Virtual Impedance Design Considerations for Virtual Synchronous Machines in Weak Grids

2020 ◽  
Vol 8 (2) ◽  
pp. 1477-1489 ◽  
Author(s):  
Alberto Rodriguez-Cabero ◽  
Javier Roldan-Perez ◽  
Milan Prodanovic
Keyword(s):  
Synchronous Machines ◽  
Design Considerations ◽  
Virtual Impedance

Damping Effect of Virtual Synchronous Machines Provided by a Dynamical Virtual Impedance

2020 ◽  
pp. 1-1
Author(s):  
Linbin Huang ◽  
Huanhai Xin ◽  
Hui Yuan ◽  
Guanzhong Wang ◽  
Ping Ju
Keyword(s):  
Synchronous Machines ◽  
Damping Effect ◽  
Virtual Impedance

Simple nonlinear MEC-based model for sensitivity analysis and genetic optimization of permanent-magnet

2015 ◽  
Vol 34 (1) ◽  
pp. 301-323
Author(s):  
Sajjad Mohammadi ◽  
Behrooz Vahidi ◽  
Mojtaba Mirsalim ◽  
Hamid Lesani
Keyword(s):  
Sensitivity Analysis ◽  
Permanent Magnet ◽  
Material Properties ◽  
Synchronous Machines ◽  
Design Parameters ◽  
Permanent Magnet Synchronous Machines ◽  
Content Type ◽  
Multi Objective ◽  
Design Considerations ◽  
Iron Saturation

Purpose – The purpose of this paper is to develop an effective, yet simple analytical framework for optimization of permanent-magnet synchronous machines. Also, single/multi-objective optimizations are performed for a case-study machine with surface-mounted permanent magnets. Design/methodology/approach – First, an accurate magnetic equivalent circuit is developed which takes all the material such as iron saturation and PM parameters into account. Then, through a Fourier analysis, it is combined with the d-q model of PM synchronous machines to achieve an optimization framework including the developed torque, back-EMF and a number of design considerations. Finally, a genetic algorithm (GA) is employed in the single/multi-objective design optimizations, which offers several design characteristics upon different desired outcomes. Findings – An analytical design framework for the optimization of permanent-magnet synchronous machines is developed in this paper that can effectively account for all material properties such as iron saturation and PM characteristics, and take into account the design considerations, all of which are shown as superiorities of the proposed approach over the existing method. In addition, the proposed framework is relatively simpler in terms of implementing. The model is verified by employing finite element method. Moreover, sensitivity analysis is carried out to investigate the influence of the design parameters on the machine performance, which provides valuable information for the designer of such devices. Finally, a GA is utilized to perform single/multi-objective optimization schemes whose objectives are minimizing the torque ripples, back-EMF total harmonic distortion and PM volume. Originality/value – The proposed framework is new approach that could be employed in the design optimization of PM synchronous machines. Contrary to existing method, it is simpler and more effective in taking the material properties such as iron saturation and PM characteristics into account.

Design considerations for fractional-slot winding configurations of synchronous machines

2006 ◽  
Vol 42 (4) ◽  
pp. 997-1006 ◽  
Author(s):  
N. Bianchi ◽  
S. Bolognani ◽  
M.D. Pre ◽  
G. Grezzani
Keyword(s):  
Synchronous Machines ◽  
Design Considerations ◽  
Fractional Slot

Morphological behavior of compatibilized ternary blends prepared by mechanical mixing

1993 ◽  
Vol 51 ◽  
pp. 1200-1201
Author(s):  
S.D. Smith ◽  
R.J. Spontak ◽  
D.H. Melik ◽  
S.M. Buehler ◽  
K.M. Kerr ◽  
...  
Keyword(s):  
Interfacial Adhesion ◽  
Diblock Copolymers ◽  
Ternary Blends ◽  
Mechanical Mixing ◽  
Design Considerations ◽  
Covalently Bonded ◽  
Homopolymer Blends ◽  
Emulsifying Agent ◽  
Surface Active ◽  
Low Entropy

When blended together, homopolymers A and B will normally macrophase-separate into relatively large (≫1 μm) A-rich and B-rich phases, between which exists poor interfacial adhesion, due to a low entropy of mixing. The size scale of phase separation in such a blend can be reduced, and the extent of interfacial A-B contact and entanglement enhanced, via addition of an emulsifying agent such as an AB diblock copolymer. Diblock copolymers consist of a long sequence of A monomers covalently bonded to a long sequence of B monomers. These materials are surface-active and decrease interfacial tension between immiscible phases much in the same way as do small-molecule surfactants. Previous studies have clearly demonstrated the utility of block copolymers in compatibilizing homopolymer blends and enhancing blend properties such as fracture toughness. It is now recognized that optimization of emulsified ternary blends relies upon design considerations such as sufficient block penetration into a macrophase (to avoid block slip) and prevention of a copolymer multilayer at the A-B interface (to avoid intralayer failure).

Theoretical And Practical Design Considerations for Ultra-High Resolution Electron Lenses

1980 ◽  
Vol 38 ◽  
pp. 266-269
Author(s):  
Y. Harada ◽  
K. Tsuno ◽  
Y. Arai
Keyword(s):  
Optical Properties ◽  
High Resolution ◽  
Chromatic Aberration ◽  
Point Of View ◽  
Pole Piece ◽  
Axial Field ◽  
Design Considerations ◽  
Resolution Electron ◽  
Practical Design ◽  
Peak Flux

Magnetic objective lenses, from the point of view of pole piece geometry, can he roughly classified into two types, viz., symmetrical and asymmetrical. In the case of the former, the optical properties have been calculated by several authors1-3) and the results would appear to suggest that, in order to reduce the spherical and chromatic aberration coefficients, Cs and Cc, it is necessary to decrease the half-width value of the axial field distribution and to increase the peak flux density. The expressions for either minimum Cs or minimum Cc were presented in the form of ‘universal’ curves by Mulvey and Wallington4).

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