Dual-Coil Power Converter Inductor for Overload Current Suppression

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Solution Overview

Problem

Inductors in power converters experience significant reduction in inductance during overload scenarios due to magnetic core saturation, leading to loss of current suppression ability and instability in control.

Innovation Solution

The power converter employs a dual-coil inductor design with a first sub-inductor and a second sub-inductor, where the first coil is a magnetic core coil and the second coil is a hollow coil, allowing the inductance to be maintained even under overload conditions by superposing the inductances of both coils, with adjustable winding turns to meet different inductance requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a magnetic core coil is used to achieve high inductance, then current suppression is effective under normal conditions, but magnetic saturation occurs under overload leading to control instability

Engineering Contradiction:
Improveinductance valueVSAvoidmagnetic permeability stability
Core Design Contradiction:
PowerVSStability of the object's composition

Solution Approach 1:

The inductor employs a composite structure combining magnetic core material and air as two different magnetic path materials. The magnetic core material provides high permeability for enhanced inductance under normal conditions, while the air core portion provides stable, saturation-free inductance under overload conditions. This composite approach allows the system to achieve high power handling capability while maintaining magnetic permeability stability across varying current conditions.

Inventive Principle:
Principle #40Composite materials

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 dual-coil design ensures stable current suppression under both rated and overload currents, improving electromagnetic compatibility and reducing magnetic flux leakage, thereby maintaining control stability and efficiency.

Implementation Method 1

The inductor includes a frame magnetic core, a separation magnetic core, a winding magnetic core, a first coil, and a second coil. The first coil is electrically connected to the second coil. When a current is applied to the first coil and the second coil, a direction of a magnetic field inside the first coil is the same as a direction of a magnetic field inside the second coil.

Methodology Applied
Scientific EffectElectromagnetic Induction: Electromagnetic Induction

Implementation Method 2

In an overload scenario (for example, an overload current is 1.5 to 2 times a rated current), the inductor is severely saturated due to impact of a material characteristic and the like of a magnetic core, the inductance is greatly reduced, and a current suppression ability is lost.

Methodology Applied
Scientific EffectMagnetic Saturation: Magnetic Saturation

Data Source

PatentEP4700805A1Power converter
Publication Date: 2026.02.25 HUAWEI DIGITAL POWER TECH CO LTD
  • EP4700805A1 patent drawingFigure 1
  • EP4700805A1 patent drawingFigure 2~3
  • EP4700805A1 patent drawingFigure 4~5

AI summary

Embodiments of this application provide a power converter, and relate to the field of energy technologies. The power converter (100) includes a housing (1), a power circuit (2), and one or more inductors (3). The housing is configured to accommodate the power circuit. The power circuit is configured to convert a direct current from a photovoltaic module or an energy storage battery into an alternating current. The inductor is fastened relative to the housing. The inductor includes a frame magnetic core (31), a separation magnetic core (32), a winding magnetic core (33), a first coil (34), and a second coil (35). The separation magnetic core is located in space enclosed by the frame magnetic core, and separates the frame magnetic core into a first accommodation cavity and a second accommodation cavity. The first accommodation cavity is configured to accommodate the winding magnetic core, and the winding magnetic core is configured to wind the first coil. The second accommodation cavity is configured to accommodate the second coil, and the first coil is electrically connected to the second coil. According to the foregoing technical solution, a possibility that an inductance of the inductor is greatly reduced can be reduced, so that the inductor in an overload scenario can suppress a current.