Topological Inverter Switch Using WBG-Silicon Load Segmentation

Solution Overview

Problem

The inefficiency of semiconductor switches in inverters for electric vehicles due to oversized surface areas of wide-bandgap semiconductors, which increases costs and reduces switching efficiency during normal driving modes.

Innovation Solution

A circuit assembly for a topological semiconductor switch in an inverter, where power semiconductors are divided into two groups made of different semiconductor materials. The first group, using WBG materials like SiC or GaN, is optimized for partial-load operations, while the second group, using conventional silicon, is optimized for full-load operations, thereby optimizing surface area and switching speed for efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the surface area of wide-bandgap semiconductors is increased to handle maximum load, then the safe operating area is ensured, but the costs increase and switching efficiency decreases during normal driving modes

Engineering Contradiction:

Improvesafe operating areaVSAvoidswitching efficiency

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The power semiconductor switch is divided into two groups: wide-bandgap semiconductors (SiC/GaN) optimized for partial-load operation and conventional silicon semiconductors optimized for full-load operation. This segmentation allows each group to be sized appropriately for its specific operating condition, preventing the waste of expensive WBG materials during full-load operation while ensuring reliable switching during normal driving modes.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different semiconductor materials are assigned to different operational regimes: WBG materials with their superior switching characteristics are used for partial-load conditions where switching efficiency matters most, while conventional silicon materials are used for full-load conditions where cost-effectiveness is prioritized. This local optimization of material properties resolves the contradiction between reliability and energy loss.

Inventive Principle:

Principle #3Local quality

2Ease of manufacture

If the surface area of wide-bandgap semiconductors is reduced to save costs, then cost-effectiveness improves, but the safe operating area is compromised

Engineering Contradiction:

Improvecost-effectivenessVSAvoidsafe operating area

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The power semiconductor switch is divided into two groups: wide-bandgap semiconductors (SiC/GaN) optimized for partial-load operation and conventional silicon semiconductors optimized for full-load operation. This segmentation allows each group to be sized appropriately for its specific operating condition, preventing the waste of expensive WBG materials during full-load operation while ensuring reliable switching during normal driving modes.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention changes the material parameter (semiconductor type) based on the operating condition parameter (load level). By switching between WBG and conventional silicon materials depending on whether the system is in partial-load or full-load mode, the invention achieves cost-effectiveness while maintaining the safe operating area through the complementary strengths of different semiconductor materials.

Inventive Principle:

Principle #35Parameter changes

3Productivity

If the switching speed is optimized for the design-relevant operating point, then switching efficiency is maximized at that point, but the efficiency is not fully exploited during normal driving modes

Engineering Contradiction:

Improveswitching efficiencyVSAvoidefficiency across operating modes

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The invention implements a dynamic semiconductor configuration where the active semiconductor group changes based on the operating condition. During partial-load operation, WBG semiconductors are activated for high switching efficiency, while during full-load operation, silicon semiconductors take over. This dynamic adaptation allows the system to optimize switching efficiency for each operating mode rather than being constrained to a single design point.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The invention changes the material parameter (semiconductor type) based on the operating condition parameter (load level). By switching between WBG and conventional silicon materials depending on whether the system is in partial-load or full-load mode, the invention achieves cost-effectiveness while maintaining the safe operating area through the complementary strengths of different semiconductor materials.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20250175173A1Circuit arrangement for a topological semiconductor switch of an inverter

Publication Date: 2025.05.29 ZF FRIEDRICHSHAFEN AG

AI summary

A circuit assembly for a topological semiconductor switch in an inverter includes at least two power semiconductors and is subdivided into two groups of power semiconductors made of different semiconductor materials. The first group of power semiconductors is made up of power semiconductors with a wide bandgap. The size of the surface area occupied by the power semiconductors in the first group and/or their switching speed are configured for a load in a partial-load operation. The size of the surface area for the second group of power semiconductors is configured for loads in a full-load operation.