Abstract:
Background Pulse thyristors operate under high-current pulse conditions, where repeated combined electromagnetic and thermal stresses cause localised overheating. This leads to electrothermal erosion of the aluminum layer, accelerating thermal fatigue failure of the thyristor.
Purpose This study aims to establish an electrothermal characterization model to evaluate the electro-erosion effect, thereby providing reliable technical support for the quantitative assessment of pulse thyristor electrical erosion failures.
Methods A micro-scale contact interface electrothermal characteristic characterization model for pulse thyristors was established. This model comprehensively considers factors such as surface roughness, applied pressure, electrode patterns, and carrier diffusion, and was simulated under pulsed operating conditions. Furthermore, an accelerated aging test for thyristor electro-erosion was designed to validate the simulation's accuracy.
Results Experimental observations revealed that after 140 repeated discharges, significant aluminum layer erosion appeared on the outer ring of the switch anode surface. When the discharge cycles reached 400, silicon pits emerged closer to the gate position.
Conclusions The experimental results successfully validated the model's predictive accuracy regarding the failure mechanisms of electrical erosion. This proposed model provides reliable technical support for the quantitative assessment of pulse thyristor electrical erosion failures.
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