DC-DC Converter Ripple Reduction via Merged Capacitor Nodes
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Solution Overview
Problem
Existing direct-current converters generate high-frequency ripples that cause electromagnetic interference, and current methods to mitigate this often require additional or larger components, which increase complexity and cost.
Innovation Solution
A direct-current converter design featuring a series arm with at least one inductance and capacitance, and a shunt arm with a second capacitance and switches, where the switches are actively controlled to minimize ripple by alternating their state and using semiconductor switches like BJT, MOSFET, or IGBT.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If larger or additional components are used to dampen ripple, then electromagnetic interference is reduced, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent merges the ripple damping function into the existing converter circuit by strategically positioning capacitors at specific nodes (between inductor and switch, and at the output). This integration allows the same circuit components to serve both power conversion and ripple filtering functions, eliminating the need for separate additional filtering components and reducing overall device complexity.
Solution Approach 2:
The patent introduces intermediary capacitive elements that mediate between the switching action and the output. These capacitors act as intermediaries that smooth out voltage variations caused by switching, thereby reducing electromagnetic interference without requiring fundamental changes to the converter architecture or adding complex filtering stages.
2Object-affected harmful factors
If larger or additional components are used to dampen ripple, then electromagnetic interference is reduced, but manufacturing cost increases
Solution Approach 1:
By combining the ripple damping function with existing converter components, the patent reduces the total component count. Fewer components mean lower manufacturing costs, simplified assembly processes, and reduced bill of materials expenses, while still achieving effective electromagnetic interference reduction.
Solution Approach 2:
The patent makes existing components multi-functional: the capacitors serve both as energy storage elements in the power conversion process and as ripple filtering elements. This universality eliminates the need for dedicated filtering components, thereby reducing manufacturing cost while maintaining electromagnetic compatibility.
3Object-generated harmful factors
If ripple is reduced through additional components, then AC component in output voltage is minimized, but device complexity increases
Solution Approach 1:
The patent combines the AC component reduction function with the existing power conversion circuitry by placing capacitors at strategic locations. This merging approach allows the same components to perform both power transfer and voltage smoothing, reducing the AC component in output voltage without increasing device complexity.
Solution Approach 2:
The patent utilizes dynamic switching control where capacitors are charged and discharged in synchronization with the switching action. This dynamic operation allows the capacitors to actively counteract voltage ripples during switching transitions, effectively reducing the AC component in the output voltage while maintaining a simple circuit structure.
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 design significantly reduces the alternating current component in the output voltage, minimizing electromagnetic interference without the need for additional components, thus simplifying and cost-reducing the converter while maintaining efficiency.
Implementation Method 1
at least one first inductor (4) and a first capacitor (5) are arranged in a longitudinal branch (11) between input (2) and output (3)
Implementation Method 2
a first capacitor (5) are arranged in a longitudinal branch (11) between input (2) and output (3)
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
The invention, which relates to a DC-DC converter (1), is based on the objective of providing a DC-DC converter (1) that is simple and inexpensive to manufacture and whose AC component superimposed on a DC current is reduced in an output voltage (ripple). This objective is achieved by arranging a first switch (9) and a second switch (10) in series in a second cross branch arranged parallel to the first cross branch, and by arranging a second inductor (7) such that its first terminal is connected to a point between the first inductor (4) and the first capacitor (5), and its second terminal is connected to a point between the first (9) and the second (10) switch.