scholarly journals Design of linear phase shift transformer and analytical calculation of no-load electromagnetic field

2021 ◽  
Vol 1802 (3) ◽  
pp. 032085
Author(s):  
Guoqiang Guo ◽  
Jinghong Zhao ◽  
Mei Wu ◽  
Yiyong Xiong
Keyword(s):  
Electromagnetic Field ◽  
Phase Shift ◽  
Analytical Calculation ◽  
Linear Phase

Pulsed Control of Thermoacoustic Instabilities: Analysis and Experiment

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
J. Matthew Carson ◽  
William T. Baumann ◽  
William R. Saunders
Keyword(s):  
Phase Shift ◽  
Limit Cycle ◽  
Fourier Component ◽  
Linear Phase ◽  
Cycle Frequency ◽  
Thermoacoustic Instabilities ◽  
Control Authority ◽  
Subharmonic Frequency ◽  
Cycling Behavior ◽  
Instability Frequency

Thermoacoustic instabilities in combustors have been suppressed using phase-shift algorithms pulsing an on-off actuator at the limit cycle frequency (flc) or at the subharmonics of flc. It has been suggested that control at a subharmonic rate may extend the actuator lifetime and possibly require less actuator bandwidth. This paper examines the mechanism of subharmonic control in order to clarify the principles of operation and subsequently identify potential advantages for combustion control. Theoretical and experimental arguments show that there must be a Fourier component of the subharmonic control signal at flc in order to stabilize the limit cycling behavior. It is also demonstrated that the magnitude of that Fourier component must be equivalent to the signal magnitude for a linear phase-shift controller that operates directly at flc. The concept of variable-subharmonic control is introduced whereby the actuator is pulsed at the instability frequency to initially stabilize the system and then is pulsed at a subharmonic frequency to maintain stability. These results imply that an actuator used for subharmonic control cannot be effective unless its bandwidth spans the instability frequency. The advantage of reduced cycling may still be realized but will require higher control authority to produce the same effect as an actuator pulsed at the instability frequency.

Influence of Stator Parameter Variation and Phase-Shift Under Synchronizing Out of Phase on Turbine Generator Electromagnetic Field

2017 ◽  
Vol 32 (2) ◽  
pp. 525-533 ◽  
Author(s):  
Weili Li ◽  
Purui Wang ◽  
Jinyang Li ◽  
Likun Wang ◽  
Shiyun Gong ◽  
...  
Keyword(s):  
Electromagnetic Field ◽  
Phase Shift ◽  
Parameter Variation ◽  
Turbine Generator

scholarly journals New Phase Shifting Algorithms Insensitive to Linear Phase Shift Errors

10.14311/376 ◽  
2002 ◽  
Vol 42 (4) ◽  
Author(s):  
J. Novák
Keyword(s):  
Phase Shift ◽  
Evaluation Process ◽  
Phase Shifting ◽  
Linear Phase ◽  
Phase Errors ◽  
Arbitrary Phase ◽  
Phase Calculation ◽  
Calculation Algorithms ◽  
Phase Evaluation ◽  
New Phase

This article describes and analyses multistep algorithms for evaluating of the wave field phase in interferometric measurements using the phase shifting technique. New phase shifting algorithms are proposed, with a constant but arbitrary phase shift between captured frames of the intensity of the interference field. The phase evaluation process then does not depend on linear phase shift errors. A big advantage of the described algorithms is their ability to determine the phase shift value at every point of the detector plane. A detailed analysis of these algorithms with respect to main factors that affect interferometric measurements is then carried out. The dependency of these algorithms on phase shift values is also studied several phase calculation algorithms are proposed. These are compared with respect to the resulting phase errors.

Numerical verification of Turowski’s coefficient

2016 ◽  
Vol 35 (6) ◽  
pp. 1965-1972
Author(s):  
Hugo Rodriguez-Ignacio ◽  
Xose M. Lopez-Fernandez
Keyword(s):  
Electromagnetic Field ◽  
Field Distribution ◽  
Hybrid Methods ◽  
Analytical Calculation ◽  
Magnetic Surface ◽  
Numerical Verification ◽  
Content Type ◽  
Electromagnetic Field Distribution ◽  
Hybrid Approaches ◽  
Current Conductor

Purpose The purpose of this paper is the numerical verification of the linearization coefficient ap proposed by Turowski for the calculation of the electromagnetic field distribution and therefore the stray losses inside magnetically saturated solid steel conductors. Design/methodology/approach The numerical verification is performed on a case study consisting of a simple current conductor sheet parallel to a solid steel plate. Numerical computations are compared with analytical calculations with and without inclusion of the semi-empirical Turowski’s coefficient. Findings Results confirm a good agreement between numerical values for steel with non-linear permeability and analytical ones applying Turowski’s coefficient. This is particularly powerful in the case of analytical calculation of the magnetic surface impedance (SI) to increase precision when hybrid methods are used. The concept of SI enables the establishment of hybrid approaches for the calculation of stray losses, combining the numerical methods (finite difference method, finite element method (FEM), etc.) together with the analytical formulation, gaining from the advantages of both methods. Originality/value Previous numerical analysis was focused on the field dependence on time for several depths inside solid steel. The aim of this paper is to investigate the electromagnetic field distribution inside solid steel on a representative FEM model and verify how the linearization coefficient ap proposed by Turowski works.

Study of the parameters of a difference image in the presence of a linear phase shift

Laser Physics ◽  
2006 ◽  
Vol 16 (3) ◽  
pp. 488-494
Author(s):  
S. N. Malov ◽  
A. A. Smirnov
Keyword(s):  
Phase Shift ◽  
Linear Phase ◽  
Difference Image
Sign in / Sign up

Export Citation Format

Share Document