Inductive Charging Offset Detection via Partial Winding Phase Difference

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Solution Overview

Problem

Existing systems for determining the optimal parking position of a vehicle for inductive energy transmission are inefficient in accurately calculating the offset between the perpendicular projections of windings, leading to suboptimal energy transfer and charging efficiency.

Innovation Solution

A method and system that determine the phase difference between induced voltages in overlapping partial windings, using one winding as a transmitter and the other as a receiver, to calculate the offset, allowing for precise alignment and automatic control of the vehicle to achieve optimal positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If complex multi-winding configurations are used for distance determination, then measurement precision improves, but device complexity increases

Engineering Contradiction:
Improvedistance determination precisionVSAvoidwinding configuration complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Each winding is divided into two partial windings arranged in parallel. By measuring the phase difference of induced voltages between corresponding partial windings, the system achieves accurate offset determination with a simpler segmented structure rather than complex multi-winding configurations.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If simultaneous voltage measurements are performed on all windings, then measurement precision improves, but use of energy increases

Engineering Contradiction:
Improvevoltage measurement accuracyVSAvoidenergy consumption for measurements
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The system performs voltage measurements in periodic alternating sequences rather than simultaneously. First, voltages are measured for one winding configuration, then alternating current directions are switched and measurements are repeated. This periodic measurement approach maintains measurement accuracy while significantly reducing energy consumption compared to continuous simultaneous measurements.

Inventive Principle:
Principle #19Periodic 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 precise determination of the offset between windings, facilitating efficient energy transfer and automatic parking, thereby improving the charging efficiency and simplicity of the system.

Implementation Method 1

a first of the two windings 3, 4 is subjected to an alternating current (50, 51), in particular a sinusoidal alternating current

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The overlapping area is selected in such a way that no voltage is induced in the second partial winding 2 when the first partial winding 1 is supplied with an alternating current

Methodology Applied
Scientific EffectMagnetic field cancellation: Magnetic Field

Data Source

PatentEP3113907B1Method and system for carrying out a method for determining a value for the offset of the perpendicular projections of two windings
Publication Date: 2019.03.20 SEW EURODRIVE GMBH & CO KG
  • EP3113907B1 patent drawingFigure 1
  • EP3113907B1 patent drawingFigure 2
  • EP3113907B1 patent drawingFigure 3

AI summary

Method and system for carrying out a method for determining a value for the offset of the perpendicular projections of two windings into a plane, in particular the plane of movement of a vehicle which can move on the underlying surface which has a first of the two windings, and which vehicle has a second of the two windings, wherein each of the windings has, in each case, a first and a second partial winding, wherein the two partial windings are arranged overlapping in such a way that, when the first partial winding of one of the windings is energized with an alternating current, no induced voltage can be detected at the second partial winding of the same winding, wherein, in order to determine a value of the distance, a winding which functions as transmitter is supplied with an alternating current, in particular both partial windings of the winding are supplied with the same alternating current and the phase difference between the voltage U1 which is induced in the first partial winding of the other winding which functions as a receiver and the voltage U2 which is induced in the second partial winding of the winding which functions as a receiver are determined, wherein, when the voltage which is induced in the first partial winding is determined, the second partial winding is switched to a currentless state and, in particular, therefore at least one terminal of the second partial winding is electrically disconnected, wherein, when the voltage which is induced in the second partial winding is determined, the first partial winding is switched to a currentless state and, in particular, therefore at least one terminal of the first partial winding is electrically disconnected.