Inductive Charging Interoperability Check via Impedance

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Ensuring interoperability between different primary and secondary units in inductive charging systems for electric vehicles is challenging due to varying coupling properties across different vehicle structures and manufacturer-specific designs, which affects the efficiency and reliability of wireless charging.

Innovation Solution

A method and evaluation unit that record and compare actual impedance values of test charging systems across various operating parameter combinations, using a reference value range to determine interoperability, involving a test secondary unit with a test secondary coil and a reference primary unit, and a test primary unit with a reference secondary coil, to regulate charging power and ensure compatibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If inductive charging systems use different primary and secondary units from different manufacturers, then device versatility is improved, but interoperability reliability deteriorates due to varying coupling properties

Engineering Contradiction:

Improvecompatibility with different vehicle structures and manufacturer designsVSAvoidinteroperability between different primary and secondary units

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies parameter changes by measuring and comparing impedance values across different operating conditions. The system varies operating parameters such as power levels and frequencies to characterize the coupling properties between primary and secondary units. By analyzing how impedance parameters change with different operating conditions, the system can determine compatibility without requiring specific manufacturer matching, thus resolving the contradiction between versatility and reliability.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If the system tests interoperability across all possible primary and secondary unit combinations, then reliability is improved, but testing complexity and time increase

Engineering Contradiction:

Improveinteroperability verificationVSAvoidtesting system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses impedance measurement as a copy or representation of the actual coupling behavior between primary and secondary units. Instead of physically testing every possible combination of units, the system measures impedance parameters that characterize the coupling properties and uses these measurements to predict interoperability. This copying approach simplifies the testing process while maintaining reliability.

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The system performs partial testing by measuring impedance at selected operating points rather than exhaustively testing all possible conditions. By measuring impedance across a representative set of operating parameters (power levels, frequencies), the system obtains sufficient information to determine compatibility without requiring complete enumeration of all test cases, thus reducing complexity while maintaining adequate reliability.

Inventive Principle:

Principle #16Partial or excessive action

3Measurement precision

If the system measures impedance across multiple operating parameter combinations, then measurement precision is improved, but measurement time and productivity decrease

Engineering Contradiction:

Improveimpedance characterization accuracyVSAvoidtesting speed

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The patent applies partial action by measuring impedance at a selected set of operating points rather than continuously across all possible parameters. The system measures impedance at multiple discrete power levels and frequencies, which provides sufficient precision to characterize coupling properties without requiring exhaustive measurement of every possible operating condition. This selective measurement approach balances precision with productivity.

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

This approach enables efficient and reliable checking of interoperability, ensuring that test units achieve predefined efficiency with qualified primary or secondary units across a defined operating range, thereby simplifying the development and testing of inductive charging systems.

Implementation Method 1

The reference primary coil is in this case able to generate a magnetic charging field that induces a current in the test secondary coil, such that electrical energy is able to be transferred from the reference primary unit to the test secondary unit

Methodology Applied

Scientific EffectMagnetic induction: Electromagnetic Induction

Data Source

PatentUS11679686B2Method for checking a primary or secondary unit of an inductive charging system

Publication Date: 2023.06.20 BAYERISCHE MOTOREN WERKE AG

AI summary

A method for checking a test secondary unit of an inductive test charging system for charging an electrical energy store, wherein the test charging system comprises the test secondary unit having a test secondary coil and a reference primary unit having a reference primary coil, includes recording a plurality of actual primary unit impedance values of the test charging system at the reference primary coil for a corresponding plurality of test combinations of values of operating parameters of the test charging system. The method also includes comparing the plurality of actual primary unit impedance values with a reference value range for a primary unit impedance.