synchronous condensers for reliable hvdc operation and ......consumption 900 - 2500 mw primary power...
TRANSCRIPT
Synchronous Condensers for reliable HVDC operation and bulk power
transfer Hans Abildgaard, Nan Qin
Energinet.dk 15PESGM3046
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Denmark is located between a thermal- and a hydro-dominated power systems
• High interconnection capacity
• First HVDC interconnector established in 1965
• DK west – 6 LCC poles (2300 MW)
– 1 VSC pole (700 MW)
• DK East – 2 LCCs (1200 MW)
Consumption 900 - 2500 MW
Primary power stations 2900 MW
Local CHP plants 650 MW
Wind turbines 1000 MW
Photo voltaic 200 MW
Dato - Dok.nr. 4
Danish Power system 2015 Two synchronous areas
Consumption 1400 - 3500 MW
Primary power stations 2250 MW
Local CHP plants 2000 MW
Wind turbines 3700 MW
Photo voltaic 450 MW
West:
East:
excl. Bornholm, mothballed and blackstart units
1632 MW
680/740 MW
600 MW 1500/1780 MW
1300/1700 MW
import / export [MW]
600 MW
AC
DC
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Energinet.dk
Wind power is still increasing
Must-run is costly 7
0
10
20
30
40
50
2006 2007 2008 2009 2010 2011 2012 2013 2014
M€ DK2
DK1
Why must-run?
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• Short circuit power – voltage step changes after shunt
switching – hvdc load rejection
• Dynamic voltage control – commutation of HVDC LCC – reactive power consumption from old
wind turbines • Continuous voltage control
– hvdc ramping – high voltages during low load (steady
state) (Active power reserves are bought in separate markets and do not give rise to must-run)
Dynamic voltage control 10
Type 1 (SCIG) 59%
Type 2 (VRIG)
8%
Type 3 (DFIG) 13%
Type 4 (FCG) 20%
Onshore capacity per technology
Simulated fault recovery without and with wind power in case of insufficient dynamic voltage support.
Minimise risk of commutation failures propagation
• On August 23, 2009 a successful reclosing on a 132 kV in the Southern part of Sweden caused a commutation failure on Kontek and Konti-Skan 1+2 (inverter).
• The current drawn by the rectifier end of the two Konti-Skan poles lead to commutation failure on Skagerrak 3 in Denmark
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Synchronous condensers in Denmark
Station Area PCC kV
Sn MVA
Year
Vr. Hassing DK1 150 100 1965/2013 Tjele DK1 150 160 1976/2012 Bjæverskov DK2 400 270 2013 Herslev DK2 400 200 2014 Fraugde DK1 400 200 2014
Kyndbyværket DK2 132 330 1976/199x Enstedværket DK1 150 880 1979/2013
Dato - Dok.nr. 13
Location of new SynCons
Dato - Dok.nr. 14
Main data of the new SynCons BJS (2013) FGD/HKS (2014)
Generator data 270MVA, 15.75kV±5% 200MVA, 15.75±10%
Cooling DAC TEWAC
Circuit Breakers HV HV+LV
Start-up time 15..20 min 10-15 min
GSU data 2W, uSC~14%, 420/15.75kV 3W, uSC~10%, 400/15.75kV
GSU energization Together with generator From 400kV side
GSU tap changer On-load ±10 steps of 1.25% None
SSC’’_HV, guaranteed >800 MVA >1000 MVA
QHV, guaranteed -150/215 Mvar -120/180 Mvar
Auxillary power Redundant from local 10kV From GSU tertiary winding
Breaking/stopping Regenerative+HV-brake Regenerative
AVR controlling node 400 kV 16 kV
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New SynCons - Purpose and requirements
• To significantly reduce the number and duration of ”must-run” requests for conventional thermal power stations, i.e. significant savings. – Short circuit level contribution – Dynamic and continuous voltage regulation – Fault-ride-through capability
• High level of availability and reliability – Well proven equipment – Redundant auxiliary systems – Detailed design reviews – Test and verification
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Inertia - currently not an issue
• In interconnected operation, the system inertia is currently sufficient – Redefinition of primary control response could be
necessary.
• The inertia provided by the new SynCons is one third of a typical steam unit. – If required additional rotating mass can be fitted to an
external flange.
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Summary and outlook • The market share for the conventional generation in
the energy market continues to fall leading to mothballing and decommissioning
• The necessary system support is built into the grid – A level playing field in the energy market – Lower socio economic costs – Maintain high security of supply
• Need for must-run will gradually decline over the next ten years – Decommissioning of Type 1 wind turbines – Commissioning of new VSC connections
(COBRAcable, Kriegers Flak DK-GE, Viking Link)
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UK NL GE
Thank you for your attention!
Hans Abildgaard Chief Engineer [email protected]
Nan Qin PhD-student [email protected]
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