Coupled Filter Inductor for Interleaved Ripple and Load-Step Control
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Solution Overview
Problem
Existing power devices, such as uninterruptible power supplies (UPS), face challenges in reducing ripple current while maintaining dynamic performance, as smaller filter components can lead to decreased output voltage during load steps and increased core loss due to excessive harmonic filtering.
Innovation Solution
The implementation of an interleaved filtering system using transformers with specific winding configurations and magnetic field cancellations to reduce ripple current and improve dynamic performance, allowing for smaller filter components without compromising performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If smaller filter components are used to reduce ripple current, then device size is reduced, but output voltage decreases during load steps
Solution Approach 1:
The filter is divided into multiple segments (first and second interleaved inputs, multiple transformers) that operate in parallel. Each segment handles a portion of the load, allowing smaller individual components while maintaining overall filtering effectiveness and dynamic performance during load transitions.
Solution Approach 2:
The filter incorporates dynamic response characteristics through its interleaved structure and transformer configurations, enabling it to adapt quickly to load changes. The coupled inductors and transformer windings provide dynamic current sharing and voltage support during load steps, maintaining output stability despite reduced component size.
2Reliability
If larger filter components are used to maintain output voltage during load steps, then reliability is improved, but device size increases
Solution Approach 1:
Multiple filter segments and transformers are merged into a unified interleaved structure that shares the filtering and voltage support functions. This combination allows the system to achieve the reliability of larger components while using smaller individual parts, as the merged structure provides cumulative filtering effectiveness and dynamic support.
3Object-generated harmful factors
If excessive harmonic filtering is applied to reduce ripple current, then ripple current is reduced, but core loss increases
Solution Approach 1:
The filter applies different filtering characteristics to different frequency components and current paths. The interleaved transformer structure provides targeted harmonic filtering where needed while maintaining lower impedance paths for fundamental frequencies, reducing unnecessary core loss while effectively suppressing ripple current and harmonics.
Solution Approach 2:
The filter parameters (inductance, transformation ratios, winding configurations) are optimized to provide effective ripple current reduction at operating frequencies while minimizing core loss. The coupled inductor design and transformer turns ratios are selected to achieve the desired filtering effect with minimal energy dissipation in the core.
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 effectively reduces ripple current and odd harmonics, enhances dynamic performance by presenting a short circuit to load-step currents, and minimizes core loss, resulting in improved filter performance and reduced component size.
Implementation Method 1
the first primary winding and the first secondary winding are configured to generate in-phase magnetic fields that cancel each other. In some examples, the second primary winding and the second secondary winding are configured to generate in-phase magnetic fields that cancel each other.
Data Source
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AI summary
Aspects of the disclosure include a filter comprising a first interleaved input, a second interleaved input, an output, a first transformer comprising a first primary winding with N1 turns and a first secondary winding with N2 turns, and a second transformer comprising a second primary winding with N3 turns and a second secondary winding with N4 turns, wherein the first primary winding and the second secondary winding are in series with the first interleaved input and the output, and the first secondary winding and the second primary winding are in series with the second interleaved input and the output.