Bus Bar Segmentation for Capacitor Thermal Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electric power conversion devices face issues with heat generation and temperature increase in capacitors due to direct current components, leading to capacitor deterioration and reduced lifespan.
Innovation Solution
The electric power conversion device design includes a main N bus bar connected to the input N bus bar outside the capacitor mold resin, preventing DC current flow through the capacitor module and thus preventing heat propagation to the capacitors, which are molded within the resin.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the capacitor bus bar is molded in the capacitor module with the capacitor, then the structure is compact and integrated, but the DC component generates heat energy that increases the capacitor temperature and causes deterioration
Solution Approach 1:
The bus bar system is segmented into two distinct parts: a capacitor bus bar (molded with the capacitor for compactness) and a main bus bar (separate from the capacitor module). This segmentation allows the capacitor bus bar to remain integrated while the main bus bar handles DC current externally, preventing heat generation within the capacitor module and resolving the contradiction between structural integration and capacitor reliability
Solution Approach 2:
The main bus bar is extracted from the capacitor module structure and positioned outside the molded capacitor assembly. By taking out the DC current-carrying component (main bus bar) from the capacitor housing, the design maintains the compact integrated capacitor bus bar while eliminating the source of heat generation that would otherwise deteriorate the capacitor and reduce its lifespan
2Device complexity
If the main bus bar is connected through the capacitor bus bar, then the connection path is simplified, but heat energy from DC current flows to the capacitor and increases its temperature
Solution Approach 1:
The connection path is segmented into two separate routes: one through the capacitor bus bar for AC current (maintaining simplified connection for capacitor function), and another through the externally positioned main bus bar for DC current. This segmentation allows the DC current path to be simplified while preventing heat energy from reaching the capacitor, thus resolving the contradiction between connection simplicity and temperature control
3Productivity
If the capacitor bus bar carries DC current, then the power supply path is direct, but the DC component generates heat energy that breaks the capacitor module
Solution Approach 1:
The power supply function is segmented between two bus bars: the capacitor bus bar handles AC current with direct connection for efficient power conversion, while the main bus bar handles DC current externally to prevent heat generation within the capacitor module. This segmentation maintains power supply efficiency while eliminating the harmful heat energy that would otherwise damage the capacitor assembly
Solution Approach 2:
The DC current-carrying main bus bar is extracted from the capacitor module and positioned outside the molded structure. By taking out the DC power supply path from the capacitor housing, the design maintains direct and efficient power conversion while preventing heat energy generation within the capacitor module, thus resolving the contradiction between power supply efficiency and protection from heat damage
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
This design effectively suppresses capacitor temperature increases, preventing deterioration and enhancing the reliability of the electric power conversion device by isolating heat generation from the capacitors.
Implementation Method 1
a capacitor mold resin 46. The capacitor P bus bar 42p, the capacitor N bus bar 42n and the first capacitor 41 are molded by the capacitor mold resin 46
Implementation Method 2
The capacitor P bus bar 42p is connected to a positive electrode terminal 41p of the first capacitor 41, and the capacitor N bus bar 42n is connected to a negative electrode terminal 41n of the first capacitor 41
Data Source
AI summary
An electric power conversion device has semiconductor modules, a main P bus bar, a main N bus bar, a capacitor module, an input P bus bar and an input N bus bar. The input N bus bar is connected to the DC power source. The main N bus bar is connected to a negative electrode terminal of the semiconductor module to supply the DC power. A capacitor N bus bar, a filter capacitor and a smoothing capacitor in the capacitor module are molded by capacitor molded resin. The capacitor N bus bar is connected to a negative electrode terminal of the filter capacitor. The input N bus bar has a first N connection section connected to the capacitor N bus bar and a second N connection section connected to the main N bus bar. The main N bus bar is arranged outside of the capacitor mold resin.