Electronic Trip Unit Thermal Failure Prediction for Semiconductor Protection
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Solution Overview
Problem
Existing solid state circuit interrupters struggle to predict thermal failure of semiconductor devices quickly enough to prevent damage, as temperature sensors lag behind current changes during severe fault conditions.
Innovation Solution
A system using a current sensor and an electronic trip unit with a thermal failure prediction module to detect current and voltage changes, enabling faster prediction of thermal failure through Di/Dt protection and other modes to trip the circuit interrupter before damage occurs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If temperature sensors are used to directly measure semiconductor device temperature, then thermal failure detection is achieved, but response time is too slow to prevent damage during severe fault conditions
Solution Approach 1:
The system performs preliminary action by detecting current and voltage changes that precede thermal failure, rather than waiting for temperature to actually rise. The thermal failure prediction module analyzes electrical parameters (current magnitude, rate of change, voltage drops) to predict impending thermal failure before the semiconductor device actually overheats, enabling proactive tripping of the circuit breaker.
Solution Approach 2:
The patent introduces an intermediary approach by using electrical measurements (current and voltage) as mediators to infer thermal conditions. Instead of directly measuring temperature with slow thermal sensors, the system uses fast electrical measurements that correlate with thermal stress, providing an indirect but rapid indication of impending thermal failure.
2Reliability
If multiple sensor types are deployed to improve detection accuracy, then measurement reliability increases, but device complexity increases
Solution Approach 1:
The system applies multi-functionality by using the existing current sensor and voltage measurement circuitry for multiple purposes: normal operation monitoring, fault detection, and thermal failure prediction. The same electrical measurements used for basic circuit protection are also analyzed by the thermal failure prediction module to predict thermal conditions, eliminating the need for separate temperature sensors.
Solution Approach 2:
The existing electrical measurement infrastructure serves itself by providing data for both normal operation and thermal failure prediction. The current and voltage measurements taken for basic circuit monitoring automatically provide the information needed for thermal stress assessment, without requiring additional dedicated measurement systems.
Data Source
AI summary
A system and method are provided for protecting semiconductor components from thermal failure in an electronic circuit interrupter. The electronic trip unit (ETU) is configured to determine what range of current the detected current signal corresponds to, out of several ranges categorized as being either non-fault/normal, non-severe fault, and severe fault. The ETU then selects a mode of operation in which to operate based on the determined range of current. In modes of operation corresponding to a fault condition, the ETU monitors certain characteristics of the current such as magnitude and/or rate of rise, and if the aforementioned current characteristics exceed a specified threshold for a minimum interval of time, the ETU will trip the electronic interrupter. If, however, the aforementioned current characteristics fall below the specified threshold prior to the minimum interval of time elapsing, the ETU will not trip the electronic interrupter.