 1992, total length 113 mwith a span of 63 m
Aluminium Alloy wires
Carbon core multistrand
Extruded tube
Tape
Carbon Multistrand
• Identified reliable Kevlar/carbon
suppliers with good production capacity
• Realized first conductor prototype (~300m) for both ACFR & Carbon
• ACFR: Developed special fittings for the core material
• Carbon:
• Finished aging test
• Stranded multi-strand carbon core
RECAP:
NEXT STEPS:
•Installation test
• Installation pilot line• Characterizations test @RSE lab
• Carbon: Stranding conductor
prototype
ADVANTAGES
• Increasing of capacity and at the same time
reduction of line losses
• Reduction of the noise due to corona effect
compared to other HTLS conductors with metallic core
• High flexibility of the core
Set of performances not achievable with existing HTLS
technologies
New technologies permit to obtain:
ECONOMICAL EVALUATIONS
ACSR Ø31,50mm
Carbon fiber solution
Aramid fiber solution
Cost* [€/km] ~5000 ~25000 ~20000
Rel. @370A [Ω/km] 0,0613 0,0589 0,0548
Losses @370A [kW/km] 8,392 8,063 7,502
1 year cost of losses [€/km] 5477 4944 4600
Saving per year [€/km] = 533 877
Pay-back time [y] - 37,5 17,1
* Budgetary cost
Cost of energy = 0,07 €/kWh
Comparison between ACSR and new conductors
ACSR Ø31,50mm
Carbon fiber solution
Cost* [€/km] ~5000 ~25000
Rel. @370A [Ω/km] 0,0613 0,0589
Losses @370A [kW/km] 8,392 8,063
1 year cost of losses [€/km] 5477 4944
Saving per year [€/km] = 533
Pay-back time [y] - 37,5
ACSR Ø31,50mm
Cost* [€/km] ~5000
Rel. @370A [Ω/km] 0,0613
Losses @370A [kW/km] 8,392
1 year cost of losses [€/km] 5477
Saving per year [€/km] =
Pay-back time [y] -
DEMO 3: ACTIVITIES
INSULATIONof HVDC overhead lines
RSE
TERNA
20
Insulation of overhead DC lines
21
• Higher accumulation of pollutants
due to electrostatic fields
• Lower dielectric strengths under DC voltage
• Use of Room Temperature Vulcanizing (RTV) silicon coating (high hydrophobicity)
• Definition of test procedures to characterize the behaviour of new and from service RTV coated insulators (fully and partially coated)
Insulation of overhead DC lines
22
• Design and realization of the test set-up for carrying out long duration, multi-stress(sun, rain, salt fog…) ageing test on 6 RTV covered insulator chains (fully and partially coated)
• Design and realization of device for daily monitoring of the level of contamination of insulators under DC voltage
• Installation in Sardinia in July 2016
• Measurements are ongoing
--- > comparison with AC Amicodevice, already installed in the site
Innovative
Multiscale approach -
small & large scale solver
• A set of 56 chemicalspecies and over 600reactions is involved
• The net production of O3is included as well
• small scale simulation computes the ion emission and electric field on the conductor
Ions currents & electric fields
• Large scale solver gives a pictureof the ions currents and theelectric field around theconductors (relevant for corona)
and on the ground (disturbances
on humans)
DEMO 3: ACTIVITIES
SYSTEM ASPECTS
RSE
TERNA
24
Context
• SACOI connects 2 (or 3) electrical AC islands
• Sardinia and Corsica have weak grids
• Large RES penetration and stability issues in Sardinia
• Another HVDC (LCC) from Sardinia to mainland Italy
Objectives
• Stable operation with the new
SACOI VSC
• Restoration of Sardinia via SACOI
• Aspects of SACOI as «embedded»
HVDC
• Evaluation of the renewable
penetration increase thanks to
new SACOI
Contingencies
Event type
Location of event
“SARCO” AC line
initial state
Initial SACOI
configuration
Initial SACOI power
flow
Initial HVDC SAPEI
state
Complex dynamics,
reduced stability margins
Frequency,
transient,
voltage,
oscillatory stability issues
Controls design ongoing
Outage of Suvereto (Tuscany)Sardinia takes over control of Vdc
-40
-30
-20
-10
0
10
20
30
40
50
0.98 1.48 1.98Act
ive
imp
ort
in S
ard
inia
[MW
]
Time [s]
P Pref
Power reversal in Sardinia
Restoration: SACOI VSC as…
27
1. Black start unit
2. STATCOM
Set-up of a methodological framework and tools for the techno-economicassessment of SACOI 3 and similar HVDC systems
Application to regional and European contexts
Focus on key aspects: reliability, social welfare, RES integration, CO2 emissions, grid losses, flexibility
Ongoing activities:
Pan-European zonal modeling implementation
in 2030 scenarios (ENTSOE TYNDP 2016 visions 1 and 3)
Set-up of nodal model including Italy+Corsica for
detailed evaluations of SACOI3 impact
by a probabilistic tool
Techno-economic evaluations of three-terminal HVDC systems
Source: ENTSO-E CBA methodology
CONTACT
29
Demo 3 leader: TERNA
Contact:
Antonio Iliceto
antonio.iliceto@terna.it
Presented by
Diego Cirio
diego.cirio@rse-web.it
www.bestpaths-project.euFollow us on Twitter: @BestPaths_eu