Fault Location, Isolation and Service Restoration (FLISR)

The Fault Location, Isolation and Service Restoration (FLISR) application is for finding ways to restore power to customers that have been unexpectedly de-energized, typically due to a fault. It is triggered by a breaker lockout and it seeks to identify the faulted section. Through the use of SCADA controllable switches it will formulate a plan to isolate the faulted section and restore service to customers above and below the faulted section where possible.

At a high level FLISR will:

1. Use the Recloser Lockout signal from SCADA to determine a genuine lockout has occurred

2. Use Fault Indication signals from devices along the feeder to identify the faulted section

3. Run a Power Flow analysis with the pre-trip load conditions to determine the state of the feeder pre-fault.

4. Identify all possible restoration scenarios

5. Run Power Flow solutions on all potential pickup feeders to determine their current state, available capacity and near-term future capacity.

6. Evaluate every restore scenario by using further Power Flow solutions to determine the effects of restoration operations. It will consider not only current network conditions, but also the affects of DER that are presently on the faulted section and future load conditions.

7. Select the best option that considers:

a. Violations that will occur

b. Conditions that might block restoration for safety reasons (tags, grounds, crews, and so on)

c. Feeders that are fed from the same substation transformers.

d. Feeders that have Co-gen or DER presence

e. Feeders that will have most capacity after the restoration sequence has been executed.