Electrical Protection Unit Testing Method Reducing Energy Consumption

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Solution Overview

Problem

Electrical network protection devices face challenges in testing their operation without significant energy overconsumption, particularly when testing devices with higher current ratings, which leads to increased internal heating and inefficiency.

Innovation Solution

A method involving a two-sequence test process, where the first sequence tests the current sensor, converter circuit, and capacitor with a reduced test current, and the second sequence tests the detection circuit by generating a charging current, optimizing energy usage and minimizing heating through precise timing and voltage thresholds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a high-amplitude test current is applied to test the protection device operation, then the testing accuracy and reliability are improved, but the energy consumption and internal heating increase significantly

Engineering Contradiction:
Improvetesting accuracyVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The test current is segmented into two distinct sequences: a first test sequence using reduced amplitude current to test basic operation, and a second test sequence using full amplitude current to test threshold activation. This segmentation allows comprehensive testing while minimizing overall energy consumption by limiting high-current exposure to only when necessary.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The test method dynamically changes current amplitude parameters based on testing needs. The first sequence uses a reduced current amplitude (below the activation threshold), while the second sequence uses full amplitude current (at or above the threshold). This parameter variation enables accurate testing of different device functions with optimized energy usage.

Inventive Principle:
Principle #35Parameter changes

2Volume of moving object

If the protection device volume is reduced to integrate more devices in a switchboard, then the device integration density is improved, but the internal heating increases due to less heat dissipation space

Engineering Contradiction:
Improvedevice volumeVSAvoidinternal heating
Core Design Contradiction:
Volume of moving objectVSTemperature

Solution Approach 1:

The testing operates periodically with two distinct phases: a low-power phase (first test sequence) for routine operation verification, and a high-power phase (second test sequence) for threshold verification. This periodic alternation between low and high power states reduces average heat generation, enabling compact device design with adequate thermal management.

Inventive Principle:
Principle #19Periodic action

3Reliability

If a single high-amplitude test is performed to verify protection device activation, then the testing completeness is improved, but the energy overconsumption increases significantly

Engineering Contradiction:
Improvetesting completenessVSAvoidenergy overconsumption
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The first test sequence applies a partial action approach by using reduced amplitude current that is sufficient to test basic operational functionality but intentionally below the level needed to activate protection thresholds. This partial testing minimizes energy consumption while still verifying device operation, with the option to perform a second sequence if full threshold testing is required.

Inventive Principle:
Principle #16Partial or excessive action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach allows for thorough testing of electrical network protection devices across various ratings without excessive energy consumption, reducing internal heating and component size, while ensuring accurate operation verification.

Implementation Method 1

a converter circuit connected, at input to the current sensor to receive the signal representative of the fault current, and connected at output to a capacitor, said converter circuit being arranged to convert the signal representative of the fault current into a capacitor voltage and also arranged to charge the capacitor to said capacitor voltage

Methodology Applied
Scientific EffectCapacitor charging: Capacitance

Implementation Method 2

a first generator circuit for generating a test current in the current sensor

Methodology Applied
Scientific EffectElectrical current generation: Electromagnetic Induction

Implementation Method 3

a second generator circuit to generate a capacitor charging current

Methodology Applied
Scientific EffectCapacitor charging: Capacitance

Data Source

PatentEP3650875B1Method for testing an electrical protection unit and protection unit implementing such a method
Publication Date: 2020.09.30 SCHNEIDER ELECTRIC IND SAS
  • EP3650875B1 patent drawingFigure 1
  • EP3650875B1 patent drawingFigure 2
  • EP3650875B1 patent drawingFigure 3A

AI summary

The invention relates to a method for testing the operation of an electrical network protection device comprising a current sensor (2), a converter circuit (3), a capacitor (4), and a detection circuit (5). The method comprises a first test sequence for testing the current sensor (2), the converter circuit (3), and the capacitor (4) using a first generator circuit (6), and a second test sequence for testing the detection circuit (5) using a second generator circuit (7). The detection circuit (5) activates a control output (53) when the second test sequence is successful. The invention also relates to an electrical network protection device (1) implementing such a method.