ABB ACS800-67, System Description And Start-Up Manual

Page: 30 / 120

30 System description
Grid codes
Grid codes specify static and dynamic requirements to be fulfilled by a wind power
installation. Static requirements mainly determine the voltage control and power control
during normal operation. Most of the recent grid codes include also power quality
requirements such as harmonics distortion limits, flicker etc. Dynamic requirements define
the dynamic behavior of a wind turbine or wind farm under grid disturbance. One of the
most important dynamic requirements is grid fault ride-through capability of the wind power
generator. Grid fault ride-through means that instead of disconnection, the wind
generators have to stay connected to the electrical power network for a certain period.
Grid fault ride-through requirements define:
•
how long a grid fault (eg, voltage dip/sag or swell) can last
•
how to operate under a balanced (symmetrical) grid fault
•
how to operate under an unbalanced (unsymmetrical) grid fault.
The power train concept can be used to find the optimal solution when balancing the
connection requirements and costs of installation. The selection of electrical power train
components (a pitch system, generator, frequency converter and transformer) has effect
on the capability of an individual turbine to comply with the grid code requirements.
Although the converter has an important role in enabling the wind turbine to fulfill the grid
code requirements, it is highly dependent on how the whole wind turbine system and its
process is functioning (the wind turbine controller, pitch system, UPS etc.). The turbine
manufacturer is responsible for fulfilling the requirements of the transmission or
distribution system operator.

Example of grid code regulations in different countries
• REE P.O.12.3 RED ELÉCTRICA DE ESPAÑA P.O.12.3 Fault ride-through capabilities
and reactive power/voltage control during faults in wind power installations
• National Grid Electricity
Transmission plc
The Grid Code, Issue 4, Revision 4, 18th October 2010
• Technical regulation 3.2.5 for
wind power plants with a power
output greater than 11 kW
Rev. 4.1. 30.9.2010
• National Grid Code (China) Technical Rule for Connecting Wind farm into Power Network, July 2009
• Transmissioncode 2007 Netz- und Systemregeln der deutschenÜbertragungsnetzbetreiber, August
2007
• transpower stromübertragungs
gmbh
Grid Code for high and extra high voltage, 1st April 2009
• transpower stromübertragungs
gmbh
Requirements for Offshore Grid Connections in the transpower Grid, 30th
April 2010
• 50Hertz Transmission GmbH Netzanschluss- und Netzzugangsregeln, May 2008
• System Service Ordinance Ordinance on System Services by Wind Energy Plants (System Service
Ordinance – SDLWindV)
• BDEW Technische Richtlinie Erzeugungsanlagen am Mittelspannungsnetz,
Richtlinie für Anschluss und Parallelbetrieb von Erzeugungsanlagen am
Mittelspannungsnetz, June 2008
• TR3 Technische Richtlinienfür Erzeugungseinheiten und –anlagen Teil 3
Bestimmung der Elektrischen Eigenschaften von Erzeugungseinheiten am
Mittel-, Hoch- und Höchstspannungsnetz;
• 111 FERC 61,252 United States of America, Federal Energy Regulatory Commission, 18
CFR part 35. 2005
• Guida Tecnica Sistemi di controllo e protezione delle centrali eoliche [prescrizioni tecniche
per la connessione]