21 research outputs found
Necessity of low range voltage stabilization and solution with transformer based AC pulse modulation system
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Possibilities of Parametric Adaptation of Inductors of Current-smoothing Converter Links to Load Conditions
No full textEfficiency Performance Evaluation on Multi-user Web Application Platforms in Cloud Computing
No full textCloud computing is a well-known paradigm nowadays because it decreases the cost to access the application, for a massive amount of data from anywhere in the world via internet. This paper takes the approach of testing the performance of web application deployment environment. The main objective of this paper was to investigate the performance of web application deployment infrastructure by growing eventually the number of users that visit the web application concurrently. The infrastructure that was used is part of the services provided by cloud computing, more specifically Platform as a Service (PaaS). This service provided a runtime environment in which we easily created, tested and deployed the web application. Tests were designed by using an open source tool. Web application subject for testing purposes was an open source pet shop application which fulfils the criteria of being a multi-user web application. Tests were created by using an open source application called Apache JMeter. One of main goals was to develop a proper test plan by considering user behaviour accessing a web application. We have developed and implemented three scenarios, started with deployment of the platform, installing dependencies and finally installing the web application used for performance testing. We have tested 2 different deployment platforms, in the first environment everything is installed in one machine and in second environment we separate application server from the database server. We have concluded in results where processes like register, login and checkout consumes much more resources of the server. In the future we will try to understand where machine learning stands in this part of web application development and how it can affect deployment infrastructure
Self-Excitation System for Synchronous Generator
No full textSelf-excitation for synchronous generator is described in the paper. The system is based on a buck converter input filter capacitor discharge through excitation winding of the generator. The buck converter is connected to the stator outputs through an uncontrollable diode rectifier, but excitation winding is used as a load. Input filter capacitor of the converter provides initial current pulse which magnetizes excitation system and produces the generator voltage increase, for this reason the capacitor is charged before self-excitation process starts. Results of the computer simulation and physical experiment are obtained and presented. These results show that the proposed self-excitation converter in conjunction with an input capacitor pre-charged from a low-power electronic generator actually magnetizes the generator excitation system therefore generator voltage and accordingly excitation current increases. Stabilization of generator output voltage occurs with a voltage surge, though its peak value slightly exceeds the reference one. The future investigation of the proposed self-excitation system may include definition of mathematical equations which describe transients in the generator’s self-excitation mode and development of control methods for purpose of self-excitation process control without voltage peaks. The computer model also should be improved
Investigation of the effectivness of nonlinear inductor in the AC/DC node of three phase rectifier
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Power Measurement and Data Logger Device with High-Resolution for Industrial DC-Grid Application
No full textAbstract – power and energy measurement and monitoring is a key leading factor for many industries in terms of energy and cost efficiency evaluation. Due to trends of Smart Grid concept application in industrial environment, including decentralized DC-Grid implementation, for precise evaluation - faster and lower cost measurement equipment is needed. Manufacturing industry use lot of industrial robots that have dynamic load characteristics, and to know their consumption faster measurement equipment is needed. This paper gives brief description of developed power measurement equipment, its structure and interconnection to industrial PROFInet network. Further as a testing method steady state and dynamic loads are selected and analyzed. For testing, specially created industrial DC-Grid testing environment and equipment has been used. Testing results shows that selected method and idea is working, and it is able to measure dynamic loads with high resolution. For other industrial load types, discussion rises, about how detailed resolution is needed in industrial SmartGrids, as energy forecast is a new trend in robotic industry, and manufacturing planning
