Low-Voltage Circuit Breaker with Semiconductor Inrush Limiting

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Solution Overview

Problem

Existing electrical installations face unintentional circuit breaker trips due to high inrush currents when starting inductive or capacitive loads, requiring separate devices for specific load types, increasing installation complexity and effort.

Innovation Solution

A low-voltage protective switching device with a semiconductor circuit and control unit limits inrush currents for both capacitive and inductive loads, eliminating the need for additional devices by integrating inrush current limitation and protection functions into a single unit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate devices are used for inrush current limitation for specific load types, then the inrush current can be limited effectively, but the installation complexity and effort increase

Engineering Contradiction:
Improveinrush current limitationVSAvoidinstallation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the inrush current limitation function with the protective switching device into a single integrated unit. The semiconductor circuit arrangement is integrated within the protective switching device, eliminating the need for separate inrush current limiters for different load types. This merging reduces installation complexity while maintaining effective inrush current limitation.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The protective switching device is designed with universal applicability to handle both capacitive and inductive loads through its semiconductor circuit arrangement. The device can limit inrush currents for various load types without requiring different configurations or additional specialized devices, providing multi-functional capability in a single unit.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If multiple separate devices are installed for motor operation, then safe operation and uninterrupted start-up are ensured, but the installation effort increases

Engineering Contradiction:
Improvesafe operationVSAvoidinstallation effort
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent merges multiple functions (protective switching, inrush current limitation, and motor operation support) into a single integrated device. The semiconductor circuit arrangement within the protective switching device eliminates the need for separate motor protection switches, circuit breakers, and starters, significantly reducing installation effort while ensuring safe operation.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The protective switching device provides universal protection and control for motor operations, handling both starting and normal operation phases. The device adapts to different operational requirements through its control unit that manages the semiconductor circuit arrangement, providing multi-functional capability for motor control applications.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If separate devices are used for different load types, then each load type can be optimized, but the flexibility of installation decreases

Engineering Contradiction:
Improveload-specific optimizationVSAvoidinstallation flexibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The protective switching device achieves universal applicability across different load types through its semiconductor circuit arrangement controlled by the control unit. The device can adapt its switching behavior for both capacitive and inductive loads without requiring separate specialized devices, thereby maintaining installation flexibility while providing load-specific optimization.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 solution reduces installation complexity and effort by allowing safe operation of various loads with a single device, eliminating the need for separate switches and breakers, and enhancing flexibility in electrical installations.

Implementation Method 1

the control unit is designed to limit an inrush current of a downstream load, to switch the semiconductor circuit arrangement on/off in a predefinable manner when the bypass switch is open

Methodology Applied
Scientific EffectSemiconductor switching:

Data Source

PatentEP3574515B1Low-voltage circuit breaker device
Publication Date: 2025.11.12 EATON INTELLIGENT POWER LTD
  • EP3574515B1 patent drawingFigure 1~2
  • EP3574515B1 patent drawingFigure 3~4

AI summary

The invention relates to a low-voltage circuit breaker device (1), in particular a motor circuit breaker, having at least one outer conductor path (2) and a neutral conductor path (5), wherein a mechanical bypass switch (8) is disposed in the outer conductor path (2); a semiconductor circuit arrangement (11) of the low-voltage circuit breaker device (1) is connected in parallel with the bypass switch (8); a current measuring arrangement (12), which is connected to an electronic control unit (13) of the circuit breaker device (1), is at least provided in the outer conductor path (2); and the electronic control unit (13) is designed to control the bypass switch (8) and the semiconductor circuit arrangement (11) in a predeterminable manner. According to the invention, a control unit (13) is designed to switch the semiconductor circuit arrangement (11) on/off in a predetermined cycle when the bypass switch (8) is open so as to limit an inrush current of a downstream load (23). The invention further relates to an electric motor connecting line comprising such a low-voltage circuit breaker device (1).