Insulation Degradation Analysis Due to Thermo-Mechanical Stress in Deep-Sea Oil-Filled Motors
Insulation Degradation Analysis Due to Thermo-Mechanical Stress in Deep-Sea Oil-Filled Motors
复制标题
深海充油电机热机械应力导致的绝缘劣化分析
作者：
Jian Zhang;Rui Wang;Youtong Fang;Yuan Lin
随着电机在深海勘探中的广泛应用，对深海电机的功率密度和寿命提出了更高的要求。电机的寿命主要取决于定子绝缘上的热机械应力(TMS)负荷。与普通发动机不同，深海发动机通常充油以补偿海水产生的高压，这会导致高附加粘性阻力损失。再加上高压，将极大地改变TMS的分布，并进一步影响电机的绝缘寿命。因此，对深海充油(DSOF)电机的TMS引起的绝缘劣化分析就显得尤为重要。本文提出了一种考虑高压和电机温度共同作用的DSOF电机绝缘的TMS分析模型。采用CFD方法对电机进行热分析，考虑了温度对粘性阻力损失的影响。采用有限元方法进行了热力分析，验证了分析模型的准确性。采用雨流计数法和Miner疲劳法对电机进行寿命评估。结果表明，与正常工作环境下的电机相比，由于高压的作用，DSOF电机绝缘上的TMS可降低59.5%，绝缘寿命可提高16.02%。因此，本研究可为高功率密度DSOF电机的设计提供参考。
With the wide application of motors in deep sea exploration, deep-sea motors require a higher power density and a longer lifetime. Motor lifetime mainly depends on the thermo-mechanical stress (TMS) load on its stator insulation. Unlike normal motors, deep-sea motors are usually filled with oil to compensate for the high pressure generated by seawater, which leads to high additional viscous drag loss. This, combined with the high pressure, will greatly change the TMS distribution and further influence motor insulation lifetime. Thus, the insulation degradation analysis of deep-sea oil-filled (DSOF) motors due to TMS has become important. This paper presents a TMS analytical model of DSOF motor insulation, considering the joint effects of high pressure and motor temperature. The CFD method is adopted to perform motor thermal analysis, considering temperature effects on viscous drag loss. The FEA method is adopted for thermo-mechanical analysis and to verify the analytical model accuracy. Rainflow counting and the Miner fatigue method are adopted to evaluate motor lifetime. Results show that compared with motors working in normal environments, TMS on DSOF motor insulation can be reduced by up to 59.5% due to high pressure and the insulation lifetime can be increased by up to 16.02%. Therefore, this research can provide references for high power density DSOF motor design.