A Technique for Multilevel and PWM Voltages Synthesis with Improved Harmonic Content

2021 ◽  
Author(s):  
Tatyana Anisimova ◽  
Anastasiya Danilina ◽  
Vadim Volkov ◽  
Vasily Kryuchkov
Keyword(s):  
Harmonic Content

A Note on Patterns of Wear Within the Tread Area

1979 ◽  
Vol 7 (1) ◽  
pp. 3-13
Author(s):  
F. C. Brenner ◽  
A. Kondo
Keyword(s):  
Content Analysis ◽  
Groove Depth ◽  
Climatic Data ◽  
Periodic Behavior ◽  
Harmonic Content ◽  
Straight Line ◽  
Data Points

Abstract Tread wear data are frequently fitted by a straight line having average groove depth as the ordinate and mileage as the abscissa. The authors have observed that the data points are not randomly scattered about the line but exist in runs of six or seven points above the line followed by the same number below the line. Attempts to correlate these cyclic deviations with climatic data failed. Harmonic content analysis of the data for each individual groove showed strong periodic behavior. Groove 1, a shoulder groove, had two important frequencies at 40 960 and 20 480 km (25 600 and 12 800 miles); Grooves 2 and 3, the inside grooves, had important frequencies at 10 240, 13 760, and 20 480 km (6400, 8600, and 12 800 miles), with Groove 4 being similar. A hypothesis is offered as a possible explanation for the phenomenon.

scholarly journals Advanced Scheme to Generate MHz, Fully Coherent FEL Pulses at nm Wavelength

2021 ◽  
Vol 11 (13) ◽  
pp. 6058
Author(s):  
Georgia Paraskaki ◽  
Sven Ackermann ◽  
Bart Faatz ◽  
Gianluca Geloni ◽  
Tino Lang ◽  
...  
Keyword(s):  
Repetition Rate ◽  
High Harmonic ◽  
High Repetition Rate ◽  
Optical Cavities ◽  
Electron Bunches ◽  
High Repetition ◽  
Average Brightness ◽  
Technical Requirements ◽  
Harmonic Content ◽  
Unique Approach

Current FEL development efforts aim at improving the control of coherence at high repetition rate while keeping the wavelength tunability. Seeding schemes, like HGHG and EEHG, allow for the generation of fully coherent FEL pulses, but the powerful external seed laser required limits the repetition rate that can be achieved. In turn, this impacts the average brightness and the amount of statistics that experiments can do. In order to solve this issue, here we take a unique approach and discuss the use of one or more optical cavities to seed the electron bunches accelerated in a superconducting linac to modulate their energy. Like standard seeding schemes, the cavity is followed by a dispersive section, which manipulates the longitudinal phase space of the electron bunches, inducing longitudinal density modulations with high harmonic content that undergo the FEL process in an amplifier placed downstream. We will discuss technical requirements for implementing these setups and their operation range based on numerical simulations.

Analysis of Drive Shaft Speed Variations in a Scotch Yoke Mechanism

1982 ◽  
Vol 104 (1) ◽  
pp. 239-246 ◽  
Author(s):  
J. L. Wiederrich
Keyword(s):  
Practical Importance ◽  
Drive Shaft ◽  
Constant Speed ◽  
Shaft Speed ◽  
Flexible Coupling ◽  
Harmonic Content ◽  
Common Drive ◽  
Scotch Yoke Mechanism

Two analyses are presented for determining the drive shaft speed variations in a scotch yoke mechanism. The first analysis determines the speed variations when the mechanism is rigidly connected to a motor having a quadratic speed versus torque characteristic. The second analysis determines the speed variations when the mechanism is connected to a constant speed source through a flexible coupling. Together these models represent the two most common drive configurations. The results are of practical importance since they can be used in the preliminary calculations necessary in either the design of a main drive or the diagnosis of a drive problem in an existing machine. The methods are also of theoretical importance since they may be extended to the analysis of mechanisms having a greater harmonic content than the simple scotch yoke mechanism.

Research of Simulation in the Main Circuit of Static Var Generator Based on Cascade H-Bride

2013 ◽  
Vol 392 ◽  
pp. 409-412
Author(s):  
Xian Bin Dai ◽  
Xiao Hua Yuan ◽  
Wei Du
Keyword(s):  
Output Voltage ◽  
Power Index ◽  
Matlab Simulation ◽  
Voltage Waveform ◽  
Distortion Factor ◽  
Harmonic Content ◽  
Three Phase ◽  
Static Var Generator ◽  
Waveform Distortion ◽  
Working Principle

This paper introduces the working principle of the research of simulation in the main circuit of Static Var Generator based on Cascade H-Bride and takes the three-phase Static Var Generator based on cascade H-Bride with rated capacity 10kVar,rated voltage 380V for example to proceed the MATLAB simulation. The research shows that the more amount of cascade H-Bride, the more number of output voltage levels in the main circuit of Static Var Generator, the smaller value of voltage waveform distortion factor, and the less harmonic content be inject in electric network, which improves power index.

On the Inherent Characteristics of the Dynamics of Robot Manipulators

1991 ◽  
Author(s):  
Q. Tu ◽  
J. Rastegar
Keyword(s):  
Path Length ◽  
Degrees Of Freedom ◽  
Inverse Dynamics ◽  
Robot Manipulators ◽  
Control Point ◽  
Coordinate Space ◽  
Relative Significance ◽  
Harmonic Content ◽  
Trajectory Pattern ◽  
Dynamics Models

Abstract The inherent characteristics of the (nonlinear) dynamics of robot manipulators are studied. The study is based on a new method, referred to as the trajectory pattern method. The inverse dynamics models of the manipulator are divided into classes of inverse dynamics models, each corresponding to a different trajectory pattern. For each trajectory pattern, the structure of the resulting inverse dynamics model is fixed and is used to study the characteristics of the dynamics of the manipulator by examining the harmonic content of the required actuation torques (forces) and the relative significance of each harmonic. The harmonic content of the actuating torques is shown to be a function of the path length in the joint coordinate space and the harmonic content of the selected trajectory pattern, but is independent of the number of degrees-of-freedom of the manipulator. The relative contribution of each harmonic is a function of the path length, direction of motion, the position of the path of motion within the workspace of the manipulator, and the magnitude of the fundamental frequency. The study provides a systematic approach to path and trajectory planning from the vibration control point of view. As an example, the characteristics of the dynamics of a spatial 3R manipulator is studied for motions with two different path lengths, starting from a specified point and extending in different directions.

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