Prediction and evaluation of PWM-induced current ripple in IPM machines incorporating slotting, saturation, and cross-coupling effects

Author(s):  
Le Chang ◽  
Thomas M. Jahns
Geophysics ◽  
1983 ◽  
Vol 48 (5) ◽  
pp. 606-610 ◽  
Author(s):  
Lucien LaCoste

The LaCoste and Romberg straight‐line gravity meter uses a new suspension in which the movable element moves vertically in a straight line rather than in an arc of a circle (LaCoste, 1973a). It was designed primarily for shipboard operation to avoid effects from cross coupling between various ship accelerations, thereby making it unnecessary to correct for such effects. The straight‐line suspension is a modification of the zero length spring suspension used in all LaCoste and Romberg gravity meters. The new model also uses silicone fluid damping rather than the air damping used in earlier models. Its main advantages over the older models appear to be: it is (1) free of cross‐coupling effects, (2) easier to build and adjust, (3) less subject to slight degradation in performance from rough handling, and (4) less sensitive to ship vibrations. In spite of the above advantages it is doubtful whether the new model will give substantially better accuracy than the previous models, if the previous models are kept in good operating condition by making occasional crosscorrelation analyses (LaCoste, 1973b). Valliant (1983, this issue) describes sea tests of the new instrument.


2018 ◽  
Vol 55 (6) ◽  
pp. 2414-2426 ◽  
Author(s):  
Aaron T. Perry ◽  
Phillip J. Ansell ◽  
Michael F. Kerho

Geophysics ◽  
1983 ◽  
Vol 48 (1) ◽  
pp. 76-86 ◽  
Author(s):  
William R. Sill

This paper discusses a new method for the investigation of self potentials (SP) based on induced current sources. The induced current sources are due to divergences of the convection current which is driven, in turn, by a primary flow, either heat or fluid. As a result of using this approach there is a shift in emphasis toward the vector flow field and its interaction with current cross‐coupling structure when compared with the total potential approach of Nourbehecht (1963) which emphasized the primary flow potential and the voltage cross‐coupling. This shift in emphasis is advantageous because it is analogous to the actual physical processes. For example, fluid flow in the ground gives rise to drag (convection) currents, and the interaction of the convection currents with the electrical structure gives rise to the electrical potentials (SP). This simple physical picture should aid in developing a better intuitive understanding of the generation of SP effects. The convective current approach is easily adapted to numerical modeling techniques, as illustrated by its implementation using a two‐dimensional (2-D) transmission surface algorithm. When the primary flow is driven by the gradient of a potential, joint modeling of the primary flow and the resultant SP is possible with this algorithm. Examples of the SP effects generated by point sources of the primary flow in the presence of simple geometrical structures show the diversity of the possible responses. The various responses can be understood in terms of the distributions of the induced current sources caused by the primary flow. The results from field studies at Red Hill Hot Springs, Utah, are used in an example of the joint modeling of thermal and SP data.


2019 ◽  
Vol 16 (1) ◽  
pp. 172988141882396 ◽  
Author(s):  
Ali Roshanbin ◽  
André Preumont

This study describes the design, development, and flight tests of a novel control mechanism to generate yaw control torque of a hovering robotic hummingbird (known as Colibri). The proposed method generates yaw torque by modifying the wing kinematics while minimizing its influence on roll and pitch torques. To achieve this, two different architectures of series and parallel mechanisms are investigated; they are mathematically analyzed to investigate their behavior with respect to cross-coupling effects. The analysis is verified by measuring the control torque characteristics. The efficacy of the proposed method is also explored by flight experiments.


2014 ◽  
Vol 7 (6) ◽  
pp. 679-683
Author(s):  
Hung-Wei Wu ◽  
Shih-Hua Huang

A new compact quad-passband bandpass filter (BPF) using multi-mode resonators (MMRs) based on multi-layered substrate technique is proposed. The filter consists of a pair of multi-mode resonators (uniform impedance resonator and stepped impedance resonator) operated at 1.8/3.7 GHz on top layer and the other pair of the multi-mode resonators operated at 2.4/3 GHz on bottom layer. Source–load coupling lines are used to be the input/output (I/O) ports for providing the multi-paths propagations by cross-coupling effects in the filter. Specifically, the operated frequencies of the filter at 1.8/2.4/3/3.7 GHz with bandwidths of 6.7, 8.2, 4.6, and 7.2% are successfully designed and implemented. The proposed filter is useful for the multi-passband filters design, especially when the passbands are needed to be very close.


2017 ◽  
Vol 53 (11) ◽  
pp. 1-6 ◽  
Author(s):  
Yunlong Zhong ◽  
Lijian Wu ◽  
Xiaoyan Huang ◽  
Youtong Fang ◽  
Jian Zhang

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