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Volumen 18 (2022): Heft 1 (June 2022)

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Volumen 7 (2014): Heft 1 (December 2014)

Volumen 6 (2014): Heft 1 (October 2014)

Volumen 5 (2014): Heft 1 (May 2014)

Volumen 4 (2013): Heft 1 (December 2013)

Volumen 3 (2013): Heft 1 (August 2013)

Volumen 2 (2013): Heft 1 (April 2013)

Volumen 1 (2012): Heft 1 (December 2012)

Zeitschriftendaten
Format
Zeitschrift
eISSN
2255-9159
Erstveröffentlichung
31 Jan 2013
Erscheinungsweise
2 Hefte pro Jahr
Sprachen
Englisch

Suche

Volumen 7 (2014): Heft 1 (December 2014)

Zeitschriftendaten
Format
Zeitschrift
eISSN
2255-9159
Erstveröffentlichung
31 Jan 2013
Erscheinungsweise
2 Hefte pro Jahr
Sprachen
Englisch

Suche

6 Artikel
Uneingeschränkter Zugang

Electromechanical Battery EMB Mass Minimization taking into Account its Electrical Machines Rotor Energy

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 5 - 10

Zusammenfassung

Abstract

In this paper the electromechanical battery (EMB) with synchronous machine is described. Theoretically, if electrical machines rotor stored energy is known, it is possible to reduce the flywheel mass of electromechanical battery. For example, the efficiency of energy recovery (kilowatt-hours out versus kilowatthours in) in nowadays appliances exceeds 95 % which is considerably better than of any electrochemical battery, such as lead-acid battery. For the rotor stored energy amount calculation, it is necessary to find all geometrical dimensions of the electrical machine. To achieve this goal the iterative calculation method was used. Electromechanical battery mass was analyzed as a discharge process rotation speed function. Taking into account the rotor stored energy, we can increase the minimum rotation speed thus reducing the electrical machine mass and increasing the flywheel mass, which provides EMB cost reduction. Additionally, the possibilities of using numerical approximation calculations of magnetization curves are discussed. Each iteration of numerical application necessary for the method for rapid calculation is essential when calculating the field problems. Nowadays there are a lot of computer added design programs for electromagnetic field calculation in different types of applications, electrical machines and apparatus. For the electromagnetic field calculation process some more commonly used magnetization curve approximation methods are described, and the machine calculation time is tested for different numbers of calculations.

Schlüsselwörter

  • Flywheels
  • Minimization methods
  • Approximation algorithms
  • Numerical simulation
  • Design optimization
Uneingeschränkter Zugang

Tesla Coil Theoretical Model and its Experimental Verification

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 11 - 19

Zusammenfassung

Abstract

In this paper a theoretical model of Tesla coil operation is proposed. Tesla coil is described as a long line with distributed parameters in a single-wire form, where the line voltage is measured across electrically neutral space. By applying the principle of equivalence of single-wire and two-wire schemes an equivalent two-wire scheme can be found for a single-wire scheme and the already known long line theory can be applied to the Tesla coil. A new method of multiple reflections is developed to characterize a signal in a long line. Formulas for calculation of voltage in Tesla coil by coordinate and calculation of resonance frequencies are proposed. The theoretical calculations are verified experimentally. Resonance frequencies of Tesla coil are measured and voltage standing wave characteristics are obtained for different output capacities in the single-wire mode. Wave resistance and phase coefficient of Tesla coil is obtained. Experimental measurements show good compliance with the proposed theory. The formulas obtained in this paper are also usable for a regular two-wire long line with distributed parameters.

Schlüsselwörter

  • Transformers
  • Resonance
  • Transmission lines
  • Mathematical model
  • Electromagnetic modeling
Uneingeschränkter Zugang

Battery Equalization Control Based on the Shunt Transistor Method

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 20 - 27

Zusammenfassung

Abstract

Electric Vehicle (EV) researches are currently becoming of special importance and the EV battery system is particularly relevant in the EV design. In these applications, series connected batteries are necessary since a single battery cannot achieve the voltage requirements. Internal and external sources lead the batteries string to become unbalanced, which is an important factor to be taken into account, as premature cells degradation, safety hazards, and reduced capacity will occur for unbalanced systems. The different balancing methods are presented and compared in this paper, and finally the switch capacitor and the double-tiered switching capacitor are considered the best option. However, their speed depends on the voltage difference between the batteries in the string, and when their voltage difference is low, the equalization speed decreases significantly, leading the battery pack to be unbalanced for longer. A novel equalization method is presented, that improves the aforementioned methods performance by applying a new control to a shunt transistor method. Low cost, size, and complexity, together with higher speed and efficiency are obtained. A prototype has been built, and experimental results are presented.

Schlüsselwörter

  • Batteries
  • Battery Management Systems
  • Battery chargers
Uneingeschränkter Zugang

Current Sensorless Control Algorithm for Single-Phase Three-Level NPC Inverter

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 28 - 33

Zusammenfassung

Abstract

The current measurement is becoming a challenging task in power converters operating at high switching frequencies, moreover traditional control system requires two control loops - first (slow) regulates DC-link voltage, second (fast) controls the shape of current, that all together results in complicated transfer function and long transition periods. The current sensorless control (CSC) allows neglecting the mentioned problems. This research for the first time presents the solution of CSC implementation in single-phase three-level neutral point clamped inverter. Mathematical equations were defined for inductor current peaks and transistor conduction time during discontinuous and continuous conduction modes, as well as major problem of current fitting between different voltage levels (consequently with different current peak-to-peak values) was solved, providing two solutions - pre-fitting and post-fitting trajectories. The verification of our theoretical assumptions and analytical equations was confirmed by the simulation analysis. Challenges of real experiments are discussed in the conclusion.

Schlüsselwörter

  • Sensorless control
  • Current control
  • Pulse width modulation inverters
Uneingeschränkter Zugang

Traffic Route Modelling and Assignment with Intelligent Transport System

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 34 - 40

Zusammenfassung

Abstract

The development of signal transmitting environment for multimodal traffic control will enhance the integration of emergency and specialized transport routing tools in usual traffic control paradigms - it is one of the opportunities offered by modern intelligent traffic control systems. The improvement of effective electric power use in public transport system is an advantage of Intelligent Transport System (ITS). The research is connected with the improvement of on-line traffic control and adaptation of special traffic lighting alternatives by ITS. The assignment of the nearest appropriate transport will be done by passenger request, but unlike information system, the transport planning is done on demand. The task can be solved with the help of modern technical methods and equipment, as well as by applying control paradigms of the distributed systems. The problem is solved with the help of calculations hyper-graph and scheduling theory. The goal of the research is to develop methods, which support scheduling of the emergency transport, using high performance computing.

Schlüsselwörter

  • Intelligent transportation systems
  • Communication networks
  • Communication system traffic control
  • Intelligent vehicles
  • Land transportation
Uneingeschränkter Zugang

Distributed Multi-Sensor Real-Time Building Environmental Parameters Monitoring System with Remote Data Access

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 41 - 46

Zusammenfassung

Abstract

In this paper the advanced monitoring system of multiple environmental parameters is presented. The purpose of the system is a long-term estimation of energy efficiency and sustainability for the research test stands which are made of different building materials. Construction of test stands, and placement of main sensors are presented in the first chapter. The structure of data acquisition system includes a real-time interface with sensors and a data logger that allows to acquire and log data from all sensors with fixed rate. The data logging system provides a remote access to the processing of the acquired data and carries out periodical saving at a remote FTP server using an Internet connection. The system architecture and the usage of sensors are explained in the second chapter. In the third chapter implementation of the system, different interfaces of sensors and energy measuring devices are discussed and several examples of data logger program are presented. Each data logger is reading data from analog and digital channels. Measurements can be displayed directly on a screen using WEB access or using data from FTP server. Measurements and acquired data graphical results are presented in the fourth chapter in the selected diagrams. The benefits of the developed system are presented in the conclusion.

Schlüsselwörter

  • Data acquisition
  • Energy efficiency
  • Remote monitoring
6 Artikel
Uneingeschränkter Zugang

Electromechanical Battery EMB Mass Minimization taking into Account its Electrical Machines Rotor Energy

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 5 - 10

Zusammenfassung

Abstract

In this paper the electromechanical battery (EMB) with synchronous machine is described. Theoretically, if electrical machines rotor stored energy is known, it is possible to reduce the flywheel mass of electromechanical battery. For example, the efficiency of energy recovery (kilowatt-hours out versus kilowatthours in) in nowadays appliances exceeds 95 % which is considerably better than of any electrochemical battery, such as lead-acid battery. For the rotor stored energy amount calculation, it is necessary to find all geometrical dimensions of the electrical machine. To achieve this goal the iterative calculation method was used. Electromechanical battery mass was analyzed as a discharge process rotation speed function. Taking into account the rotor stored energy, we can increase the minimum rotation speed thus reducing the electrical machine mass and increasing the flywheel mass, which provides EMB cost reduction. Additionally, the possibilities of using numerical approximation calculations of magnetization curves are discussed. Each iteration of numerical application necessary for the method for rapid calculation is essential when calculating the field problems. Nowadays there are a lot of computer added design programs for electromagnetic field calculation in different types of applications, electrical machines and apparatus. For the electromagnetic field calculation process some more commonly used magnetization curve approximation methods are described, and the machine calculation time is tested for different numbers of calculations.

Schlüsselwörter

  • Flywheels
  • Minimization methods
  • Approximation algorithms
  • Numerical simulation
  • Design optimization
Uneingeschränkter Zugang

Tesla Coil Theoretical Model and its Experimental Verification

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 11 - 19

Zusammenfassung

Abstract

In this paper a theoretical model of Tesla coil operation is proposed. Tesla coil is described as a long line with distributed parameters in a single-wire form, where the line voltage is measured across electrically neutral space. By applying the principle of equivalence of single-wire and two-wire schemes an equivalent two-wire scheme can be found for a single-wire scheme and the already known long line theory can be applied to the Tesla coil. A new method of multiple reflections is developed to characterize a signal in a long line. Formulas for calculation of voltage in Tesla coil by coordinate and calculation of resonance frequencies are proposed. The theoretical calculations are verified experimentally. Resonance frequencies of Tesla coil are measured and voltage standing wave characteristics are obtained for different output capacities in the single-wire mode. Wave resistance and phase coefficient of Tesla coil is obtained. Experimental measurements show good compliance with the proposed theory. The formulas obtained in this paper are also usable for a regular two-wire long line with distributed parameters.

Schlüsselwörter

  • Transformers
  • Resonance
  • Transmission lines
  • Mathematical model
  • Electromagnetic modeling
Uneingeschränkter Zugang

Battery Equalization Control Based on the Shunt Transistor Method

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 20 - 27

Zusammenfassung

Abstract

Electric Vehicle (EV) researches are currently becoming of special importance and the EV battery system is particularly relevant in the EV design. In these applications, series connected batteries are necessary since a single battery cannot achieve the voltage requirements. Internal and external sources lead the batteries string to become unbalanced, which is an important factor to be taken into account, as premature cells degradation, safety hazards, and reduced capacity will occur for unbalanced systems. The different balancing methods are presented and compared in this paper, and finally the switch capacitor and the double-tiered switching capacitor are considered the best option. However, their speed depends on the voltage difference between the batteries in the string, and when their voltage difference is low, the equalization speed decreases significantly, leading the battery pack to be unbalanced for longer. A novel equalization method is presented, that improves the aforementioned methods performance by applying a new control to a shunt transistor method. Low cost, size, and complexity, together with higher speed and efficiency are obtained. A prototype has been built, and experimental results are presented.

Schlüsselwörter

  • Batteries
  • Battery Management Systems
  • Battery chargers
Uneingeschränkter Zugang

Current Sensorless Control Algorithm for Single-Phase Three-Level NPC Inverter

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 28 - 33

Zusammenfassung

Abstract

The current measurement is becoming a challenging task in power converters operating at high switching frequencies, moreover traditional control system requires two control loops - first (slow) regulates DC-link voltage, second (fast) controls the shape of current, that all together results in complicated transfer function and long transition periods. The current sensorless control (CSC) allows neglecting the mentioned problems. This research for the first time presents the solution of CSC implementation in single-phase three-level neutral point clamped inverter. Mathematical equations were defined for inductor current peaks and transistor conduction time during discontinuous and continuous conduction modes, as well as major problem of current fitting between different voltage levels (consequently with different current peak-to-peak values) was solved, providing two solutions - pre-fitting and post-fitting trajectories. The verification of our theoretical assumptions and analytical equations was confirmed by the simulation analysis. Challenges of real experiments are discussed in the conclusion.

Schlüsselwörter

  • Sensorless control
  • Current control
  • Pulse width modulation inverters
Uneingeschränkter Zugang

Traffic Route Modelling and Assignment with Intelligent Transport System

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 34 - 40

Zusammenfassung

Abstract

The development of signal transmitting environment for multimodal traffic control will enhance the integration of emergency and specialized transport routing tools in usual traffic control paradigms - it is one of the opportunities offered by modern intelligent traffic control systems. The improvement of effective electric power use in public transport system is an advantage of Intelligent Transport System (ITS). The research is connected with the improvement of on-line traffic control and adaptation of special traffic lighting alternatives by ITS. The assignment of the nearest appropriate transport will be done by passenger request, but unlike information system, the transport planning is done on demand. The task can be solved with the help of modern technical methods and equipment, as well as by applying control paradigms of the distributed systems. The problem is solved with the help of calculations hyper-graph and scheduling theory. The goal of the research is to develop methods, which support scheduling of the emergency transport, using high performance computing.

Schlüsselwörter

  • Intelligent transportation systems
  • Communication networks
  • Communication system traffic control
  • Intelligent vehicles
  • Land transportation
Uneingeschränkter Zugang

Distributed Multi-Sensor Real-Time Building Environmental Parameters Monitoring System with Remote Data Access

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 41 - 46

Zusammenfassung

Abstract

In this paper the advanced monitoring system of multiple environmental parameters is presented. The purpose of the system is a long-term estimation of energy efficiency and sustainability for the research test stands which are made of different building materials. Construction of test stands, and placement of main sensors are presented in the first chapter. The structure of data acquisition system includes a real-time interface with sensors and a data logger that allows to acquire and log data from all sensors with fixed rate. The data logging system provides a remote access to the processing of the acquired data and carries out periodical saving at a remote FTP server using an Internet connection. The system architecture and the usage of sensors are explained in the second chapter. In the third chapter implementation of the system, different interfaces of sensors and energy measuring devices are discussed and several examples of data logger program are presented. Each data logger is reading data from analog and digital channels. Measurements can be displayed directly on a screen using WEB access or using data from FTP server. Measurements and acquired data graphical results are presented in the fourth chapter in the selected diagrams. The benefits of the developed system are presented in the conclusion.

Schlüsselwörter

  • Data acquisition
  • Energy efficiency
  • Remote monitoring

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