Toroidal Inductor Double Winding Stray Field Reduction
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Solution Overview
Problem
High power and high frequency applications, such as X-ray generators, face challenges with stray fields and eddy currents in metal enclosures, leading to high losses and electromagnetic interference.
Innovation Solution
A toroidal inductor design with a double or triple winding scheme, using Litz wire and an air core, where inner windings are stacked and outer windings are adjacent, minimizing stray fields and optimizing the core's cross-section to reduce losses and enhance electromagnetic compatibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a transformer delivers complete inductance, then inductance requirement is met, but stray fields increase causing eddy currents in adjacent parts
Solution Approach 1:
The inductance is segmented into two parts: the transformer provides only the necessary inductance for the resonant circuit operation, while a separate resonance inductor provides the remaining inductance. This segmentation allows the transformer to operate with reduced stray fields while meeting the total inductance requirement through the combined system.
Solution Approach 2:
A separate resonance inductor is introduced as an intermediary component between the transformer and the resonant circuit. This intermediary inductor absorbs the stray field effects and provides the additional inductance needed, protecting the transformer from generating excessive eddy currents in adjacent parts.
2Power
If high power and high frequency operation is implemented, then power delivery capability is improved, but losses increase due to eddy currents
Solution Approach 1:
The inductance function is segmented between the transformer and a separate resonance inductor, allowing the transformer to operate at lower stray field levels while still delivering high power. The separate inductor handles the resonant function with minimized eddy current losses.
Solution Approach 2:
The system changes the operating parameters by introducing a dedicated resonance inductor with optimized characteristics for high frequency operation. This allows the transformer to operate at reduced stray field levels while maintaining high power delivery capability through the resonant circuit.
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 design achieves low noise, high quality factor, and reduced ac losses, enabling high stored energy capability while mitigating eddy current losses and improving electromagnetic compatibility.
Implementation Method 1
an inductor for high frequency and high power applications... Windings of the at least one wire conductor comprises the at least one wire conductor being wound around the coil zone to form a substantially torus shape
Implementation Method 2
These solutions have the drawback that they are linked to relatively high stray fields, which can produce eddy currents in adjacent parts like printed circuit boards and metal enclosures
Implementation Method 3
using Litz wire and an air core, where inner windings are stacked and outer windings are adjacent, minimizing stray fields and optimizing the core's cross-section to reduce losses
Data Source
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AI summary
The present invention relates to an inductor (10) for high frequency and high power applications. The inductor (10) comprises at least one wire conductor (20), and a coil zone (30). Windings of the at least one wire conductor comprises the at least one wire conductor being wound around the coil zone to form a substantially torus shape centred around an axis extending in an axial direction of the torus shape. At an outer extent of the coil zone, outer windings of the at least one wire conductor are substantially at a first radial distance from the axis. At an inner extent of the coil zone, inner windings of the at least one wire conductor are substantially at a second radial distance from the axis and substantially at a third radial distance from the axis respectively. When an inner winding of the at least one conductor is at the second radial distance the next inner winding of the at least one conductor is at the third radial distance.