Integrated HV Contactor Busbar for Current Sensing and Low Loss

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Solution Overview

Problem

Conventional high voltage power supply systems in electric vehicles face issues with increased interconnection resistances and energy losses due to numerous interfaces, leading to inefficiencies and complex battery management systems, which are exacerbated by the need for separate shunt resistors and overcurrent protection devices.

Innovation Solution

Integration of a contactor device with a current sensing element and actuator, where the current sensing element is integrally formed with the bus bars, reducing the need for external shunt resistors and simplifying the assembly by merging components, thereby minimizing interconnection resistances and enhancing functional integration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate shunt resistors and overcurrent protection devices are used in conventional high voltage power supply systems, then current measurement and safety protection functions are provided, but interconnection resistances increase and energy losses occur

Engineering Contradiction:
Improvecurrent measurement accuracyVSAvoidenergy loss
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent merges the shunt resistor and overcurrent protection device into a single integrated component. The shunt resistor is formed as an integral part of the contactor device, eliminating separate connections and reducing interconnection resistances. This integration maintains current measurement accuracy while reducing energy losses at connection interfaces.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The contactor device is designed to perform multiple functions: it serves as both a switching device and a current measurement device. The shunt resistor is integrated into the contactor's busbar structure, allowing the same component to provide both circuit switching and current sensing functions, thereby eliminating the need for separate dedicated shunt resistors.

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

2Reliability

If separate shunt resistors and overcurrent protection devices are used in conventional high voltage power supply systems, then current measurement and safety protection functions are provided, but the battery management system becomes complex

Engineering Contradiction:
Improvesafety protectionVSAvoidbattery management system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple safety and measurement functions into a single integrated contactor device. By integrating the shunt resistor, overcurrent protection, and switching functions into one component, the number of separate devices and their interconnections is reduced, thereby simplifying the overall battery management system architecture while maintaining comprehensive safety protection.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The contactor device is designed as a multi-functional component that performs switching, current measurement, and overcurrent protection functions simultaneously. This universal design reduces the total number of components required in the power supply system, leading to a less complex battery management system with fewer interconnections and control points.

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

3Adaptability or versatility

If numerous interfaces and interconnections are used in conventional high voltage power supply systems, then separate components perform their functions, but interconnection resistances increase leading to inefficiencies

Engineering Contradiction:
Improvecomponent functionalityVSAvoidsystem efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent merges multiple components into a single integrated contactor device, reducing the number of interfaces and interconnections. The shunt resistor is formed as an integral part of the contactor's busbar structure, eliminating separate connection points and reducing interconnection resistances, thereby improving overall system efficiency while maintaining all necessary component functionalities.

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 integration reduces energy losses, simplifies assembly, and enhances the safety and efficiency of high voltage power supply systems by providing a more compact and cost-effective solution with redundant current measurement capabilities.

Implementation Method 1

The power supply system 10 usually also comprises one or more current sensors, often in form of a dedicated shunt resistor 15, which is electrically connected in series with the HV battery 11. The power supply system 10 contains electronics to measure a voltage drop across the shunt resistor 15.

Methodology Applied
Scientific EffectVoltage drop measurement: Ohm's Law

Implementation Method 2

at least one electromagnetic actuator (118), which is configured to move the at least one moveable bus bar (106, 108) between the open position and the closed position

Methodology Applied
Scientific EffectElectromagnetic actuation: Electromagnetic Induction

Data Source

PatentEP4390998B1Contactor device, high voltage power supply system and method for controlling a contactor device
Publication Date: 2025.07.02 MUNICH ELECTRIFICATION GMBH
  • EP4390998B1 patent drawingFigure 1
  • EP4390998B1 patent drawingFigure 2~3
  • EP4390998B1 patent drawingFigure 4~5

AI summary

The present disclosure relates to a contactor device, a high voltage power supply system comprising the contactor device. The contactor device (100) comprises a contact arrangement, which includes at least one moveable bus bar (106, 108) and at least one fixed bus bar (102, 104), wherein the at least one moveable bus bar (106, 108) has a first contact region and the at least one fixed bus bar (102, 104) has a second contact region, and at least one actuation element (118), which is configured to change a state of the contactor device (100) at least to and from an open state, and to and from a closed state, wherein in the open state the first contact region is electrically isolated from the second contact region, and in the closed state the first contact region is conductively coupled to the second contact region. The contact arrangement further comprises a first current sensing element (152) with a first predetermined resistance, which is integrally formed with one of the bus bars (102, 104, 106, 108) included in the contact arrangement.