Transmission overhead lines Irish context

Transcription

1 Transmission overhead lines Irish context Mark Norton Oct 2010

2 Agenda 1.What s so great about an overhead line? 2.Overhead line use in Ireland 3.Solutions to needs 1. CIGRÉ WGB2-C1.19 on Increasing Capacity of Overhead Transmission Lines Needs and Solutions 2. Selection of new conductors for use in Irish network 3. Voltage uprating 4. HVDC 5. Other future technologies

3 What s so great about an overhead line?

4 What s so great about an overhead line? EirGrid is required as the licensed Transmission System Operator in Statuary Instrument 445, 8(1a) to: to operate and ensure the maintenance of and, if necessary, develop a safe, secure, reliable, economical and efficient electricity transmission system, and having due regard for the environment; Overhead lines provide the best balance of these statuary requirements

5 Overhead line use in Ireland

6 110 kv Line Hydro Station 38 kv Line Thermal Station 110 kv Transformer Station KILBARRY CITY km LOUGH M AHON 220 kv Line Hydro Station 110 kv Line Thermal Station 220 kv Transformer Station 220 kv Cable 110 kv Transformer Station 110kV Cable CAHIRCIVEEN TRALEE BELLACORICK TARBERT TRABEG KILBARRY MARINA CITY CASTLEBAR GALWAY DUNMANWAY RAFFEEN ENNIS COBH CARRIGADROHID KNOCKRAHA ARDNACRUSHA KILBARRY LIMERICK HARBOUR KILBARRY INNISCARRA HAULBOWLINE SEE AREA CATHALEEN'S FALL SLIGO DERRYFRENCH CARRICK-ON- SHANNON ARDNACRUSHA KILLONAN MALLOW MARINA TRABEG RAFFEEN ARIGNA SEE AREA WHITEGATE GI LETTERKENNY CLIFF LANESBORO ATHLONE SHANNONBRIDGE TYNAGH KNOCKRAHA CAHIR FERBANE MAYNOOTH THURLES SHANKILL PORTLAOISE KILKENNY DUNGARVAN RHODE PORTARLINGTON WATERFORD NORTHERN IRELAND ALLENWOOD RB M ACETOWN PIGEON HOUSE GH INCHICORE COOKSTOWN INCHICORE NORTHERN IRELAND MAYNOOTH NEWBRIDGE CARLOW GREAT ISLAND POLLAPHUCA FINGLAS WEXFORD DUNDALK DRYBRIDGE INCHICORE POLLAPHUCA FINGLAS FRANCIS ST. INCHICORE FINGLAS SHELTON ABBEY SEE DUBLIN AREA PIGEON HOUSE NORTH WALL SEE PIGEON HOUSE DUBLIN RINGSEND AREA CARRICKMINES MILLTOWN ARKLOW CARRICKMINES NORTH WALL PIGEON HOUSE RINGSEND 110 kv Line Hydro Station 38 kv Line Thermal Station 110 kv Transformer Station KILBARRY CITY 220 kv Line Hydro Station 110 kv Line Thermal Station 220 kv Transformer Station Pumped Storage Station 110 kv Transformer Station 220 kv Cable TRALEE BELLACORICK TARBERT TRABEG KILBARRY 110 kv Cable TAWNAGHMORE MARINA CITY MOY CASTLEBAR GALWAY RAFFEEN MACROOM DUNMANWAY ENNIS KNOCKRAHA DUNKETTLE CASHLA LIMERICK RATHKEALE CARRIGADROHID COWCROSS ARDNACRUSHA KILBARRY KILBARRY INNISCARRA BANDON OLDCOURT CARRICK-ON- SHANNON 38kV SEE AREA CATHALEEN'S FALL SLIGO DERRYFRENCH CARRICK-ON- SHANNON ARDNACRUSHA AHANE KILLONAN CHARLEVILLE MALLOW MARINA TRABEG RAFFEEN ARIGNA SEE AREA MIDLETON WHITEGATE CAHIR ATHLONE KILTOY LETTERKENNY CLIFF LANESBORO ATHLONE SHANNONBRIDGE TYNAGH KNOCKRAHA MIDLETON FERBANE MAYNOOTH THURLES PORTLAOISE SHANKILL GRIFFINRATH WATERFORD MULLINGAR PORTLAOISE KILKENNY BALLYDINE DUNGARVAN RHODE PORTARLINGTON WATERFORD ALLENWOOD NORTHERN IRELAND NORTHERN IRELAND CARLOW NAVAN MAYNOOTH NEWBRIDGE LOUTH KNOCKUMBER COOKSTOWN INCHICORE INCHICORE GREAT ISLAND 275kV 38kV TO TANDRAGEE WEXFORD DUNDALK DRYBRIDGE PLATIN SEE PIGEON HOUSE DUBLIN AREA PIGEON HOUSE NORTH WALL SEE POOLBEG DUBLIN INCHICORE AREA CARRICKMINES POLLAPHUCA TURLOUGH HILL FINGLAS FINGLAS SHELTON ABBEY McDERMOTT FRANCIS ST. INCHICORE RINGSEND MILLTOWN ARKLOW CARRICKMINES NORTH WALL POOLBEG BLACKROCK 110 kv Line Hydro Station 110 kv Transformer Station Thermal Station KILBARRY CITY 400 kv Line Hydro Station 220 kv Line Thermal Station 110 kv Line Pumped Storage Station 400 kv Transformer Station 220 kv Cable 220 kv Transformer Station 110 kv Cable 110 kv Transformer Stations TRALEE BELLACORICK TULLABRACK MONEYPOINT TARBERT TRABEG KILBARRY TAWNAGHMORE TRIEN MARINA CITY MOY DUNMANWAY KNOCKRAHA DUNKETTLE RAFFEEN BARNAHELY OLDCOURT COWCROSS KILBARRY CARRICK-ON- SHANNON ARDNACRUSHA SEE AREA CARRICK-ON- SHANNON DRUMLINE ARDNACRUSHA PROSPECT MUNGRET AHANE CASTLEFARM MONETEEN KILLONAN AUGHINISH LIMERICK RATHKEALE KNOCKEARAGH CASTLEBAR GALWAY MACROOM ENNIS CASHLA CARRIGADROHID KILBARRY INNISCARRA BANDON CATHALEEN'S FALL SLIGO CHARLEVILLE MALLOW MARINA TRABEG RAFFEEN ARIGNA FLAGFORD MIDLETON AGHADA WHITEGATE IKERRIN CAHIR KILTOY LETTERKENNY CLIFF LANESBORO ATHLONE SHANNONBRIDGE BARRYMORE KNOCKRAHA MIDLETON SEE AREA AGHADA RICHMOND FERBANE THURLES DOON ANNER MAYNOOTH PORTARLINGTON PORTLAOISE SHANKILL MULLINGAR PORTLAOISE WATERFORD KILKENNY BALLYDINE DUNGARVAN GRIFFINRATH RHODE WATERFORD ALLENWOOD BUTLERSTOWN NORTHERN IRELAND LISDRUM ALLENWOOD NORTHERN IRELAND CARLOW NAVAN MAYNOOTH NEWBRIDGE LOUTH KNOCKUMBER DUNSTOWN INCHICORE 275kV WOODLAND GREAT ISLAND DRYBRIDGE NORTH WALL SEE PIGEON HOUSE DUBLIN INCHICORE AREA POLLAPHUCA TO TANDRAGEE PLATIN TURLOUGH HILL NORTH WALL PIGEON HOUSE FINGLAS GRANGE NORTH WALL SEE POOLBEG DUBLIN INCHICORE AREA CARRICKMINES CRANE WEXFORD COOKSTOWN DUNDALK DRYBRIDGE POLLAPHUCA SHELTON ABBEY FINGLAS McDERMOTT FASSAROE ARKLOW FRANCIS ST. INCHICORE RINGSEND HAROLDS CROSS MILLTOWN CARRICKMINES NORTH WALL GRANGE POOLBEG SHELLYBANKS BLACKROCK 110 kv Line Hydro Station 110 kv Transformer Station Thermal Station 110 kv Cable CAHIRCIVEEN TRALEE KILBARRY MARINA CITY 400 kv LineHydro Station 220 kv LineThermal Station 110 kv LinePumped Storage Station 400 kv Transformer Station 220 kv Cable 220 kv Transformer Station110 kv Cable 110 kv Transformer Stations TRALEE BELLACORICK TULLABRACK MONEYPOINT TARBERT OUGHTRAGH TRABEG KILBARRY LIBERTY STREET TAWNAGHMORE TRIEN MARINA CITY MOY GALWAY LIMERICK CARRIGADROHID DUNMANWAY DUNMANWAY KNOCKRAHA DUNKETTLE 38kV RAFFEEN BARNAHELY OLDCOURT KILBARRY INNISCARRA COWCROSS CATHALEEN'S FALL CARRICK-ON- SHANNON LANESBORO ARDNACRUSHA MARINA ARIGNA WHITEGATE SEE AREA WHITEGATE CARRICK-ON- SHANNON DRUMLINE ARDNACRUSHA PROSPECT MUNGRET AHANE CASTLEFARM MONETEEN KILLONAN AUGHINISH LIMERICK RATHKEALE KNOCKEARAGH CASTLEBAR GALWAY CLOON ENNIS CASHLA KILBARRY INNISCARRA MACROOM MARINA TRABEG CARRIGADROHID RAFFEEN BRINNY BANDON CATHALEEN'S FALL SLIGO CHARLEVILLE MALLOW BINBANE FLAGFORD SOMERSET ARIGNA MIDLETON AGHADA WHITEGATE CLIFF ATHLONE CAHIR IKERRIN CAHIR KILTOY LETTERKENNY CLIFF LANESBORO ATHLONE SHANNONBRIDGE BARRYMORE KNOCKRAHA MIDLETON SEE AREA AGHADA GILRA DALLOW GOLAGH THURLES MAYNOOTH FERBANE TO ENNISKILLEN RICHMOND RYEBROOK GRIFFINRATH KILTEEL PORTLAOISE KILKENNY DUNGARVAN RHODE PORTARLINGTON WATERFORD RINAWADE WATERFORD ALLENWOOD BUTLERSTOWN MACETOWN CITYWEST NORTHERN IRELAND RHODE MAYNOOTH ALLENWOOD THORNSBERRY CUSHALING FERBANE NEWBRIDGE DOON ANNER GORTAWEE ARVA LISHEEN SHANKILL MULLINGAR PORTLAOISE KILKENNY DUNGARVAN TO STRABANE BALLYDINE NORTHERN IRELAND LISDRUM DUNSTOWN CARLOW LOUTH MEATH HILL NAVAN KNOCKUMBER COOKSTOWN WEXFORD INCHICORE 275kV WOODLAND KELLIS GREAT ISLAND TO TANDRAGEE FINGLAS McDERMOTT HAROLDS CROSS DUNDALK DRYBRIDGE NORTH WALL SEE PIGEON HOUSE DUBLIN RINGSEND INCHICORE AREA CARRICKMINES POLLAPHUCA PLATIN FINGLAS TURLOUGH HILL FINGLAS FINGLAS GRANGE NORTH WALL POOLBEG FRANCIS ST. INCHICORE RINGSEND MILLTOWN CARRICKMINES ARKLOW CARRICKMINES INCHICORE CARRICKMINES CRANE WEXFORD DUNDALK MULLAGHARLIN KILTEEL DRYBRIDGE POLLAPHUCA SHELTON ABBEY FASSAROE ARKLOW NORTH WALL NORTH WALL PIGEON HOUSE RINGSEND AREA GRANGE POOLBEG SHELLYBANKS BLACKROCK Overhead line use in Ireland Transmission System 1930 Transmission System 1940 Transmission System 1950 Transmission System 1960 LEGEND LEGEND LEGEND LEGEND DUBLIN AREA DUBLIN AREA DUBLIN AREA DUBLIN AREA AREA AREA AREA AREA Transmission System 1970 LEGEND Transmission System 1980 LEGEND Transmission System 1990 LEGEND Transmission System 2000 LEGEND SEE DUBLIN DUBLIN AREA DUBLIN AREA DUBLIN AREA DUBLIN AREA AREA AREA AREA AREA RINGASKIDDY HAULBOWLINE RINGASKIDDY HAULBOWLINE RINGASKIDDY HAULBOWLINE

7 Overhead line use in Ireland Present - Drivers Renewables impact Complex power flows Development constraints Growth in demand/economy Europe

8 Overhead line use in Ireland Present and ongoing needs Higher capacity circuits Faster solutions Higher utilisation of network, losses Comparable maintenance/life cycle Flexible to strategic thinking, GRID25/ Offshore study

9

10 EirGrid overhead line solution development Cognisance given to CIGRÉ WGB2-C1.19 on Increasing Capacity of Overhead Transmission Lines Needs and Solutions Some CIGRÉ solutions deemed not suitable HSIL lines distance in Ireland Operational techniques (monitoring) for long term planning Add a circuit to a line Planning permission Add a circuit to right of way Planning Permission Higher capacity lines Conductor based techniques (HTLS) Increase the voltage of a line (up-rate a circuit) HVDC Combination of ampacity and voltage (probably a new line)

11 Conductors

12 Conductor based techniques CIGRÉ The PERFECT Conductor would: weigh nothing be immune to fatigue failure be perfectly conductive be immune to thermal sag change be immune to ice load sag change be free No single HTLS conductors can improve all these over another conductor but should be selected to provide the right improvement balance of them Our constraints and goals will determine the best choice for us

13 SAG Solutions to needs The Sag-Temperature Relationship large The name of the game is to: * flatten the slopes, and * move the kneepoint to a cooler temperature Kneepoint The slope flattens at higher temperatures IF the metal with the lower Cf value takes over. (IE: if the other metal stops carrying tension) small The slope of the relationship is a result of the combined thermal coefficient of thermal expansion, Cf cold TEMPERATURE hot

14 Conductor based techniques CIGRÉ Core Material HS EHS EXHS Alum Clad Galv. Invar Al. Clad Invar Mish metal Al Matrix Carbon Fiber No Core Hard Drawn 1350-H19 HS Alloy 6201-T81 ACSR ACSR/TW AACSR ACSR/ EHS AACSR/ EHS ACSR/AW AAC AAAC ACAR Aluminum Material 1350-O TAI ACSS/GA ACSS/TW TACSR ACSS/ HS285 ACSS/AW TACSR/ AW ACSS/MM ACSS/TW ACCC/ TW KTAI KTACSR KTACSR/ AW ZTAI (UTAI) ZTACSR GZTACSR ZTACIR ACCR ACCR/ TW XTAI XTACIR

15 Conductor based techniques TSO/TAO analysis Increases of at least 100% possible ACCC, not considered due to track history, following its development AAAC, ASCC and GAP type conductor examined in detail Although all acceptable GAP considered to best

16 Increased Voltage

17 Increase the voltage of a line CIGRÉ Voltage uprating is a very efficient way to increase the power transfer capabilities(220 kv 380 kv 172%) Voltage uprating reduce the joule losses P losses = V 2 / R (220 kv 380 kv factor 3)

18 Case study Double circuit 110 kv converted to single circuit 275 kv structure

19 Increase the voltage of a line Concerns Sacrifice of a OHL can cause redundancy problems OHL must be diverted to another substation The OHL is out of service for a long period of time Needs a broader safety strip (ROW) (cost, vegetation) Corona problems (audible noise) Do not introduce another voltage level

20 Increase the voltage of a line EirGrid Conclusions Voltage Uprating of existing OHL could be achieved The number of the parts that must be replaced varies but even with high replacement Voltage Uprating can still be profitable As many design parameters can be economised, agreement on reliability and availability of a OHL between Planners and OHL Engineers can help Existing structures not sufficient for increasing 110 to 220kV Analysis of uprating of specific 220kV to 400kV lines is in progress at this time

21 HVDC

22 HVDC - CIGRÉ WGB2-C1.19. Findings are: AC lines could be converted to DC operation with minimal modifications insulators Capacity increases can be as much as c.170%

23 HVDC - CIGRÉ Solutions to needs Insulation level (V AC / 3) * 2 V DC The power transfer for DC is 2 larger than AC equivalent Allowing for benefit of no skin effect and reactive compensation needs this can rise to c1.8 times better However for a 3 phase line a reduction of only using two phases would reduced this by a third to c.1.2 Could this be avoided?

24 Pole Current Modulation I max P 3 /P 2 L 3 /L 2 A B C 1-Pole Convertor A B C 1-Pole Convertor A B C 1-Pole Convertor 1 2 a 1 N /A N/A 3 If pole1 is positive pole 2 en 3 are negative, sharing the return current 1 b Each conductor sees a high current a third of the time The currents are adjusted to maintain the rms value of the conductors 1 c Resulting in a 1.41 * 1.2 = 1.7 times AC equivalent d

25 HVDC Transgrid report completed for Eirgrid Findings are: HVDC has its uses in Irish network Failure of specialised control systems risk network stability VSC is required to ensure no commutation failure No rational for using at this time Use of HVDC, ongoing to be involved in CIGRÉ JWG C4/B4/C1 604 Influence of embedded HVDC transmission on system security and AC network performance

26 HVDC Transgrid EirGrid/NIE report 4 project scenairos Studies Power Flow (PSSE) Short Circuit (PSSE) Transient Stability (PSSE) Subsynchronous Resonance Screening Frequency Scans (PSCAD) Large Scale Wind Farm Connection 5-terminal Ring North-South Power Corridor Drawing Power out of Cork

27 Loss of Double Circuit 275 kv Louth-Tandragee lines Otherwise: - Potential to overload NI-RoI 110 kv circuits -Potential system instability, loss of synchronism between north & south Lose these AC lines New Circuit must take over some of this power transfer 70-80%

28 V (pu) Ang (deg) Solutions to needs Angles are far apart at normal 600msec reclosing time Angles are close together at 1.8 seconds ANGL [TANDRAGE ] ANGL [LOUTH ] ANGL [LOUTH ] Angle Louth and Tandragee Time (s) VOLT [TANDRAGE ] VOLT 3772 [CAVAN ] VOLT 5464 [WOODLAND ] Reclosing when angles are close together minimizes impact compared to earlier figure Time (s) LCC AC Voltages at North-South Terminals

29 HVDC Concerns System Expansion difficult and expensive to tap into HVDC; AC can easily be tapped Power scheduling of HVDC, although it is also a benefit, it could also add some operational complexity, especially in a very meshed AC network Failure of control systems Good use of existing conductor capacities

30 HVDC EirGrid Conclusions HVDC could be used in Irish network Restricted specialised use at present, currently higher risk and higher capital cost However currently being considered for onshore projects and as a technology medium for offshore

31 Future ACCC conductors Solutions to needs Partially insulated conductors

32 Conclusions Overhead lines are good, and we need them now more than ever! New conductor, Voltage uprating and DC solutions offer the best use of overhead lines in Ireland Other new technologies will also be considered when the time is right

33 Thanks for your attention