Parallel Hybrid Circuit Breaker Current Equalization

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Solution Overview

Problem

Existing low-voltage protective switching devices face challenges in increasing current-carrying capacity and preventing uneven current distribution when hybrid switching devices are connected in parallel, leading to potential premature aging and failure due to excessive power loss.

Innovation Solution

The solution involves connecting at least one bypass line in parallel, allowing the electronic control units to manage current distribution between multiple outer conductor sections, preventing excessive power loss on one line and enabling efficient emergency shutdowns by regulating current intensity through semiconductor and mechanical bypass switches.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If hybrid switching devices are connected in parallel to increase current-carrying capacity, then the current load is distributed among multiple devices, but uneven current distribution and drift in internal resistances occur leading to premature aging and failure

Engineering Contradiction:
Improvecurrent-carrying capacityVSAvoidcurrent distribution stability
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent introduces semiconductor switching elements (IGBTs or MOSFETs) as intermediary components between the parallel hybrid switching devices. These semiconductor elements act as active mediators that dynamically adjust and equalize the current distribution among parallel-connected devices, compensating for drift in internal resistances and preventing uneven loading. The semiconductor intermediaries ensure stable current sharing while maintaining the increased current-carrying capacity provided by parallel connection.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If one line handles the entire current load during emergency shutdown, then the switching device can be simplified, but excessive power loss causes premature aging and failure of that line

Engineering Contradiction:
Improveswitching device structureVSAvoidpower loss
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The patent segments the current path by introducing multiple parallel outer conductor sections (at least two), where each section can independently carry current. During emergency shutdown, the semiconductor switching elements enable current to be distributed across multiple segmented paths rather than concentrating the entire load on a single line. This segmentation reduces power loss in each individual conductor while maintaining the ability to perform protective shutdown functions.

Inventive Principle:
Principle #1Segmentation

3Loss of energy

If multiple outer conductor sections are used to distribute current, then power loss is reduced and aging is prevented, but the device structure becomes more complex

Engineering Contradiction:
Improvepower lossVSAvoidconductor path structure
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent designs the multiple outer conductor sections and semiconductor switching elements to serve multiple functions simultaneously. The parallel conductor sections not only distribute current to reduce power loss but also provide redundant paths for protective shutdown operations. The semiconductor switching elements serve both as current equalizers during normal operation and as protective switches during emergencies. This multi-functionality reduces the need for additional dedicated components, thereby limiting the increase in device complexity while achieving energy loss reduction.

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 approach allows for safe and permanent increase in current-carrying capacity, preventing premature aging and failure of individual lines during emergency shutdowns by distributing current load evenly and reducing power loss, thus enhancing the reliability of the switching device.

Implementation Method 1

a first semiconductor circuit arrangement (11) connected in parallel to the bypass switch (8), a second semiconductor circuit arrangement (14) arranged in the first outer conductor path (2) in series with the bypass switch (8) and in parallel with the first semiconductor circuit arrangement (11)

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP3514814B1Electrical circuit breaker assembly
Publication Date: 2021.04.07 EATON INTELLIGENT POWER LTD
  • EP3514814B1 patent drawingFigure 1~2
  • EP3514814B1 patent drawingFigure 3~4
  • EP3514814B1 patent drawingFigure 5

AI summary

In an electrical protection circuit arrangement (50) comprising a first external conductor section (2) and a second external conductor section (51), wherein the first external conductor section (2) is arranged in parallel to the second external conductor section (51) in terms of circuitry, wherein the first external conductor section (2) has a first hybrid protection circuit with a first and a second semiconductor arrangement (11, 14), each controlled by a first electronic control unit (13), and wherein the second external conductor section (51) has a first hybrid protection circuit with a third and a fourth semiconductor arrangement (53, 54), each controlled by a second electronic control unit (56), it is proposed thatthat the first control unit (13) controls the second semiconductor circuit arrangement (14) and the second control unit (56) controls the fourth semiconductor circuit arrangement (54) to equalize a first current through the first outer conductor (2) and a second current through the second outer conductor (51), and/or that the first control unit (13) and the second control unit (56) switch off the second outer conductor (51) when a first current and/or a second current falls below a predefinable limit value.