Power Module Short-Circuit Protection via Series MOSFET Switch
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Solution Overview
Problem
Conventional power modules lack protection functions to instantly interrupt short-circuit currents, leading to rapid temperature increases and difficulties in detecting and addressing individual short-circuit failures in multiple module systems.
Innovation Solution
A power module design that includes a power semiconductor device, a detection mechanism for monitoring its operation state, and a current-interrupting switch connected in series, which can be controlled to interrupt the current upon detection of a short-circuit failure, preventing radical temperature rises.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fuse is used to prevent overcurrent in external circuits, then overcurrent protection is provided, but the circuit cannot be interrupted instantly and individual module protection is not achieved
Solution Approach 1:
The invention divides the protection function into individual modules, with each power module containing its own current-interrupting switch and control circuit. This segmentation allows each module to independently detect and respond to short-circuit failures, enabling instant interruption of short-circuit current within that specific module without affecting other modules or requiring external fuse intervention.
2Reliability
If detection means is added to detect power semiconductor device operation state, then short-circuit failure detection is enabled, but device complexity increases
Solution Approach 1:
The invention merges the detection means, control circuit, and current-interrupting switch into an integrated protection system within each power module. The control circuit receives detection signals from the power semiconductor device and directly controls the current-interrupting switch, creating a self-contained protection mechanism that, while adding components, provides essential safety functionality and enables individual module protection.
Data Source
AI summary
When a short-circuit failure has occurred in a power semiconductor device provided in a power module, a radical and rapid temperature increase is prevented by instantly interrupting a short-circuit current. A power module 10 has a package 10a. Provided in the package 10a are: a MOSFET 21 serving as the power semiconductor device; a resistor 23 serving as a detecting means for detecting an operation state of the MOSFET 21 and outputting a detection signal; and a MOSFET 22 serving as a current-interrupting purpose switch connected in series to the MOSFET 21. In response to a control signal Si2 generated on the basis of the detection signal, the MOSFET 22 goes into a conduction state during a normal operation of the MOSFET 21 and goes into an interruption state so as to interrupt a current flowing in the MOSFET 21 when a short-circuit failure has occurred in the MOSFET 21.