Three-Level NPC Power Module Layout for Low-Inductance WBG Inverters
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power modules, particularly those based on traditional silicon devices, face issues with high power loop inductance, high gate loop inductance, and excessive heat generation, which are unsuitable for wide-band-gap (WBG) devices used in electric vehicle propulsion systems.
Innovation Solution
The implementation of three-level neutral point clamped (NPC) power modules with ultra-fast WBG semiconductors like gallium nitride (GaN), featuring low power-loop inductance, low gate-drive-loop inductance, symmetrical layout, distributed terminals, decoupling capacitors, and double-sided cooling, along with mechanical robustness and flexible PCB interconnections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional silicon devices are used in power modules, then the device structure is well-established and manufacturable, but the power loop inductance and gate loop inductance are high, and excessive heat is generated
Solution Approach 1:
The patent transitions from traditional silicon devices to wide band gap (WBG) devices such as GaN and SiC, fundamentally changing the material parameter to achieve lower power loop inductance and gate loop inductance while maintaining manufacturability through adapted fabrication processes
Solution Approach 2:
The patent employs hybrid material structures combining WBG semiconductors with optimized substrate materials and packaging components to create a composite power module that achieves low inductance while remaining manufacturable
2Ease of manufacture
If traditional silicon devices are used in power modules, then the device structure is well-established and manufacturable, but excessive heat is generated during operation
Solution Approach 1:
The patent changes the material parameter from silicon to wide band gap materials (GaN, SiC) which inherently operate at higher temperatures with lower losses, reducing heat generation while maintaining manufacturability through established WBG fabrication processes
Solution Approach 2:
The patent replaces the thermal management requirements of traditional silicon devices with a cooling system design optimized for WBG devices, substituting the need for extensive heat dissipation infrastructure with more efficient thermal management approaches
3Ease of manufacture
If existing power module structures are used, then the design is simple and manufacturable, but the structure is not optimal for WBG based power modules
Solution Approach 1:
The patent segments the power module into distinct functional layers including WBG device layer, substrate layer, and packaging layer, allowing each segment to be optimized for WBG devices while maintaining overall manufacturing simplicity through modular assembly
Solution Approach 2:
The patent transitions from planar two-dimensional layouts to three-dimensional vertical stacking architectures, enabling better utilization of WBG device characteristics while maintaining manufacturability through vertical integration processes
4Reliability
If WBG devices are implemented with optimized low inductance design, then power loop inductance and gate loop inductance are reduced, but the device complexity increases
Solution Approach 1:
The patent merges the power loop and gate loop pathways into a unified packaging structure with shared substrates and interconnects, reducing the number of discrete components and assembly steps while achieving low inductance performance
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 design achieves low power and gate loop inductance, balanced current sharing, and efficient heat dissipation, supporting high-power density and compact designs for electric vehicle traction inverters.
Implementation Method 1
double-sided cooling
Implementation Method 2
double-sided cooling
Data Source
AI summary
A power module comprises: an upper arm structure that includes a first semiconductor switch, a second semiconductor switch and a first diode; a lower arm structure that includes a third semiconductor switch, a fourth semiconductor switch and a second diode; a first gate driving board, attached with the upper arm, wherein the first gate driving board includes a first gate driver connected to a first gate of the first semiconductor switch and a second gate driver connected to a second gate of the second semiconductor switch; a second gate driving board, attached with the lower arm, wherein the second gate driving board includes a third gate driver connected to a third gate of the third semiconductor switch and a fourth gate driver connected to a fourth gate of the fourth semiconductor switch; etc.