In order to respond to worldwide environmental problems such as global warming and demands for saving fuel cost of aircrafts from the aviation industry, researches on More Electric Aircraft (MEA) are actively conducted. Conventional hydraulic, pneumatic, and mechanical power sources from aero engines for flight actuators or auxiliary systems are replaced by electric motors in MEA. Interior permanent magnet synchronous motors (IPMSMs) are widely used in various applications for high power density and high efficiency. It is considered that rectangular windings can greatly improve the slot factor, thereby making it possible to increase the power density of IPMSMs. Additionally, in the concentrated winding stator, the coil end can be made shorter than that of the distributed winding stator, which is possible to downsize the stator in the axial direction. In this paper, a high power density concentrated winding IPMSMs which employs rectangular windings for MEA is simulated by 2D-FEA. However, this simulation result reveals that considerable amount of eddy current loss generated in the windings of the motor. Excessive eddy current loss in the windings…

This paper aims to study the NVH and acoustic performance of a 3-phase AC induction motor in order to develop an approach to reduce the magnetic component of noise from an electric motor in an electric vehicle (EV). The final goal of this project is to reduce the magnetic component of sound from the motor by making modifications to the end bracket of the motor housing.EVs are being considered the future of mobility mainly due to the fact that they are environment-friendly. As many companies are already investing in this technology, electric drives are set to become extremely popular in the years to come. The heart of an EV is its motor. Modern electric vehicles are quiet, furthermore with the lack of an IC engine to mask most sounds from other components, the sound from the electric motor and other auxiliary parts become more prominent. The primary source of electromagnetic noise in a motor arises from magnetic flux variations in the air gap which interfere with the resonant frequencies of the stator core. These flux…

A new proportional electromagnetic dynamic vibration absorber (EDVA) is proposed for control of engine vibration during idling. The device consists of an electromagnetic actuator attached to the primary structure through elastic element, where the driving force pair is implemented between the reaction-mass and the primary structure. The design of the proportional electromagnetic actuator is realized considering the geometric parameters of the core to achieve nearly constant magnetic force over a broad range of its dynamic displacement but proportional to square of the current. A methodology is proposed to achieve magnetic force proportional to square of current and consistent with the disturbance frequency. The proportional EDVA is subsequently applied to a single-degree-of-freedom primary system with an acceleration feedback control algorithm for attenuation of primary system vibration in a frequency band around the typical idling vibration frequencies. The effectiveness of the hybrid proportional EDVA is evaluated through simulations and laboratory experiments under harmonic excitations in the 20-30 Hz frequency range. Both the simulation and measurements show that the hybrid proportional EDVA can yield effective attenuation of periodic…

This specification covers a magnetically soft nickel-iron alloy in the form of sheet and strip.

This specification covers a magnetic nickel-iron alloy in the form of sheet and strip.

This specification covers a magnetically soft nickel-iron alloy in the form of bars, rods, forgings, mechanical tubing, and forging stock.

This specification covers the characteristics of glass beads used for peening, and provides for standard glass bead size numbers.

This specification covers a copper-beryllium alloy in the form of bars, rods, shapes, and forgings.