Charging Plug Impedance Spectroscopy for EV Battery State Detection

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Solution Overview

Problem

Existing methods for detecting the state of a battery in electrically powered motor vehicles are inefficient, requiring additional contacts or complex disassembly, and often tie up computing resources, making it difficult to assess battery condition without significant effort or accessibility issues.

Innovation Solution

A device with a charging plug and integrated impedance spectroscopy unit that connects directly to the vehicle's DC charging interface, allowing for impedance measurement without additional contacts, using the existing charging infrastructure to supply and record spectroscopy signals, and communicate with the battery management system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If additional measuring taps are provided to enable impedance spectroscopy measurement, then battery state detection becomes possible, but device complexity and installation difficulty increase

Engineering Contradiction:
Improvebattery state detection capabilityVSAvoidadditional measuring taps and installation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The charging plug is designed to serve dual purposes: it functions as a standard charging connector for power transfer while simultaneously serving as the interface for impedance spectroscopy measurements. The impedance spectroscopy unit utilizes the existing DC charging contacts to inject test signals and measure battery response, eliminating the need for separate measuring taps. This multi-functionality approach allows battery state detection to be performed through the universal charging interface already present in electric vehicles.

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

2Stability of the object's composition

If the battery is permanently installed in the motor vehicle, then vehicle integration is improved, but accessibility for measurement deteriorates

Engineering Contradiction:
Improvepermanent battery installationVSAvoidaccessibility for measurement
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

The charging plug acts as an intermediary device that bridges the gap between the permanently installed battery and the external measurement system. By connecting the charging plug to the vehicle's DC charging interface, operators can access the battery for impedance spectroscopy measurements without requiring physical access to the battery itself or performing disassembly operations. The charging plug serves as a convenient access point that maintains both permanent battery installation and measurement accessibility.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If impedance spectroscopy is performed using existing vehicle computing resources, then additional hardware is reduced, but computing availability for other applications decreases

Engineering Contradiction:
Improvehardware requirementsVSAvoidcomputing resource availability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The impedance spectroscopy unit is designed to perform measurements using partial computing resources or dedicated minimal processing capabilities. Rather than requiring full vehicle computing power, the system can perform battery state detection using embedded controllers or microcontrollers within the charging infrastructure. This partial action approach allows impedance spectroscopy to be executed without monopolizing the vehicle's main computing resources, enabling parallel operations and maintaining system versatility.

Inventive Principle:
Principle #16Partial or excessive action

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 efficient and non-destructive battery state detection with minimal effort, utilizing existing vehicle systems to simplify the process and reduce computational load, allowing for accurate assessment of battery functionality, aging, and charge state without additional disassembly or complex measurement setups.

Implementation Method 1

a so-called impedance spectroscopy is used for this purpose, by means of which an object to be examined (test piece) is characterized in a comparatively simple and non-destructive manner. In this case, the test object is supplied with an alternating voltage or an alternating current of a specified frequency as a spectroscopy signal and a resulting and possibly phase-shifted alternating current or a resulting and possibly phase-shifted alternating current is recorded as a response signal

Methodology Applied
Scientific EffectImpedance spectroscopy: Electrical Resistance

Data Source

PatentEP3608156B1Device, charging column and method for detecting the condition of a motor vehicle battery
Publication Date: 2021.12.01 VOLKSWAGEN AG
  • EP3608156B1 patent drawingFigure 1
  • EP3608156B1 patent drawingFigure 2
  • EP3608156B1 patent drawingFigure 3

AI summary

The invention relates to a device (2) for detecting the state of a battery (4) of an electrically powered motor vehicle (6), wherein the device (2) comprises a charging plug (8) with DC contacts (10) for supplying a charging voltage (UL) to the battery (4), and an impedance spectroscopy unit (12) which is connected to the DC contacts (10) of the charging plug (8) both for supplying a spectroscopy signal (S) to the battery (4) and for detecting a response signal (A), and wherein the charging plug (8) is provided and configured for connection to a DC charging interface (54) of the electrically powered motor vehicle (6). The invention further relates to a charging station (52) with such a device (2) and a method for detecting the state of a battery (4) of an electrically powered motor vehicle (6).