Phase-Level Fault Isolation in Power Distribution Without Looping

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Solution Overview

Problem

Existing power distribution networks often interrupt power for all customers on a transmission line due to single or two-phase faults, even when only one or two phases are affected, leading to unnecessary outages and inefficiencies in fault isolation and restoration.

Innovation Solution

A system and method for controlling power distribution networks using an electronic processor to identify subsets of phases affected and unaffected by a fault, sending specific commands to isolation devices to isolate and restore power while avoiding loop configurations, thereby isolating only the necessary sections and minimizing power outages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If all three phases are isolated in response to a detected fault, then fault isolation reliability is improved, but the number of customers affected by power interruption increases

Engineering Contradiction:
Improvefault isolation reliabilityVSAvoidnumber of customers affected
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent segments the fault isolation process by phase, allowing independent identification and isolation of faulty phases rather than isolating all three phases together. The system identifies which specific phase(s) are faulty and sends targeted open commands only to those phases at the downstream isolation device, while keeping healthy phases closed and operational.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by treating each phase differently based on its fault status. Healthy phases receive close commands to maintain power supply, while faulty phases receive open commands for isolation. This phase-specific treatment allows the system to maintain power quality for unaffected phases while ensuring reliable isolation of problematic phases.

Inventive Principle:
Principle #3Local quality

2Quantity of substance

If targeted phase-level isolation commands are sent, then the number of customers affected is reduced, but system complexity increases

Engineering Contradiction:
Improvenumber of customers affectedVSAvoidsystem complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent implements feedback mechanisms where isolation devices monitor phase conditions and provide status information to the system. Based on this feedback, the system determines which phases are faulty and sends appropriate open or close commands. The system also receives confirmation of command execution and adjusts its behavior accordingly, creating a closed-loop control system that manages complexity through intelligent decision-making.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent sends open commands for faulty phases before sending close commands for healthy phases. This preliminary action ensures that faulty phases are isolated first, preventing any potential issues during the transition, and then healthy phases are closed to restore power. This sequencing reduces customer impact while managing system complexity through controlled operation sequences.

Inventive Principle:
Principle #10Preliminary action

3Speed

If close commands are sent before open commands during restoration, then power restoration speed is improved, but loop configurations may be created causing system instability

Engineering Contradiction:
Improvepower restoration speedVSAvoidsystem configuration stability
Core Design Contradiction:
SpeedVSStability of the object's composition

Solution Approach 1:

The patent sends open commands for healthy phases at the downstream isolation device before sending close commands. This preliminary opening of the downstream device prevents the formation of loop configurations that would occur if the close command were sent first. By establishing the correct topological state beforehand, the system safely restores power without creating unstable loop conditions.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent prevents loop configurations by sending open commands before close commands, which is the opposite of the intuitively faster approach. This preliminary anti-action (doing the reverse of what would be faster) prevents the harmful loop condition from forming, thereby sacrificing some restoration speed to maintain system stability and prevent configuration errors.

Inventive Principle:
Principle #9Preliminary anti-action

Data Source

PatentEP3944441B1Single phase fault isolation and restoration with loop avoidance
Publication Date: 2026.04.08 G & W ELECTRIC CO
  • EP3944441B1 patent drawingFigure 1
  • EP3944441B1 patent drawingFigure 2
  • EP3944441B1 patent drawingFigure 3

AI summary

Techniques for controlling a power distribution network are provided. An electronic processor receives, a fault indication associated with a fault from a first isolation device of a plurality of isolation devices. The processor identifies a first subset of a plurality of phases associated with the fault indication and a second subset of the plurality of phases not associated with the fault indication. The processor identifies a downstream isolation device downstream of the fault. The processor sends send a first open command to the downstream isolation device for each phase in the first subset. The processor sends a close command to a tie-in isolation device for each of the plurality of phases. The processor sends a second open command to the downstream isolation device for each phase in the second subset. Responsive to identifying a potential loop configuration, the processor sends the second open command prior to the close command.