Centralized versus decentralized FLISR – what’s right for your network?

Decentralized vs Centralized

Fault location, isolation, and service restoration (FLISR) is a software application that reroutes powers in the event of a fault to restore power to as many customers as possible, as quickly as possible. Service restoration times range from sub-second to seconds depending on the type of FLISR solution used.

There are two main categories of FLISR – decentralized and centralized:

Decentralized FLISR Survalent's Centralized FLISR
  • Decentralized – A scripted solution that executes pre-defined, programmed activities to re-energize feeders using power from adjacent feeders
  • Requires script creation for every possible network configuration
  • Difficult to scale to large grids because the number of restoration scenarios increases exponentially with each additional device
  • Best suited for feeders with critical loads that require sub-second restoration, such as hospitals
  • May prove to be laborious to maintain long term
  • Centralized – A model-based solution that uses real-time data from the network to identify the best network reconfiguration, isolate the faulted area, and restore power to customers outside the faulted area
  • No need to define a “normal” state. FLISR will base its analysis on the current state of the network eliminating the need to write a script for each possible state
  • Before transferring load to an adjacent feeder, the solution analyzes that the feeder has sufficient capacity to avoid overloading it
  • Vastly scalable, so ideal for any size of network, small to large

Due to the expense and complexity of maintaining scripts for every possible scenario, centralized (model-based) FLISR is typically the ideal solution when you want to set up FLISR on more than 10 devices in your network. By being able to adapt to any network configuration, centralized solutions like SurvalentONE FLISR can help avoid the widespread, sustained outages that cause customer outrage, make newspaper headlines, and result in high profile public inquiries.

That doesn’t mean you have to choose one or the other.  Advanced model-based solutions like SurvalentONE FLISR let you have the best of both worlds. You can set up decentralized FLISR in areas where restoration times are critical and, for the rest of your network, take advantage of the scalability of a centralized solution to turn a sustained outage into a momentary outage for customers outside the faulted area. Learn more about FLISR and its benefits in Can a 2-hour outage last just 20 seconds? You bet it can.


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