The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
It is possible to carry out activities related to load profiling, energy consumption estimation, planning, taking new investment decisions, managing voltage and energy quality, system efficiency and loss of line with the evaluation of collected data from smart grid. Therefore, it is important to analyze and forecast the smart grid. Energy efficiency in fast-growing countries like Turkey is an important...
Design of traveling-wave tubes requires accurate estimate of interaction impedance for the fundamental and nonfundamental space harmonics of the slow wave structures such as circular helix. Previous work based on Fourier decomposition has shown that the interaction impedance for the fundamental space harmonic can be estimated accurately using simulations. Here, we consider the interaction impedance...
Ships stability and safety are always threatened by the unavoidable sway in the complicated situation of the sea, e.g. strong wind and roaring waves. Ensuring the stability of the ship as a difficult task has received its popularities in the community in the past few decades. However, conventional control methods such as sliding mode control (SMC) and Proportional integral derivative (PID) fail to...
There were significant difference of demodulation spectrum featrue between simulation signal according to the existed modulation models of ship radiated noise and actual ship radiated noise. This paper analysis the modulation feature of ship radiated noise based on sub-bands DEMON estimation. The results demonstrate that ship radiated noise is amplitude-modulated by propeller's beat and the modulation...
This paper presents a step by step modeling of a new improved hybrid photovoltaic fed distributed static compensator (PV-DSTATCOM) in a-b-c reference frame. Further the system average model is transformed to orthogonal synchronous (d-q) reference frame. The new improved PV-DSTATCOM is used to compensate the current distortion and reactive power, generated by a non-linear three phase bridge uncontrolled...
This paper proposes a modeling and control to enhance a grid on/ofï operation of a single-phase system consisting of a Single-Phase Five-Level Inverter (SPFLI). The Sliding mode control is adopted to compensate the current harmonics, the reactive power and the regulation of the DC bus voltage at the PCC during grid operation. The renewable energy based PMSG wind turbine is used to reduce the energy...
We push forward setting of the elevator for barrier-free and exchanging of the LED light for energy saving in stations. But harmonic currents may increase by these facilities in the power distribution network. It is effective to take measures for harmonic currents from the design phase. In this paper, the method of this report can estimate harmonic current emissions in case of stations improved by...
A new method for reducing harmonics involved in input voltages of a three-phase voltage source diode rectifier is proposed. It is applied to the conventional 6-step diode rectifier with a three-phase autotransformer. By injecting harmonics to the neutral point of the autotransformer from an auxiliary circuit, input voltages of the proposed diode rectifier can be almost the same as a conventional 36-step...
In two-level PWM rectifiers, two common control strategies are respectively VOC (Voltage Oriented Control) and DPC (Direct Power Control). In high power applications, the converter performance may suffer seriously from the non-ideal characteristics of the sampling and control system. The effects of the non-ideal characteristics will be analyzed in this paper for classic VOC, DPC and PDPC (Predictive...
Switch mode power supplies generated a wide range of conductive and inductive interference. Moreover, the spectrum dominated by discrete components with a switching frequency of a power transistor and its harmonics. To ensure the electromagnetic compatibility of devices necessary to reduce the amplitude of these spectral components. In this paper the questions of usage of spread spectrum technology...
This paper presents a model predictive control strategy to control the active and reactive powers for three-phase three-level NPC PWM rectifier directly. This method is based on converter model. It uses voltages and currents of the converter and does not use hysteresis or PI controllers for active and reactive powers control loop. This algorithm is robust against to tolerances of input inductances...
This paper is focused on the improvement of the grid current at the point of common coupling of a three-phase grid connected photovoltaic system supplying a non-linear load. This improvement is achieved by using the PV inverter as a shunt active power filter in addition to its main function of power injection in the grid. The shunt active power filtering is performed to compensate the disturbing grid...
This paper deals with the control design of an asymmetrical cascaded multilevel inverter. This structure therefore provides the capability to produce higher voltages at higher speeds with low switching frequency which has inherent low switching losses and high converter efficiency. Selective harmonic elimination(SHE) for asymmetrical multilevel CHB inverter control is proposed. The technique utilized...
Modulation techniques for the modular multilevel converter consider that the total number of sub-modules in the phase-leg is, either instantaneously or on average, equal to N balancing the capacitor voltages to a constant reference. This paper proposes an offset PWM technique that utilises the total number of the SMs in the arms of the MMC, particularly under low modulation indices. The result is...
This paper presents an improvement in the harmonics compensation performance of a previously proposed smart charger (SC) with a constant dc-capacitor voltage-control (CDCVC)-based strategy for electric vehicles (EVs) in single-phase three-wire distribution feeders (SPTWDFs). A current controller of a three-leg pulse-width modulated rectifier with proportional-integral (PI) controllers in d-q coordinates...
In the literature, passive filters have been commonly used to mitigate the harmonic currents in industrial distribution systems because they are inexpensive, simple, and reliable. The aim of this paper is presenting different design methods for multiple-arm shunt passive filters based on various reactive power sharing approaches for an industrial distribution system of a petrochemical plant in Egypt...
This work is interested by modeling and simulation of an association Inverter-asynchronous machine. the modeling of the asynchronous machine made by a study, by using the simplifying assumptions. the order of the converter (inverter) is based on the method — Pulse Width of Modulation (PWM)-. Which brought better a quality of control, dynamics and precision.
This paper presents the performance verification of accuracy between simulation and real-time harmonic source identification system. The simulation and real-time system are implementing spectrogram as analysis technique that offers high accuracy and represent signals in time-frequency representation (TFR). From the TFR, signal parameters such as instantaneous of root mean square (RMS), fundamental...
Synchronization control is of great importance for grid-connected power converter so that precise phase angle information of the grid voltage is required. As three-phase grid voltages are imbalanced or distorted, Synchronous Reference Frame Phase-Locked Loop (SRF-PLL) aims to track fundamental frequency positive sequence with zero steady state error. The in-loop Cascaded Delayed Signal Cancellation...
The Airborne Gravimeter is a precision instrument for measure of the earth's gravity, in order to make the gravimeter isolate all kinds of disturbances in flight, and always keep an upright and stable state. In this paper, a high accuracy Airborne Gravimeter inertial stable platform was designed for this purpose. Also in order to shorten the design cycle of stable platform and ensure the performance...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.