Concentric Ring Capacitor Core for Low Stray Inductance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing thin-film capacitors in new energy vehicle drive motor controllers suffer from high stray inductance, leading to switching losses, voltage overshoot, and instability, which hinders the development towards high power density and efficiency.
Innovation Solution
A low inductance capacitor design featuring a concentric ring capacitor core similar to water ripple diffusion, incorporating a laminated bus bar, a filler, and a shell, with the bus bar embedded in the center of the capacitor core and the filler poured between the core and the shell, to reduce stray inductance and achieve uniform temperature distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If multiple capacitor cores are placed in close proximity to reduce stray inductance, then stray inductance is reduced, but temperature concentration occurs and performance deteriorates
Solution Approach 1:
The capacitor core is segmented into multiple independent units (first capacitor core, second capacitor core, third capacitor core, fourth capacitor core) arranged in a specific spatial configuration. Each unit has its own terminal connections, allowing independent current paths that prevent thermal concentration while maintaining low inductance through topological cancellation.
Solution Approach 2:
The capacitor units are arranged in a three-dimensional configuration with specific spatial relationships (front-to-back, left-to-right positioning). The terminal connections extend in multiple dimensions (first terminal group at front, second terminal group at back, third terminal group at left, fourth terminal group at right), creating multi-dimensional current paths that reduce inductance without causing thermal concentration in a single location.
2Ease of manufacture
If conventional cuboid capacitor cores are used, then manufacturing is simple, but stray inductance is high causing switching loss and voltage overshoot
Solution Approach 1:
The capacitor is divided into multiple discrete capacitor units (first, second, third, and fourth capacitor cores) with distinct terminal groups. This segmentation enables topological cancellation of inductance through strategic arrangement while maintaining relatively simple manufacturing processes for each individual unit.
Solution Approach 2:
The capacitor employs a composite structure combining multiple capacitor units with different terminal connection configurations. Each unit contains metal electrode layers, insulating envelopes, and terminal structures, creating a composite assembly that achieves low inductance through the interaction of multiple components rather than a single complex structure.
3Volume of moving object
If capacitor core volume is reduced for high power density, then power density increases, but stray inductance reduction becomes more difficult
Solution Approach 1:
The invention utilizes three-dimensional spatial arrangement of capacitor units and terminal connections to reduce inductance. Terminals are positioned at different spatial locations (front, back, left, right) and connected through multi-dimensional current paths, achieving effective inductance reduction within a compact volume by exploiting spatial relationships rather than simply increasing component size.
Solution Approach 2:
The capacitor core is segmented into multiple compact units arranged in a space-efficient configuration. This segmentation allows for optimized current paths within each unit while maintaining overall compactness, reducing stray inductance through the distributed structure rather than requiring a single large component.
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 effectively reduces stray inductance, improves heat dissipation with uniform temperature distribution, and enhances the compactness and performance of the capacitor, aligning with the requirements of high power density and efficiency in new energy vehicle drive motor controllers.
Implementation Method 1
a low inductance capacitor design featuring a concentric ring capacitor core similar to water ripple diffusion
Implementation Method 2
improves heat dissipation with uniform temperature distribution
Data Source
AI summary
A low inductance capacitor with a concentric ring capacitor core similar to water ripple diffusion is provided, including a laminated bus bar, a capacitor core, a filler and a shell; where the laminated bus bar is embedded in a center of the capacitor core; and the filler is poured between the capacitor core and the shell. The capacitor features a concentric ring-shaped design. The capacitor core consists of metal electrode layers, insulating inner films, and a central gap hole, with the metal electrode layers arranged in a concentric pattern that decreases in thickness, mimicking the diffusion of water ripples.