Lifetime Estimation of DC-Link Capacitors in Adjustable Speed Drives Under Grid Voltage Unbalances
Lifetime Estimation of DC-Link Capacitors in Adjustable Speed Drives Under Grid Voltage Unbalances
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DOI：
10.1109/tpel.2018.2863701
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发表时间：
2019-05
影响因子：
6.7
通讯作者：
Haoran Wang;P. Davari;Huai Wang;D. Kumar;Firuz Zare;F. Blaabjerg
中科院分区：
文献类型：
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作者：
Haoran Wang;P. Davari;Huai Wang;D. Kumar;Firuz Zare;F. Blaabjerg
带直流侧电感的电解电容是并网二极管整流调速驱动器（asd）中典型的直流链路滤波配置。确定直流滤波器尺寸的标准主要从稳定性和电能质量两个方面来考虑。然而，直流链路滤波器的可靠性也是一个需要考虑的重要性能因素，这取决于组件的固有能力和现场操作条件（例如电热应力）。目前，在许多配电网中，电压不平衡是最常见的现象。它给元件带来更大的电热应力，影响电容器的可靠性。为了定量研究ASD系统中LC滤波器的可靠性性能，提出了一种基于任务剖面的电容器可靠性评估方法。与传统的寿命估计不同，考虑到等效串联电阻生长和退化过程中电容减小的非线性过程，提出了一种非线性累积损伤模型进行长期估计。基于所提出的寿命估计方法，研究了四个案例：首先，对LC滤波和薄电容滤波配置中的电容器进行寿命基准测试；其次，从系统额定功率和电网不平衡水平两方面分析了电容器寿命的可扩展性；第三，具有长期任务剖面的直流链路滤波器电容器寿命估计；第四，在电网平衡和电网不平衡条件下，电容器尺寸对直流链路电容器寿命的影响。结果可作为正确选择直流链路配置和参数以满足asd规范的指南。
Electrolytic capacitor with a dc-side inductor is a typical dc-link filtering configuration in grid-connected diode rectified adjustable speed drives (ASDs). The criteria to size the dc-link filter are mainly from the aspects of stability and power quality. Nevertheless, the reliability of the dc-link filter is also an essential performance factor to be considered, which depends on both the component inherent capability and the operational conditions (e.g., electrothermal stresses) in the field operation. Nowadays, unbalanced voltage has the most frequent occurrence in many distribution networks. It brings more electrical-thermal stress to the component, affecting the reliability of the capacitors. In order to study the reliability performance of the LC filter in an ASD system quantitatively, this paper proposes a mission profile based reliability evaluation method for capacitors. Different from the conventional lifetime estimation, a nonlinear accumulated damage model is proposed for the long-term estimation, considering the nonlinear process of equivalent series resistor growth and capacitance reduction during the degradation. Based on the proposed lifetime estimation procedure, four case studies are investigated: first, lifetime benchmarking of capacitors in LC filtering and slim capacitor filtering configurations; second, scalability analysis for the lifetime of capacitors in terms of system power rating and grid-unbalanced levels; third, lifetime estimation of capacitors in the dc-link filter with long-term mission profile; and fourth, the impact of the capacitor sizing on the lifetime of the dc-link capacitor under grid-balanced and grid-unbalanced conditions. The results serve as a guideline for proper selection of dc-link configurations and parameters to fulfill a specification in ASDs.