Isolated DC-DC Converter Using Capacitive Isolation Resonance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional DC-DC converters using transformers face issues with large size, high loss, low heat dissipation, and reduced power density due to transformer limitations, making it difficult to improve efficiency and power density.
Innovation Solution
An isolated DC-DC converter design utilizing n conversion circuit units, each comprising primary and secondary bridge arms, coupling inductors, and capacitors, which replace transformers with capacitors for electrical isolation, achieving smaller size, lower loss, and higher heat dissipation through resonance conversion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a transformer is used to realize isolation in a DC-DC converter, then the insulation requirement is met, but the size increases and power density decreases
Solution Approach 1:
The patent replaces the traditional transformer-based isolation mechanism with a capacitor-based isolation mechanism. Specifically, it uses a bridge circuit configuration with capacitors (C1, C2, C3, C4) to achieve electrical isolation between primary and secondary sides, eliminating the need for a magnetic transformer and significantly reducing the converter's size while maintaining isolation functionality.
Solution Approach 2:
The patent changes the fundamental parameter of isolation implementation from magnetic coupling (transformer) to electrostatic coupling (capacitors). By using capacitive isolation, the system achieves the same insulation effect with much smaller physical dimensions, directly resolving the contradiction between meeting insulation requirements and minimizing transformer size.
2Reliability
If a transformer is used in a DC-DC converter, then isolation is achieved, but energy loss increases
Solution Approach 1:
The patent substitutes the lossy magnetic transformer with a low-loss capacitive bridge circuit for isolation. The capacitors in the bridge configuration exhibit minimal energy loss compared to transformer windings, thereby reducing overall converter energy loss while maintaining effective isolation between circuits.
Solution Approach 2:
The patent employs capacitors that can operate at high frequencies with minimal losses, effectively replacing the inefficient transformer. The capacitive isolation mechanism provides low-loss operation suitable for high-frequency DC-DC conversion applications.
3Reliability
If a transformer is used for isolation, then insulation is provided, but heat dissipation capacity decreases
Solution Approach 1:
The patent replaces the transformer with a capacitive bridge circuit that generates significantly less heat during operation. The capacitors exhibit lower equivalent series resistance and minimal core losses compared to transformers, improving heat dissipation capacity while maintaining isolation functionality.
4Reliability
If the number of turns of the transformer is increased to meet isolation requirements, then insulation is improved, but device complexity and design difficulty increase
Solution Approach 1:
The patent eliminates the complex multi-turn transformer winding design by using a capacitive bridge circuit. The isolation function is achieved through the bridge configuration of capacitors rather than through magnetic coupling requiring multiple turns, significantly simplifying the design process and reducing engineering complexity.
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 achieves higher efficiency and power density with balanced currents across circuit units, utilizing capacitors for electrical isolation and inductors for resonance, reducing size and loss compared to conventional converters.
Implementation Method 1
a first coupling inductor L1 and a first capacitor C1 are electrically coupled in series between the first connection node and the third connection node. The second coupling inductor L2 and a second capacitor C2 are electrically coupled in series between the second connection node and the fourth connection node
Implementation Method 2
a first coupling inductor L1 and a first capacitor C1 are electrically coupled in series between the first connection node and the third connection node
Data Source
AI summary
An isolated DC-DC converter including n conversion circuit units is provided. In each conversion circuit unit, a first connection node is formed between two switching components of a first primary bridge arm, and a second connection node is formed between two electronic components of a second primary bridge arm. A third connection node is formed between two switching components of a first secondary bridge arm, and a fourth connection node is formed between two switching components of a second secondary bridge arm. A first coupling inductor and A first capacitor are serially coupled between the first and third connection nodes. A second coupling inductor and a second capacitor are serially coupled between the second and fourth connection nodes. In the n conversion circuit units, the primary circuit units are electrically connected in series or in parallel, and the secondary circuit units are electrically connected in parallel or in series correspondingly.