Dual-Pole DC Contactor With Single Drive for Low On-State Loss

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Solution Overview

Problem

High-voltage direct current contactors in new energy vehicle charging systems require higher voltage and current levels, leading to increased volume and cost, and existing designs face challenges in synchronizing the opening and closing of positive and negative electrode contacts, resulting in high on-state current loss and increased manufacturing costs.

Innovation Solution

A direct current contactor design utilizing a housing with a single drive mechanism to control two pairs of contacts, where the first and second moving contacts are connected to the first and second fixed contacts via elastic metal sheets, reducing total contactor resistance and drive power consumption, and employing a U-shaped magnetic conductive member for improved arc extinguishing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If two separate high-voltage direct current contactors are installed in positive and negative electrode lines, then safety isolation requirement is met, but total costs and total volume of charging loop apparatus are greatly increased

Engineering Contradiction:
Improvesafety isolationVSAvoidtotal volume
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines two separate contactors into a single integrated contactor that controls both positive and negative electrode lines. The housing contains two pairs of contacts (first and second fixed contacts, first and second moving contacts) that are simultaneously controlled by a single drive mechanism, achieving safety isolation while reducing total volume and cost.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single contactor performs multiple functions by controlling both positive and negative electrode lines. The drive mechanism is designed to simultaneously actuate both pairs of contacts, making one device universal for dual-pole control in the charging loop.

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

2Device complexity

If traditional contactor design with sliding moving contacts is used, then structural simplicity is maintained, but total contactor resistance and on-state current loss are high

Engineering Contradiction:
Improvestructural simplicityVSAvoidon-state current loss
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The patent replaces the traditional sliding contact mechanism with a rotating contact mechanism. The moving contacts are designed to rotate into contact with fixed contacts, eliminating sliding friction and reducing contact resistance. This mechanical substitution significantly reduces on-state current loss while maintaining structural simplicity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Ease of operation

If separate drive mechanisms are used for positive and negative electrode contacts, then independent control is achieved, but drive power consumption is high

Engineering Contradiction:
Improveindependent controlVSAvoiddrive power consumption
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The patent uses a single drive mechanism that simultaneously controls both pairs of contacts. The drive shaft connects to both moving contacts through a common drive structure, enabling synchronized control of positive and negative electrode contacts with a single actuation, thereby halving the drive power consumption compared to separate drive mechanisms.

Inventive Principle:
Principle #5Merging (Combining)

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 design reduces total contactor resistance by half, minimizes on-state current loss, and simplifies the structure by using only two pairs of contacts, while reducing drive power consumption and enhancing arc extinguishing efficiency, thus lowering manufacturing costs and improving synchronicity between electrode contacts.

Implementation Method 1

a first elastic metal sheet connected to the first body, and the second moving contact comprises a second body and a second elastic metal sheet connected to the second body

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

employing a U-shaped magnetic conductive member for improved arc extinguishing

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Implementation Method 3

an electromagnet that drives the armature to rotate

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4030458B1Direct current contactor and automobile
Publication Date: 2024.02.14 HUAWEI DIGITAL POWER TECH CO LTD
  • EP4030458B1 patent drawingFigure 1~2
  • EP4030458B1 patent drawingFigure 3
  • EP4030458B1 patent drawingFigure 4~5

AI summary

This application provides a direct current contactor and a vehicle. The direct current contactor includes a housing, and a first fixed contact and a second fixed contact that are fastened into the housing; a first moving contact and a second moving contact that are located in the housing; a drive mechanism, including: an insulation rod connected to the first moving contact and the second moving contact, and a drive component that drives the insulation rod to drive the first moving contact and the second moving contact to synchronously move toward the first fixed contact and the second fixed contact; and a pressing component configured to push the moving contact firmly against the fixed contact. It can be learned from the foregoing description that, in this application, only two pairs of contacts are used to implement connection/disconnection of two electrode lines, so that a total contactor resistance is reduced by half compared with that in the conventional technology, thereby resolving a problem of a large on-state current loss in the conventional technology. In addition, drive power consumption of a coil is reduced by half; and only a single drive mechanism is needed to drive two contacts, thereby greatly reducing difficulty in implementing closing and opening synchronicity between two electrode contacts.