Contactless Power Transmission Device Phase Delay Control
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Solution Overview
Problem
In contactless power transmission systems, the existing technologies face limitations in the selection of driving frequency due to strict restrictions to avoid phase advance mode, which reduces the degree of freedom in frequency selection and can lead to hard switching and potential damage to power elements.
Innovation Solution
The system includes a power transmission unit with a coil and resonator, where the inductance and capacitance values are adjusted to extend the frequency range where the phase difference between the primary side current and voltage is zero or more, allowing for a wider phase delay region and enabling soft switching, thereby improving the degree of freedom in selecting a driving frequency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the inverter is operated in phase advance mode to simplify control, then control simplicity is improved, but power element damage risk increases due to hard switching
Solution Approach 1:
The patent changes the operating parameter from phase advance mode to phase delay mode, where the primary side current phase is delayed relative to the primary side voltage phase. This parameter change enables soft switching operation, reducing stress on power elements while maintaining operational simplicity through controlled phase relationship management
2Reliability
If the inverter is operated in phase delay mode to prevent hard switching, then power element reliability is improved, but frequency selection freedom is reduced
Solution Approach 1:
The patent introduces dynamic adjustment capability for the resonant frequency of the primary side resonant circuit. By making the resonant frequency adjustable rather than fixed, the system can adapt to different operating conditions and load requirements while maintaining phase delay mode operation, thus restoring frequency selection freedom without compromising power element safety
Solution Approach 2:
The patent changes the resonant frequency parameter of the primary side resonant circuit to be adjustable. This allows the system to optimize operating frequency based on specific application requirements while ensuring operation remains within the safe phase delay region, preventing hard switching across varying operating conditions
3Device complexity
If fixed inductance and capacitance values are used to simplify design, then design complexity is reduced, but operating frequency range is limited
Solution Approach 1:
The patent introduces dynamic adjustability to the resonant frequency parameter of the primary side resonant circuit. This allows the system to adapt its operating characteristics to different frequency requirements while maintaining a relatively simple overall design structure, effectively decoupling design simplicity from operational flexibility
Solution Approach 2:
The patent enables the resonant frequency parameter to be changed based on operating requirements. By making this key parameter adjustable rather than fixed, the system achieves broader operating frequency range coverage without substantially increasing design complexity, as the adjustment mechanism builds upon the existing resonant circuit topology
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 adjustment allows for a broader range of drivable frequencies in the phase delay region, reducing the risk of hard switching and enhancing the flexibility and efficiency of power transmission.
Implementation Method 1
contactless power transmission between a primary side coil of a power transmission device provided on the ground side, and a secondary side coil of a power reception device provided on the vehicle side, by using an electromagnetic force
Implementation Method 2
a transmission-side resonator which resonates with the power transmission side coil, and an inverter which supplies power to the transmission-side resonator
Data Source
Figure 1
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Figure 3A~3D
AI summary
This contactless power transmission device transmits power to a contactless power reception device having a reception-side coil and a reception-side resonator which resonates with the reception-side coil. The contactless power transmission device has a transmission unit including a transmission-side coil, a transmission-side resonator which resonates with the transmission-side coil, and an inverter for feeding power to the transmission-side resonator. The inductance value of the transmission-side coil and/or the capacitance value of the transmission-side resonator is set so that the frequency range in which the phase difference of a primary-side current flowing through the transmission unit relative to a primary-side voltage applied to the transmission unit is zero or above is wider than when the inductance value of the reception-side coil are equal to each other as are the capacitance value of the reception-side resonator and the capacitance value of the transmission-side resonator.