Influence of parallel wire placement on the AC copper losses in electrical machines
Influence of parallel wire placement on the AC copper losses in electrical machines
复制标题
平行布线对电机交流铜损的影响
DOI：
10.1109/iemdc.2015.7409221
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
E. Nolle
中科院分区：
文献类型：
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作者：
D. Bauer;Paul Mamuschkin;H. Reuss;E. Nolle
由于电动汽车和混合动力汽车的高续航里程和持续功率需求，电机的效率是一个关键参数。本文主要研究了交流铜损耗对循环电流的影响。用于电动和混合动力汽车的永磁电机显示6极对，最大功率为80kW，最大转速为12000 rpm，用于此分析。一般来说，平行的小直径线用于处理任务，并尽量减少皮肤和接近的影响。但在设计过程中，往往没有考虑到由于线束分布不合适而产生的可行环流。此外，由于采用了自动绕线技术，电线的分布往往是未知的。因此，本研究的主要课题是分析基于所述机器的平行线放置的影响，并提出一种测量技术，可用于判断含有未知线放置的自动绕线机器。本研究采用手工绕线的方法，建立了一个好盒和坏盒机，以明确其影响。为了实现高质量的测量，两台机器使用完全相同的转子，大约60个热电偶和一个特定的电流测量系统在每一个平行的一相链。结果表明，测量的损耗相差超过3kW，这意味着在11000 rpm时额外损耗量为65%。观察测量电流，可以清楚地看到频率依赖性。与理想的导线分布相比，在某些股中确定了大约三倍高的电流负载。所以过热和可能的故障是可能的。测量数据被用来验证一个通用的分析模型以及一个瞬态有限元模型。虽然有限元分析与测量结果几乎完全匹配，但分析方法会产生一些偏差，特别是在恶劣的情况下。最后对温度相关损耗标度的研究进行了展望。不同的交流损耗量会产生不同的标度行为。
Due to high range and continious power requirements in electric and hybrid cars the efficiency of electrical machines is one key parameter. In this paper ac copper loss effects, mainly circulating currents, are investigated. A permanent magnet machine used for electric and hybrid cars showing 6 pole pairs, a maximum power of 80kW and a maximum speed of 12000 rpm is used for this analysis. In general parallel strands of small diameter are used to facilitate handling tasks and to minimize skin and proximity effects. But in the design process feasible circulating currents due to unsuitable strand distribution are often not considered. Furthermore the wire distribution is very often unkown due to automatic winding technology. So the main topic of this study is to analyze the impact of the parallel wires' placement based on the described machine and to propose a measurement technique which could be used later to judge automatically wound machines containing unknown strand placement. For this study a good and bad case machine is built up by hand winding to clarify the influence. To realize high quality measurements both machines use exactly the same rotor, about 60 thermocouples and a specific current measurement system in each parallel strand of one phase. It is shown that the measured losses differ for more than 3kW, meaning an additional loss amount of 65% at 11000 rpm. Looking at the measured currents the frequency dependency can be clearly seen. About three times higher current load in some strands is identified compared to ideal wire distribution. So overheating and possible cases of failure are possible. The measured data is used to validate a common analytical as well as a transient FEA model. While the FEA matches the measurement almost perfectly the analytical approach delivers some deviations, especially in bad case conditions. At the end an outlook regarding the temperature dependent loss scaling is given. Addicted to the ac loss amount different scaling behaviors occur.