浪涌负荷条件下银氧化锡触点材料电性能的实验研究

发布时间：2018-07-10 01:31

本文选题：浪涌负荷 + 银氧化锡触点　；参考：《哈尔滨工业大学》2017年硕士论文

【摘要】：触点是低压电器内完成信号导通和分断功能的直接执行部分,其在浪涌负荷条件下电性能的加速退化及诱发的动熔焊失效现象已成为影响电器寿命和可靠性的关键。作为低压电器领域用途最广、用量最大的贵金属功能材料,银氧化锡在浪涌负荷条件下的电性能和抗浪涌能力一直受到多方关注。本文以开发的新型触点材料电性能模拟实验系统为基础,进而实验研究了浪涌负荷条件下银氧化锡触点材料电性能基本特征、退化过程和熔焊失效物理机制。首先,设计并实现了一种新型两工位触点材料电性能模拟实验系统。通过设计的机械机构实现了推杆作用点、空程、超程和触点开距等机械参数的调节;以电磁铁实现触点分合运动的模拟;开发的硬件测试电路实现了触点力和电参数的同步实时测量;基于LabVIEW开发的操作软件实现了回跳时间、回跳能量、燃弧能量等电性能综合参数的计算、显示和存储。其次,结合容性负载条件下触点闭合过程和分断过程的触点电压和触点电流的典型波形,对实验电路和典型波形进行了理论分析,建立了电路暂态过程的数学模型;进而分析了浪涌电流峰值、浪涌时间等参数对触点分合过程电气特性的影响。接着,实验研究了耐久性电寿命实验过程中银氧化锡触点回跳能量、静压力、燃弧能量等电性能敏感参数的退化过程,总结了各电性能敏感参数的退化规律,分析了其发生退化的原因和物理机制。最后,改变负载性质、负载电容和触点开距等因素,实验研究了银氧化锡触点动熔焊失效现象,总结归纳了触点发生动熔焊失效时电性能敏感参数的主要特征表现,结合触点表面微观形貌特征与元素分布状态,阐述了触点发生动熔焊的物理过程和失效机理。本研究可为触点材料电性能的科学评价与优化改进提供实验手段,对于低压电器的长寿命设计和接触失效分析亦具有实用价值。
[Abstract]:The contact is the direct executive part of the signal conduction and breaking function in the low voltage electrical apparatus. The accelerated degradation of electrical performance and the induced dynamic welding failure under surge load have become the key to affect the life and reliability of electrical apparatus. As the most widely used and used noble metal functional materials in the field of low-voltage electrical appliances, the electrical properties and anti-surge ability of silver tin oxide under surge load have been paid much attention to. Based on a new type of contact material electrical performance simulation experimental system, the basic characteristics of electrical properties, degradation process and the physical mechanism of welding failure of silver tin oxide contact materials under surge load are studied experimentally in this paper. First, a new two-position contact material electrical performance simulation system is designed and implemented. Through the designed mechanical mechanism, the mechanical parameters such as the action point of the push rod, the space range, the overrun range and the contact opening distance are adjusted, and the electromagnet is used to simulate the movement of the contact points. The hardware test circuit realizes the synchronous real-time measurement of contact force and electrical parameters, and the operation software based on LabVIEW realizes the calculation, display and storage of the comprehensive parameters of electrical performance, such as rebound time, rebound energy, arc burning energy, etc. Secondly, combined with the typical waveform of contact voltage and current in capacitive load, the experimental circuit and typical waveform are analyzed theoretically, and the mathematical model of circuit transient process is established. Furthermore, the influence of peak surge current and surge time on the electrical characteristics of the contact is analyzed. Then, the degradation process of sensitive parameters of silver tin oxide contacts, such as rebound energy, static pressure, arc energy and so on, is studied, and the degradation laws of these sensitive parameters are summarized. The causes and physical mechanism of its degradation are analyzed. Finally, by changing the load property, load capacitance and contact distance, the failure phenomenon of silver tin oxide contact dynamic fusion welding is studied experimentally, and the main characteristics of electrical property sensitive parameters when contact failure occurs are summarized. The physical process and failure mechanism of contact dynamic fusion welding are described in combination with the microcosmic morphology of contact surface and the distribution of elements. This study can provide experimental means for scientific evaluation and optimization improvement of electrical properties of contact materials, and also has practical value for long life design and contact failure analysis of low voltage electrical appliances.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM24

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