Shared-Core AC/AC Filter Inductor for Lower-Cost Noise Suppression

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Solution Overview

Problem

Conventional AC/AC power supplies require multiple filter inductors and magnetic cores, leading to high circuit costs and volume occupancy due to separate input and output filters.

Innovation Solution

A power conversion device with a single filter inductor and magnetic core that serves both input and output filtering functions, reducing the number of inductor windings and magnetic cores needed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate input filter and output filter with multiple inductors and magnetic cores are used, then filtering performance is improved, but circuit cost and device volume increase

Engineering Contradiction:

Improvefiltering performanceVSAvoidcircuit cost

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the input filter inductor and output filter inductor into a single shared inductor structure. The first inductor winding serves as the input filter inductor, the second inductor winding serves as the output filter inductor, and both windings share the same first inductor magnetic core. This merging eliminates the need for separate inductors and magnetic cores for input and output filtering, thereby reducing circuit cost while maintaining filtering performance.

Inventive Principle:

Principle #5Merging (Combining)

2Reliability

If separate input filter and output filter with multiple inductors and magnetic cores are used, then filtering performance is improved, but device volume increases

Engineering Contradiction:

Improvefiltering performanceVSAvoiddevice volume

Core Design Contradiction:

ReliabilityVSVolume of stationary object

Solution Approach 1:

The patent merges the input filter and output filter into a single integrated structure by sharing the first inductor magnetic core. The first inductor winding and second inductor winding are both wound around the same magnetic core, eliminating the need for separate magnetic cores and reducing overall device volume while maintaining effective filtering performance for both input and output sides.

Inventive Principle:

Principle #5Merging (Combining)

3Object-affected harmful factors

If multiple filter inductors and magnetic cores are used, then noise filtering capability is improved, but manufacturing cost increases

Engineering Contradiction:

Improvenoise filtering capabilityVSAvoidmanufacturing cost

Core Design Contradiction:

Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The patent combines multiple filtering functions into a single manufactured component. The shared inductor structure with multiple windings on one magnetic core reduces the number of discrete parts that need to be manufactured and assembled, thereby reducing manufacturing cost while maintaining effective noise filtering capability for both input and output sides.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The first inductor magnetic core serves multiple functions simultaneously: it provides magnetic coupling for the input filter inductor (first inductor winding) and the output filter inductor (second inductor winding). This multi-functionality reduces the total number of magnetic cores needed and simplifies the manufacturing process while maintaining comprehensive noise filtering capability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 configuration reduces circuit costs and volume by consolidating filtering functions, while maintaining effective noise reduction and compliance with noise standards for AC power supplies.

Implementation Method 1

The AC/AC power supply filters high-frequency noise of an internal switch circuit by using the two filters

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

the input filter inductor Lin includes inductor windings Lin1 and Lin2 and a first magnetic core, and the inductor windings Lin1 and Lin2 are both wound around the first magnetic core

Methodology Applied

Scientific EffectMagnetic field storage: Magnetic Field

Data Source

PatentEP4492656A1Power conversion device

Publication Date: 2025.01.15 HUAWEI DIGITAL POWER TECH CO LTD

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AI summary

This application provides a power conversion device. The power conversion device includes an alternating current input end, an alternating current output end, a first filter inductor, and an AC/AC circuit, where the first filter inductor includes a first inductor winding, a second inductor winding, a third inductor winding, and a first inductor magnetic core. The first inductor winding, the second inductor winding, and the third inductor winding are all wound around the first inductor magnetic core. A first end of the first inductor winding is connected to a first input end of the power conversion device, a first end of the second inductor winding is connected to a second input end and a second output end of the power conversion device, a second end of the first inductor winding and a second end of the second inductor winding are separately connected to an input end of the AC/AC circuit, a first end of the third inductor winding is connected to a first output end of the power conversion device, and the second end of the second inductor winding and a second end of the third inductor winding are separately connected to an output end of the AC/AC circuit. According to this application, circuit costs of the power conversion device can be reduced.