Triple-Terminal Power Module Electrode Arrangement for Low Inductance

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Solution Overview

Problem

Conventional railway-vehicle three-level power converters using dual-element power modules do not adequately utilize the low-inductance structure, resulting in insufficient contribution to the required low-inductance circuit, which hampers the effective use of dual-element power modules.

Innovation Solution

A three-level power converter configuration utilizing three dual-element power modules with a specific arrangement of electrodes and switching elements, where each module is configured as a triple-terminal module with internal connections reducing inductance within and between modules, forming low-inductance inductance loops.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional dual-element power modules are used with separate diode modules for clamp diodes, then the circuit can be assembled with existing components, but the inductance within the module is not sufficiently reduced

Engineering Contradiction:
Improvelow-inductance circuit performanceVSAvoidmodule configuration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the clamp diodes and switching elements into a single integrated dual-element power module, eliminating the need for separate diode modules. This integration reduces the overall inductance by minimizing the loop area and connection length between components, while maintaining a manageable device complexity through standardized module design.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The power converter is segmented into multiple dual-element power modules, each containing specific switching elements and clamp diodes. This segmentation allows for modular assembly with optimized internal connections, reducing inductance within each module while enabling flexible system configuration.

Inventive Principle:
Principle #1Segmentation

2Productivity

If the low-inductance structure within the module is not optimized, then the module configuration remains simple, but the railway-vehicle three-level power converter cannot sufficiently take advantage of the dual-element power module features

Engineering Contradiction:
Improvepower converter performanceVSAvoidelectrode arrangement complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent employs a three-dimensional electrode arrangement within the dual-element power module, with electrodes positioned at different spatial locations and orientations. This dimensional optimization reduces the current loop area and inductance, enabling the power converter to fully utilize the dual-element module features while maintaining a systematic electrode configuration.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The electrode arrangement is optimized locally within each dual-element power module, with specific electrode positions and connection paths designed to minimize inductance. This local optimization allows the module to deliver high performance while the overall device complexity is managed through standardized module design.

Inventive Principle:
Principle #3Local quality

3Reliability

If separate diode modules are used for clamp diodes, then component assembly is straightforward, but the inductance loops between modules are not minimized

Engineering Contradiction:
Improvelow-inductance circuit configurationVSAvoidmodule assembly ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The clamp diodes are merged with the switching elements within the same dual-element power module, creating an integrated unit with minimized inductance loops. This merging eliminates the need for separate diode module assembly while reducing the overall inductance, and the standardized module design maintains ease of manufacture through modular replacement.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2884650B1Power module comprising two elements, and three-level power conversion device using same
Publication Date: 2018.09.19 MITSUBISHI ELECTRIC CORP
  • EP2884650B1 patent drawingFigure 1
  • EP2884650B1 patent drawingFigure 2~3
  • EP2884650B1 patent drawingFigure 4

AI summary

A first electrode M1 that is connected to a higher-side potential portion of a first element pair 10, a second electrode M2 that is connected to a connection portion between a lower-side potential portion of the first element pair 10 and a higher-side potential portion of a second element pair 12, and a third electrode M3 that is connected to a lower-side potential portion of the second element pair 12, are provided on one of the main-surface sides of a module casing. The first electrode M1 and the third electrode M3 are arrayed in a direction orthogonal to a longitudinal direction of the module casing on one of the end sides in the longitudinal direction. The second electrode M2 is arranged on the other end side in the longitudinal direction of the module casing. Three dual-element triple-terminal power modules with the same configuration, configured as described above, are used to configure a three-level power converter of one phase.