Gate Insulating Layer Damage Prediction in Power Semiconductor Switching Elements
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Solution Overview
Problem
Power semiconductor switching elements in AC-DC and DC-DC converters face damage due to high current driving capacity, leading to gate voltage overshoots and undershoots, which accumulate damage in the gate insulating layer, potentially causing element destruction without predictive measures.
Innovation Solution
A damage predicting device is implemented, comprising a resistor connected to the gate of the power semiconductor switching element and control circuitry that compares a detection voltage to a reference voltage to predict damage accumulation in the gate insulating layer, using a potential difference detecting circuit and microcomputer to adjust switching signal periods and prevent damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If power semiconductor switching element is used with large current driving capacity, then productivity and power conversion capability are improved, but gate voltage ringing and overshoot occur causing damage accumulation in gate insulating layer
Solution Approach 1:
The patent applies preliminary action by detecting the leak current flowing through the gate insulating layer before catastrophic failure occurs. The detection circuit continuously monitors the gate-source leak current, and when it exceeds a predetermined threshold, the system predicts impending gate breakdown and takes preventive action by stopping switching operations, thus preventing complete element destruction
Solution Approach 2:
The patent implements feedback by using the detected gate leak current as a diagnostic parameter. The control circuitry compares the detected leak current against a reference threshold and uses this feedback information to predict gate insulating layer damage and adjust switching element operation accordingly, creating a closed-loop protection mechanism
2Loss of energy
If gate voltage is monitored to reduce switching loss and noise, then energy efficiency is improved, but predictive capability of gate insulating layer damage is not achieved
Solution Approach 1:
The patent replaces conventional voltage-based monitoring with a current-based detection system. Instead of measuring gate voltage to infer switching conditions, the system directly measures the leak current flowing through the gate insulating layer, substituting voltage measurement with a more informative current measurement that directly indicates insulating layer degradation
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The device effectively predicts and prevents damage to the power semiconductor switching elements, ensuring the longevity and reliability of AC-DC and DC-DC converters by accurately monitoring and controlling the gate voltage to prevent excessive stress on the gate insulating layer.
Implementation Method 1
a resistor (109) connected to a gate (108g) of the power semiconductor switching element (108)... a detection voltage VDET matching a voltage generated between two ends of the resistor (109)
Data Source
AI summary
A damage predicting device of a power semiconductor switching element includes a resistor connected to a gate of the power semiconductor switching element, and control circuitry. The control circuitry compares a detection voltage matching a voltage generated between two ends of the resistor and a reference voltage, and predicts that predetermined damage has been accumulated in a gate insulating layer in the power semiconductor switching element when the detection voltage exceeds the reference voltage.