displaying 1000 best results Help
Search results for: CAPACITOR VOLTAGE BALANCING
-
Neutral earthing reactor protection
PublicationThe IEEE and CIGRE recommend protection systems for high voltage shunt reactors. Unfortunately the recommendations do not include guidelines for the protection of neutral earthing reactors, which are often connected to shunt reactors to increase the effectiveness of single pole auto-reclosing. The paper discusses earthing reactor protection issues with particular emphasis on the detection of internal faults. An analysis carried...
-
SEM images of symmetrical cell interface with Sr1.05Ti0.30Fe0.70O3-d electrodes and CGO-20 substrate sintered at 800 °C, 900 °C and 1000 °C
Open Research DataThis dataset contains images of polished cross section of symmetrical cell interface with Sr1.05Ti0.30Fe0.70O3-d electrodes and CGO-20 substrate sintered at three different temperatures 800 °C, 900 °C and 1000 °C. Images were obtained using a PhenomXL (Thermo Fisher Scientific, the Netherlands) scanning electron microscope (SEM) with an accelerating...
-
SEM images of symmetrical cell interface with Sr1.00Ti0.30Fe0.70O3-d electrodes and CGO-20 substrate sintered at 800 °C, 900 °C and 1000 °C
Open Research DataThis dataset contains images of polished cross section of symmetrical cell interface with Sr1.00Ti0.30Fe0.70O3-d electrodes and CGO-20 substrate sintered at three different temperatures 800 °C, 900 °C and 1000 °C. Images were obtained using a PhenomXL (Thermo Fisher Scientific, the Netherlands) scanning electron microscope (SEM) with an accelerating...
-
SiC-based phase-shift dual half bridge DC-DC converter as a key component of multilevel cascaded MV converters
PublicationThe paper describes SiC-based dual half bridge (DHB) DC-DC converter considered as a key component of high frequency isolated multilevel cascaded medium voltage converters. Two topologies of bi-directional DC-DC converters: the resonant half-bridge DC-DC converter and the phase-shift DHB converter are compared in the paper. Experimental results of SiC-based 50 kHz DHB DC-DC converter are presented in the paper.
-
Experimental and numerical analysis of wave propagation in ground anchors
PublicationThe article focuses on wave propagation phenomenon in ground anchors. The main aim of the investigation is the non-destructive diagnostics and the assessment of the state of ground anchors, using the guided wave propagation method. Laboratory models of anchors with different lengths of the anchor body were tested and voltage signals of propagating waves were registered at several locations. For all tested specimens corresponding...
-
Impulse Impedance Measurements of Lightning Protection Earthings
PublicationLightning protection earthing systems should be tested at currents with time parameters similar to those of lightnings. A method and definition of a measured value of impulse impedance are introduced. The impulse impedance was determined by a quotient of voltage drop on the tested earthing to a value of current in measure circuit. The usefulness of the impulse method for lightning protection evaluation is tested on radio base stations...
-
A novel approach to energy safety improvement in the marine power plants with active power surge compensator
PublicationPaper raises a point of power surges and theirs adverse effects in the marine power plants. The article explains a source of surges appearance, and presents measurements carried out on a modern ship. It discusses effects of dynamic power transients on the ship’s energy safety. Finally it proposes, a novel approach for power surge elimination, based on medium voltage active conditioner. As well as it propose the topology and control...
-
Impedance spectra of ZnO varistor type 280 model O M ver. 89
Open Research DataThe impedance spectrum of high-voltage ZnO varistor obtained using FRA EIS impedance spectrosocpy measurement method. The 1V sinusoidal excitation was used. The frequency range was chosen from 10 kHz down to 100 uHz. The object under test and the measuring instrument were placed in a Faraday cage due to high impedance of the object. The data was acquired...
-
SEM images of symmetrical cell interface with Sr0.90Ti0.30Fe0.70O3-d electrodes and CGO-20 substrate sintered at 800 °C, 900 °C and 1000 °C
Open Research DataThis dataset contains images of polished cross section of symmetrical cell interface with Sr0.90Ti0.30Fe0.70O3-d electrodes and CGO-20 substrate sintered at three different temperatures 800 °C, 900 °C and 1000 °C. Images were obtained using a PhenomXL (Thermo Fisher Scientific, the Netherlands) scanning electron microscope (SEM) with an accelerating...
-
SEM images of symmetrical cell interface with Sr0.95Ti0.30Fe0.70O3-d electrodes and CGO-20 substrate sintered at 800 °C, 900 °C and 1000 °C
Open Research DataThis dataset contains images of polished cross section of symmetrical cell interface with Sr0.95Ti0.30Fe0.70O3-d electrodes and CGO-20 substrate sintered at three different temperatures 800 °C, 900 °C and 1000 °C. Images were obtained using a PhenomXL (Thermo Fisher Scientific, the Netherlands) scanning electron microscope (SEM) with an accelerating...
-
Nowa metoda optymalizacji pracy ogniw paliwowych.
PublicationPrzedstawiono dynamiczną technikę impedancją jako doskonałe narzędzie służące do określenia optymalnych warunków pracy ogniw paliwowych. Możliwości tej techniki zostały przedstawione na przykładzie ustalenia optymalnej temperatury pracy. Otrzymane wyniki zostały skonfrontowane z charakterystykami prądowo napięciowymi ogniwa.
-
Unraveling the Interplay between DNA and Proteins: A Computational Exploration of Sequence and Structure-Specific Recognition Mechanisms
PublicationMy PhD dissertation focused on DNA-protein interactions and the recognition of specific DNA sequences and structures. I discovered that acidic amino acid residues (Asp/Glu) play a crucial role by exhibiting a preference for cytosine. Their contribution to binding affinity depends on nearby cytosines, balancing electrostatic repulsion with specific interactions. Acidic residues act as negative selectors, discouraging non-cytosine...
-
Shaking table experimental study on damage mechanism of the disconnecting switch under seismic excitation
PublicationThe efficiency of the energetic network is a very import safety issue in the region experienced by the earthquake. High voltage disconnecting switches are important elements of the energetic infrastructure used to separate electric circuits (i.e. during repairs), which should not be damaged remaining fully operational. The aim of the paper is to show the results of the shaking table experimental investigation focused on damage...
-
A Simplified SVPWM Technique for Five-leg Inverter with Dual Three-phase Output
PublicationThis article proposes a simplified space vector pulse-width modulation (SVPWM) technique five-leg inverter with dual three-phase output. An idea to fed the dual tree-phase machine by the multiphase voltage source inverters (VSIs) is not new. Dual- and multi-motor drive systems are widely used in the industry applications. The most popular fields are: electric vehicles (EVs) and traction systems. Moreover, the specific characteristic...
-
Hybrid‐mode single‐slope ADC with improved linearity and reduced conversion time for CMOS image sensors
PublicationIn the paper, a single‐slope analog‐to‐digital converter (ADC) for integrated CMOS image sensor applications with an improved technique of conversion has been proposed. The proposed hybrid‐mode ADC automatically uses one of the following conversion techniques: time based (i.e. PWM) or voltage based (i.e. single‐slope). During the ADC operation, the clock frequency and reference voltage are modified in order to reduce the conversion...
-
Calculations of material factors for a set of 20 thermistors
Open Research DataThe presented data set is part of the research aimed at determining the actual characteristics of each thermistor in a package of twenty NTC10k type sensors.
-
Calculations of the resistance values of 10 ratio resistors
Open Research DataThe presented data set is part of the research aimed at determining the actual characteristics of each thermistor in a package of twenty NTC10k type sensors.
-
Nonlinear high temperature impedance of 35P2O5-30Fe2O3-27.5Nb2O5-7.5TiO2 glass
Open Research DataThe nonlinear high temperature impedance of iron- phosphate glasses doped with niobium oxide was measured. Glass samples of the composition of 35P2O5-30Fe2O3-27.5Nb2O5-7.5TiO2 (in %mol) were prepared by the conventional melt quenching technique. Appropriate amounts of reagents ((NH4)2HPO4 (≥99.9%, POCH), Fe2O3 (≥99.9%, POCH), Nb2O5 (≥99.9%, PLUKA AG)...
-
Nonlinear impedance of 50(2Bi2O3-V2O5)-50SrB4O7 glass-ceramic heat-treated at 813 K measured with impedance spectroscopy method at high temperature region
Open Research DataNonlinear electrcial properties of 50(2Bi2O3-V2O5)-50SrB4O7 glass-ceramic heat treated at 813 K was measured by impedance spectroscopy method.
-
Nonlinear impedance of 58(2Bi2O3-V2O5)-42SrB4O7 glass heat-treated for 3 hours at 693 K, measured with impedance spectroscopy method at low temperature region
Open Research DataThe nonlinear electrcial properties of partially crystallized 58(2Bi2O3-V2O5)-42SrB4O7 glass was measured by impedance spectroscopy method.
-
Nonlinear impedance as a function of frequency for Bi2VO5.5 ceramic of thickness 2.88 mm was measured at high temperature range with impedance spectroscopy method
Open Research DataThe nonlinear electrical properties of Bi2VO5.5 ceramic of thickness 2.88 mm was measured by impedance spectroscopy method.
-
Nonlinear impedance of 5(2Bi2O3-V2O5)-95SrB4O7 glass measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrcial properties of 5(2Bi2O3-V2O5)-95SrB4O7 glass was measured by impedance spectroscopy method.
-
Nonlinear impedance of 58(2Bi2O3-V2O5)-42SrB4O7 glass heat-treated for 10 hours at 693 K, measured with impedance spectroscopy method at low temperature region
Open Research DataThe nonlinear electrcial properties of partially crystallized 58(2Bi2O3-V2O5)-42SrB4O7 glass was measured by impedance spectroscopy method.
-
SVC and power transformers controllers coordination
PublicationThe use of shunt compensators such as FACTS (for example SVC) in power systems gives possibility of fast and flexible control of voltage or reactive power. An efficient cooperation between a transformer and compensator connected to busbars, or transformer’s tertiary winding, requires a proper coordination of controls. The article contains theoretical considerations and simulation results which indicate that such co-ordination is...
-
Diagnostics of zno varistors by means of nondestructive testing
PublicationStandard industrial testing of high-voltage varistors for surge arresters demands application of high voltages and intensive currents. Nondestructive methods for varistor quality and endurance evaluation have been proposed and described. They rely on the application of resonant ultrasound spectroscopy, electro-ultrasonic spectroscopy, noise measurement and nonlinearity testing at voltages lower than continuous operating range....
-
Evaluation of the fast impedance spectroscopy method in the laboratory measurement system
PublicationIn this paper the method for fast impedancespectroscopy of technical objects with very high impedance(|Zx| ≥ 1 GΩ) is evaluated by means of simulation and practicalexperiment. The method is based on excitation of an object, witha square pulse and measurements of voltage and currentresponses with DAQ card. The object impedance spectrum isobtained with use of continuous Fourier transform. Someimprovements of the method concerned...
-
Time domain model of the resonance-based electromagnetic pulses emission system
PublicationIn the literature, the emission properties of the electromagnetic field pulse systems based on high voltage antennas (HVR) have been widely described. In order to increase the emission efficiency by extending duration and increasing amplitude of the impulse it is possible to use a resonance system tuned to the parameters of the signal shaped in the pulse forming circuit. The synthesis of a time-domain simulation model of a complex...
-
Determining the leakage current resistive component by the orthogonal vector method
PublicationThe measurement of the metal – oxide surge arresters (MOSA) leakage current and the analysis of its components is a key diagnostic criterion according to technical standards. During on site MOSA condition assessment, the easy way is based on the measurement only leakage current, without the inconvenient live working measurements of supply voltage. Orthogonal vectors method of determination the resistive leakage current is presented....
-
Compensation of Dead Time Effects for Shunt Active Power Filters
PublicationThe paper presents a comprehensive approach to the compensation of the grid current distortion for shunt active power filter systems. Four different sources of current distortion are addressed: imperfect grid synchronization caused by the distortion in the grid voltages, time delays in the estimation of compensating currents and grid voltages, fluctuations of the dc bus voltage, and the distortion of inverter output voltages due...
-
Cyclic voltammetry curves of the V2O5 nanorods (Na-ion batteries)
Open Research DataThe DataSet contains the next thirty cycles voltammetry curves for the V2O5 nanorods obtained by the sol-gel method. The cyclic voltammetry was measured using the AUTOLAB 302N potentiostat-galvanostat. The measurements were carried out in a voltage range of 2 V to 4 V vs. Na/Na+ at a scan rate of 1 mV/s. As an electrolyte 1M NaPF6 was applied.
-
Cyclic voltammetry curves of the V2O5 nanocrystals (Na-ion batteries)
Open Research DataThe DataSet contains the next thirty cycles voltammetry curves for the V2O5 nanocrystals obtained by the sol-gel method. The cyclic voltammetry was measured using the AUTOLAB 302N potentiostat-galvanostat. The measurements were carried out in a voltage range of 2 V to 4 V vs. Na/Na+ at a scan rate of 1 mV/s. As an electrolyte 1M NaPF6 was applied.
-
Synthesis and Testing of BCZY/LNZ Mixed Proton–electron Conducting Composites for Fuel Cell Applications
PublicationA composite of BaCe0.6Zr0.2Y0.2O3–δ and Li2O:NiO:ZnO was investigated for fuel cell applications. The composite was successfully synthesized and its phase stability was confirmed at temperatures up to 900 °C. The influence of sintering and pressing aids on density was also investigated. Electrical properties were measured. DC electrical conductivity was about 8•10-4 S/m at 845 K. Open circuit voltage measurements in wet hydrogen...
-
Study of prototype multi-pole non-salient field winding for high speed brushless synchronous generator
PublicationIn this paper a non-salient field winding for a brushless synchronous generator working with high speed in an autonomous energy generation system (e.g. airplane power grid) has been presented. A conception of a six-pole cylindrical-rotor with distributed field winding has been proposed. Comparison study of salient and prototype non-salient field winding has been carried out. Chosen simulation and measurement results of the generator...
-
Comprehensive compensation of grid current distortion by shunt active power filters
PublicationThe paper presents a comprehensive approach to the compensation of grid current distortion in shunt active power filter systems. Four sources of current distortion are addressed: imperfect grid synchronization caused by the distortion in the grid voltages, time delays in the evaluation of grid voltages and computation of compensating currents, fluctuations of the dc bus voltage, and the distortion of inverter output voltages due...
-
Computer-aided analysis of resonance risk in power system with Static Var Compensators
PublicationStatic Var Compensators operation in a power system may significantly improve voltage profiles in nodes and the reactive power balance, as well as ensure greater system stability in emergency conditions. However these devices may be a cause of a resonance in the system. The aim of this paper is to call attention to the need to include resonance phenomena in a compensator’s location evaluation process. The analysis performed in...
-
Sensorless Rotor Position Estimation of Doubly-Fed Induction Generator Based on Backstepping Technique
PublicationThis paper proposes a speed observer algorithm for the sensorless control of a doubly-fed induction generator based on classical adaptive backstepping technique. The sensorless control is shown using classic stator field oriented control which is used to active and reactive power control. Performance of the proposed algorithm of a speed observer is validated by simulation and experimental results obtained using a small-rating generator...
-
Development of beltless respiration and heartbeat sensor based on flexible piezoelectric film
PublicationThe main goal of this work is to report initial development on a respiration and heartbeat measurement sensor that can be used in continuous monitoring conditions at a minimal impact on the patient. General description of the sensor, consisting of a PVDF film and the bonding layer, is given. Open-circuit voltage generated by the sensor is estimated by analytical and numerical calculations. Analog and digital interface used to extract...
-
Determination of chlorine concentration using single temperature modulated semiconductor gas sensor
PublicationA periodic temperature modulation using sinusoidal heater voltage was applied to a commercial SnO2 semiconductor gas sensor. Resulting resistance response of the sensor was analyzed using a feature extraction method based on Fast Fourier Transformation (FFT). The amplitudes of the higher harmonics of the FFT from the dynamic nonlinear responses of measured gas were further utilized as an input for Artificial Neural...
-
Design of a SiC based triple active bridge ceil for a multi-megawatt DC-DC converter
PublicationThe paper describes the design methodology of a novel Triple Active Bridge cell used as the building block for modular DC-DC converters. The intended application is for Medium Voltage Direct Current grids, such as the DC collector for offshore wind farms. The latest generation of SiC MOSFET semiconductors is utilized to operate in the medium frequency range while optimizing the efficiency. The dimensioning of the main cell components,...
-
Noise spectral density computation based on finite element model of piezoceramic sensor
PublicationThe high sensitivity with wide bandwidth is required for sensor applications in non-destructive testing (NDT). The sensitivity of piezoceramic sensors demands to minimize their noise especially thermal noise, polarisation noise and low frequency 1/f noise,which are the main sources of voltage or current fluctuation in this sort of sensors. For simplicity, only the piezoceramic part of sensor was under study. the theoretical and...
-
Solutions of inverter systems in Shore-to-Ship Power supply systems
PublicationThe article presents a clearly formulated need for installing S2SP (Shore to Ship Power) systems, in particular Medium Voltage (MV) systems, along with certain solutions of modern inverter systems used in those systems. Requirements and basic configurations of S2SP systems are discussed, focusing in particular on capabilities of the S2SP system with DC distribution busbar. Moreover, on the background of the executing assumptions...
-
WARUNKI REZONANSOWE W WĘŹLE Z KOMPENSATOREM SVC
PublicationInstalowanie kompensatorów statycznych w sieciach rozdzielczych i przesyłowych służy poprawie profili napięciowych. Kompensatory jako źródła mocy biernej zwiększają stabilność napięciową systemu. Pozwalają także na szybszą odbudowę systemu w przypadku awarii napięciowej. W artykule zaprezentowano wpływ struktury i wysterowania układu SVC na zmianę impedancji w układzie zasilania. Ma to bezpośredni wpływ na częstotliwości, przy...
-
Broadband Modeling of Motor Cable Impact on Common Mode Currents in VFD
PublicationExamination of conducted EMI generation and propagation in AC motor drives fed by frequency converter requires to consider parasitic capacitances in converters, motor windings and feeding cables to be taken into account. AC motor winding voltage transients and related common mode currents are significantly correlated with resonance effects occurring in converter's load circuits. Intensity levels of these phenomena depend...
-
Optimization of electrochemical doping approach resulting in highly photoactive iodine-doped titania nanotubes
PublicationThe paper focuses on the optimization procedure concerning the synthesis method resulting in highly ordered titania nanotubes doped with iodine atoms. The doping process was based on the electrochemical treatment of a titania nanotube layer immersed in a potassium iodide (KI) solution acting as an iodine precursor. A number of endeavors were undertaken in order to optimize the doping conditions. Electrolyte concentration, reaction...
-
A measurement method for capacitive sensors based on a versatile direct sensor-to-microcontroller interface circuit
PublicationIn the paper, there is presented a new time-domain measurement method for determining the capacitance values of capacitive sensors, dedicated, among others, to capacitive relative humidity sensors. The method is based on a versatile direct sensor-to-microcontroller interface for microcontrollers with internal analog comparators (ACs) and with precision voltage reference sources, e.g. digital-to-analog converters (DACs). The reference...
-
Nanostructures fabrication with use of electrical AFM litography
Open Research DataIn the last 10 years, one of the nanotechnological trends has been observed, consisting in the development of new variants of computer memory systems with high capacity and speed of access, using quantum dots. One of the techniques for creating nanodots and other nanostructures is based on the use of an atomic force microscope acting as a lithographic...
-
Scanning Electrone Microscope images of biochar produced from straw and wood chips
Open Research DataThis dataset contains scanning electron microscope images of two types of biochars derived from waste plant biomass: straw and wood chips. Imaging was performed using a scanning electron microscope, FEI Quanta FEG250. with a SE-ETD detector (secondary electron – Everhart-Thornley detector), using 20 kV accelerating voltage.
-
Electrical responses of nanostructured ZrS3 as field-effect transistor for nitrogen dioxide, ethanol, and acetone detection enhanced by visible light
Open Research DataSmall-area layers of nanostructured ZrS3 were fabricated and measured in the field-effect transistor configuration. Irradiation with visible light enabled generating photocurrent and increasing the sensitivity to selected ambient gases: nitrogen dioxide, ethanol, and acetone. The data set consists of electrical responses (current vs. voltage characteristics...
-
Rate performance of the V2O5 nanocrystals as cathode material in Li-ion batteries
Open Research DataThe DataSet contains the galvanostatic charge/discharge curves of the V2O5 nanocrystals obtained by the sol-gel method. The battery tests of the samples were performed using the Atlas-Sollich 0961 (Atlas-Sollich, Poland) with different current densities in the voltage range between 2.0 V and 4.0 V vs. Li/Li+. Here 1C is 294 mAh g-1.
-
Cyclic voltammetry curves of the V2O5 nanorods (Li-ion batteries)
Open Research DataThe DataSet contains the next thirty cycles voltammetry curves for the V2O5 nanocrystals obtained by the sol-gel method. The cyclic voltammetry was measured using the AUTOLAB 302N potentiostat-galvanostat. The measurements were carried out in a voltage range of 2 V to 4 V vs. Li/Li+ at a scan rate of 1 mV/s. The results show that in the subsequent cycles,...