Analysis of a Three-Phase Buck-Boost AC Chopper Controlled in Two Phases

Author(s):  
Shinichiro Fujikura ◽  
Akiteru Ueda ◽  
Akihiro Torii ◽  
Nariaki Kobayashi
Keyword(s):  
2020 ◽  
Vol 38 (8A) ◽  
pp. 1187-1199
Author(s):  
Qaed M. Ali ◽  
Mohammed M. Ezzalden

BLDC motors are characterized by electronic commutation, which is performed by using an electric three-phase inverter. The direct control system of the BLDC motor consists of double loops; including the inner-loop for current regulating and outer-loop for speed control. The operation of the current controller requires feedback of motor currents; the conventional current controller uses two current sensors on the ac side of the inverter to measure the currents of two phases, while the third current would be accordingly calculated. These two sensors should have the same characteristics, to achieve balanced current measurements. It should be noted that the sensitivity of these sensors changes with time. In the case of one sensor fails, both of them must be replaced. To overcome this problem, it is preferable to use one sensor instead of two. The proposed control system is based on a deadbeat predictive controller, which is used to regulate the DC current of the BLDC motor. Such a controller can be considered as digital controller mode, which has fast response, high precision and can be easily implemented with microprocessor. The proposed control system has been simulated using Matlab software, and the system is tested at a different operating condition such as low speed and high speed.


Axioms ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 17
Author(s):  
Maria Laura Delle Delle Monache ◽  
Karen Chi ◽  
Yong Chen ◽  
Paola Goatin ◽  
Ke Han ◽  
...  

This paper uses empirical traffic data collected from three locations in Europe and the US to reveal a three-phase fundamental diagram with two phases located in the uncongested regime. Model-based clustering, hypothesis testing and regression analyses are applied to the speed–flow–occupancy relationship represented in the three-dimensional space to rigorously validate the three phases and identify their gaps. The finding is consistent across the aforementioned different geographical locations. Accordingly, we propose a three-phase macroscopic traffic flow model and a characterization of solutions to the Riemann problems. This work identifies critical structures in the fundamental diagram that are typically ignored in first- and higher-order models and could significantly impact travel time estimation on highways.


1981 ◽  
Vol 59 (1) ◽  
pp. 127-131 ◽  
Author(s):  
Alan N. Campbell

The properties named in the title have been determined by standard methods. Viscosity, molar volume, and orientation polarisation all indicate abnormalities of the nature of association between the components.The most interesting result is that of surface tension which indicates that, in the case of the binary system triethylamine–water, a surface layer of constant composition is formed over a wide range of total composition. When, by a rise in temperature of two or three degrees, this layer becomes unstable, it splits into two phases of different composition. The surface layer may then be instantaneously reformed and so on. A mechanism for the generation of a two-phase system is thus established. The data for the three-phase, isothermal, system are not so convincing, for reasons that are suggested.


Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4930
Author(s):  
Francisco Elvis Carvalho Souza ◽  
Werbet Silva ◽  
Andrés Ortiz Salazar ◽  
José Paiva ◽  
Diego Moura ◽  
...  

In order to reduce the costs of implementing the radial position control system of a three-phase bearingless machine with split winding, this article proposes a driving method that uses only two phases of the system instead of the three-phase traditional one. It reduces from six to four the number of inverter legs, drivers, sensors, and current controllers necessary to drive and control the system. To justify the proposal, this new power and control configuration was applied to a 250 W machine controlled by a digital signal processor (DSP). The results obtained demonstrated that it is possible to carry out the radial position control through two phases, without loss of performance in relation to the conventional three-phase drive and control system.


2004 ◽  
Vol 13 (6) ◽  
pp. 096369350401300 ◽  
Author(s):  
Olesja Starkova ◽  
Andrey Aniskevich

The results of experimental investigation and modelling of moisture sorption by CFRP rebars and vinylester matrix are presented. Experimental values of the rebar diffusion coefficients essentially differ from those predicted using structural approach. Essential anisotropy of sorption process in longitudinal and transverse directions is observed. Quasi three phase model is suggested for description of the CFRP rebar sorption. The model is based on consideration of sorption process of the diffusion character in the composite consisted of two phases: resin and microplastic, which includes fibres and fibre-resin interphase. The suggested model describes the experimental sorption data quite satisfactorily and explains high anisotropy effect.


2020 ◽  
Vol 56 (31) ◽  
pp. 4312-4315
Author(s):  
Yihan Sun ◽  
Jinxia Huang ◽  
Zhiguang Guo

Fluid repellence in one arbitrary phase for repelling the other two phases in a generalized liquid–liquid–air system was achieved on a hydrogen peroxide-treated surface.


Author(s):  
F. Reyhaneh Mehdizadeh ◽  
Daryoush Nazarpour

The paper presents the potential use of supplemental control of a new economical phase imbalanced shunt compensation concept for damping sub synchronous resonance (SSR) oscillations. In this scheme, the shunt capacitive compensation in one phase is created by using a Single-Phase Static Synchronous Compensator (STATCOM) in parallel with a fixed capacitor (Cc), and the other two phases are compensated by fixed shunt capacitor (C). The proposed arrangement would, certainly, be economically attractive when compared with a full three-phase STATCOM which have been used/proposed for power swings and SSR damping. SSR mitigation is achieved by introducing a supplemental signal into the control loops of single phase STATCOM. The validity and effectiveness of the proposed structure and supplemental control are demonstrated on a modified version of the IEEE second benchmark model for computer simulation of sub synchronous resonance by means of time domain simulation analysis using the Matlab program.


2005 ◽  
Vol 64 (3) ◽  
pp. 269-275 ◽  
Author(s):  
Angela Dickinson ◽  
Carol Welch ◽  
Laurie Ager ◽  
Aileen Costar

Poor nutritional care within the hospital setting continues despite decades of work chronicling and measuring the problems. To address the problem changes in practice have been attempted to improve the patients’ experience of mealtimes. In order to implement patient-centred mealtimes for older patients by changing the focus from institutional convenience to one that focuses on the requirements of the patients, an action research approach has been used that focuses on action and change, and thus appears to have much to offer those who seek to change practice. The present paper focuses on the first two phases in a three-phase approach. In phase one the nature of everyday mealtime care and the wider context are explored using focus groups, interviews and observations. The data fall into three main themes that all impact on patients’ experiences of mealtimes: institutional and organisational constraints; mealtime care and nursing priorities; eating environment. Following feedback of phase 1 findings to staff and identification of areas of concern a model of practice development was selected to guide the change process of the second phase. Changes to mealtime nursing practice and the ward environment have been made, indicating that action research has the potential to improve the mealtime care of patients.


Author(s):  
Istifatun Zaka

This paper describes about the phenomenon of slang language on social network, namelyfacebook and twitter. Slang in this paper belongs to sociolinguistics study, especially sociolect. This isa descriptive qualitative method, which consists of three phase: data collection, data analysis, andpresentation of the result of data analysis. The data were collected by observing the netters utterance.Data were analysed through two phases. First, analyzing the meaning of the slang. Second, wasanalysing the categories of the slang.There are four point findings in this study. Firstly, the various forms of slang expression unitsare words and phrases. Secondly, the variety of linguistic processes forming units slang expression areby adding sound, erasing sound, changing vocal, replacing consonant, shifting sound, returning sound,repeating, and changing spell. Thirdly, the source languages of various slang reference units are fromnational language, regional languages, and foreign languages. Fourthly, the communicative functionsof various units of slang expressions are informative function, directive function, expressive function,komisif function, phatic function, and poetic function. Finally, from the finding of those four points inthis study, we know that slang language on facebook and twitter has its own uniqueness compared toother types of language.


2019 ◽  
Vol 28 (08) ◽  
pp. 1950138 ◽  
Author(s):  
WangLok Do ◽  
Farzin Asadi ◽  
Kei Eguchi

The paper presents the theoretical analysis way of the switched capacitor converter (SCC). The main goal of this research is to suggest the analysis way of three-phase SCC. A common SCC operates by two phases; charging phase and discharging phase. Therefore, state-space averaging model or slow and fast switching limit (S-FSL) model has been suitable. Although the four-terminal equivalent model can cover all situation including three-phases cases, this model does not include the parameter of frequency and capacitance. Therefore, the four-terminal model has a weakness. In this situation, we selected the Fibonacci sequence SCC operated by three-phase as the target circuit, which topology has been proved to have higher efficiency, small size in the previous research. In the paper, we suggest the new analysis way of the three-phase SCC by combination of the four-terminal equivalent model and RC circuit model from each loop equation of the equivalent circuits of the SCC. By using the suggested way, it is possible to analyze the three-phase SCC, deriving the effect of the load, operation frequency and duty ratio variation. In order to verify the feasibility and the cogency of the suggested analysis way, comparative analysis is implemented by SPICE simulations. The error in the load regulation between the suggested way and the simulation result is negligible. Through this result, we establish the foundation of the analysis of the three-phase SCC.


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