Modular DC Bus Connector System for Power Converters

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Solution Overview

Problem

Current systems for connecting multiple power converters sharing a DC bus are complex and require trained technicians for installation and maintenance, especially when more than two converters are involved, as they necessitate securing multiple conductors in series, which complicates the process.

Innovation Solution

A connector system comprising DC bus stabs and connector assemblies with bus bar assemblies that establish a shared DC bus link between power converters, featuring plug portions, mounting portions, and non-conductive housings to facilitate easy and modular connections, allowing for a fast and safe connection between DC busses of different power converters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple conductors are secured in series to connect power converters sharing a DC bus, then the electrical connection is established, but the installation and maintenance complexity increases significantly

Engineering Contradiction:
Improveelectrical connectionVSAvoidinstallation and maintenance complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple separate conductor connections into a single integrated bus bar assembly. The bus bar assembly includes multiple conductive elements (first bus bar, second bus bar, third bus bar, fourth bus bar) that are pre-assembled and connected to the connector assembly as one unit, eliminating the need to individually secure multiple conductors in series during installation.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent divides the connection system into modular components: DC bus stabs mounted on PCBs within individual power converters, connector assemblies with receptacles, and a separate bus bar assembly. This segmentation allows each component to be prepared independently and connected through a simple plugging operation, reducing installation complexity.

Inventive Principle:
Principle #1Segmentation

2Reliability

If trained technicians are required for installation and maintenance of multiple power converters sharing DC bus, then proper connection is ensured, but the time and cost for installation and maintenance increases

Engineering Contradiction:
Improveconnection qualityVSAvoidinstallation and maintenance time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The connector assembly and bus bar assembly are designed with self-aligning features and intuitive mating interfaces. The connector assembly includes a housing with receptacles that guide the bus bar assembly into proper alignment during insertion, allowing technicians to perform connections without extensive training on complex wiring procedures.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The bus bar assembly is pre-assembled with all conductive elements and connections prepared before installation. The first bus bar is connected to the first receptacle, the second bus bar to the second receptacle, and the third and fourth bus bars to the third receptacle, all pre-configured in the bus bar assembly. This preliminary preparation eliminates the need for technicians to perform complex wiring operations on-site.

Inventive Principle:
Principle #10Preliminary action

3Strength

If screw clamps or bolt holes are used to secure conductors to power converters, then mechanical connection strength is achieved, but the number of components and assembly steps increases

Engineering Contradiction:
Improvemechanical connection strengthVSAvoidnumber of components and assembly steps
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent replaces traditional mechanical fastening methods (screw clamps, bolt holes requiring separate lugs and conductors) with a plug-and-receptacle mating system. The bus bar assembly plugs directly into the connector assembly receptacles, establishing both mechanical and electrical connections in a single operation without requiring separate fastening components.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Reliability

If multiple conductors are chained in series between power converters, then power distribution is achieved, but the safety risks increase due to exposed conductors

Engineering Contradiction:
Improvepower distributionVSAvoidsafety risks from exposed conductors
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent combines multiple exposed conductors into a single enclosed bus bar assembly that is housed within a non-conductive housing. The housing encloses the conductive elements (first bus bar, second bus bar, third bus bar, fourth bus bar) and provides a safety barrier, eliminating the safety risks associated with exposed conductors while maintaining power distribution functionality.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2858229B1Apparatus for Connecting a Shared DC Bus Link
Publication Date: 2016.12.14 ROCKWELL AUTOMATION TECH INC
  • EP2858229B1 patent drawingFigure 1
  • EP2858229B1 patent drawingFigure 2~3
  • EP2858229B1 patent drawingFigure 4

AI summary

A system for connecting a shared DC bus between multiple power converters is disclosed. The DC bus includes a positive and a negative rail across which the DC voltage is present. A pair of DC bus stabs is mounted to a PCB within the power converter. Each DC bus stab is electrically connected to either the positive or negative rail. A connector assembly is mounted to the housing of the power converter such that a first receptacle engages a plug portion of the DC bus stab. The connector assembly also includes a second receptacle extending to the exterior of the power converter. The connector assembly is positioned on each power converter such that a known distance, or one of a number of known distances, is established between adjacent connector assemblies. A DC bus assembly extends between and is plugged into the second receptacle of the two adjacent connector assemblies.