Cape Scott Wind Farm model validation exercise Presentation to WECC REMTF November 18, 2014

99 MW Cape Scott Wind Plant Located at the Northern tip of Vancouver Island Very weak interconnection (SCR as low as 1.5 on 34.5 KV bus Extensive PSCAD simulations done during interconnection studies Custom PSSE models developed by Vestas have been successfully validated against PSCAD studies BC Hydro has asked for generic models to satisfy WECC requirements

Original Parameters provided by Vestas, with turbines controlling voltage… Poor comparison with Generic Model, initial conditions suspect!

/ 9073 'USRMDL' 1 'REECAU1' / 9073 'USRMDL' 1 'REGCAU1' / 9073 'USRMDL' 1 'WTPTAU1' / 9073 'USRMDL' 1 'WTARAU1' / 9073 'USRMDL' 1 'WTDTAU1' / 9073 'USRMDL' 1 'WTTQAU1' / / Most recent generic models provided by Vestas… controlling Q rather than voltage. Vestas says the model doesn’t work for voltage control. Note that if the voltage at terminals is initialized below 1.0 pu, initial condition suspect occur.

The Vestas parameters were mainly taken from an EPRI model document. The parameters highlighted in yellow are parameters which don’t map perfectly to the PTI PSSE program, therefore Electranix guessed at them.

Immediately after the fault, the power reference in the electrical model (REEC) goes above 1.0 pu, and begins oscillating sinusoidally. As long as it stays above 1, there is no problem, but if it dips below 1, problems occur as seen below…

Vestas is still working! Some parameters provided by Vestas are not clear. We have guessed at these. Generic model performance doesn’t match custom model performance Inverse current limit characteristic seems to break PTI instructions for REECA

Conclusion and Status Vestas is reviewing the comparison between custom model and generic model Vestas is reviewing inverse characteristic violation of PTI data sheet Vestas has been shown the steady state post fault disturbances. These are not acceptable… PTI has been informed that voltage control doesn’t work for the Vestas model Electranix will send the generic model to BC Hydro when the following criteria are met: – No initial conditions suspect. (may be subject to voltage being over 1.0) – No steady state post fault disturbances – Model will be set up to control Q, and voltage control will be handled by STATCOM – Incorrect behaviour based on custom model validation will be acceptable, provided the plant rides through faults – A strong recommendation will be made that the generic model not be used for any studies near Cape Scott