Core Losses and Machine Design for Electric/Hybrid Vehicles

随着高速电机的设计具有复杂的几何形状，导致复杂的磁通模式，电机的铁心损耗领域越来越引起人们的关注。焊剂可能主要是交替的，但机器的很大一部分经历了旋转损失，这是一个几乎没有做过功的领域。建议的工作分为三个部分。第一个是为主要是脉动的波形开发更准确的模型。申请人发现，由于测量方法的不同，在将损耗分离为涡流和磁滞方面存在根本性错误。在典型的爱泼斯坦样品中，整个通量是在叠层中测量的，但随着频率的增加，集肤效应开始发挥作用，并且在叠层厚度内的通量密度的大小和相位发生变化。更准确的建模使这一变化得以考虑在内，但这仍然必须转化为对实际损失的更准确的计算。最近在测量机器旋转铁耗方面做了一些基础性的工作。设计和制造了一种新的测试夹具，并进行了有限的试验。这项任务的目的是在磁通旋转时推进测量以包括非正弦激励，并包括更广泛的材料和量规。在建模方面，需要做的基础工作是建立磁通旋转时磁滞和涡流损耗的公式，类似于对脉动磁通所做的工作。第三个任务是利用铁心损耗建模的结果来设计一种新的低转矩脉动的同步磁阻电机，而不需要偏心。定子或转子的偏斜增加了制造的复杂性。平均磁通密度也降低了。提出了一种与转子肋骨方向相关的新技术，该技术可以在没有偏斜的情况下最小化扭矩脉动。

The area of core losses in electrical machines is of growing interest as higher speed machines are being designed with complicated geometries, leading to complex flux patterns. The fluxes may be primarily alternating, but a significant portion of the machine experiences a rotational loss, an area in which very little work has been done. The work proposed is divided into three sections. The first is to develop more accurate models for waveforms that are primarily pulsating. The applicant has found that fundamental errors are being made in the separation of losses into eddy currents and hysteresis because of how the measurements are made. In typical Epstein specimens the entire flux is measured flowing in the lamination, yet as frequency increases, skin effect takes over and there is a variation in the magnitude and phase of flux density within the thickness of the lamination. More accurate modeling has allowed this variation to be taken into account, but this must still be translated into more accurate calculations of the actual losses. Some fundamental work in the measurement of rotational iron losses in machines have been done recently. A new test fixture has been designed and built and limited tests have been conducted. The purpose of this task is to advance the measurement to include non-sinusoidal excitations, while the flux is rotating and to include a wider range of materials and gauges. On the modeling side, fundamental work needs to be done on developing a formula for hysteresis and eddy current losses while the flux is rotating, similar to what has been done for pulsating fluxes. The third task is to use the results in the core loss modeling to design a new synchronous reluctance motor with low torque ripple, without the need for skewing. Skewing of the stator or rotor increases the manufacturing complexity. Also the average flux density is reduced. A new technique related to the orientation of the ribs in the rotor is proposed which can allow torque ripple minimization in the absence of skewing.