Accelerated Ageing of Metallized Film Capacitors Under High Ripple Currents Combined With a DC Voltage
Accelerated Ageing of Metallized Film Capacitors Under High Ripple Currents Combined With a DC Voltage
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DOI：
10.1109/tpel.2014.2351274
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发表时间：
2015-05-01
影响因子：
6.7
通讯作者：
Joubert, Charles
中科院分区：
文献类型：
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作者：
Makdessi, Maawad;Sari, Ali;Joubert, Charles
金属化薄膜电容器具有高的介电击穿强度、低的耗散系数和在宽频率和温度范围内良好的介电稳定性，是航空应用中非常常用的元件。然而，电容器仍然是不可靠的组件；很好地了解它们随时间的退化将使我们能够对组件执行预测性维护，从而提高整个系统的可用性。此操作需要了解电容器老化规律及其与应用相关的失效机制。在标准的六脉冲整流馈电脉宽调制逆变器中，由于遇到电应力，直流链路电容器通常受到温度梯度的影响。由于传统的浮动老化测试，即在组件上施加恒定的电压和温度，不能反映组件的正常老化，因此我们在本文中建议研究高纹波电流下金属化薄膜电容器的降解动力学，单独或与器件终端上的直流电压相结合。因此，与传统的浮动老化试验相比，它将以更有代表性的方式再现组件的老化。根据谐振电路的特性，专门为本研究开发的老化试验台可从低功率源提供高电流和高电压。通过对高纹波电流作用下电容器参数演化的研究和分析，提出了基于电容器电极电化学腐蚀的原始老化规律来模拟电容随时间的衰减。实验点与模型之间的充分性证明了所提规律的有效性。
In view of their potential for high dielectric breakdown strengths, low dissipation factors, and good dielectric stability over a wide range of frequencies and temperature, metallized films capacitors are very used components for aeronautic applications. Nevertheless, capacitors remain unreliable components; a good acquaintance of their deterioration over time would enable us to perform a predictive maintenance on the component and thus improve the availability of the whole system. This operation requires the knowledge of the capacitor ageing law and their failure mechanisms associated with the application. In a standard six pulses rectifier-fed pulse width modulation inverter, dc-link capacitors are generally subjected to gradients of temperature due to the encountered electrical stresses. Since traditional floating ageing tests, which consist on applying constant voltages and temperature across the component, do not reflect the normal ageing of the component, we propose in this paper to study the degradation kinetics of metallized films capacitors under high ripple currents, alone or combined with a dc voltage across the devices terminals. It will therefore reproduce with a more representative way the ageing of the component in comparison with the traditional floating ageing tests. Based on the resonant circuit properties, the ageing test bench especially developed for our study provides high currents and voltages from a low power source. Through the study and analysis of the capacitors parameters evolution under high ripple currents, an original ageing law is proposed to model the capacitance decrease with time based on the electrochemical corrosion of the capacitors electrodes. The adequacy between the experimental points and the model proved the validity of the proposed law.