Inverter Conduction Angle Control for Wireless Power Transfer
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Solution Overview
Problem
Existing wireless power transfer systems for electric vehicles face challenges in maintaining optimal power delivery due to variations in coupling between primary and secondary coils, leading to increased stress on power electronic components and undesirable harmonic distortion, which affects reliability and efficiency.
Innovation Solution
A wireless power transfer system with an adjustable DC power source and an inverter that converts the DC voltage to AC, while controlling the conduction angle to reduce distortion signals and maintain a constant AC current in the primary inductive element, thereby generating a stable magnetic field for efficient power transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If wireless power transfer systems operate with varying coupling between primary and secondary coils, then power delivery adapts to different positions, but harmonic distortion increases and stress on power electronic components worsens
Solution Approach 1:
The system dynamically adjusts the conduction angle of the inverter based on detected coupling conditions. When coupling varies between primary and secondary coils, the controller modifies the conduction angle in real-time to maintain optimal power transfer while preventing excessive harmonic distortion and component stress
Solution Approach 2:
The invention changes the conduction angle parameter of the inverter to optimize system performance under varying coupling conditions. By adjusting this specific parameter, the system maintains reliable operation and reduces harmonic distortion while adapting to different positional couplings
2Productivity
If inverter conduction angle is increased to improve power transfer under varying coupling, then power delivery improves, but harmonic distortion increases
Solution Approach 1:
The system implements feedback control by detecting the actual coupling conditions and using this information to adjust the conduction angle. This closed-loop approach ensures that the conduction angle is optimized for power transfer while automatically limiting harmonic distortion by preventing excessive angle increases
Solution Approach 2:
The conduction angle is made dynamic rather than fixed, allowing the system to optimize power transfer efficiency under varying coupling conditions while automatically adjusting to prevent harmful harmonic distortion levels
3Stability of the object's composition
If AC current is maintained constant in primary inductive element, then magnetic field stability improves, but control complexity increases
Solution Approach 1:
The system achieves constant AC current in the primary inductive element by dynamically adjusting the conduction angle parameter. This single parameter change approach maintains magnetic field stability without requiring complex control mechanisms, as the conduction angle adjustment inherently compensates for coupling variations
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 solution reduces harmonic distortion and stress on components, improving the reliability and efficiency of wireless power transfer by maintaining a stable AC current and optimizing power delivery across varying coupling conditions.
Implementation Method 1
an inverter configured to convert the adjustable output voltage to an alternating current
Implementation Method 2
a first inductive element configured to receive the alternating current from the inverter and generate a magnetic field
Implementation Method 3
at least one controller configured to reduce at least one distortion signal in the alternating current while maintaining the alternating current in the first inductive element substantially constant
Data Source
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AI summary
This disclosure provides systems, methods and apparatus for wireless power transfer and particularly wireless power transfer to remote system such as electric vehicles. In one aspect an apparatus for use with a wireless power transfer transmitter device comprising a first inductive element for generating a magnetic field, is provided. The apparatus comprises a direct current (DC) power source having an adjustable output voltage. The apparatus also comprises an inverter configured to convert the adjustable output voltage of the DC power source to alternating current. The apparatus also comprises at least one controller configured to receive an indication of current in the first inductive element and control the output voltage of the DC power source in response to the indication of current in the first inductive element. The apparatus reduces distortion signals in the alternating current output of the inverter while maintaining current in the inductive element substantially constant.