scholarly journals Improving the Quality of Electricity in Installations with Mixed Lighting Fittings

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6017
Author(s):  
Tomasz Popławski ◽  
Marek Kurkowski ◽  
Jarosław Mirowski
Keyword(s):  
Single Phase ◽  
Reactive Power ◽  
Supply Voltage ◽  
Higher Harmonics ◽  
Energy Parameters ◽  
Wide Range ◽  
Single Complex ◽  
The Asymmetry ◽  
Mixed Systems

The issues that are presented in the article concern the broadly understood parameters of the operation of lighting fixtures in mixed systems and the improvement of the quality of electricity, considered in two aspects: as receivers of the energy consumed, determining and generating reactive power, influencing the asymmetry of currents and the production of higher harmonics, determined by the parameters of current and supply voltage (independent of the consumers connected at the connection point), which are influenced by the consumers that are connected at the connection point. After the tests, in order to improve the quality of energy, a proprietary program for the design of passive resonance filters was developed. A wide range of measurements of various types of lighting devices was carried out in single, complex, and mixed systems. Luminaires with discharge and LED sources were selected for the analysis of energy parameters. The tests were carried out in accordance with the IEEE 1459-2010 standard for single-phase circuits with distorted waveforms.

scholarly journals The influence of the network asymmetry on the settings and sensitivity of an earth fault protection using higher harmonics

2019 ◽  
Vol 84 ◽  
pp. 02008
Author(s):  
Lubomir Marciniak ◽  
Mateusz Piątek
Keyword(s):  
Reactive Power ◽  
Higher Harmonics ◽  
Medium Voltage ◽  
Earth Fault ◽  
Power Setting ◽  
Zero Sequence ◽  
The Asymmetry ◽  
Supply Voltages ◽  
Zero Sequence Voltage

Detection of high resistance earth faults in medium voltage networks is an important problem due to ineffectiveness of traditional earth fault protections. Such short circuits can be detected by the criterion of a reactive power of higher harmonics for zero sequence current and voltage. The main problem is determination of the power setting value in the protection, which depends on the asymmetry of phase-to-earth capacitances and higher harmonics in supply voltages, which are generated by non-linear loads. The intensive tests of the asymmetry of the zero sequence currents and voltages for harmonics and their reactive power have been carried out in 15 kV compensated network as a function of all relevant parameters, i.e.: maximum capacitance deviation of the network and protected line, percentage content of harmonics in supply voltages, capacitive current of the network and the line. It has been shown that third harmonics of the zero sequence voltage and current are the best suited for practical use, since the asymmetry reactive power of these components is the smallest among the considered harmonics and the protection sensitivity will be the highest.

Structural, dielectric, electrical and piezoelectric properties of Ba4SrRTi3V7O30 (R=Sm, Dy) ceramics

Open Physics ◽  
2008 ◽  
Vol 6 (4) ◽  
Author(s):  
Priyadarshini Sahoo ◽  
Anuradha Panigrahi ◽  
Sunanda Patri ◽  
Ram Choudhary
Keyword(s):  
Room Temperature ◽  
Single Phase ◽  
Complex Impedance ◽  
Tungsten Bronze ◽  
Negative Temperature ◽  
Scanning Electron Micrographs ◽  
Polarization Study ◽  
Semiconducting Properties ◽  
Wide Range

AbstractPolycrystalline samples of Ba4SrRTi3V7O30 (R=Sm and Dy), members of the tungsten-bronze family, were prepared using a high-temperature, solid-state reaction technique and studied their electrical properties (using complex impedance spectroscopy) in a wide range of temperature (31–500°C) and frequency (1 kHz-1 MHz). Preliminary structural (XRD) analyses of these compounds show the formation of single-phase, orthorhombic structures at room temperature. The scanning electron micrographs (SEM) provided information on the quality of the samples and uniform distribution of grains over the entire surface of the samples. Detailed studies of the dielectric properties suggest that they have undergone ferroelectric-paraelectric phase transition well above the room temperatures (i.e., 432 and 355°C for R= Sm and Dy, respectively, at frequency 100 kHz). Measurements of electrical conductivity (ac and dc) as a function of temperature suggest that the compounds have semiconducting properties much above the room temperature, with negative temperature coefficient of resistance (NTCR) behavior. The existence of ferroelectricity in these compounds was confirmed from a polarization study.

Application of Novel Techniques in Active Power Filter

2020 ◽  
pp. 158-191
Author(s):  
Karunendra Kumar Verma ◽  
V. M. Mishra ◽  
Niraj Kumar
Keyword(s):  
Single Phase ◽  
Reactive Power ◽  
Supply Voltage ◽  
Semiconductor Devices ◽  
Active Power Filter ◽  
Active Power ◽  
Current Control ◽  
Active Power Filters ◽  
Power Filter ◽  
Power Filters

Traditionally, the major part of the electrical power is generally consumed by the non-linear loads due to frequent application of the semiconductor devices in the form of domestic and industrial loads. This results from distortion in the actual supply voltage waveform at the source end due to the interference of the multiple harmonics generated out of semiconductor devices used at load end and excessive absorption of the reactive power. The insufficiency of these compensation techniques leads to the advent of the phase multiplication techniques as well as the most reliable and economic active power filtering scheme. A deep analysis showing tedious waveforms using the ORCAD simulation package for the various kind of loads in conjunction with the single-phase active power filter shunted to the single-phase line at the load end for the two current control techniques (i.e., hysteresis band current control, triangularization of current control) has been done. The results are analyzed and tested to lead the optimistic approach for APF (active power filters).

scholarly journals Determination of Inactive Powers in a Single-Phase AC Network

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4814
Author(s):  
Nickolay I. Shchurov ◽  
Sergey V. Myatezh ◽  
Boris V. Malozyomov ◽  
Alexander A. Shtang ◽  
Nikita V. Martyushev ◽  
...  
Keyword(s):  
Single Phase ◽  
Reactive Power ◽  
Supply Voltage ◽  
Time Base ◽  
Nonlinear Loads ◽  
Nonlinear Load ◽  
Voltage Curve ◽  
Current Curve ◽  
Definition Of

Based on the development of the theory of reactive power and distortion power, starting with the works of Fryze and Budeanu, it has been found that the contradictions in the definition of the components of inactive powers are caused by errors in the introduced intermediate concepts and corresponding calculations when switching to nonlinear and non-sinusoidal AC circuits. The materials of the works of modern researchers and the numerical calculations carried out made it possible to trace the differences between reactive power and distortion power, to confirm the orthogonality properties of the active, reactive power, and distortion power components. The paper defines the conditions for achieving a power balance in an AC network with nonlinear loads, compiled and tested criteria leading to the absence of distortion power in a single-phase AC network. Using the time base of the projection of the generalized vectors in vector diagrams, it is shown that compliance with the criteria for the absence of distortion power does not determine the mutual similarity of the voltage curve with the current curve for a nonlinear load. It has been found that the well-known term “distortion power” has an unfortunate wording, since this power, although it characterizes the interaction of harmonics of currents and voltages with different ordinal numbers, is not determined by the visual similarity or the degree of distortion of the load current waveforms relative to the supply voltage curve.

Inactive capacity compensation device in frequency converters in the composition of electric power systems of marine vehicles

2021 ◽  
pp. 118-123
Author(s):  
Б.Ф. Дмитриев ◽  
С.Я. Галушин ◽  
А.С. Корнев ◽  
К.В. Балицкая
Keyword(s):  
Power Systems ◽  
Power Factor ◽  
Reactive Power ◽  
Autonomous Underwater Vehicles ◽  
Negative Consequences ◽  
Higher Harmonics ◽  
Frequency Converters ◽  
Operating Modes ◽  
Active Filtering

Управление режимами работы гребного электрического двигателя осуществляется полупроводниковыми преобразователями частоты, применение которых значительно ухудшает качество электроэнергии на общих шинах судовых электроэнергетических систем. Основными причинами являются уменьшение коэффициента мощности и появление высших гармоник в потребляемом токе. В результате этого снижается надежность работы потребителей, и увеличиваются потери электроэнергии. Поэтому уменьшение указанных негативных последствий является актуальной задачей. В связи с этим, большое внимание уделяется вопросам, связанным с изучением и разработкой различных методов и устройств обеспечения качества электроэнергии, увеличения коэффициента мощности и фильтрации высших гармоник. В настоящее время, перспективным методов улучшения качества электроэнергии, является применение устройств управления реактивной мощностью и активной фильтрации, т.е. компенсаторов неактивной мощности. Подобные системы можно применять не только для надводных судов, но и в автономных подводных транспортных средствах, в качестве энергетической установки которых выступает батарея топливных элементов. The control of the operating modes of the propulsion electric motor is carried out by semiconductor frequency converters, the use of which significantly degrades the quality of electricity on the common buses of the ship power systems. The main reasons are a decrease in the power factor and the appearance of higher harmonics in the current consumption. As a result, the reliability of the consumers is reduced, and the losses of electricity increase. Therefore, the reduction of these negative consequences is an urgent task. In this regard, much attention is paid to issues related to the study and development of various methods and devices for ensuring the quality of electricity, increasing the power factor and filtering higher harmonics. Currently, a promising method for improving the quality of electricity is the use of reactive power control devices and active filtering, i.e. compensators of inactive power. Such systems can be used not only for surface crafts, but also in autonomous underwater vehicles, the power plant of which is a fuel-cell stack.

scholarly journals Direct control of active and reactive power for a grid-connected single-phase photovoltaic inverter

2021 ◽  
Vol 12 (1) ◽  
pp. 139
Author(s):  
Eyad Radwan ◽  
Mutasim Nour ◽  
Ali Baniyounes ◽  
Khalid S. Al Olimat ◽  
Emad Awada
Keyword(s):  
Power Factor ◽  
Power Flow ◽  
Single Phase ◽  
Reactive Power ◽  
Voltage Source ◽  
Direct Control ◽  
Utilization Factor ◽  
Pv Inverter ◽  
Active And Reactive Power ◽  
Wide Range

This paper presents a single-phase grid-connected photovoltaic system with direct control of active and reactive power through a power management system of a Photovoltaic inverter. The proposed control algorithm is designed to allow maximum utilization of the inverter’s available KVA capacity while maintaining grid power factor and current total harmonic distortion (THD) requirements within the grid standards. To reduce the complexity and improve the efficiency of the system, two independent PI controllers are implemented to control single-phase unipolar PWM voltage source inverter. One controller is used to control the power angle, and hence the active power flow, while the other controller is used to control the reactive power, and consequently the power factor by adjusting the voltage modulation index of the inverter. The proposed system is modelled and simulated using MATLAB/Simulink. The PV inverter has been examined while being simultaneously connected to grid and local load. Results obtained showed the ability of the PV inverter to manage the active and reactive power flow at, and below rated levels of solar irradiances; resulting in an increased inverter utilization factor, and enhanced power quality. The proposed system, was capable of operating at power factors in the range of 0.9 lead or lag for reactive power compensation purposes and delivered its power at a wide range of solar irradiance variations.

scholarly journals Design of type-1 servo controller for grid voltage modulated direct-power control of single-phase grid-connected PV inverter

2021 ◽  
Vol 11 (3) ◽  
pp. 1912
Author(s):  
Eyad Radwan ◽  
Mutasim Nour ◽  
Ali Baniyounes ◽  
Khalid S. Al Olimat
Keyword(s):  
Single Phase ◽  
Pulse Width Modulation ◽  
Reactive Power ◽  
Multiple Input Multiple Output ◽  
Photovoltaic System ◽  
Pole Placement ◽  
Grid Voltage ◽  
Wide Range ◽  
Single Phase Inverter

This paper presents direct control of active and reactive power using grid voltage modulation for single-phase grid-connected photovoltaic inverter. A design of type-1 servo system based on pole-placement method is proposed to control the power flow using a simplified multiple-input multiple-output (MIMO) model of the system. Phase-locked loop (PLL) with a quarter cycle time delay is used to estimate the grid phase angle for the purpose of performing the stationary and synchronous reference frame transformation. Unipolar pulse width modulation (PWM) technique is used to control a single-phase inverter with 2.7 KVA capacity connected to the photovoltaic system. The proposed controller can simply be tuned using minimum number of controller gains to achieve the transient and steady-state performance requirements. The proposed system, was capable of operating for a wide range of solar irradiance levels with a power factor in the range of 0.95 (leading/lagging), for the reactive power compensation purposes.

scholarly journals Nonlinear load influence on single-phase fault current in shipboard electric networks

2021 ◽  
pp. 59-64
Author(s):  
И.Е. Кажекин ◽  
С.П. Финько ◽  
М.С. Харитонов
Keyword(s):  
Single Phase ◽  
Fault Current ◽  
Electric Networks ◽  
Steady State Mode ◽  
Nonlinear Load ◽  
Load Current ◽  
Higher Harmonics ◽  
Ground Fault ◽  
Electrical Installation

Описаны результаты исследований влияния показателей качества электроэнергии на токи однофазных замыканий в судовых электроустановках. Выявлены основные элементы бортовых электроустановок, влияющие на качество электроэнергии. Проанализировано формирование высших гармоник в токе однофазного замыкания. На физической модели электроустановки проведены исследования влияния нелинейной нагрузки на ток однофазного замыкания. Результаты экспериментов подтвердили установленные закономерности. Выявлено, что в установившемся режиме ток однофазного замыкания определяется не только величиной фазной емкости и напряжением сети, но и несинусоидальностью тока нагрузки. Экспериментально показано, что высшие гармоники, присутствующие в токе нагрузки, усиливаются в токе однофазного замыкания. При этом увеличение их амплитуд пропорционально номеру гармоники и ее амплитуде в токе нагрузки. Экспериментально установлено, что формирование высших гармоник в токе однофазного замыкания в результате эмиссии нелинейной нагрузкой приводит к увеличению его действующего значения. The paper represents the research results of the power quality indicators influence on the currents of single-phase ground faults in ship electrical installations. The main elements of on-board electrical installations that affect the quality of electricity are identified. The process of higher harmonics formation in the single-phase ground fault current is analyzed. Studies of the nonlinear load influence on the single-phase fault current are carried out on the physical model of the electrical installation. The experimental results confirmed the established patterns. For the steady-state mode it was discovered that the single-phase ground fault current is determined not only by the phase capacitance value and the mains voltage, but also by the non-sinusoidality of the load current. It has been shown experimentally that the higher harmonics of the load current are amplified in the single-phase ground fault current. In this case, the increase at their amplitudes is proportional to the harmonic number and its amplitude in the load current. It has been experimentally established that the formation of higher harmonics at a single-phase ground fault current as a result of emission by a nonlinear load leads to an increase in its effective value.

scholarly journals Suppression of Supply Current Harmonics of 18-Pulse Diode Rectifier by Series Active Power Filter with LC Coupling

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6060
Author(s):  
Wojciech Sleszynski ◽  
Artur Cichowski ◽  
Piotr Mysiak
Keyword(s):  
Single Phase ◽  
Control Method ◽  
Supply Voltage ◽  
Harmonic Distortion ◽  
Control Object ◽  
Experimental Tests ◽  
Active Filter ◽  
Current Control ◽  
Additional Line

The reported research aims at improving the quality of three-phase rectifier supply currents. An effective method consists of adding properly formed booster voltages to the fundamental supply voltages using a series active filter. In the proposed solution, the booster voltages are generated by three single-phase systems consisting of inverters, LC filters, and single-phase transformers. The application of LC couplings ensures low emission of disturbances, but may provoke compensator stability problems. The article presents the current control system for a series active filter designed to suppress the dominant harmonics in the supply currents of an 18-pulse rectifier, without interference into fundamental current components. A proportional control is proposed in combination with integral terms implemented in the orthogonal coordinate systems, which synchronically rotate with frequencies equal to those of the harmonic components to be eliminated. The use of complex gains in integral terms allows a simple phase correction of the output signals. A description is given of the method to determine controller parameters based on the mathematical model of the control object. Sample results of experimental tests performed in steady-state and transient conditions are included to illustrate the quality of performance of the series active filter as compared to the results recorded for the rectifier alone, and for the rectifier with additional line reactor. The applied control method of active filter significantly reduces harmonic distortion of the grid current, which is particularly advantageous at nonideal supply voltage and low loads.

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