Power Converter Bus Bar Layout for Cooler, Low-Inductance Gate Circuits
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Solution Overview
Problem
In low-floor power conversion devices for electric railway vehicles, the limited height space poses challenges in placing bus bars away from the gate circuit board, leading to increased temperatures and potential malfunctions due to heat confinement, and the configuration of main circuit current wires orthogonal to air flow results in increased inductance and overshoot voltage issues.
Innovation Solution
The power conversion device separates the bus bar from the drive circuit board, positions the bus bars adjacent to each other to reduce mutual inductance, and configures the main circuit current passage width to match the power module's long-side direction, allowing for efficient heat dissipation and reduced noise interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If bus bars are placed close to the gate circuit board to reduce size, then packaging density is improved, but temperature rise of components on the gate circuit board increases due to heat confinement
Solution Approach 1:
The patent transitions from vertical stacking (bus bar above capacitor) to horizontal arrangement (bus bar adjacent to capacitor with side-by-side configuration). This dimensional change allows heat dissipation in lateral directions rather than being confined vertically, reducing temperature rise while maintaining compact packaging density.
Solution Approach 2:
The gate circuit board is extracted and positioned away from the bus bar and capacitor assembly, isolating it from heat-generating components. This separation removes the gate circuit board from the heat confinement zone, allowing it to operate at lower temperatures while the overall device maintains compact dimensions.
2Object-affected harmful factors
If main circuit current wires are configured orthogonal to air flow to reduce noise interference, then electromagnetic noise is reduced, but inductance increases leading to higher overshoot voltage
Solution Approach 1:
The patent changes the geometric parameters of the current passage by increasing its width in the air flow direction. This parameter modification reduces inductance (L ∝ length/width), thereby reducing overshoot voltage, while maintaining the orthogonal configuration to preserve noise reduction benefits.
Solution Approach 2:
The patent applies different configurations to different parts of the bus bar structure: the main circuit current passage is widened locally where it intersects with air flow, while other sections maintain the orthogonal arrangement for noise reduction. This localized optimization balances both requirements.
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 minimizes heat-induced malfunctions, reduces noise interference, and suppresses overshoot voltage, enabling compact, high-density packaging while maintaining component reliability.
Implementation Method 1
heat dissipation with a reduction in size
Implementation Method 2
heat generating component that is a self-heating component
Implementation Method 3
tempering air passing between the cooling fins of a cooler
Implementation Method 4
a high magnetic field is generated due to a large electric current
Implementation Method 5
a base placed below the lower side of the semiconductor device isolates a filter capacitor from a gate circuit
Data Source
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AI summary
In a high-density mounting small power conversion device in which a distance between a bus bar and a drive circuit board in reduced, the driving circuit board receives a blast of heat from the bus bar. Heat buildup due to self-heating of the drive circuit board is generated by mounting a capacitor on the upper side in close proximity to the drive circuit board. These factors cause a problem such as a malfunction or life reduction of the drive circuit board. To cope with this, in a cooler for cooling a 2in1 power module, a plurality of 2in1 power modules are arranged side by side in the vertical direction, which is the longitudinal direction of the 2in1 power modules, bus bars connected to the 2in1 power modules are arranged on one sides in the transverse direction of the 2in1 power modules, and control signal lines connected to the 2in1 power modules are arranged, together with a drive circuit board for sending a control signal to the control signal lines, on the opposite sides of the one sides in the transverse direction of the 2in1 power modules.