直流支撑电容器工作温升特性研究及优化设计

Research and optimization on operating temperature rise of DC-link capacitor

直流支撑电容器作为储能元件,在变流系统中主要起到电压支撑、滤波等作用。在连续工作中,持续的冲击电压、纹波电压及纹波电流加剧了电容器工作温升,严重影响电容器运行的可靠性。以某型号直流支撑电容器为研究对象,搭建了电容器有限元仿真模型,分析了芯子和铜排损耗对电容器工作温升的影响,通过仿真结果与试验结果对比分析验证了仿真模型的正确性。重点研究了铜排功率损耗对电容器工作温升的影响,通过遗传算法对铜排结构参数进行优化设计,设计方案有效降低了电容器内部温升。研究结果表明:当铜排厚度为0.4 mm,铜排宽度为9 mm时,电容器工作温度可以有效降低3.15℃。

As an energy storage component,DC-link capacitor plays the roles such as voltage support and harmonic filtering in converter circuit.During long-term operation,the continuous pulse voltage,rippled voltage and current could cause temperature rise and seriously affect the reliability of the capacitor.Here,a finite element simulation model was built for a type of DC-link capacitor.The effect of the power loss of core and copper busbar was analyzed on the temperature rise of the capacitor.The correctness of the simulation model was verified by comparing the simulation with the experimental results.Emphasis was put on the influence of copper busbar power loss on the working temperature rise of the capacitor.The structure parameters of copper busbar were optimally designed by genetic algorithm,and the proposed optimization scheme can effectively reduce the internal temperature rise of the capacitor.The research results show that when the structural parameters of the copper busbar are d=0.4 mm and w=9 mm,the working temperature of the capacitor could be effectively reduced by 3.15℃.