Integrated IGBT Module Reducing Surge Voltage in Multi-Level Converters

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Solution Overview

Problem

In multi-level power conversion systems, long wires between semiconductor modules and the direct current power source increase wire inductance, leading to excessive surge voltages when IGBTs switch, necessitating high-voltage-rated components, larger module sizes, and higher costs.

Innovation Solution

The power semiconductor module integrates a first IGBT with a reverse parallel diode and a second IGBT or diode with reverse blocking voltage in a single package, with external terminals for collector and emitter connections, reducing wire inductance and allowing for low-voltage-rated chip usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If long wires are used to connect semiconductor modules to the direct current power source, then the modules can be positioned flexibly, but wire inductance increases causing excessive surge voltages

Engineering Contradiction:

Improvemodule positioning flexibilityVSAvoidsurge voltage

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent merges the IGBT and diode into a single integrated module package, allowing the module to be positioned directly adjacent to the direct current power source. This eliminates long connecting wires and their associated inductance, thereby preventing excessive surge voltages during switching operations while maintaining positioning flexibility.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The integrated module package serves as an intermediary that directly interfaces with the direct current power source terminals. By incorporating both the IGBT and diode within the same package that connects to the power source, the design eliminates the need for separate wire connections, thus reducing inductance and surge voltage effects.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If high-voltage-rated IGBTs and diodes are used to handle surge voltages, then switching reliability is maintained, but module size and cost increase

Engineering Contradiction:

Improveswitching reliabilityVSAvoidmodule size

Core Design Contradiction:

ReliabilityVSVolume of moving object

Solution Approach 1:

The patent extracts the surge voltage problem from the component selection requirement by removing the source of surge voltages (long wires and their inductance) from the system. This allows the use of standard-voltage-rated IGBTs and diodes without requiring high-voltage components, thereby reducing module size and cost while maintaining switching reliability.

Inventive Principle:

Principle #2Taking out (Extraction)

3Volume of moving object

If standard-voltage-rated IGBTs and diodes are used, then module size and cost are reduced, but surge voltages cause switching failures

Engineering Contradiction:

Improvemodule sizeVSAvoidswitching reliability

Core Design Contradiction:

Volume of moving objectVSReliability

Solution Approach 1:

The patent takes preliminary action by integrating the IGBT and diode into a single package and positioning it directly at the power source terminals before switching operations occur. This pre-positioning eliminates the inductance that would otherwise cause surge voltages during switching, allowing standard-voltage-rated components to operate reliably without failure.

Inventive Principle:

Principle #10Preliminary action

4Adaptability or versatility

If multiple separate modules are used to configure phase arms and bidirectional switches, then circuit functionality is achieved, but wire length and inductance increase

Engineering Contradiction:

Improvecircuit functionalityVSAvoidwire length

Core Design Contradiction:

Adaptability or versatilityVSLength of stationary object

Solution Approach 1:

The patent combines multiple functional elements (IGBT, diode, and connection terminals) into a single integrated module package. This merging reduces the number of separate components and their associated wire connections, thereby minimizing total wire length and reducing cumulative inductance while maintaining all necessary circuit functionalities for phase arms and bidirectional switches.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS9130476B2Power semiconductor device and power conversion system using the device

Publication Date: 2015.09.08 FUJI ELECTRIC CO LTD

AI summary

Aspects of the invention are related to a power semiconductor module applied to a multi-level converter circuit with three or more levels of voltage waveform. Aspects of the invention can include a first IGBT to which a diode is reverse parallel connected and a second IGBT having reverse blocking voltage whose emitter is connected to the emitter of the first IGBT are housed in one package, and each of the collector of the first IGBT, the collector of the second IGBT, and the connection points of the emitter of the first IGBT and the emitter of the second IGBT, is an external terminal.