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Search results for: HIGH FREQUENCY POWER CONVERTER
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Expedited Optimization of Passive Microwave Devices Using Gradient Search and Principal Directions
PublicationOver the recent years, utilization of numerical optimization techniques has become ubiquitous in the design of high-frequency systems, including microwave passive components. The primary reason is that the circuits become increasingly complex to meet ever growing performance demands concerning their electrical performance, additional functionalities, as well as miniaturization. Nonetheless, as reliable evaluation of microwave device...
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DLC coating doped with W in ring-on-ring sliding with saline solution (0.9% wt.) lubrication 20MPa/0.1m/s
Open Research DataWear tests in sliding friction of 1% W (tungsten) doped DLC coating on 1.4021 (EN 10088-1) heat treated stainless steel. Ring - on - ring contact in unidirectional sliding, DLC-W over DLC-W. Mean contact stress: 20MPa. Sliding velocity: 0,1 m/s. Mean friction radius: 9.5mm. Lubricant: SALINE SOLUTION (0.9% wt.). Tribometer: PT-3. Overall test time >15h....
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DLC coating doped with W in ring-on-ring sliding with saline solution (0.9% wt.) lubrication 10MPa/0.1m/s
Open Research DataWear tests in sliding friction of 1% W (tungsten) doped DLC coating on 1.4021 (EN 10088-1) heat treated stainless steel. Ring - on - ring contact in unidirectional sliding, DLC-W over DLC-W. Mean contact stress: 10MPa. Sliding velocity: 0,1 m/s. Mean friction radius: 9.5mm. Lubricant: SALINE SOLUTION (0.9% wt.). Tribometer: PT-3. Overall test time >15h....
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Predicting cutting power for band sawing process of pine and beech wood dried with the use of four different methods
PublicationWood drying is an important stage in the woodworking process. After drying, wood is subject to a re-sawing process, for which a high quality surface, low material loss, and high efficiency are often required. In this paper, forecasted values were presented of cutting power for the re-sawing process of pine and beech wood that were dried with four different methods. Forecasting of cutting power for an industrial band saw machine...
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Microfluidic SIW-Based Tunable Self-Diplexing Antenna for Sub-6 GHz Band Applications
PublicationThis work introduces a novel frequency tunable self-diplexing antenna (SDA) design based on substrate integrated waveguide (SIW) technology. A modified A-shaped slot is employed on the cavity’s top plane, which is excited by two independent 50 Ω microstrip feed lines to operate at each resonant frequency. The frequency flexibility of the proposed antenna allows for fine-tuning at each resonance frequency. The frequency flexibility...
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Rapid dimension scaling of compact microwave couplers with power split correction
PublicationIn this paper, a technique for rapid re-design ofcompact microwave couplers with respect to operating frequency is discussed. Our methodology involves an inverse surrogate model setup using several reference designs optimized (at the level of equivalent circuit representation of the coupler) for a set of operating frequencies within a range of interest. The surrogate establishes the relationship between the operating frequency...
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Ionospheric scintillations computation using real-time GPS observations
PublicationThe following paper presents the results of quasi-real-time determination of the values of phase scintillations indices at the period of ionospheric disturbances that occurred as a consequence of the Sun flares observed on March 7 and 9, 2012. Double-frequency observations with 1-second measurement interval from the EPN (EUREF Permanent Network) network sites located at high latitudes were used for the analysis. To determine the phase...
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Novel structure and size-reduction-oriented design of microstrip compact rat-race coupler
PublicationIn this paper, a novel structure of a miniaturized microstrip rat-race coupler has been proposed. Surrogate-based optimization procedures are applied to explicitly reduce the coupler size while maintaining equal power split at the operating frequency of 1 GHz and sufficient bandwidth for return loss and isolation characteristics. The optimization is performed using the objective function with four penalty components. The footprint...
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Narrowband Transmission Quality in Presence of Modified IEEE 802.15.4a UWB Signal
PublicationThis paper presents results of measurement of narrowband transmission quality in presence of impulse radio UWB interference. In the first part of paper, unmodified IEEE 802.15.4a IR UWB signal is used. Then some modification of transmitted pulse sequence is proposed, which allow to reduce UWB power spectral density at frequency of narrowband transmission. Finally narrowband transmission quality in presence of modified ultrawideband...
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Measurements of the mechanical system properties of "SpeedLine magnetic" ultra-fast robot prototype for IML labeling
Open Research DataThe mechanical system tests of the high-speed IML labeling robot "SpeedLine Magnetic" were carried out in order to analyze the effects of the drive system's operating parameters on vibration and noise.
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Impedance spectra of ZnO varistor type 440 model A ver. M
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...
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Impedance spectra of ZnO varistor type 680 model A M ver. 93
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...
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Impedance spectra of ZnO varistor type 680 model O M ver. 65 13
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...
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Impedance spectra of ZnO varistor type 680 model A M ver. xx
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...
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Impedance spectra of ZnO varistor type 280 model A ver. M
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...
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Impedance spectra of ZnO varistor type 280 model 0 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...
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Impedance spectra of ZnO varistor type 280 model O ver. 68
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 100 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...
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Impedance spectra of ZnO varistor type 440 model O ver. 68
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 10 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...
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Impedance spectra of ZnO varistor type 680 model O M ver. 65 60
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 10 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...
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Multi-objective optimization of microwave couplers using corrected domain patching
PublicationPractical design of microwave components and circuits is a compromise between various, often conflicting objectives. In case of compact structures, the trade-offs are typically concerned with the circuit size and its electrical performance. Comprehensive information about the best possible trade-offs can be obtained by means of multi-objective optimization. In this paper, we propose a computationally efficient technique for identifying...
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The radiated immunity test of an astable multivibrator at over-normative field strengths
Open Research DataThe dataset presents a result of measurements that are a part of electromagnetic field immunity tests. The radiated, radio frequency, immunity tests were carried out for a typical astable electronic multivibrator. Tests of immunity of electronic systems to radiated radio frequency (RF) disturbances in the frequency range from 80 MHz to 1 GHz were performed...
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Overheating of underground power cable line due to its partial exposition to solar radiation
PublicationCurrent-carrying capacity of underground power cable lines depends, among others, on thermal resistivity of the soil and cables layout: trefoil formation, flat formation with or without spacing. If conditions for heat transfer in the ground are favorable, the current-carrying capacity is relatively high. Therefore, it generates risk of the power cables overheating, if part of the cable line is located vertically in the air, to...
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Non-Wave Variations in Temperature Caused by Sound in a Chemically Reacting Gas
PublicationA weakly nonlinear generation of non-acoustic modes in the field of sound in a gas is considered. An exotericchemical reaction of A->B type, which takes place in a gas, may be reversible or not. Two types of sound areconsidered, low-frequency and high-frequency as compared with the characteristic time of a chemical reaction.For both these cases, the governing equations of non-acoustic modes are derived and conclusions of the efficiencyof...
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Modelling and Control of a Brushless Multiphase Doubly-Fed Induction Generator in a Stand-Alone Wind Generation System
PublicationThe development of the novel multiphase brushless doubly-fed generator system and voltage controller for stand-alone mode configuration is proposed in this paper. The generator system is based on the new machine construction with multiphase control winding and traditional three-phase power winding. The dynamic model of multiphase brushless doubly-fed generator is presented, and the control strategy for voltage amplitude and frequency...
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Control system for contactless electrical energy transfer with varying air gap
PublicationInductive power transfer (IPT) is a system by which electrical energy may be transmitted without electrical connection through a large air gap between coils. Systems usually considered in the literature are the ones with a constant air gap. The paper describes the analysis of IPT, which allows for supplying an electrical load in the conditions of slow, in relation to the dynamics of power supply, changes in the dimensions of the...
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Design and evaluation of a base module of active power electronic transformer
PublicationThis paper presents an active power electronic transformer (APET) based on modular structure. The proposed three phase APET consists of at least three base modules (BM). The input/output stage of the BM is based on half-bridge sub modules. The isolation stage includes a medium frequency transformer and is realized as a dual half-bridge. The paper describes construction process and explains the control strategy. The theoretical...
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The Possibility to use a Nuclear Power Plant as a Source of Electrical Energy and Heat
PublicationIn this article issues concernig the possibility of nuclear power plant (NPP) operation also as a source of heat, which means combined heat and power production, have been described. CHP work is possible and profitable only in those areas where high thermal power demand occurs, which means near city agglomerations such as Warsaw or the Tri-City. Two levels of thermal power delivered to the heating system have been considered. Preliminary...
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Impact of R/X ratio of distribution network on selection and control of energy storage units
PublicationThe interest in energy storage is still increasing. Energy storage units are installed in high voltage networks, medium voltage networks and low voltage distribution networks as well. These units are often used to improve power quality. One of the criteria for improving power quality is reducing voltage deviations. Depending on the type of network and specifying its R/X ratio, this criterion can be fulfilled by control of active...
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Resonant ultrasonic spectroscopy in high-voltage varistor spectroscopy
PublicationResonant spectroscopy is an effective non-destructive testing method focused on defects in tested objects. The testing procedure, based on the resonant pattern, allows rejection of the tested samples with defects which do not fit the pattern. A sweeping frequency method has been used to measure the spectrum of resonances in high-voltage varistors. As a result we can observe resonances that depend directly on inhomogeneity of the...
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The luminescence study of Ga1.98–xAlxO3:0.02Cr3+ coumpounds.
Open Research DataA chemical and mechanical pressure-induced photoluminescence tuning method was developed through structural evolution and hydrostatic pressure involving phase transition. A series of Ga1.98−xAlxO3:0.02Cr3+ phosphors were synthesized by collaborators from National Taiwan University. Structural evolution reveals a crystal phase change with the incorporation...
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Technical and Economic Analysis of the Supercritical Combined Gas-Steam Cycle
PublicationCombined cycle power plants are characterized by high efficiency, now exceeding 60%. The record-breaking power plant listed in the Guinness Book of World Records is the Nishi-Nagoya power plant commissioned in March 2018, located in Japan, and reaching the gross efficiency of 63.08%. Research and development centers, energy companies, and scientific institutions are taking various actions to increase this efficiency. Both the gas...
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Detection of dialogue in movie soundtrack for speech intelligibility enhancement
PublicationA method for detecting dialogue in 5.1 movie soundtrack based on interchannel spectral disparity is presented. The front channel signals (left, right, center) are analyzed in the frequency domain. The selected partials in the center channel signal, which yield high disparity with left and right channels, are detected as dialogue. Subsequently, the dialogue frequency components are boosted to achieve increased dialogue intelligibility....
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Optimization of Nuclear Power Share in the Structure of Electricity Production in Poland in Time Perspective by 2060
PublicationThe author of this paper presented the results of a system analysis using MARKAL model, aiming at the optimization of nuclear power share in power generation structure in Poland in time perspective by 2060. Optimization criterion is the minimization of the objective function, i.e. the total cost of energy system, taking into account constraints related to CO2, SOx and NOx emissions and obligatory shares of electricity from renewable...
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Flicker Noise in Resistive Gas Sensors—Measurement Setups and Applications for Enhanced Gas Sensing
PublicationWe discuss the implementation challenges of gas sensing systems based on low-frequency noise measurements on chemoresistive sensors. Resistance fluctuations in various gas sensing materials, in a frequency range typically up to a few kHz, can enhance gas sensing by considering its intensity and the slope of power spectral density. The issues of low-frequency noise measurements in resistive gas sensors, specifically in two-dimensional...
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Simulation of the weight averaging of pulse frequency modulated sensor output signal
Open Research DataThe aim of the research is investigation of the efficiency of weight averaging of pulse frequency modulated signal. It was shown that from the point of view of the reduction of the sampling error the best are polynomial weighing functions, for which the maximum of this component error decreases proportionally to the appropriate power of the number of...
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Multibaem Sonar Records Data Decimation Using Hierarchical Spline Interpolation
PublicationMultibeam sonar records feature high vertical and horizontal resolution. Interpolating and approximating, eventually displaying of of high volume scattered 3D raster data leads to some difficulties related to a computer processing power. The paper presents some advantages of using hierarchical splines in the context. Such an approach facilitates real time 3D MBS data rendering.
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Efficiency of gas detection algorithms using fluctuation enhanced sensing
PublicationEfficiency of various gas detection algorithms by applying fluctuation enhanced sensing method was discussed. We have analyzed resistance noise observed in resistive WO3- nanowires gas sensing layers. Power spectral densities of the recorded noise were used as the input data vectors for two algorithms: the principal component analysis (PCA) and the support vector machine (SVM). The data were used to determine gas concentration...
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An Ultra-Low-Energy Analog Comparator for A/D Converters in CMOS Image Sensors
PublicationThis paper proposes a new solution of an ultra-low-energy analog comparator, dedicated to slope analog-to-digital converters (ADC), particularly suited for CMOS image sensors (CISs) featuring a large number of ADCs. For massively parallel imaging arrays, this number may be as high as tens-hundreds of thousands ADCs. As each ADC includes an analog comparator, the number of these comparators in CIS is always high. Detailed analysis...
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HIERARCHICAL CYCLES IN MODERN POWER SYSTEMS – EXERGY ANALYSIS UNDER PART LOADS
PublicationThe aim of the paper is to investigate thermodynamic efficiency of advanced hierarchic power cyclesunder partial loads by using of exergy analyze. Advanced hierarchical power systems arecomposed of few energy conversion cycles, most common are steam and gas cycles in various configurations, but they may contain fuel cells, ORC, lithium bromide absorption chillers and others. Moreover hierarchical cycles can be powered by several...
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The Design of Cavity Resonators and Microwave Filters Applying Shape Deformation Techniques
PublicationThis article introduces shape deformation as a new approach to the computer-aided design (CAD) of high-frequency components. We show that geometry deformation opens up new design possibilities and offers additional degrees of freedom in the 3-D modeling of microwave structures. Such design flexibility is highly desirable if the full potential of additive manufacturing (AM) is to be exploited in the fabrication of RF and microwave...
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Bearing estimation using double frequency reassignment for a linear passive array
PublicationThe paper demonstrates the use of frequency reassignment for bearing estimation. For this task, signals derived from a linear equispaced passive array are used. The presented method makes use of Fourier transformation based spatial spectrum estimation. It is further developed through the application of two-dimensional reassignment, which leads to obtaining highly concentrated energy distributions in the joint frequency-angle domain...
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Conducted emi propagation modelling in the wound components.
PublicationThe modelling of EMC behaviour of power electronics converters require specific models of devices which are adequate in a wide frequency range. A novel equivalent-circuit model of the inductor, suitable for EMC applications, has been developed and validated. The model can be used for the analyses of wounded components' behaviour in the conducted-EMI frequency range. The parameters of the proposed model can be evaluated based on...
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Efficient FPGA Implementation of an RFIR Filter Using the APC–OMS Technique with WTM for High-Throughput Signal Processing
PublicationNowadays, Finite Impulse Response (FIR) filters are used to change the attributes of a signal in the time or frequency domain. Among FIR filters, a reconfigurable filter has the advantage of changing the coefficient in real-time, while performing the operation. In this paper, the Anti-Symmetric Product Coding (APC) and Odd Multiple Storage (OMS) modules are utilized to implement the reconfigurable FIR filter (RFIR–APC–OMS). Herein,...
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GRAPHENE-BASED SUPERCAPACITORS APPLICATION FOR ENERGY STORAGE
PublicationRecent advances in graphene-based supercapacitor technology for energy storage application were summarized. The comparison of different types of electrode materials in such supercapacitors was performed. The supercapacitors with graphene-based electrodes exhibit outstanding performance: high charge-discharge rate, high power density, high energy density and long cycle-life, what makes them suitable for various applications, e.g....
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Nuclear Co-generation: The Analysis of Technical Capabilities and Cost Estimates
PublicationThis paper presents a concept of the parallel connection of a nuclear power plant fitted to provide heat for district heating application, with the CHP and heat plants existing in the supply region, in this case with the heating systems of Wejherowo and Gdynia. Presented variant proposes to add heat to a nuclear power plant’s total output by supplying heat exchangers with the steam from bleeders of low pressure (LP) turbine stage...
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Underfrequency Load Shedding: An Innovative Algorithm Based on Fuzzy Logic
PublicationIn contemporary power systems, the load shedding schemes are typically based on disconnecting a pre-specified amount of load after the frequency drops below a predetermined value. The actual conditions at the time of disturbance may largely dier from the assumptions, which can lead to non-optimal or ineective operation of the load shedding scheme. For many years, increasing the eectiveness of the underfrequency load shedding (UFLS)...
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Using concentrated spectrogram for analysis of audio acoustic signals
PublicationThe paper presents results of time-frequency analysis of audio acoustic signals using the method of Concentrated Spectrograph also known as ''Cross-spectral method'' or ''Reassignment method''. Presented algorithm involves signal's local group delay and channelized instantaneous frequency to relevantly redistribute all Short-time Fourier transform lines in time-frequency plain. The main intention of the paper is to compare various...
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Problems of varistor quality assessment during exploitation
PublicationVaristors are commonly used elements which protect power supply networks against high-voltage surges or lightning. Therefore, quality and endurance of these elements is important to avoid losses when an expensive laboratory equipment would not be protected from random overvoltages. Additionally, excessive leakage currents generate serious costs due to high energy consumption. The paper presents shortly properties of varistors that...
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APPLICABILITY OF INLET AIR FOGGING TO MARINE GAS TURBINE
PublicationThe dependency of marine gas turbine on the ambient temperature leads to a decrease of the gas turbine power output in arid areas. Very often gas turbine power output demand is high and the power margins originally designed into the driver , has been exhausted. In such circumstances the inlet air fogging is an effective compensation of gas turbine power. In this paper an analysis of inlet air fogging applicability to marine gas...
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Estimation of the Maximum Permissible PV Power to be Connected to the MV Grid
PublicationIn recent decades, a significant increase in the share of renewable energy sources in power grids at various voltage levels has been observed. A number of articles have been published highlighting emerging problems in low-voltage grids with a large share of prosumers and in medium- and high-voltage grids to which photovoltaic (PV) plants are connected. The article analyzes the medium-voltage grid in terms of the possibility of...