Rogowski Coil Load Break Switch for Phase Current Measurement

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Solution Overview

Problem

Existing load-break switch devices and switch fuse devices lack user-friendliness and efficient measurement capabilities, particularly in three-pole systems, requiring separate current measuring devices and often compromising on size and cooling efficiency.

Innovation Solution

A load-break switch device with a housing featuring planar foot contacts and Rogowski coils for independent current measurement, capacitive voltage measurement, and a compact design that ensures reliable operation and flexibility, along with a fitting sleeve and spring clip for secure fuse insertion, enhancing user accessibility and cooling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If separate current measuring devices are used for each phase, then measurement capability is improved, but device complexity and cost increase

Engineering Contradiction:
Improvecurrent measurement capabilityVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent integrates three Rogowski coils into a single unified structure that measures all three phases simultaneously. The coils are arranged concentrically around a common axis, with each coil measuring one phase current. This merging of multiple measurement functions into one device eliminates the need for separate measuring devices for each phase, reducing overall system complexity while maintaining comprehensive measurement capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The Rogowski coil assembly serves multiple functions: it measures current for all three phases, provides structural support for the fuse insertion mechanism, and enables compact device design. The universal design allows a single component to perform what would traditionally require multiple separate devices, thereby reducing complexity without compromising measurement precision.

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

2Volume of moving object

If a compact design is implemented, then device size is reduced, but cooling efficiency may worsen

Engineering Contradiction:
Improvedevice sizeVSAvoidcooling efficiency
Core Design Contradiction:
Volume of moving objectVSTemperature

Solution Approach 1:

The patent transitions from a planar or linear arrangement of components to a three-dimensional concentric configuration. The Rogowski coils are arranged in nested circular patterns around a central axis, allowing efficient use of vertical and radial space. This dimensional reorganization enables compact footprint while maintaining adequate spacing for thermal management, as heat can dissipate radially outward from the central measurement axis.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The three Rogowski coils are arranged in a nested configuration, with each coil positioned within the spatial envelope of the others along the same axis. This nesting allows the measurement system to occupy minimal space while the surrounding structure provides pathways for cooling airflow. The nested arrangement ensures that no single component blocks the thermal path, maintaining cooling efficiency despite the compact overall size.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Ease of operation

If planar foot contacts with protrusions are used, then ease of operation is improved, but manufacturing complexity increases

Engineering Contradiction:
Improveease of fuse insertionVSAvoidmanufacturing complexity
Core Design Contradiction:
Ease of operationVSEase of manufacture

Solution Approach 1:

The foot contact is divided into two functional segments: a planar base surface for stable contact with the fuse, and a protruding section that extends upward to guide and engage with corresponding features on the fuse. This segmentation allows each part to perform its specific function optimally while being manufacturable using standard processes. The protrusion can be formed as a simple extrusion or injection-molded feature, adding minimal manufacturing complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The foot contact structure exhibits local quality variation: the planar base area provides a large contact surface for electrical connection and mechanical stability, while the localized protrusion provides precise positioning and insertion guidance. This differentiation of local properties optimizes both ease of operation and manufacturability, as each region can be designed and manufactured for its specific purpose without over-engineering the entire component.

Inventive Principle:
Principle #3Local quality

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

Enables reliable current and voltage measurements for each phase without additional measuring devices, maintains compact size, and ensures effective cooling, improving system monitoring and control while reducing costs.

Implementation Method 1

a Rogowski coil (400) at each of its foot contacts (160), which has an opening, in particular a central opening, that at least partially surrounds the elevation of the foot contact

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a device for capacitive voltage measurement, preferably for each individual phase (for each individual pole)

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP3915126B1Load break switch device and fused switch device having a fuse
Publication Date: 2023.03.15 KLAUS BRUCHMANN
  • EP3915126B1 patent drawingFigure 1
  • EP3915126B1 patent drawingFigure 2
  • EP3915126B1 patent drawingFigure 3

AI summary

The invention relates to a load break switch device or to a fused switch device for receiving at least one fuse or a fuse plug for a fuse. The device according to the invention comprises a housing and at least one input terminal and at least one output terminal for connection to at least one electric device, wherein three-pole devices are preferably provided. The device according to the invention furthermore comprises a Rogowski coil provided on a base contact of the device.