Transcript Highlights of 2011-2012

WG B4.62
Connection of Windfarms to
Weak AC networks
Dr Mark Davies
Team Leader System Performance
Experiences with low SCR connections
1. SVCs on long radial feeder
2. LCC HVDC with very low SCR (near 1 !!)
3. LCC HVDC with WTG interaction
4. VSC HVDC with WTG interaction
5. WTG with SCR < default requirement
Item 1: Risk - Understand & Define
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Generators that require a minimum SCR (e.g.
HVDC or WTGs) by implication also create some
system degradation.
Item 1 : Risk – Managing it
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How can the system impact:
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•
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be measured
extreme effects be mitigated and
a fair system of management be applied?
Item 2: Technical – The Challenges
1. Make WTG synchronisation performance closer
to that of synchronous generators
2. Make WTGs behave more like synchronous
voltage sources
Item 2: Technical – Improvements ?
•
•
Due to their large ratings HVDC systems often
operate with low SCR. Can WTG systems
leverage off the experiences of these related
power conversion devices?
Two areas of synergy are:
1. (re)synchronisation performance - (PLL delays)
2. fault current limitation