Shielded Busbar Casing for Power Converter EMI Suppression
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Solution Overview
Problem
Power converters with busbars built into resin cases experience electromagnetic noise interference, causing malfunctions in circuit boards and peripheral devices due to uncontrolled electromagnetic noise emission.
Innovation Solution
Incorporating a shield layer on the inner or outer surfaces of the casing to cover the built-in busbar portions, which are electrically conductive and grounded, to prevent the propagation and emission of electromagnetic noise through the casing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a busbar is built into a resin case for structural integration, then manufacturing simplicity and structural compactness are improved, but electromagnetic noise interference increases causing malfunctions in circuit boards and peripheral devices
Solution Approach 1:
A shield layer is introduced as an intermediary component between the busbar and the surrounding environment (circuit board and peripheral devices). This shield layer acts as a mediator that blocks electromagnetic noise from propagating, thereby resolving the contradiction between maintaining structural integration and preventing electromagnetic interference.
Solution Approach 2:
A thin film shield layer is applied to the busbar surface. This flexible thin film structure effectively blocks electromagnetic noise while maintaining the compact integrated structure of the busbar within the resin case, thus resolving the contradiction between structural simplicity and electromagnetic shielding.
2Object-affected harmful factors
If a shield layer is added to block electromagnetic noise, then electromagnetic noise interference is reduced, but device complexity and manufacturing steps increase
Solution Approach 1:
Instead of adding complex bulky shielding structures, a thin film shield layer is used. This thin film approach provides effective electromagnetic noise blocking while adding minimal structural complexity and maintaining the compact design of the overall device.
Solution Approach 2:
The shield layer is integrated with the busbar to form a composite structure. This composite material approach combines the conductive properties of the busbar with the shielding properties of the shield layer, achieving electromagnetic noise reduction without significantly increasing device complexity.
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
The shield layers effectively suppress electromagnetic noise interference, reducing noise interference to both internal circuit components and external devices by blocking noise emissions from the busbars, thereby enhancing the reliability of the power converter.
Implementation Method 1
The shield layer is electrically conductive and provided on an inner surface or an outer surface of the casing such that the shield layer covers the built-in portion
Data Source
AI summary
A power converter includes semiconductor modules, a capacitor, a circuit board, a casing, a busbar and a shield layer. The capacitor is electrically connected to the semiconductor modules. The casing accommodates the circuit board, the semiconductor modules and the capacitor. The busbar has an input terminal portion, an output terminal portion and an electric pathway connecting the input terminal portion and the output terminal portion. The electric pathway is connected to at least one of electronic components including the semiconductor modules and the capacitor. The busbar has a built-in portion incorporated into the casing. The shield layer is electrically conductive and provided on an inner surface or an outer surface of the casing such that the shield layer covers the built-in portion.