Inductive Vehicle Charging Resonance Frequency Adjustment
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Solution Overview
Problem
Induction charging of electric vehicles faces inefficiencies and electromagnetic pollution due to variable magnetic coupling between primary and secondary coils, leading to suboptimal power transfer and increased current requirements, which are not adequately addressed by existing solutions.
Innovation Solution
The method involves setting a first power transmission parameter, such as frequency, and iteratively adjusting a second parameter, like power supply voltage, to optimize power transfer, while varying the magnetic coupling and using capacitors to control resonance, allowing for efficient power delivery beyond the limitations of resonance frequency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If induction charging is performed with variable magnetic coupling between primary and secondary coils, then contactless power transfer is achieved, but energy efficiency deteriorates and electromagnetic pollution increases
Solution Approach 1:
The patent applies dynamics by making the resonant frequency adjustable rather than fixed. The system dynamically adapts the resonant frequency of the primary or secondary coil to match the operating frequency, maintaining optimal resonance conditions despite variations in magnetic coupling. This dynamic adjustment ensures efficient energy transfer while minimizing electromagnetic radiation losses.
Solution Approach 2:
The patent changes the resonant frequency parameter of the coils to optimize power transfer. By adjusting the resonant frequency to match the operating frequency, the system maximizes the quality factor (Q) and minimizes reactive power consumption, thereby improving energy efficiency and reducing electromagnetic pollution associated with off-resonance operation.
2Adaptability or versatility
If induction charging is performed with variable magnetic coupling, then adaptability to different vehicle positions is achieved, but power transfer efficiency deteriorates
Solution Approach 1:
The system dynamically adjusts the resonant frequency in response to changing magnetic coupling conditions caused by vehicle position variations. Sensors detect coupling status, and the control system modifies the resonant frequency accordingly to maintain optimal power transfer efficiency across different positioning scenarios.
Solution Approach 2:
The patent implements feedback control by monitoring the actual power transfer efficiency and adjusting the resonant frequency based on detected deviations. This closed-loop control ensures that the system adapts to varying vehicle positions while maintaining high efficiency through continuous optimization of the resonant matching condition.
3Productivity
If resonance frequency matching is performed, then power transfer efficiency is improved, but device complexity increases due to frequency adjustment mechanisms
Solution Approach 1:
The patent changes the resonant frequency parameter through controlled adjustment of capacitor values or coil configurations. By providing aĉé set of discrete frequency adjustment options, the system achieves efficient resonance matching without requiring complex continuous control mechanisms, thus balancing efficiency improvement with acceptable device complexity.
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 energy efficiency, reduces electromagnetic pollution, and minimizes the maximum current constraints on the voltage inverter, enabling consistent and efficient power transfer to the vehicle battery regardless of vehicle positioning.
Implementation Method 1
The transformer comprises a primary coil connected electrically to the charge converter situated in the ground and a secondary coil connected electrically to the receiver embedded in the vehicle. The charger converter generates a current in the primary. This current generates a magnetic field, some of which passes through the secondary. This then induces a current in the secondary, which will make it possible to charge the battery.
Implementation Method 2
To minimize the drawbacks described above, capacitors C1, C2 are used to compensate the reactive energy of the inductances L1, L2. In this exemplary application, the capacitors are placed in series relative to the primary coil and the secondary coil.
Data Source
AI summary
The invention relates to a method for charging a vehicle battery by induction from a charging device including a charge transmitter including a primary coil L1 and an inverter capable of supplying the primary coil L1 with an AC supply voltage E. Said device also includes a charge receiver including a secondary coil L2 arranged in a vehicle. Said method consists of adjusting a frequency f of the power supply voltage (E) to the resonance frequency fo, when a motor vehicle is located in a parking space. Said method comprises the following steps: setting a first power-transmission parameter (E, f); starting an iterative test which consists of: setting a value of a second power-transmission parameter (E, f); varying the second power-transmission parameter (E, f) in a second authorized adjustment range; measuring the power (Pbat) transmitted between the charge transmitter and the charge receiver; determining if the power (Pbat) is no lower than a predetermined operating threshold (PObj); determining if the power (Pbat) increases; ending the iterative test if the transmitted power (Pbat) is higher than the predetermined operating threshold (PObj); setting the power supply voltage (E) in order to reach the measured transmitted power (Pbat), said first and second transmission parameters being set to the previously established value thereof.