Interleaved Power Supply Circuit with Magnetic Coupling for Noise Suppression
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Solution Overview
Problem
Conventional power supply circuits using interleaving methods fail to adequately reduce noise frequencies that are even multiples of the switching frequency, leading to increased noise propagation and potential circuit malfunctions.
Innovation Solution
The power supply circuit incorporates magnetically coupled reactors and inductors with a bypass capacitor and inductor configuration, utilizing an interleaving method for switching control to cancel out noise frequencies, including those equal to odd multiples and even multiples of the switching frequency, by adjusting the electrical elements' constants to satisfy specific formulas, thereby reducing ripple components effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional interleaving method is used for switching control, then noise reduction is achieved, but noise frequencies that are even multiples of switching frequency are not adequately reduced
Solution Approach 1:
The power supply circuit is divided into multiple independent power supply modules that operate in parallel with interleaved switching. Each module processes a portion of the input power, and their combined output achieves broader noise suppression across multiple frequency bands including even multiples of the switching frequency.
Solution Approach 2:
The circuit employs a composite filtering approach combining multiple inductors with different inductance values and capacitors with different capacitance values. This composite structure creates multiple resonance frequencies that collectively suppress a wider spectrum of noise frequencies, particularly targeting even multiples of the switching frequency that single-stage filters cannot adequately address.
2Object-affected harmful factors
If multiple inductors and capacitors are added to suppress even multiple frequency noise, then noise reduction improves, but circuit complexity increases
Solution Approach 1:
The power supply modules are designed to perform multiple functions simultaneously: power conversion, noise filtering, and impedance matching. The inductors and capacitors serve dual purposes as both energy storage elements for power conversion and as filtering components for noise suppression, eliminating the need for separate dedicated filtering circuits.
Solution Approach 2:
The filtering function is merged into the power conversion path itself. The inductors Lc1 and Lc2 are integrated into the switching paths of the power supply modules, and capacitors Cb1 and Cb2 are placed in parallel with the output. This merging allows the same components to perform both power processing and noise filtering without requiring additional dedicated filtering stages.
3Object-affected harmful factors
If inductors and capacitors are used for noise filtering, then noise suppression improves, but circuit size increases
Solution Approach 1:
The circuit employs a multi-stage filtering approach where each stage uses smaller inductors and capacitors with specifically optimized parameter values. By distributing the filtering function across multiple stages with progressively smaller components, the total component size is reduced while maintaining effective noise suppression across the target frequency range.
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 significantly reduces noise propagation, minimizing normal mode noise and allowing for a more compact and efficient power supply design, while maintaining circuit symmetry and reducing the risk of circuit malfunctions.
Implementation Method 1
the first reactor (Lr1) and the first inductor (Lc1) are magnetically coupled to each other
Implementation Method 2
the second reactor (Lr2) and the second inductor (Lc2) are magnetically coupled to each other
Implementation Method 3
a bypass capacitor (Cb3)... configured to form a resonant circuit with the first inductor (Lc1) and the second inductor (Lc2), and having a resonance frequency equal to two times a switching frequency
Data Source
AI summary
Provided is a power supply circuit in which a first end of a first inductor is connected to a path linking a first input terminal to a first connection point, a second end of the first inductor is connected to a first end of a bypass capacitor, a first end of a second inductor is connected to a path linking the first input terminal to a second connection point, a second end of the second inductor is connected to a first end of the bypass capacitor, a second end of the bypass capacitor is connected to a second output terminal, a first reactor and the first inductor are magnetically coupled to each other, a second reactor and the second inductor are magnetically coupled to each other, and a control circuit performs switching control over a first switching element and a second switching element, using an interleaving method.