Increasing quality of SMPS through proper design of a high-frequency transformer

2020 ◽  
Vol 11 (4) ◽  
pp. 541
Author(s):  
M. Frivaldsky ◽  
P. Spanik ◽  
V. Jaros ◽  
A. Kanovsky
Keyword(s):  
High Frequency ◽  
High Frequency Transformer ◽  
Proper Design

Increasing quality of SMPS through proper design of a high-frequency transformer

2020 ◽  
Vol 11 (4) ◽  
pp. 541
Author(s):  
A. Kanovsky ◽  
P. Spanik ◽  
V. Jaros ◽  
M. Frivaldsky
Keyword(s):  
High Frequency ◽  
High Frequency Transformer ◽  
Proper Design

scholarly journals Modified Structure of Sepic Based Single-Phase Five-Level T-Type Inverter for Photovoltaic Applications

2019 ◽  
Vol 9 (1) ◽  
pp. 3852-3856 ◽  
Keyword(s):  
High Frequency ◽  
Single Phase ◽  
Pulse Width Modulation ◽  
Prototype Model ◽  
Matlab Simulation ◽  
Voltage Level ◽  
High Frequency Transformer ◽  
Photovoltaic Applications ◽  
Quality Of Supply

In this paper, a modified structure of two-stage sepic based five-level T-type inverter is presented for photovoltaic applications. The proposed topology consists of a frond-end sepic converter cascaded with full bridge T-type inverter through a high-frequency transformer. The proposed topology owns the merits of high boost output voltage level, modularity, reduced device parts, and better quality of supply. Therefore, a detailed operation of the proposed topology and the level generations using sine pulse width modulation are presented. Finally, the performance of the proposed topology is validated through Matlab simulation and experimental prototype model results

Design of High Current Two-Way DC/DC Converter in Lithium-Ion Battery Formation Equipment

2012 ◽  
Vol 241-244 ◽  
pp. 671-675
Author(s):  
Dong He ◽  
Gen Wang Liu ◽  
Ke Song ◽  
Dan Wu
Keyword(s):  
High Frequency ◽  
Low Voltage ◽  
High Reliability ◽  
Lithium Ion ◽  
High Current ◽  
High Frequency Transformer ◽  
Feedback Module ◽  
Driving Circuit ◽  
Critical Process

As the critical process in battery production, formation is related to the quality of battery and directly affects production cost. A low voltage, high current DC/DC converter is designed for large capacity lithium battery formation equipment. Design of basic topological structure, feedback module and peripheral steering circuit are introduced. Besides, design of PWM driving circuit and parameters of high- frequency transformer are presented in detail. This two-way DC/DC converter has features of high stability, high reliability, small size, light weight and its efficiency of buck-boost can be up to 84% and 83% respectively.

Simulation of vibration piercing of pipe blank at press

2020 ◽  
Vol 76 (11) ◽  
pp. 1128-1138
Author(s):  
S. R. Rakhmanov
Keyword(s):  
High Frequency ◽  
Deformation Zone ◽  
Pipe Blank ◽  
Equipment Operation ◽  
Metal Deformation ◽  
Technological Tool ◽  
High Frequency Vibrations ◽  
Pipe Blanks ◽  
Wave Phenomena

In some cases, the processes of piercing or expanding pipe blanks involve the use of high-frequency active vibrations. However, due to insufficient knowledge, these processes are not widely used in the practice of seamless pipes production. In particular, the problems of increasing the efficiency of the processes of piercing or expanding a pipe blank at a piercing press using high-frequency vibrations are being solved without proper research and, as a rule, by experiments. The elaboration of modern technological processes for the production of seamless pipes using high-frequency vibrations is directly related to the choice of rational modes of metal deformation and the prediction resistance indicators of technological tools and the reliability of equipment operation. The creation of a mathematical model of the process of vibrating piercing (expansion) of an axisymmetric pipe blank at a piercing press of a pipe press facility is an actual task. A calculation scheme for the process of piercing a pipe plank has been elaborated. A dependence was obtained characterizing the speed of front of plastic deformation propagation on the speed of penetration of a vibrated axisymmetric mandrel into the pipe workpiece being pierced. The dynamic characteristics of the occurrence of wave phenomena in the metal being pierced under the influence of a vibrated tool have been determined, which significantly complements the previously known ideas about the stress-strain state of the metal in the deformation zone. The deformation fields in the zones of the disturbed region of the deformation zone were established, taking into account the high-frequency vibrations of the technological tool. It has been established that the choice of rational parameters (amplitude-frequency characteristics) of the vibration piercing process of a pipe blank results in significant increase in the efficiency of the process, the durability of the technological tool and the quality of the pierced blanks.

Dynamics of the processes in metal machining

1998 ◽  
Vol 2 ◽  
pp. 115-122
Author(s):  
Donatas Švitra ◽  
Jolanta Janutėnienė
Keyword(s):  
High Frequency ◽  
Machine Tools ◽  
Metal Cutting ◽  
Cutting Tool ◽  
Low Frequency ◽  
Metal Cutting Machine ◽  
Cutting Machine ◽  
Metal Machining

In the practice of processing of metals by cutting it is necessary to overcome the vibration of the cutting tool, the processed detail and units of the machine tool. These vibrations in many cases are an obstacle to increase the productivity and quality of treatment of details on metal-cutting machine tools. Vibration at cutting of metals is a very diverse phenomenon due to both it’s nature and the form of oscillatory motion. The most general classification of vibrations at cutting is a division them into forced vibration and autovibrations. The most difficult to remove and poorly investigated are the autovibrations, i.e. vibrations arising at the absence of external periodic forces. The autovibrations, stipulated by the process of cutting on metalcutting machine are of two types: the low-frequency autovibrations and high-frequency autovibrations. When the low-frequency autovibration there appear, the cutting process ought to be terminated and the cause of the vibrations eliminated. Otherwise, there is a danger of a break of both machine and tool. In the case of high-frequency vibration the machine operates apparently quiently, but the processed surface feature small-sized roughness. The frequency of autovibrations can reach 5000 Hz and more.

Systematic literature review of clinical outcomes in adults with metastatic or advanced synovial sarcoma

2020 ◽  
Vol 16 (35) ◽  
pp. 2997-3013
Author(s):  
Kentaro Kogushi ◽  
Michael LoPresti ◽  
Shunya Ikeda
Keyword(s):  
Synovial Sarcoma ◽  
High Frequency ◽  
Clinical Evidence ◽  
Systemic Treatment ◽  
Progression Free Survival ◽  
Treatment Modalities ◽  
Free Survival ◽  
New Treatment ◽  
Poor Outcomes

Background: Synovial sarcoma (SS) is a rare, aggressive soft tissue sarcoma with a poor prognosis after metastasis. The objective of this study was to conduct a systematic review of the clinical evidence for therapeutic options for adults with metastatic or advanced SS. Materials & methods: Relevant databases were searched with predefined keywords. Results: Thirty-nine publications reported clinical data for systemic treatment and other interventions. Data on survival outcomes varied but were generally poor (progression-free survival: 1.0–7.7 months; overall survival: 6.7–29.2 months) for adults with metastatic and advanced SS. A high frequency of neutropenia with systemic treatment and low quality of life post-progression were reported. Conclusion: Reported evidence suggests poor outcomes in adults with metastatic and advanced SS and the need for the development of new treatment modalities.

scholarly journals How Good Is the STW Sensor? An Account from a Larger Shipping Company

2021 ◽  
Vol 9 (5) ◽  
pp. 465
Author(s):  
Angelos Ikonomakis ◽  
Ulrik Dam Nielsen ◽  
Klaus Kähler Holst ◽  
Jesper Dietz ◽  
Roberto Galeazzi
Keyword(s):  
High Frequency ◽  
Additional Data ◽  
Empirical Method ◽  
Influential Factor ◽  
Sensor Data ◽  
Sea State ◽  
Shipping Company ◽  
Frequency Sensor ◽  
Semi Empirical

This paper examines the statistical properties and the quality of the speed through water (STW) measurement based on data extracted from almost 200 container ships of Maersk Line’s fleet for 3 years of operation. The analysis uses high-frequency sensor data along with additional data sources derived from external providers. The interest of the study has its background in the accuracy of STW measurement as the most important parameter in the assessment of a ship’s performance analysis. The paper contains a thorough analysis of the measurements assumed to be related with the STW error, along with a descriptive decomposition of the main variables by sea region including sea state, vessel class, vessel IMO number and manufacturer of the speed-log installed in each ship. The paper suggests a semi-empirical method using a threshold to identify potential error in a ship’s STW measurement. The study revealed that the sea region is the most influential factor for the STW accuracy and that 26% of the ships of the dataset’s fleet warrant further investigation.

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