Anisotropy-based Sensorless Control at Excessive Load

通过在电驱动装置中避免位置传感器，阿利亚可以节省成本和空间，并实现改进的可靠性。在较低速度范围内的无传感器控制的方法采用所谓的电感的各向异性来进行位置估计。由于磁饱和，各向异性通常是电流/负载相关的。这导致了在低速时无传感器控制的负载极限，超过该负载极限，基于各向异性的方法在闭环操作中变得不稳定。负载极限的确切值主要取决于机器设计，因此可以在设计过程中受到影响或优化。但是，在设计过程中，必须能够正确计算荷载极限值。在文献中已经零星地提出了这样的方法，其使用各向异性比和各向异性角作为稳定性指标。然而，由于实际上这两个标准没有直接的不稳定性，这些预测导致不正确的优化结果。本申请是基于第一个完整的理论推导的不稳定性问题，其中的各向异性，adacement率原来是关键措施。简化形式（2D）的理论已经得到了模拟的支持，现在必须进行实验验证。该理论的扩展（3D）将提高载荷极限预测的准确性，并将在项目中进行实验验证。在验证3D预测规则后，将其集成到机器设计过程中，以制造针对各向异性载荷极限进行优化的机器。本文将最终证明，无传感器过载能力可以增加到何种程度，以及即使在没有编码器的情况下，是否甚至可以实现迄今为止被排除的应用，例如电动汽车。

By avoiding position sensors in electric drives, it is possible, inter alia, to save cost and space, and achieve improved reliability. Methods for sensorless control in the lower speed range employ the so called anisotropy of the inductance for the position estimation. Due to magnetic saturation, the anisotropy is generally current-/load-dependent. This results in a load limit for sensorless control at low speeds, above which anisotropy-based method become unstable in a closed loop opration.The exact value of the load limit mainly depends on the machine design and could therefore be influenced or optimized in the design process. But for this it is essential to be able to correctly calculate the value of the load limit already in the design process. Such approaches have been proposed sporadically in the literature which use the anisotropy ratio and the anisotropy angle as stability indicators. However, since actually both criteria have no direct connection with the instability, those predictions lead to incorrect optimization results.This application is based on a first complete theoretical derivation of the instability problem, wherein the anisotropy-displdacement rate turned out to be the critical measure. The theory in simplified form (2D) has been supported by simulations and must now be experimentally verifified. An extension of the theory (3D) shall improve the accuracy of the prediction of the load limit and also will be verified experimentally in the project.After verification of the 3D prediction rule it will be integrated into the machine design process in order to manufacture machines optimized with respect to the anisotropy-load limit. It will herein finally turn out, to which extent the sensorless overload capacity can be increased and whether even hitherto excluded applications, such as electromobility, can be realized even without encoder.