Integrated Bus Bar Inductance Reduction in Power Conversion
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Solution Overview
Problem
Existing power conversion apparatuses face challenges in reducing the inductance of bus bars and connections between bus bars and semiconductor modules, which is essential for high-speed switching and minimizing switching loss.
Innovation Solution
The power conversion apparatus incorporates a configuration where positive and negative electrode bus bars have coexisting parts placed between the power terminals of upper-arm and lower-arm semiconductor modules, allowing these parts to be close to each other, thereby reducing inductance. This configuration includes both arrangement and protruding facing parts on the bus bars that facilitate close placement and simplify connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If bus bars and semiconductor modules are placed adjacent to each other with individual terminals between every adjacent positive and negative electrode terminal, then connections are established, but inductance cannot be sufficiently reduced
Solution Approach 1:
The patent merges the positive electrode bus bar and negative electrode bus bar into a single integrated bus bar structure. This integration allows the bus bars to be placed closer together, reducing the loop area and thereby reducing inductance, which minimizes switching loss during high-speed switching operations.
Solution Approach 2:
The patent transitions from a conventional separate bus bar arrangement to an integrated structure where positive and negative electrode bus bars coexist in the same spatial dimension. This dimensional reorganization enables closer placement and reduces the current loop area, effectively reducing inductance.
2Volume of moving object
If semiconductor modules are placed adjacent to each other, then space utilization improves, but inductance of connections remains high
Solution Approach 1:
By integrating the positive and negative electrode bus bars into a single structure, the patent enables closer placement between adjacent semiconductor modules while reducing the connection loop area. This merging approach simultaneously achieves compact volume and reduced inductance, minimizing switching loss.
3Ease of operation
If individual terminals are placed between every adjacent positive and negative electrode terminal, then connections are simplified, but inductance cannot be reduced
Solution Approach 1:
The integrated bus bar structure maintains ease of connection through its design with protruding connection portions that align with semiconductor module terminals, while simultaneously reducing inductance by minimizing the current loop area through close placement of positive and negative electrode connections.
4Loss of energy
If bus bars are placed closer together, then inductance is reduced, but connection complexity increases
Solution Approach 1:
The integrated bus bar is segmented into multiple protruding connection portions, each designed to connect with corresponding terminals on adjacent semiconductor modules. This segmentation approach simplifies the connection process while maintaining the low-inductance structure, as each segment can be independently positioned and connected.
Data Source
AI summary
A power conversion apparatus has a positive electrode bus bar and a negative electrode bus bar. The power conversion apparatus has a first semiconductor module incorporating an upper-arm switching element and including a positive electrode terminal and a second semiconductor module incorporating a lower-arm switching element and including a negative electrode terminal. The first semiconductor module and the second semiconductor module are placed such that the positive electrode terminal and the negative electrode terminal face each other in a direction orthogonal to a protruding direction. The positive electrode bus bar and the negative electrode bus bar respectively have coexisting parts placed together between the positive electrode terminal and the negative electrode terminal as seen in the protruding direction of power terminals. The coexisting parts are at least partially placed in a space between the positive electrode terminal and the negative electrode terminal.