Protective Relay Test Control for Isolated Function Switching

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Solution Overview

Problem

Current methods for testing digital protection relays require manual deactivation of non-test protection functions, leading to false tripping and inefficiency, and cannot guarantee all protection levels are correctly configured according to specifications.

Innovation Solution

A control unit for a protective relay that automatically activates and deactivates protection levels and functions using a data structure to prevent interactions, allowing for automated testing without manual intervention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If manual deactivation of non-test protection functions is performed, then false tripping is reduced, but testing time and operational complexity increase significantly

Engineering Contradiction:
Improvefalse tripping preventionVSAvoidtesting time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The control unit automatically manages the activation and deactivation of protection functions during testing. When a protection function is selected for testing, the control unit self-service deactivates all other protection functions and automatically reactivates them after testing completes, eliminating the need for manual intervention and reducing testing time while preventing false tripping.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The control unit performs preliminary actions by automatically deactivating non-test protection functions before the actual testing begins and reactivating them after testing completes. This preliminary management of protection function states ensures that only the intended function is active during testing, preventing false tripping without requiring manual time-consuming operations.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If manual configuration of protection levels is performed, then configuration accuracy can be verified, but the process is time-consuming and error-prone

Engineering Contradiction:
Improveconfiguration accuracyVSAvoidtesting efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The control unit performs self-service by automatically configuring protection levels according to stored test data and specifications. It retrieves the required protection level values, applies them to the protection functions, and verifies the configuration, eliminating manual configuration steps while ensuring accuracy through automated validation against stored specifications.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The control unit implements feedback mechanisms to verify that protection levels are correctly configured according to specifications. It continuously monitors the configured values, compares them against the stored test data and requirements, and provides feedback to ensure configuration accuracy, thereby maintaining high precision while improving productivity through automation.

Inventive Principle:
Principle #23Feedback

3Stability of the object's composition

If all protection functions remain active during testing, then system state is maintained, but interactions between functions cause false tripping

Engineering Contradiction:
Improvesystem state maintenanceVSAvoidfalse tripping
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The control unit applies segmentation by isolating the protection function under test from all other protection functions. When a specific protection function is selected for testing, the control unit deactivates all other protection functions, creating a segmented testing environment where only the targeted function is active. This prevents interactions between functions that could cause false tripping while maintaining the overall system structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control unit extracts the protection function under test from the complete set of active protection functions. By selectively deactivating all protection functions except the one being tested, the control unit removes potential sources of interaction and false tripping. After testing completes, the extracted function is reinserted into the active set, maintaining system stability while preventing false tripping during the testing process.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP4711781A1Protective relay control unit, communication interface, protective relay test device
Publication Date: 2026.03.18 SIEMENS ENERGY GLOBAL GMBH & CO KG
  • EP4711781A1 patent drawingFigure 1
  • EP4711781A1 patent drawingFigure 2
  • EP4711781A1 patent drawing

AI summary

The invention relates to a control unit (1) and/or a communication interface (7) for a protective relay (2), wherein the control unit (2) has a plurality of protective functions (3, 5, 6) each comprising at least one protection level (4) stored in a memory and is configured to output a signal for opening the protective relay (2) when the respective protection level (4) has been exceeded by a corresponding operating parameter of the protective relay (2). For testing the plurality of protection levels (4) and/or protective functions (3, 5, 6) of the protective relay, the control unit (1) and/or the communication interface (7) is configured to keep at least one selected protection level (4) of the selected protective function (5) active or to activate it and to deactivate all other protection levels (4) of the selected protective function (5) and/or other protective functions (6) of the plurality of protective functions (3, 5, 6).