2008 - 2012

Type III WTG Fault Performance

• Fault current in stator “feeds back” to overdrive the converter• Type III WTG have some sort of “crowbar” functionality to protect the

converter• Crowbar is activated during faults exceeding a severity threshold• Crowbar may remain activated until fault is cleared• Severity thresholds vary substantially with design• When crowbar is on, becomes an ordinary induction generator (like Type I)• Performance is defined by the machine’s flux equations• Faults where severity is insufficient to trigger crowbar

• Remains in normal regulation modes• Constant real power• Reactive power may be increased in attempt to regulate voltage• Performance similar to a Type IV WTG

Actual Performance Experiance

Data Requirements

Type I & II –Transient and reactance or lock rotor current – provide output in the transient and subtransient time frame

Type III & IVOption 1 contributions to multiple faults at multiple locations at multiple timesOption 2 curves showing contributions at various voltages (at specific times)

Type V Subtransient, transient & negative sequence impedance

Questions?

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