Analytical calculation model for stator winding faults in synchronous machines

Author(s):  
Jens Rosendahl ◽  
Hendrik Steins
2012 ◽  
Vol 63 (3) ◽  
pp. 162-170 ◽  
Author(s):  
Peter Sekerák ◽  
Valéria Hrabovcová ◽  
Juha Pyrhönen ◽  
Lukáš Kalamen ◽  
Pavol Rafajdus ◽  
...  

Ferrites and Different Winding Types in Permanent Magnet Synchronous MotorThis paper deals with design of permanent magnet synchronous machines with ferrites. The ferrites became popular due to their low cost and cost increasing of NdFeB. The progress in ferrite properties in the last decade allows the use of ferrites in high power applications. Three models of ferrite motors are presented. It is shown that also the type of stator winding and the shape of the slot opening have an important effect on the PMSM properties. The first motor has a distributed winding, the second motor has concentrated, non-overlapping winding and open stator slots. The third motor has a concentrated non-overlapping winding and semi - open slots. All models are designed for the same output power and they do not have the same dimensions. The paper shows how important the design of an electric machine is for excellent motor properties or better to say how the motor properties can be improved by an appropriate design.


Author(s):  
Florian Franke ◽  
Michael Schwab ◽  
Uli Burger ◽  
Christian Hühne

AbstractIn addition to the well-known threats of bird and hail strikes, small unmanned aerial vehicles (sUAV) pose a new threat to manned aviation. Determining the severity of collisions between sUAVs and aircraft structures is essential for the safe use and integration of drones in airspace. A generic analytical calculation model needs to be developed to supplement the existing test and simulation data. This paper presents an analytic model for drone collisions with perpendicular and inclined targets. The targets have a rigid or elastic material behavior. The aircraft impact model, which is used for the design of nuclear reactor structures, is transferred and adjusted for sUAV impacts to calculate the impact force. A mass- and a burst load distribution are needed as input parameters. Both distributions are determined for an sUAV design depending on the flight direction. Compared to previous calculations, the new approach is to consider a moving target structure, which produces more realistic results. We compare the calculation results with simulation data from sUAV collisions with a commercial airliner windshield from the literature. The calculations show plausible results and a good agreement with literature data. Subsequently, the influence of the input parameters on the impact force is investigated. We see that spring stiffness, target mass, burst load distribution and damping have minor influence on the overall impact force. The impact velocity, mass distribution and flight orientation on the other hand have a major influence on the impact force. Further tests are needed to validate the impact model.


Author(s):  
Ruxin Lu ◽  
Wencheng Tang

The temperature has a great contribution to the mesh stiffness and backlash of the gear pair. Presence of thermal deformation caused by temperature will complicate the gear teeth interaction. In this paper, the thermal time-varying stiffness model and thermal time-varying backlash model are proposed with the consideration of tooth profile error and total thermo-elastic deformation consists of the teeth deformation, teeth contact deformation, and gear body-induced deformation. The key parameters of thermo-elastic coupling deformation affected by temperature are calculated. Based on the proposed models, the influencing mechanism of temperature on the tooth profile error, mesh stiffness, total deformation, and backlash are revealed. The effects of shaft radius and torque load on the thermal stiffness and thermal backlash are studied. The proposed thermal stiffness and backlash calculation model are proven to be more comprehensive and the correctness is validated.


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