scholarly journals Simulation of Phase Angle Control and Condition Based Synchronization Techniques for Parallel Inverters

Parallel connection of inverters is one useful method for solving the high power requirements. It reduces the current stress on inverter switches and makes the way for continuous supply to the load.Though any one of the inverter supplying the load gets faulted, the other inverter connected would supply the load. But the problem in this kind of set up is that it needs synchronization techniques for parallel operation or else the inverters will operate in unsynchronized manner and the supply would be in distorted form for the motor load leading to overheating of the load. This paper proposes two software drive control techniques for the parallel operation of inverters in synchronized condition.These software techniques are implemented and results are analysed in the MATLAB environment.

Author(s):  
Rachana Kamtekar

Chapter 1 lays out the methodological approach employed throughout the book, which is to pay attention to the dialectical dependence of what the main speaker in the dialogue says on the intellectual problem(s) set up in the dialogue both by himself and the other speakers. To illustrate, Chapter 1 describes Socrates’ use of the method of hypotheses from the Meno and Phaedo to answer questions that go beyond his claims to knowledge in the Republic.


2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Elodie Di-Falco ◽  
Johan Bourbon ◽  
Isalyne Sbaffe ◽  
Jean-Daniel Kaiser

AbstractAlsace, in particular Haut-Rhin, is one of the main clusters of COVID-19 in France. There has been a shortage of essential supplies in the area, especially alcohol-based hand sanitizer. In this context, and in accordance with the decree dated March 6, 2020, our hospital management team asked us to start local production of alcohol-based handrub. This was a real challenge: In one week, we had to implement the production of handrub to meet the needs of a 1,400-bed hospital. The production had to comply with the French preparation guidelines and take place on specific premises, with qualified and calibrated equipment, by qualified staff, under the supervision of a pharmacist. The other big challenge we faced was the supply of pharmaceutical raw and packaging materials. During this particular critical period, all suppliers were out of stock. Here, we describe the organizational set-up and the decisions made, e. g., to use technical-grade ethanol before the publication of the decrees dated March 13 and March 23, 2020.


1998 ◽  
Vol 162 ◽  
pp. 211-213
Author(s):  
S. Isobe

Astronomy is an important science in understanding a human environment. However, it is thought by most politicians, economists, and members of the public that astronomy is a pure science having no contribution to daily human activities except a few matters relating to time. The Japanese government is studying a reorganisation of our school system to have 5 school days per week, instead of 6 days per week, and this July its committee made a recommendation to reduce school hours for science and set up new courses for practical computers and environmental science. I currently made a proposal. It is very difficult for most of the school pupils, who will have non-scientific jobs, to understand science courses currently taught in school, because each science is taught independently from the other sciences. Therefore, their knowledge of sciences obtained during their school period does not greatly help their understanding of global environmental problems.


1979 ◽  
Vol 44 (1) ◽  
pp. 239-242 ◽  
Author(s):  
Dean Tjosvold ◽  
Morris Okun
Keyword(s):  

Participants were randomly assigned to be high or low power and interacted with another who consistently cooperated, or consistently competed, or alternatively cooperated and competed. Results indicate that low power participants acted more cooperatively, were more attracted to, and wanted to facilitate the other's outcomes to the extent the other had cooperated; the cooperativeness of the high power participants was unaffected by the low power person's actions.


2011 ◽  
Vol 343-344 ◽  
pp. 661-667 ◽  
Author(s):  
Yun Xue ◽  
De Wei Weng ◽  
Gang Ming Gong

Mechanical model of nucleoside and its equilibrium equations are set up, and the mechanical properties on the equilibrium position are analyzed. In the case constraint force and electrostatic attraction between cylinder OH and elastic rod are balanced, the analytic expression of nutation angle of the section and its conditions of existence are given. It is show that the cylinder OH can maintain equilibrium at any range of the precession angle. In the other case when unbanced, there is phenomenon of separation of elastic rod from cylinder OH in the spiral wound 2 circles, and numerical solution of the precession angle at separation points are calculated. Analysis of equilibrium of cylinder H1 illustrates that the generatrix of cylinder H1 and OH are not parallel, and the angle between them is obtained


2021 ◽  
Author(s):  
Paul Swindell ◽  
Danielle Stephens

Abstract The Federal Aviation Administration (FAA) has been participating with the Society of Automotive Engineers (SAE) Aerospace Industry Steering Committee (AISC) to develop a methodology for calculating the Probability of Detection (POD) for Structural Health Monitoring (SHM) for damage detection on commercial aviation. Two POD methodologies were developed: one by Dr. William Meeker, Iowa State University, and the other by Dennis Roach, Sandia National Laboratories (SNL). With Dr. Seth Kessler, Metis Design Corp, a test program of 24 samples of aluminum strips to be fatigued on MTS machines was developed. The samples were designed to meet the ASTM E647. Twelve samples had two SHM modalities on the front and back from Metis (PZT and carbon nanotubes), and the other twelve had SHM sensors from Structural Monitoring Systems (SMS) (comparative vacuum monitoring – CVM) and Acellent Technologies (PZT). The tests were performed at the FAA William J Hughes Technical Center in Atlantic City, NJ. The samples were cycled every 1500 cycles and then stopped for SHM data collection. Once the crack exceeded 0.125 inches and provided for a minimum of 15 inspections, a new sample was tested until all 12 samples were completed. The data was provided to each company to be set up in the format needed to run through the POD methodologies. Then the data was provided to Dr. Meeker and Dr. Roach for analysis. This paper will provide the results of those tests.


1950 ◽  
Vol 17 (4) ◽  
pp. 448-453 ◽  
Author(s):  
Dana Young

Abstract Ritz’s method is one of several possible procedures for obtaining approximate solutions for the frequencies and modes of vibration of thin elastic plates. The accuracy of the results and the practicability of the computations depend to a great extent upon the set of functions that is chosen to represent the plate deflection. In this investigation, use is made of the functions which define the normal modes of vibration of a uniform beam. Tables of values of these functions have been computed as well as values of different integrals of the functions and their derivatives. With the aid of these data, the necessary equations can be set up and solved with reasonable effort. Solutions are obtained for three specific plate problems, namely, (a) square plate clamped at all four edges, (b) square plate clamped along two adjacent edges and free along the other two edges, and (c) square plate clamped along one edge and free along the other three edges.


1980 ◽  
Vol 85 (1) ◽  
pp. 21-31
Author(s):  
U. ACHENBACH ◽  
K. E. WOHLFARTH-BOTTERMANN

A new experimental investigation chamber was used to analyse the control of rhythmic contractile activity in Physarum. A strand was mounted in such a way that isometric tension measurements of contraction forces could be made on two regions independently, the two regions remaining connected. It was possible to disturb one region experimentally and to compare its behaviour with the other. A short time after being set up in the apparatus, the isometric contraction cycles in the two regions became synchronous. Stretching one region by 50% of its original length induced a phase delay relative to the other. A brief unilateral cold shock (Δt = 5舑15 °C) had a similar phase-retarding effect. Synchrony was subsequently reattained, unless the connecting region was cut or, for example, treated with 30 mM benzamide. In approximately 25% of the investigated strands, a rapid change to a higher temperature (Δt = 2舑5 °C) caused the warmed side to be phase-advanced. However, 75% of the strands did not show a phase shift, suggesting that a rapid phase regulation is supported by increased temperature. The described experimental assay is suitable for analysing the pathway and the nature of signal transmission in plasmodial strands. Note: Partly presented at the International Titisee-Conference on Cellular Oscillators, 22舑24 March 1979 (see J. exp. Biol. (1979)).


Sign in / Sign up

Export Citation Format

Share Document