Electric Vehicle Power Module Sandwich Structure Inductance Cancellation
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Solution Overview
Problem
Existing power modules for electric vehicle drivetrains face challenges in reducing parasitic inductance, which affects efficiency and size, due to the inherent self-inductance of current paths, and existing inverter modules have a large footprint and high inductance due to the arrangement of power modules.
Innovation Solution
A power module design featuring a sandwich structure with overlapping current paths to cancel out self-inductance through mutual inductance, and an inverter module arrangement with power modules positioned in rows on either side of a capacitor to reduce overall inductance and footprint.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional current path arrangement is used in power modules, then electrical connection is achieved, but parasitic inductance increases reducing efficiency
Solution Approach 1:
The patent applies mutual inductance cancellation by arranging current paths such that the magnetic fields generated by adjacent conductors oppose each other. The return current path is positioned to create a magnetic field that cancels the self-inductance of the forward current path, converting the harmful parasitic inductance into a beneficial cancellation effect that reduces overall loop inductance and energy loss.
Solution Approach 2:
The patent transitions from planar current path arrangement to a three-dimensional overlapping configuration. Current paths are arranged in multiple layers with vertical spacing, allowing the return path to be positioned directly above or below the forward path. This dimensional change enables closer coupling and more effective mutual inductance cancellation while maintaining electrical connectivity.
2Area of stationary object
If power modules are arranged in conventional configurations, then electrical functionality is achieved, but footprint area increases
Solution Approach 1:
The patent implements a nested arrangement where power modules are positioned in rows on opposite sides of a central capacitor. The capacitor serves as the core element, with power module rows nested around it in a compact configuration. This nesting approach minimizes the overall footprint by efficiently utilizing the space around the central component while maintaining necessary electrical connections.
Solution Approach 2:
The patent combines multiple functional elements into a compact integrated assembly. The capacitor and power modules are arranged in a unified configuration where the return current paths of adjacent modules overlap and cancel each other's inductance. This merging of functional elements achieves both electrical performance and space efficiency simultaneously.
3Area of stationary object
If power modules are arranged in rows on either side of capacitor, then footprint is reduced, but inductance cancellation requires precise alignment
Solution Approach 1:
The patent incorporates alignment features and pre-configured mounting structures that establish the correct spatial relationship between power modules and the capacitor before final assembly. The modular design includes integrated positioning elements that guide the placement of current paths into the correct overlapping configuration, ensuring proper alignment is achieved during assembly without requiring high-precision manual adjustment.
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 power module design reduces parasitic inductance and the inverter module design achieves a smaller footprint and lower inductance, enhancing efficiency and compactness, thereby improving the performance and packaging of electric vehicle drivetrain systems.
Implementation Method 1
The power loop can have an overall inductance value corresponding to a self-inductance of the first current path and a self-inductance of the second current path subtracted by a mutual inductance value of the overlapping current path
Data Source
AI summary
Provided herein are systems and methods described related to a power module of a drivetrain system of an electric vehicle. The power modules as described herein can include a sandwich structure that reduces a parasitic inductance of the power module through mutual inductance cancellation. For example, the power modules can include at least two current paths that overlap or are formed over each other in a sandwich like formation to form a power loop having an overlapping current path. The power loop can have an overall inductance value corresponding to a self-inductance of the first current path and a self-inductance of the second current path subtracted by a mutual inductance value of the overlapping current path.