研究目的
To obtain a better understanding of the failure phenomenon under high current impulse with short duration and to draw conclusions about varistor design and manufacture.
研究成果
The electro-thermal-mechanical model for ZnO varistor in response to a high current impulse can reflect nonuniform current distribution and explain factors affecting temperature and stress distribution. The model offers a new perspective about failure modes, especially cracking, and can be used to optimize the design of ZnO varistor.
研究不足
The model assumes top and bottom surfaces of the varistor model to be fixed and neglects heat transfer from ZnO varistor to the surroundings due to the short duration of the current impulse. The simulation also assumes a linear increase in current distribution from the center to the edge of the varistor model.
1：Experimental Design and Method Selection:
The study uses finite element method for electro-thermal-mechanical simulation of a ZnO varistor exposed to a 4/10μs current impulse.
2：Sample Selection and Data Sources:
Five samples of the distribution class varistor from the same company were applied to one 4/10μs current impulse with the value of 65kA.
3：List of Experimental Equipment and Materials:
The experimental setup includes a thermal infrared imager, impulse current generator, voltage divider, current divider, and oscilloscope.
4：Experimental Procedures and Operational Workflow:
The varistor samples were subjected to a 4/10μs current impulse, and temperature change was recorded by the thermal infrared imager.
5：Data Analysis Methods:
The simulation results of temperature and stress distribution were analyzed to discuss the effects of the magnitude of current, the diameter, and the degree of inhomogeneity on the performance of varistors.
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容
