Wireless Power Transfer System Reactive Power Balance
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Solution Overview
Problem
Current wireless vehicle charging systems require stationary vehicles and often use ferromagnetic materials, which can disrupt the reactive power balance, and lack efficient dynamic charging solutions.
Innovation Solution
A wireless power transfer system using a coupler with a ferromagnetic core, capacitors, and switches to balance reactive power, allowing for dynamic charging by coordinating power transfer across a series of base couplers along a vehicle's path, enabling continuous charging while in motion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If ferromagnetic materials are used in wireless charging systems, then power transfer capability is improved, but reactive power balance is disrupted
Solution Approach 1:
The patent extracts the ferromagnetic core from the power transfer path by using air-core couplers for power transfer, while separately managing reactive power compensation through capacitors. This separation allows power transfer capability to be maintained through efficient air-core inductive coupling while reactive power balance is independently controlled without the disruptive effects of ferromagnetic materials.
Solution Approach 2:
The patent introduces capacitors as intermediary components to compensate for reactive power. These capacitors act as mediators that counterbalance the reactive power effects, enabling stable power transfer while maintaining reactive power balance. The capacitors are strategically placed in the circuit to provide reactive power compensation without interfering with the primary power transfer function.
2Reliability
If stationary charging is used, then reactive power balance is easier to maintain, but vehicle charging efficiency and user convenience deteriorate
Solution Approach 1:
The patent implements dynamic reactive power compensation that adapts to changing coupling conditions as the vehicle moves. The system continuously monitors and adjusts capacitor switching to maintain optimal reactive power balance despite varying distances and alignment between base couplers and vehicle coupler. This dynamic adaptation enables efficient charging while the vehicle is in motion, transforming the static charging process into a dynamic one that maintains efficiency throughout the driving cycle.
Solution Approach 2:
The patent enables continuous power transfer by coordinating multiple base couplers along the vehicle's path. As the vehicle moves from one base coupler to the next, power transfer continues without interruption through seamless handoff between couplers. This continuous action eliminates the need for the vehicle to stop for charging, maintaining both reactive power balance and charging efficiency throughout the journey.
3Duration of action of stationary object
If multiple base couplers are coordinated for dynamic charging, then charging continuity is improved, but system complexity increases
Solution Approach 1:
The patent divides the charging system into multiple independent base coupler units, each capable of autonomous operation with its own reactive power compensation circuitry. This segmentation allows each unit to be controlled independently, simplifying the overall system architecture. The segmentation enables continuous charging through coordinated operation of multiple units while keeping individual unit complexity manageable through modular design.
Solution Approach 2:
The patent designs base couplers with universal functionality that can operate in multiple modes: individual standalone operation, coordinated operation with adjacent couplers, and dynamic reactive power compensation. This multi-functionality allows the same hardware architecture to serve multiple purposes, reducing overall system complexity while enabling continuous charging through coordinated operation of multiple couplers.
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
The system achieves balanced reactive power transfer, allowing for efficient and continuous wireless charging of vehicles in motion, reducing the need for auxiliary systems and improving charging efficiency.
Implementation Method 1
a first coupler having a first reactance at an operating frequency. The first coupler is configured to wirelessly receive power from a power source. The first coupler is wound on a ferromagnetic core
Implementation Method 2
a first capacitor having a second reactance at the operating frequency. The second reactance has a magnitude equal to a magnitude of the first reactance
Data Source
AI summary
An apparatus for transmitting charging power wirelessly to a vehicle is provided. The apparatus comprises a first coupler having a first reactance at an operating frequency and configured to wirelessly receive power from a power source, the first coupler wound on a ferromagnetic core. The apparatus comprises a first capacitor having a second reactance at the operating frequency and electrically connected in series with the first coupler, the second reactance having a magnitude equal to a magnitude of the first reactance. The apparatus comprises a second capacitor electrically connected in parallel across the first coupler and the first capacitor. The apparatus comprises a first base coupler configured to be electrically connected in parallel across the second capacitor via a first switch. A magnitude of a peak voltage across the second capacitor is proportional to a magnitude of a peak voltage induced in the first coupler at the operating frequency.