Power Inverter Busbar Orientation for Noise Reduction
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Solution Overview
Problem
Power inverters used in vehicles generate significant noise, which affects the controllability of electrical motors and can interfere with vehicle auxiliary components like radios, necessitating a reduction in noise-related deterioration and interference.
Innovation Solution
The power inverter design includes a power semiconductor module, control circuit board, driver circuit board, conductive base plate with a fine and long wiring opening, control wiring, and AC busbars arranged perpendicular to the wiring opening, with current sensors and a magnetic core to reduce noise immunity and electromagnetic interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the AC busbar is arranged parallel to the wiring opening portion, then the wiring layout is simplified, but electromagnetic noise increases and noise immunity deteriorates
Solution Approach 1:
The AC busbar is arranged perpendicular to the wiring opening portion rather than parallel, creating an asymmetric layout that minimizes the coupling between the AC busbar and the control wiring. This asymmetric arrangement reduces electromagnetic noise interference while maintaining manufacturing feasibility.
Solution Approach 2:
A conductive base plate is introduced as an intermediary component between the driver circuit board and the control circuit board. The base plate provides a reference potential that shields the control wiring from electromagnetic noise generated by the AC busbar, effectively mediating the interaction between noisy power components and sensitive control circuits.
2Device complexity
If the conductive base plate is removed to reduce component count, then device complexity decreases, but noise immunity and electromagnetic interference protection worsen
Solution Approach 1:
The conductive base plate serves as an intermediary shielding component that provides electromagnetic noise protection. By placing the base plate between the power circuit components and control circuit components, it creates a reference potential barrier that prevents noise coupling, justifying its inclusion despite the increase in component count.
Solution Approach 2:
The conductive base plate, which could be seen as an additional component increasing complexity, actually converts the electromagnetic noise problem into a benefit by providing a controlled reference potential that actively shields sensitive circuits. The base plate transforms the noise environment into a protected environment through its shielding function.
3Stability of the object's composition
If the AC busbar extends parallel to the wiring opening, then the magnetic field distribution is more uniform, but magnetic field leakage to the control circuit board increases
Solution Approach 1:
The AC busbar is positioned perpendicular to the wiring opening portion, creating an asymmetric orientation that minimizes the projection of the busbar's magnetic field onto the control circuit board. This perpendicular arrangement reduces magnetic field leakage to sensitive areas while maintaining adequate uniformity in the power distribution region.
Solution Approach 2:
The conductive base plate acts as an intermediary that provides magnetic shielding between the AC busbar and the control circuit board. The base plate's high permeability material properties redirect magnetic flux lines, preventing leakage to the control circuits while maintaining stable magnetic field distribution in the power circuit region.
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 configuration enhances noise immunity by shortening the induced current detour path, reducing magnetic fields that leak to the control circuit board and minimizing electromagnetic noise, thereby improving the reliability and performance of the power inverter.
Implementation Method 1
a conductive base plate arranged in a space between the driver circuit board and the control circuit board
Implementation Method 2
at least a portion of the AC busbar that faces the wiring opening portion extends in a direction perpendicular to a longitudinal direction of the fine and long wiring opening portion
Implementation Method 3
a power semiconductor device inverting a DC current into an AC current
Implementation Method 4
a control circuit board that outputs a control signal used for controlling the power semiconductor device
Data Source
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AI summary
There is provided a power inverter including a power semiconductor module (300) that includes a power semiconductor device, a control circuit board (20) that outputs a control signal used for controlling the power semiconductor device, a driver circuit board (22) that outputs a driving signal used for driving the power semiconductor device, a conductive metal base plate (11) arranged in a space between the driver circuit board (22) and the control circuit board (20) in which a fine and long opening portion (113) is formed, a wiring (115) that connects the driver circuit board (22) and the control circuit board (20) through the opening portion (113) and delivers the control signal to the driver circuit board (22), and an AC busbar (802) that is arranged on a side opposite to the metal base plate (11) through the driver circuit board (22) and delivers an AC current output from the power semiconductor module (300) to a drive motor, and at least a portion of the AC busbar (802) that faces the opening portion (113) extends in a direction directly running in a longitudinal direction of the fine and long opening portion (113).