el apoyo de parques eólicos a sistemas eléctricos ...€¦ · el apoyo de parques eólicos a...
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El apoyo de parques eólicos a sistemaseléctricos débiles – servicios auxiliares
Wind farms support to weak electrical systems – auxiliary services
E. QuitmannENERCON GmbH
Power Expo Zaragoza September 2008 Eckard Quitmann, Sales - Technical Support, © ENERCON GmbH 2008
Slide 2
Technical criteria for integration of wind power into power systems
Technical criteria for large scale integration of wind powerin the European mainland grid (UCTE)
Electrical issues are in general similar, just the timing when being relevant is different
in small electrical systems (Islands)
What is relevant:• Dispatching P• Dispatching Q• Voltage control• Fault-Ride-Through• Power-frequency control• …
Power Expo Zaragoza September 2008 Eckard Quitmann, Sales - Technical Support, © ENERCON GmbH 2008
Slide 3
Wind Energy Converters and their integration into power systems
Brief Introduction to ENERCON and itstechnology for wind energy converters
Electrical criteria for power system integration - Dispatching P and Q- Voltage control- Fault-Ride-Through- Power-frequency control
Conclusions
Power Expo Zaragoza September 2008 Eckard Quitmann, Sales - Technical Support, © ENERCON GmbH 2008
Slide 4
ENERCON TechnologyVariable speed - gearless drive - full scale power electronics
The gearless ENERCON concept is technically and economically far superior to all conventional turbine concepts.
Characteristics:► Gearless direct drive► Slow machine rotation► Variable speed► Yield-optimised blade design
and WEC control► Full scale power electronics
for power plant capabilities► FACTS Capabilities meet the
most advanced grid codes and connection requirements
* FACTS = Flexible AC Transmission Systems
Power Expo Zaragoza September 2008 Eckard Quitmann, Sales - Technical Support, © ENERCON GmbH 2008
Slide 5
Introduction to ENERCONENERCON Product Line
PR = 2.300kW
E-70
PR = 330kW
E-33
PR = 800kW(900kW
for E-44)
E-44/E-48/E-53
PR = 2.000kW
E-82
PR = 100kW
E-20
Power Expo Zaragoza September 2008 Eckard Quitmann, Sales - Technical Support, © ENERCON GmbH 2008
Slide 6
Introduction to ENERCONENERCON Product Line: E-126 6MW
E-126PR = 6.000 kW
13 machines installed(10 as E-112)
135 m hub heightIEC Class I a
Most powerful wind turbine worldwide
Power Expo Zaragoza September 2008 Eckard Quitmann, Sales - Technical Support, © ENERCON GmbH 2008
Slide 7
ENERCON TechnologyCharacteristic of the WEC for the power system
Filter Trans-former
Circuit Breaker Seen from the
grid the performance
is defined by the inverters
DC-Link
Ring Generator
==
Excitation Controller
=
Rectifier
≈≈ =
Inverter
≈≈
ControlSystem
Power flow
• Seen from the grid the ENERCON WEC is mainly a source of current.
• As long as frequency and voltage at the WEC terminals are within the specified ranges, the WEC injects the maximum possible current.
• The individual WEC controls the power factor (or reactive power) but not the voltage. The entire wind farm can be equipped with voltage control, if required.
Power Expo Zaragoza September 2008 Eckard Quitmann, Sales - Technical Support, © ENERCON GmbH 2008
Slide 8
Wind Energy Converters and their integration into power systems
Brief Introduction to ENERCON and itstechnology for wind energy converters
Electrical criteria for power system integration - Dispatching P and Q- Voltage control- Fault-Ride-Through- Power-frequency control
Conclusions
practiced in Spain
Power Expo Zaragoza September 2008 Eckard Quitmann, Sales - Technical Support, © ENERCON GmbH 2008
Slide 9
Wind farms with Voltage Control System (VCS) and the benefits for the integration of wind power into power systems
Qwind farm
Pwind farm
UPoC
ENERCON Grid Data
Acquisition
ENERCON SCADA PC
Point of Connection (PoC)
Automatic, dynamic Voltage Control System:
- Can improve quality of power supply
- Impact on voltage depends on a) Q-range from WFb) stiffness of PoCc) dynamics
- Needs to be studied project specifically
Power Expo Zaragoza September 2008 Eckard Quitmann, Sales - Technical Support, © ENERCON GmbH 2008
Slide 10
Example from actual grid code requirementsSpain: P.O. 12.3.
Typical voltage-time-limiting curve
Minimum reactive current requirement while voltage is depressed during a fault.Reference: “Total current”Consequence: minimum tanϕ for current injection during a fault.
ENERCON WEC with UVRT Option:- Passes voltage dips, even with U=0- For up to 5 seconds- Fault Ride Through capability is adjustable
to optimize benefit for the power system- Can provide reactive current up to I rated
Power Expo Zaragoza September 2008 Eckard Quitmann, Sales - Technical Support, © ENERCON GmbH 2008
Slide 11
Future aspects of Fault-Ride-ThroughTo be discussed with system operators
Effects of voltage dips to be addressed more in detail when going to really high wind power penetration or weak power systems:
- Transients during beginning and clearance of fault- Transformer inrush (reference point for P- and Q-limit
is usually the HV side)- Reasonable contribution of reactive current:
+ during unbalanced faults+ in radial distributed systems (risk of islanding)+ considering PoC specific dynamics of the
power system (voltage recovery)
Future: PoC specific contribution of reactive current during faults
Power Expo Zaragoza September 2008 Eckard Quitmann, Sales - Technical Support, © ENERCON GmbH 2008
Slide 12
ENERCON technology capability to ride through frequency disturbances
- Example: Measurement in Corsica
- High frequency gradients observed
- Could occur similar on Canarias
- Remember November 4th 2006 !
ENERCON WECs pass frequency disturbances up to 4 Hz/second
Reasonable future requirement: WECs to stay connected during frequency disturbances
Generation unit trips
Wind power plant active power
Wind power plantvoltage
Wind power plant current
Frequency
Power Expo Zaragoza September 2008 Eckard Quitmann, Sales - Technical Support, © ENERCON GmbH 2008
Slide 13
Future needs of the power system Contribution of WECs during frequency disturbances
For wind energy the requirements about power and frequency must distinguish between:- Incidents of overfrequency versus underfrequency- Incidents during strong wind versus slow wind- Permanent requirements (minutes, hours) versus temporary (sec)
The power system operator shall define: - requirements independent of the WEC technology- economical value for power-frequency system services
WEC manufacturers then shall develop the optimum technical- and economical solution that meets the requirements
Basic: All modern WECs operate with variable speed.
Consequence: If any dependency Power = f(Frequency) is desired, it has to be implemented “artificially” through the control of the WEC.
Power Expo Zaragoza September 2008 Eckard Quitmann, Sales - Technical Support, © ENERCON GmbH 2008
Slide 14
ENERCON Technology Power reduction for overfrequency incidents
1. Overfrequency: - Relatively easy to respond to- WEC must reduce active power - Detailed dynamic parameters to be determined
Pelectric = f(frequency)
Power Expo Zaragoza September 2008 Eckard Quitmann, Sales - Technical Support, © ENERCON GmbH 2008
Slide 15
ENERCON Technology Power reserve for underfrequency incidents
wind speed
Prated
• If system tends to become critical, signal can be sent to wind farms: “reduce active power”(temporarily for precaution)
• If system frequency really falls below f low, wind farm increases active power
• Economical disadvantage for WF acceptable, if it is limited to a few hours per year
Technology is available,but exact dynamic requirements
need to be specified !
fhigh fmaxfrated
Pavailible
normalfrequ.range
flow
Plimited
Active power reserve
frequency
Active power2. Underfrequency:
Prated – x%Preserve as percentage of Pactual
Power Expo Zaragoza September 2008 Eckard Quitmann, Sales - Technical Support, © ENERCON GmbH 2008
Slide 16
Wind Energy Converters and their integration into power systems
Brief Introduction to ENERCON and itstechnology for wind energy converters
Electrical criteria for power system integration - Dispatching P and Q- Voltage control- Fault-Ride-Through- Power-frequency control
Conclusions
Power Expo Zaragoza September 2008 Eckard Quitmann, Sales - Technical Support, © ENERCON GmbH 2008
Slide 17
Conclusions ENERCON Technology and power system integration
ENERCON WECs:
► Generating unit and FACTS device merged in one single device
► Wide range of available options and parameters to optimize wind farm benefit for power system
General:
► Future issues to be discussed between wind farm promoters, manufacturers and power system operators:
• Reactive power provision & voltage control
• Refined Fault-Ride-through requirements
• WEC to withstand high frequency gradients
• WEC contributions to power-frequency control