EV Field Winding Wireless Power Transfer

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Solution Overview

Problem

The existing wireless power transfer (WPT) systems for electric vehicles (EVs) are limited by the need for a secondary pad, which restricts the design freedom and increases costs due to the constraints on the placement and installation of the WPT system, particularly when charging high-voltage batteries.

Innovation Solution

A WPT method that utilizes the field winding of a driving motor on an EV to receive wireless power from a primary coil on the ground side, eliminating the need for a secondary pad and allowing for increased design flexibility by using a field winding as a secondary coil, connected through a controller system that manages power transfer and positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a secondary pad is installed on the EV for wireless power transfer, then power transfer efficiency is improved, but the degree of freedom in installation of other parts is reduced and device complexity increases

Engineering Contradiction:

Improvepower transfer efficiencyVSAvoiddegree of freedom in installation

Core Design Contradiction:

Loss of energyVSAdaptability or versatility

Solution Approach 1:

The field winding of the driving motor is made to serve dual purposes: its original function of generating magnetic field for motor operation, and an additional function as the secondary coil for wireless power transfer. This eliminates the need for a separate secondary pad, thereby maintaining power transfer efficiency while preserving design freedom for other vehicle components

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the field winding of the driving motor with the secondary coil function by electrically connecting the field winding to the battery through a switch. This combination allows the same component to perform both motor operation and wireless power reception, reducing device complexity and increasing installation flexibility

Inventive Principle:

Principle #5Merging (Combining)

2Loss of energy

If a secondary pad is installed on the EV for wireless power transfer, then power transfer efficiency is improved, but manufacturing cost increases

Engineering Contradiction:

Improvepower transfer efficiencyVSAvoidmanufacturing cost

Core Design Contradiction:

Loss of energyVSEase of manufacture

Solution Approach 1:

By making the field winding serve dual purposes (motor operation and wireless power transfer), the patent eliminates the need for an additional secondary pad component, thereby reducing manufacturing costs while maintaining power transfer efficiency

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The combination of the field winding with the secondary coil function reduces the total number of components required, simplifying the manufacturing process and reducing assembly costs while preserving the power transfer efficiency benefits of having a dedicated secondary pad

Inventive Principle:

Principle #5Merging (Combining)

3Device complexity

If the field winding is used as secondary coil for wireless power transfer, then device complexity is reduced, but power transfer efficiency may be compromised

Engineering Contradiction:

Improvenumber of componentsVSAvoidpower transfer efficiency

Core Design Contradiction:

Device complexityVSLoss of energy

Solution Approach 1:

The patent implements a dynamic switching mechanism where a switch connects the field winding to the battery during wireless power transfer operations. This dynamic control allows the system to optimize power transfer efficiency by properly managing the electrical connection, while maintaining the simplicity of using the existing field winding

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The vehicle controller monitors and controls the switching of the field winding connection based on charging conditions, allowing the system to optimize performance and maintain power transfer efficiency while using the multi-functional field winding configuration

Inventive Principle:

Principle #23Feedback

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 enhances the design freedom and reduces costs by eliminating the need for a secondary pad, improving the efficiency of WPT and simplifying the installation and maintenance of the WPT system, while enabling effective charging of EV batteries.

Implementation Method 1

a vehicle controller or a vehicle assembly (VA) controller connected to the vehicle controller performing communications, for charging of a battery of the EV, with a ground assembly (GA) controller of a charger connected to a primary coil or a primary pad located outside the EV; and connecting the battery to a field winding of a driving motor of the EV before starting the WPT. The battery may be charged by a power magnetically induced at the field winding from the primary coil.

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS10640001B2Wireless power transfer method using field winding and vehicle assembly and electric vehicle using the same

Publication Date: 2020.05.05 HYUNDAI MOTOR CO LTD

AI summary

A wireless power transfer (WPT) method for an electric vehicle (EV) may include a vehicle controller or a vehicle assembly (VA) controller connected to the vehicle controller performing communications, for charging of a battery of the EV, with a ground assembly (GA) controller of a charger connected to a primary coil or a primary pad located outside the EV; and connecting the battery to a field winding of a driving motor of the EV before starting the WPT. The battery is charged by a power magnetically induced at the field winding from the primary coil.