Contactless Power Supply Phase Control for Coil Position Variations
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Solution Overview
Problem
Non-contact power supply systems using electromagnetic induction face challenges in maintaining consistent output power due to changes in the relative positional relationship between primary and secondary coils, leading to reduced power transmission efficiency.
Innovation Solution
A non-contact power supply apparatus incorporating an inverter circuit, a primary coil, a variable capacitance circuit, and a control circuit that adjusts the phase difference of drive signals to maintain optimal output power by estimating the initial operational mode and setting a prescribed range for phase difference adjustment, ensuring efficient power transmission even with changing coil positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the relative positional relationship between the primary coil and the secondary coil changes, then the coupling coefficient changes, but the output power decreases and may become smaller than the required electric power
Solution Approach 1:
The patent applies dynamics by making the capacitance value adjustable through the variable capacitance circuit. The capacitance can be dynamically changed based on the coupling coefficient conditions, allowing the system to adapt to varying positional relationships between coils while maintaining stable output power.
Solution Approach 2:
The patent changes the electrical parameter (capacitance value) to compensate for variations in the coupling coefficient. By adjusting the capacitance in the variable capacitance circuit, the system maintains optimal resonant conditions and ensures required electric power is secured even when coil positions change.
2Productivity
If the coupling coefficient between the primary coil and the secondary coil changes, then the power transmission efficiency decreases, but the system structure remains simple
Solution Approach 1:
The variable capacitance circuit introduces dynamic adjustability to the system, enabling real-time optimization of power transmission efficiency based on coupling conditions without requiring complex multi-component structures.
Solution Approach 2:
By changing the capacitance parameter in the variable capacitance circuit, the system optimizes power transmission efficiency in response to coupling coefficient variations, achieving improved productivity with minimal additional structural complexity.
3Power
If the phase difference of the drive signal is adjusted to maintain output power, then the power transmission efficiency is improved, but the control complexity increases
Solution Approach 1:
The control circuit uses feedback to monitor the output power and adjusts the phase difference of the drive signal accordingly. This feedback mechanism enables automatic maintenance of required electric power levels while managing control complexity through intelligent algorithms.
Solution Approach 2:
The control circuit adjusts the phase difference parameter of the drive signal to optimize output power. By dynamically changing this electrical parameter based on system conditions, the patent maintains high power transmission efficiency without requiring overly complex control architecture.
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 securely provides required electric power by adjusting the phase difference within a set range, maintaining efficient power transmission and operating in a lagging phase mode to reduce switching losses, even when the coupling coefficient between coils changes.
Implementation Method 1
A non-contact power supply apparatus configured to supply power to a load by using electromagnetic induction in a non-contact manner has been proposed
Implementation Method 2
The primary coil is electrically connected between the output points in the pair and is configured to supply output power to a secondary coil in a non-contact manner when the alternating-current voltage is applied to the primary coil
Implementation Method 3
The variable capacitance circuit includes an adjustment capacitor and a plurality of adjustment switching elements. The variable capacitance circuit is configured to adjust a magnitude of a capacity component between the pair of output points and the primary coil by switching the plurality of adjustment switching elements
Data Source
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AI summary
A non-contact power supply apparatus, a program, a method for controlling the non-contact power supply apparatus, and a non-contact power transmission system which easily secure required electric power even when the relative positional relationship between a primary coil and a secondary coil changes are provided. A control circuit (23) is configured to adjust a phase difference which is a delay of the phase of each of the second drive signals (G6, G7) to the phase of each of the first drive signals (G1, G4) to a set value within a prescribed range to adjust the magnitude of output power. The control circuit (23) includes an estimator (231) and a setter (232). The estimator (231) estimates whether an initial mode which is an operation mode of an inverter circuit (21) in the case of a variable capacitance circuit (22) being disabled is a leading phase mode or a lagging phase mode while the variable capacitance circuit (22) is operating. The setter (232) sets the prescribed range in accordance with the initial mode estimated by the estimator (231).