Resonant Wireless Power Transfer for Coil Position Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless power transfer systems require large current control elements, such as saturable reactors, which increase the size of the components and lead to magnetic flux leakage, and struggle to efficiently control power supply based on the relative positions of power transmission and reception coils.
Innovation Solution
The system employs a power transmission circuit and a power reception circuit with resonance modes, where the resonance frequency is set to either the first or second resonance frequency, deviating from the reference frequency by a predetermined amount, allowing for controlled power supply based on coil positions and reducing magnetic flux leakage by eliminating the need for large current control elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If large current control elements (saturable reactors) are used to control power supply, then power supply control is achieved, but device size increases and magnetic flux leakage occurs
Solution Approach 1:
The patent replaces mechanical/current control elements (saturable reactors) with electromagnetic resonance-based control. By adjusting the resonance frequency of the power transmission coil system to match the driving frequency, power supply is controlled through resonance conditions rather than physical current control elements, eliminating the need for large saturable reactors and reducing magnetic flux leakage.
Solution Approach 2:
The patent changes the operating parameters of the power transmission coil system by adjusting its resonance frequency. The resonance frequency is tuned to match the driving frequency based on the relative position between transmission and reception coils, enabling dynamic power supply control without physical control elements. This parameter-based control resolves the contradiction by providing operational control without increasing device size.
2Loss of energy
If current control elements are used to suppress current supply, then power efficiency is improved, but magnetic flux leakage increases
Solution Approach 1:
The patent substitutes the function of current control elements with resonance-based electromagnetic control. By controlling the resonance frequency of the power transmission coil system, current supply is suppressed or enhanced based on resonance conditions rather than using saturable reactors. This eliminates the magnetic flux leakage problem associated with physical current control elements while maintaining power efficiency.
Solution Approach 2:
The power transmission coil system controls its own current supply through resonance conditions. When the resonance frequency matches the driving frequency, the system naturally draws the required current; when mismatched, current supply is suppressed. This self-regulating resonance mechanism eliminates the need for external current control elements that cause magnetic flux leakage.
3Productivity
If resonance frequency is set to deviate from reference frequency, then power transfer efficiency is improved, but system complexity increases
Solution Approach 1:
The patent implements dynamic frequency adjustment where the resonance frequency of the power transmission coil system is continuously adapted to match the driving frequency based on the relative position between transmission and reception coils. This dynamic resonance tuning maximizes power transfer efficiency at different positions without requiring complex control systems, as the resonance condition naturally adapts to operational conditions.
Solution Approach 2:
The system uses feedback from the relative position between coils to adjust the resonance frequency. By detecting the coupling coefficient or position information, the system adjusts the resonance frequency to maintain optimal power transfer efficiency. This feedback mechanism achieves high efficiency without excessive complexity by leveraging natural resonance phenomena.
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 power transfer by controlling power supply according to coil positions, reducing unnecessary power consumption and magnetic flux leakage, thereby enhancing transmission efficiency.
Implementation Method 1
a power transmission coil 112 and a power reception coil 212 that are coupled to each other with a predetermined coupling coefficient, resonance of a first resonance mode and resonance of a second resonance mode are generated in the power transmission resonance circuit and the power reception resonance circuit
Implementation Method 2
resonance of a first resonance mode and resonance of a second resonance mode are generated in the power transmission resonance circuit and the power reception resonance circuit, and the first resonance mode has a first resonance frequency and the second resonance mode has a second resonance frequency
Data Source
AI summary
A power supplying device includes a power transmission circuit transmitting AC power and a power transmission resonance circuit including a power transmission coil. A power receiving device includes a power reception resonance circuit including a power reception coil. When a coupling coefficient between the power transmission coil and the power reception coil is a predetermined coupling coefficient, resonance of a first resonance mode having a first resonance frequency and a second resonance mode having a second resonance frequency are generated, a resonance frequency of the power transmission resonance circuit and the power reception resonance circuit is set to a value which is one of the first and second resonance frequencies, and the set value is a frequency deviating from a reference resonance frequency of the power transmission resonance circuit alone by a predetermined deviation frequency or more. A driving frequency of the AC power is set to the set value.