1. BPA RAS Misoperations 11/2016, 6/19/2017 and 6/21/2017
Daniel Goodrich
To WECC OPAS
August 22, 2017

2. 11/21/2016 Pinched wire caused DC ground

3. Alvey 500 Station
RAS made the controller thing that both Marion-Alvey and Alvey-Dixonville were both out of service

4. Alvey False Line Loss Signals
Because the RAS equipment falsely reported a line loss of two 500 kV lines into Alvey, the RAS controls properly dropped generation. Here is a portion of the Sequential Events Recorder:
The false line loss signals are at the top.
Note that it is just the “A” side, pointing to a RAS unnecessary operation.
11/21/16, 12:42:32.474
RAS AC A MARION-ALVEY LINE LOSS RECEIVED
RAS AC A ALVEY-DIXONVILLE LINE LOSS RECEIVED
11/21/16, 12:42:32.500
RAS ACA AC INTERTIE DYNAMIC BRAKE ALGORITHM TRIPPED
RAS AC A AC INTERTIE LOW GEN DROP ALGORITHM TRIPPED

5. Card Performance Characteristic Setting Performance
DC Volt input threshold 84
81-83 Vdc
Debounce Time 2
0.75 milliseconds
The DC grounds caused brief inputs into the RAS equipment, but because it was triggering sooner than the 2 msec setting, the misoperations occurred. The above times are based on BPA testing.

6. Next Steps
BPA Protection and RAS Design determined which Units are affected: 287 cards at about 50 sites.
Replace the cards (ongoing), to be completed by the end of 2017
Increasing the input debounce time from 2 to 16 msec was completed at all critical sites by mid-August.