Power Converter Busbar Bypass Design for Inductance Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional power converters with DC busbars have larger parasitic inductance due to the presence of through holes in the near busbar, leading to increased size and parasitic inductance, which affects the efficiency and size of the converter.
Innovation Solution
The configuration of the power converter includes a direct-current busbar assembly with near and far busbars, where the far busbar bypasses the near busbar terminals, eliminating the need for through holes in the near busbar, thereby increasing the area of the busbars and reducing parasitic inductance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If through holes are formed in the near busbar for insertion of near terminals, then the near terminals can be connected to the busbar, but the area of the busbar is reduced and parasitic inductance increases
Solution Approach 1:
The busbar system is divided into near busbar and far busbar with distinct functions. The near busbar serves only as an intermediate connection point with terminals connected directly to its surface, while the far busbar provides the main current path. This segmentation allows the near busbar to have smaller area without affecting overall performance, resolving the contradiction between connection ease and area maintenance.
Solution Approach 2:
The near busbar acts as an intermediary component between the near terminals and the far busbar. Current flows from near terminals through the near busbar to the far busbar, which then provides the main current path. This intermediary role allows the near busbar to be optimized for connection purposes while the far busbar is optimized for current carrying capacity, resolving the area-inductance contradiction.
2Ease of operation
If through holes are formed in the near busbar, then near terminals can be inserted, but parasitic inductance in the direct-current busbars increases
Solution Approach 1:
The harmful function of through holes (which create discontinuities and increase inductance) is extracted from the near busbar by eliminating them entirely. Instead of forming through holes in the near busbar, the design connects near terminals directly to the near busbar surface and uses the far busbar to provide the main current path, thereby removing the source of parasitic inductance while maintaining terminal insertion capability.
Solution Approach 2:
The connection approach is changed from a through-hole (3D penetration) method to a surface-mount (2D connection) method. Near terminals are connected to the near busbar through surface connections rather than through holes, and the current path is extended into the spatial dimension by using both near and far busbars in combination, thereby reducing parasitic inductance while maintaining connectivity.
3Loss of energy
If the area of the busbars is increased to reduce parasitic inductance, then efficiency improves, but the overall size of the power converter increases
Solution Approach 1:
The near busbar and far busbar are merged into a integrated busbar assembly where both components work together as a unified current path. The near busbar handles terminal connections while the far busbar provides the main current path, and their combined effect achieves low parasitic inductance without requiring either component to be excessively large, thus reducing overall converter size while maintaining efficiency.
Solution Approach 2:
Instead of increasing the area of a single busbar in the planar dimension, the design utilizes the spatial dimension by introducing a second busbar (far busbar) positioned at a different location. This dimensional approach allows the current path to be optimized for low inductance through spatial arrangement rather than area expansion, thereby reducing parasitic inductance without increasing the overall footprint of the power converter.
Data Source
AI summary
In a power converter, an insulation member is interposed between a first overlap portion of the near DC busbar and a second overlap portion of the far DC busbar in a protrusion direction. The first overlap portion is located closer to the converter component in the protrusion direction than the second overlap portion is. A near DC terminal is arranged to be closer to the first and second overlap portions than a far DC terminal is in an arrangement direction perpendicular to both the stack and protrusion directions. The near and far DC busbars are joined to the respective near and far DC terminals. The far DC busbar is joined to the far DC terminals of the respective semiconductor modules while bypassing the near DC terminals of the respective semiconductor modules.