Nested DC Bus Bar Assembly for Inverter Noise Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inverter assemblies face challenges in efficiently converting DC input to three-phase AC output while minimizing noise pickup and inductance, particularly due to the design of DC bus bars which can lead to suboptimal performance and increased noise from stray fields.
Innovation Solution
A DC bus bar sub-assembly with a nested structure of positive and negative bus bars, each with input and output tabs, is used, where the bus bars are electrically isolated and spaced to reduce inductance and noise, and an insulating housing encloses the input section to minimize noise pickup, with the positive bus bar nested within the negative bus bar and both being secured with an insulating material to reduce noise and enhance performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If traditional DC bus bar design is used, then the structure is simple, but noise pickup and inductance increase
Solution Approach 1:
The positive and negative bus bars are nested within each other, with the positive bus bar positioned inside the negative bus bar. This nested configuration reduces the loop area for current flow, minimizing stray fields and noise pickup while maintaining a compact structure.
Solution Approach 2:
The bus bars are arranged in a three-dimensional nested configuration rather than a simple planar layout. The input tabs extend in one direction while output tabs extend normally to the bar body, creating a multi-dimensional arrangement that reduces inductance and noise.
2Loss of energy
If bus bars are spaced apart to reduce inductance, then inductance decreases, but the space required increases
Solution Approach 1:
By nesting the positive bus bar within the negative bus bar, the design achieves optimal spacing for reduced inductance without increasing the overall volume. The nested arrangement allows the bus bars to be closely spaced while maintaining the electrical separation needed to minimize inductance.
Solution Approach 2:
The three-dimensional nested arrangement optimizes the spatial relationship between bus bars, achieving low inductance through vertical stacking rather than horizontal spreading. This reduces the assembly volume compared to traditional side-by-side configurations.
3Object-affected harmful factors
If insulating housing encloses the bus bars, then noise pickup is reduced, but manufacturing complexity increases
Solution Approach 1:
The nested bus bar configuration creates a compact, self-contained structure that simplifies the insulating housing design. The housing only needs to enclose the nested arrangement rather than accommodate a larger, more complex bus bar layout, reducing manufacturing complexity.
Solution Approach 2:
The insulating housing integrates with the nested bus bar structure to form a unified assembly. The housing simultaneously provides electrical insulation, mechanical support, and noise shielding, combining multiple functions into a single manufactured component.
Data Source
AI summary
Power inverter assemblies are provided herein for use with motor vehicles. An inverter assembly may have a symmetrical structure configured to convert DC input power to AC output power. The inverter assembly may include a housing enclosing a symmetrical DC input portion, a symmetrical AC output portion, a DC link capacitor, and a gate drive portion having a pair of power modules. The symmetrical DC input portion can include a DC input bus bar sub-assembly to which the DC link capacitor is coupled, and a second DC bus bar sub-assembly that may electrically couple the DC link capacitor with the power modules. The symmetrical AC output portion may include a three phase output AC bus bar sub-assembly to which the power modules can be electrically coupled. A cooling sub-assembly may be provided for cooling the power modules with fluid transfer using a coolant.