Simulated Wind Power Ramp Event in the North Sea: Video

This video, created by SET Master's student Aymeric Buatois from numerical weather prediction model data, demonstrates how wind farms in the North Sea can experience large power ramps over time.  The wind speed at each site, the total North Sea wind farm power, and the wind speed field (in colour) over the North Sea are shown.

In the period chosen, a ramp from zero output to full output (for a fleet of about 3700 MW) occurs, followed by a large downward ramp due to a passing storm front that drives the wind turbines beyond their cut-out wind speed (denoted by a line in the bar chart).  The downward ramp from 3700 MW to 1000 MW occurs over approximately five hours and results in a ramp rate of 9MW/min- close to the limit set for >150MW farms in Scotland.  While large, the ramp would be integrated into several different systems and could be accommodated with appropriate unit commitment if anticipated.

See/download the video here or below:

 

Visualizations of Power System Stability

There have been some beautiful visualizations of power system stability issues created by researchers.

 

Simulation of blackout event with small-signal stability the root cause: (PNNL)

Description (from PNNL page)

August 10, 1996, blackout of the Western Interconnection. The mode with a red circle around it (0.25 Hz North-South mode) went unstable during this event. Operators had about 5 minutes to respond after observing that this mode was moving toward a lower and lower damping ratio. 

The top chart of the video shows synchrophasor data of real power imported into California from the Pacific Northwest (California-Oregon Intertie) in the time domain. The bottom left signal is a Fast Fourier Transform of the same data showing the energy content in each major inter-area oscillatory mode on the Western Interconnection. The bottom right chart is the S-Plane showing lines of constant damping ratio for each of these modes. As each dot moves toward the right side of the chart, it represents an increasingly unstable condition. Movement of these modes is due to two factors: 1) changing grid conditions, and 2) the continuous re-calculation using streaming synchrophasor data.

Description, Movie

Spatial Propagation of Frequency Disturbances (Power Information Technology Lab)


The Power Information Technology Lab in Knoxville, Tennessee has produced a series of animated colour maps based on distributed frequency measurements that together comprise FNET.  (See live frequency measurements and maps)

 

They have selected interesting power system events and demonstrate how frequency disturbances propagate through the North American power grid.

 

You can see selected disturbances, including the 2003 East Coast blackout, on their YouTube channel here.