Cast Winding Inductor Structure for High-Frequency Harmonic Filtering

Solution Overview

Problem

Existing power filtering systems using traditional inductors overheat due to high frequency harmonics, as these systems are not efficient in managing frequencies above 50-100 kHz, leading to increased AC resistance and overheating of cables and associated devices.

Innovation Solution

A distributed gap inductor with a powdered core is used, which efficiently passes carrier frequencies above 700 Hz while attenuating fundamental frequencies, reducing harmonic amplitudes by up to 99% through a combination of notch filters and high-frequency roll-off filters, and is designed for high current applications exceeding 50 amperes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional inductors are used for power filtering, then basic filtering function is provided, but high frequency harmonics above 50-100 kHz cause overheating and increased AC resistance

Engineering Contradiction:

Improveoverheating preventionVSAvoidenergy efficiency at high frequencies

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent changes the core material parameter from traditional steel to powdered core material, and modifies the magnetic path by introducing distributed air gaps. These parameter changes enable the inductor to maintain low AC resistance and prevent overheating at high frequencies above 50-100 kHz, while preserving the filtering function.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs a composite structure combining powdered core material with distributed air gaps throughout the magnetic path. This composite approach creates a magnetic circuit that efficiently handles high frequency harmonics, reducing energy losses and preventing overheating in high current applications.

Inventive Principle:

Principle #40Composite materials

2Loss of energy

If standard industrial power cables are used for 60 Hz current, then basic power transmission is achieved, but high frequency currents in 50-100 kHz range travel only on outside diameter causing severe increase in AC resistance

Engineering Contradiction:

ImproveAC resistance reductionVSAvoidcable and device overheating

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The patent applies parameter changes to the inductor core material and magnetic path structure, using powdered core with distributed gaps to reduce AC resistance at high frequencies. This enables efficient power transmission without the skin effect-related overheating that plagues standard cables at 50-100 kHz frequencies.

Inventive Principle:

Principle #35Parameter changes

3Loss of energy

If distributed gap inductor with powdered core is used, then high frequency harmonic amplitudes are reduced by up to 99%, but device complexity increases compared to traditional steel-based inductors

Engineering Contradiction:

Improveharmonic amplitude reductionVSAvoidinductor structure complexity

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The patent segments the magnetic path by distributing multiple air gaps throughout the powdered core structure. This segmentation approach reduces harmonic amplitudes by up to 99% while maintaining a manufacturable structure through standardized core and winding assemblies.

Inventive Principle:

Principle #1Segmentation

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 distributed gap inductor effectively reduces high-frequency harmonic amplitudes, preventing overheating and enhancing energy processing efficiency in high-frequency applications, outperforming traditional steel-based inductors at high currents and voltages.

Implementation Method 1

A distributed gap inductor with a powdered core is used, which efficiently passes carrier frequencies above 700 Hz while attenuating fundamental frequencies, reducing harmonic amplitudes by up to 99% through a combination of notch filters and high-frequency roll-off filters

Methodology Applied

Scientific EffectElectromagnetic filtering: Filter (electronic)

Implementation Method 2

The distributed gap inductor effectively reduces high-frequency harmonic amplitudes, preventing overheating and enhancing energy processing efficiency in high-frequency applications, outperforming traditional steel-based inductors at high currents and voltages

Methodology Applied

Scientific EffectHeat dissipation: Heat Sink

Data Source

PatentUS12051533B2Cast winding inductor apparatus and method of use thereof

Publication Date: 2024.07.30 MACLENNAN GRANT A

AI summary

The invention comprises an apparatus, comprising an inductor, the inductor comprising: an inductor core; a first winding section comprising a first cast shape and a second winding section comprising the first cast shape, the first winding section mechanically joined to the second winding section to form a winding, the winding forming a wound shape about the inductor core. Optionally and preferably, a third winding section, comprising a second cast shape, mechanically joins the first winding section to the second winding section and a mechanical connector and/or an aluminum weld join the first winding section to the third winding section.