Design Of High-speed Motor Research Articles

Fault Detection based on MCSA for a 400Hz Asynchronous Motor for Airborne Applications

Future health monitoring concepts in different fields of engineering require reliable fault detection to avoid unscheduled machine downtime. Diagnosis of electrical induction machines for industrial applications is widely discussed in literature. In aviation industry, this topic is still only rarely discussed. A common approach to health monitoring for electrical induction machines is to use Motor Current Signature Analysis (MCSA) based on a Fast Fourier Transform (FFT). Research results on this topic are available for comparatively large motors, where the power supply is typically based on 50Hz alternating current, which is the general power supply frequency for industrial applications.
 In this paper, transferability to airborne applications, where the power supply is 400Hz, is assessed. Three phase asynchronous motors are used to analyse detectability of different motor faults. The possibility to transfer fault detection results from 50Hz to 400Hz induction machines is the main question answered in this research work. 400Hz power supply frequency requires adjusted motor design, causing increased motor speed compared to 50Hz supply frequency. The motor used for experiments in this work is a 800W motor with 200V phase to phase power supply, powering an avionic fan. The fault cases to be examined are a bearing fault, a rotor unbalance, a stator winding fault, a broken rotor bar and a static air gap eccentricity. These are the most common faults in electrical induction machines which can cause machine downtime. The focus of the research work is the feasibility of the application of MCSA for small scale, high speed motor design, using the Fourier spectra of the current signal.
 Detectability is given for all but the bearing fault, although rotor unbalance can only be detected in case of severe damage level. Results obtained in the experiments are interpreted withrespect to the motor design. Physical interpretation are given in case the results differ from those found in literature for 50Hz electrical machines.

A New High-Frequency Iron Loss Model Including Additional Iron Losses due to Punching and Burrs’ Connection

A variable magnetic permeability is introduced to the skin effect coefficient to reflect the influence of flux density variation on eddy current losses. The evaluation results show that the new iron loss model can cover a wide range of frequencies without using piecewise functions. Two types of punched edges are defined and the additional iron losses are tested, separated, and modeled, so that the punching and burrs’ connection effects on iron losses can be considered more accurately. The iron loss model proposed in this article is very useful for a more accurate design of high-speed motors including the punching effects.

Robust Optimization of High-Speed PM Motor Design

This paper proposes a robust optimization algorithm, enabling global optimum tracking and manufacturing uncertainty factors handling, for high-speed permanent magnet motor design. A new robustness criterion is introduced, considering effectively the impact of the construction tooling uncertainties on the design variables in all objectives. An adaptive-network-based fuzzy inference system is adopted acting as a surrogate for the time-consuming finite-element (FE) analyses and results in computationally fast robust electric machine design procedure. The procedure has been validated through FE high-speed motor design.

Optimization of High-Speed Motors Considering Centrifugal Force and Core Loss Using Combination of Stress and Electromagnetic Field Analyses

A shape optimization method by using combination of stress and electromagnetic field analyses has been developed for the design of high-speed motors. In the stress analysis, the mechanical stress caused by centrifugal force in the rotor is estimated. In the electromagnetic field analysis, the loss and torque of the motor are estimated. The permeability and the core-loss coefficients used in the electromagnetic field analysis are modified due to the results of the stress analysis. The validity of the optimization is confirmed by the measurement of a prototype motor. The measured and calculated results are found to be in good agreement. The proposed method is useful for high-speed motor designs.