Desaturation Detection Diode Integration for Low-Inductance Power Modules
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional desaturation detection systems for power electronic switches face challenges with high voltage cables leading to increased parasitic inductance and reliability issues, particularly for high voltage switches, where silicon carbide diodes with low reverse recovery times but high current ratings are bulky and not easily integrated within gate driver circuits.
Innovation Solution
A power electronic module design featuring a discrete driver module coupled to a switch module with a desaturation detection diode, where the diode is coupled to the switching connection of a power semiconductor switch, allowing for a voltage signal to be obtained and the switch to be turned off when the signal exceeds a threshold, reducing the need for high voltage cables and enhancing reliability by using a low voltage signal of less than or equal to seventy volts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional high voltage cables are used to connect the gate driver circuit to the power switch module, then the desaturation detection system can function, but parasitic inductance increases and reliability deteriorates
Solution Approach 1:
The patent extracts the high voltage cable from the system by integrating the desaturation detection diode directly into the power switch module. This eliminates the need for external high voltage cables to carry desaturation signals, thereby removing the source of parasitic inductance and improving reliability.
Solution Approach 2:
The patent merges the desaturation detection diode with the power switch module into a single integrated package. This combining of components eliminates separate high voltage connections and reduces the overall system complexity, directly addressing the reliability and parasitic inductance issues.
2Speed
If silicon carbide diodes are used for desaturation detection in high voltage switches, then reverse recovery time is reduced, but current ratings become greater than five amperes and the diodes become bulky
Solution Approach 1:
The patent applies local quality by using a silicon carbide diode specifically for desaturation detection only when and where needed, rather than using it for all power handling applications. The diode is configured to handle only the small desaturation detection current (typically 10-20mA), allowing the use of a compact package that would be insufficient for full power current but adequate for detection purposes.
Solution Approach 2:
The patent employs partial action by using the silicon carbide diode's capabilities only to the extent needed for desaturation detection. The diode is not required to handle full power current, only the small detection current, which allows the use of a smaller, more compact package than would be required for full power applications.
3Device complexity
If desaturation detection diodes are integrated within the gate driver circuit, then the system can be compact, but high voltage cables are still required and parasitic inductance remains
Solution Approach 1:
The patent merges the desaturation detection diode with the power switch module rather than keeping it separate in the gate driver circuit. This integration eliminates the need for external high voltage cables and their associated parasitic inductance, while maintaining compactness through the unified package design.
Solution Approach 2:
The patent extracts the high voltage cable requirement from the system architecture by placing the detection diode inside the power switch module. This removes the need for external high voltage connections for desaturation detection, eliminating parasitic inductance while preserving circuit integration benefits.
Data Source
AI summary
A power electronic module includes: a switch module including a desaturation detection diode and a power semiconductor switch, and wherein the desaturation detection diode is coupled to a switching connection of the power semiconductor switch; and a driver module coupled to the switch module, wherein the driver module is configured for obtaining a voltage signal across the desaturation detection diode and the power semiconductor switch and configured for turning off the power semiconductor switch upon the voltage signal exceeding a threshold. In one example, the driver module is discrete from the switch module. In another example, the switch module and driver modules are configured to respectively provide and receive a voltage signal of less than or equal to seventy volts.