Magnetic Pole Protrusion Structure for Stronger HVDC Relay Attraction

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Solution Overview

Problem

Existing high-voltage DC relays face a contradiction between the need for strong electromagnetic attraction to withstand short-circuit current, which requires larger coil winding space and higher coil driving power consumption, and the desire for a smaller size and lower power consumption, hindering their effective application in new energy vehicles.

Innovation Solution

A magnetic circuit system with enhanced initial electromagnetic attraction is designed, featuring a coil, a movable magnetizer, and a stationary magnetizer, where one magnetic pole surface has a protrusion that fits into a recess on the other, aligning the resultant attractive force to minimize magnetic resistance and reduce coil volume and power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If larger coil winding space and higher coil driving power consumption are used to achieve strong electromagnetic attraction to withstand short-circuit current, then the electromagnetic attraction force is improved, but the device size and power consumption increase

Engineering Contradiction:
Improveelectromagnetic attraction forceVSAvoidcoil volume
Core Design Contradiction:
ForceVSVolume of moving object

Solution Approach 1:

The patent applies local quality by creating a protrusion on one magnetic pole surface and a corresponding recess on the other magnetic pole surface. This localized structural modification concentrates the magnetic flux in a specific region, enhancing the magnetic field density and electromagnetic attraction force at the contact point without requiring an increase in overall coil volume or winding space.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the geometric parameters of the magnetic pole surfaces by adding a protrusion and recess structure. This modifies the magnetic gap distribution and flux path, thereby changing the magnetic field characteristics to achieve stronger electromagnetic attraction with the same coil parameters, effectively resolving the contradiction between force and volume.

Inventive Principle:
Principle #35Parameter changes

2Force

If larger coil winding space and higher coil driving power consumption are used to achieve strong electromagnetic attraction to withstand short-circuit current, then the electromagnetic attraction force is improved, but the power consumption increases

Engineering Contradiction:
Improveelectromagnetic attraction forceVSAvoidcoil driving power consumption
Core Design Contradiction:
ForceVSUse of energy by stationary object

Solution Approach 1:

By concentrating the magnetic flux through the protrusion-recess structure, the patent achieves higher magnetic field density in the critical attraction region. This allows the same electromagnetic force to be achieved with lower overall power consumption, as the energy is more efficiently utilized in the localized high-flux region rather than being dispersed across a larger volume.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The geometric modification of the magnetic pole surfaces changes the magnetic circuit parameters, reducing the overall magnetic resistance and improving flux efficiency. This enables the system to achieve the required electromagnetic attraction force with reduced driving power consumption.

Inventive Principle:
Principle #35Parameter changes

3Volume of moving object

If the coil volume is reduced to achieve smaller device size, then the device compactness is improved, but the electromagnetic attraction force decreases

Engineering Contradiction:
Improvecoil volumeVSAvoidelectromagnetic attraction force
Core Design Contradiction:
Volume of moving objectVSForce

Solution Approach 1:

The protrusion-recess structure creates a localized concentration of magnetic flux, compensating for the reduced overall coil volume. By intensifying the magnetic field in the critical contact region, the patent maintains strong electromagnetic attraction force even with a smaller coil, thus resolving the contradiction between compactness and force.

Inventive Principle:
Principle #3Local quality

4Use of energy by stationary object

If the power consumption is reduced to achieve lower energy loss, then the energy efficiency is improved, but the electromagnetic attraction force decreases

Engineering Contradiction:
Improvecoil driving power consumptionVSAvoidelectromagnetic attraction force
Core Design Contradiction:
Use of energy by stationary objectVSForce

Solution Approach 1:

The patent modifies the magnetic circuit parameters through the protrusion-recess structure, optimizing the flux distribution and reducing magnetic resistance. This improves the energy efficiency of the magnetic circuit, allowing the system to achieve the required electromagnetic attraction force with lower power consumption by reducing energy losses in the magnetic path.

Inventive Principle:
Principle #35Parameter changes

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

The system increases initial electromagnetic attraction while maintaining coil volume and power consumption, or reduces coil volume and power consumption while maintaining attraction, optimizing the relay for smaller size and lower power consumption.

Implementation Method 1

a coil, being provided so that the movable iron core moves towards the fixed iron core when the coil is energized

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

the movable magnetizer moves towards the stationary magnetizer when the coil is energized

Methodology Applied
Scientific EffectMagnetic attraction: Magnetism

Data Source

PatentEP4369375B1Magnetic circuit part having enhanced initial electromagnetic attraction force, and high-voltage direct-current relay
Publication Date: 2025.11.19 XIAMEN HONGFA ELECTRIC POWER CONTROLS CO LTD
  • EP4369375B1 patent drawingFigure 1
  • EP4369375B1 patent drawingFigure 2~3
  • EP4369375B1 patent drawingFigure 4~5

AI summary

Disclosed in the present invention are a magnetic circuit part having an enhanced initial electromagnetic attraction force, and a high-voltage direct-current relay. The magnetic circuit part comprises a coil, a movable magnetic conductor and a static magnetic conductor, wherein the coil, the movable magnetic conductor and the static magnetic conductor are respectively mounted at suitable positions, such that a magnetic pole surface of the movable magnetic conductor and a magnetic pole surface of the static magnetic conductor are in opposite positions with a preset magnetic gap; and one of the two magnetic pole surfaces is provided with a protrusion that protrudes toward the other magnetic pole surface, and the other magnetic pole surface is provided, at a position corresponding to the protrusion, with a recess in which the protrusion of one of the magnetic pole surfaces can be embedded when the movable magnetic conductor and the static magnetic conductor attract each other. According to the present invention, the initial electromagnetic attraction force can be enhanced under the same volume and power consumption of the coil; or under the same initial electromagnetic attraction force, the volume of the coil is reduced, and the power consumption of the coil is decreased.