Inductive Charging Transmitter Element Foreign Body Detection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing inductive charging systems for electric vehicles face challenges in reliably detecting foreign bodies and living objects within strong magnetic fields without increasing space requirements or manufacturing costs, as separate sensors are needed to monitor these areas for safety and prevent fires.

Innovation Solution

Integration of a capacitance measuring arrangement and a voltage measuring arrangement within the transmitter element, utilizing existing components like the primary coil and housing, to detect changes in capacitance and voltage between the coil and a reference potential, eliminating the need for additional sensors and minimizing space and cost.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate capacitive sensors are attached to the housing to detect foreign bodies and living objects, then detection reliability is improved, but space requirements and manufacturing costs increase

Engineering Contradiction:
Improvedetection reliabilityVSAvoidspace requirements
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the foreign body detection function with existing transmitter element components (primary coil and housing) by measuring capacitance changes between these components. This merging eliminates the need for separate capacitive sensors, thereby maintaining detection reliability while reducing space requirements and device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent makes existing components (primary coil and housing) serve dual functions: energy transmission and foreign body detection. By measuring capacitance changes between these components, they become universal elements that perform both their original function and the additional detection function, eliminating the need for dedicated separate sensors.

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

2Reliability

If separate capacitive sensors are attached to the housing to detect foreign bodies and living objects, then detection reliability is improved, but manufacturing costs increase

Engineering Contradiction:
Improvedetection reliabilityVSAvoidmanufacturing costs
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent merges the detection function into existing components, eliminating the need to manufacture and assemble separate sensor units. This reduces manufacturing steps, assembly operations, and associated costs while maintaining detection capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

By making existing components multi-functional, the patent eliminates the need to manufacture separate dedicated sensors, thereby reducing material costs, manufacturing complexity, and overall production expenses while maintaining reliable detection.

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

3Reliability

If additional separate sensors are used for detection, then detection capability is improved, but the electromagnetic coupling increases causing interference with energy transmission

Engineering Contradiction:
Improvedetection capabilityVSAvoidelectromagnetic interference
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent combines detection with existing energy transmission components in a way that minimizes additional electromagnetic coupling. By using the primary coil and housing as both energy transmission and detection elements, the system avoids introducing separate sensor elements that would add to electromagnetic interference, thus reducing energy loss and maintaining transmission efficiency.

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 solution allows for the simple and reliable detection of foreign and living objects with minimal additional effort and space, while maintaining low electromagnetic coupling to prevent interference with energy transmission, ensuring safety and efficiency in inductive charging systems.

Implementation Method 1

at least one capacitance measuring arrangement for measuring and determining a capacitance between at least the primary coil (2) of the transmitter element (U) and the housing (1) accommodating this primary coil (2) or between at least one of these components and a reference potential

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

at least one voltage measuring arrangement for measuring and determining a voltage between at least the primary coil (2) of the transmitter element (U) and the housing (1) accommodating this primary coil (2) or between at least one of these components and a reference potential

Methodology Applied
Scientific EffectVoltage: Electric Field

Implementation Method 3

a magnetic flux is generated via a primary coil of the transmission device that is supplied with an input alternating current and also passes through a secondary coil of the receiving device

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP2891575B1Transfer element for a system for inductive energy transfer
Publication Date: 2019.05.15 BRUSA ELEKTRONIK AG
  • EP2891575B1 patent drawingFigure 1~2
  • EP2891575B1 patent drawingFigure 3~4
  • EP2891575B1 patent drawingFigure 5~6

AI summary

A transformer element (U) for an inductive energy transfer system between two transformer elements comprises at least one substantially planar coil (2) which is housed in a casing (1). At least one measuring arrangement (4, 4a) for the capacitance and/or the voltage is connected between the coil (2) and/or the casing (1) or an electrically conductive structure (3) with respect to a reference potential with at least one of these elements (1, 2, 3).