A properly designed and constructed ground electrode should perform well for many years. It must be periodically inspected to know its current technical condition. This obligation falls on the installation's owner. Depending function of in entire installation, it may a working, protective or lightning protection earth. The choice measurement method depends installation. paper presents results measurements resistance selected facility, performed throughout year. Repeating multiple times...

The photoreflectance spectra for heavily doped p-type GaAs/SI-GaAs structures have been measured at room temperature the energies in vicinity of GaAs band gap. complex function is defined and determined by means a Kramers–Krönig analysis from spectra. modulus gives us critical point energy whereas phase this can be used topographical study homogeneity internal electric field structure.

The paper presents the results of laboratory tests concerning measurements electrical parameters road lighting luminaires. These were focused on determining dependence luminaires versus changes RMS (Root Mean Square) value supply voltage and level disturbances in voltage. basic for light-emitting diode (LED) analysed with option luminous flux adjustment if it existed. During measurements, powered from Agilent 6834B distorted generator within assumed acceptable range deformation resulting...

Abstract Epitaxial undoped and doped (Si Zn) GaAs GaAIAs layers as well heterostructures of GaAs/GaAIAs have been grown in an atmospheric pressure, vertical MOCVD system. Room temperature photoreflectance (PR) has applied to characterise the multiple quantum wells. The surface‐ interface‐related PR studied by application Kramers–Kronig analysis. A decomposition spectrum into spectra connected with surface region interface proposed.

Before the use of regulated street luminaires with variable power and luminous flux, computations were performed using constant values for their electrical photometric parameters. At present, where such lighting is in use, it no longer possible to base calculations on assumptions. Computations energy losses, example, need be all dimming levels based applied regulation algorithm. Based measurements carried out luminaires, was found that certain parameters have a nonlinear dependence level....

In accordance with the requirements of PN EN 13201-5 standard for road lighting installation, energy performance indicators should be descripted. order to calculate indicators, it is necessary know active power system. The above does not specify whether losses taken into account in calculations. main purpose article estimate installation. presents methods calculating losses, taking all elements obtained calculation results show relationship between and luminaires, their number spacing poles....

Purpose The purpose of this paper is to estimate that the start-up current parameters are stochastic or not. Electronic equipment in luminaries significantly improves their luminous efficiency, thereby increasing energy efficiency lighting installations. However, use electronics [e.g. electronic ballasts for discharge lamps power supply units light-emitting diode (LED) luminaries] may also cause some negative effects One such large inrush current, which can greatly exceed admissible line...

Road lighting is an important element of road infrastructure influencing on the safety. It helps users to identify potential hazards and reduces risk a accident. Improving energy efficacy installations requires using new technologies. Currently, high-pressure sodium (HPS) lamps are still most commonly used in lighting. Many luminaires with HPS good technical condition there no economic justification for replacing them (except improving efficacy). One methods their replace electromagnetic...

Photoreflectance (PR) spectra are measured at room temperature for energies in the vicinity of E0 critical point doped GaAs/SI-GaAs structures. In analysis obtained assumption that PR signal is created due to internal electric field both surface and interface regions verified. calculation procedure dispersion relations (Kramers-Kronig analysis) used heavily epilayers. this case possibility very precise surface-interface distance determination suggested.

The article presents the analysis results of effectiveness limitation step voltage by forming an electric field on ground surface.For shaping field, a method consisting screens placed around point earth current flow was used.The performed using example MV/LV substation grounding system.This research conducted applying mathematical model system and means finite element method.The influence metal, insulating surface material step/touch values for considered estimated.Most methods described can...

Light sources and luminaires made in the LED technology are nowadays widely used industry at home.The use of these devices affects operation power grid energy efficiency.To estimate this impact, it is important to know electrical parameters light luminaires, especially with possibility dimming.The article presents results measurements as well luminous flux dimmable a function dimming RMS supply voltage.On basis performed measurements, model luminaire was developed for prediction set values...

The development and increasing use of renewable energy sources has revived interest in low-voltage direct current (LVDC) networks. Their reduces the number used inverters, which affects both cost construction operation, efficiency transmission distribution electricity, elimination problems related to reactive power reduction negative impact on quality electricity. LVDC networks also an electric shock protection. basic element protection against shock, as case alternating networks, are earth...

Electrical equipment with nonlinear current-voltage characteristics are the source of numerous unfavorable phenomena in power supply networks. One such phenomenon is harmonic current disturbance, level which characterized by a total distortion THD <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I</sub> . The value depends on many factors, primarily construction, principle operation and degree voltage. typical LED luminaire an impulse for...

Currently most of the growth human population takes place in cities. Urban areas become more densely populated. Simultaneously cities are recognized as leading producers CO2 emissions. For these reasons, coming years, reducing energy use and mitigating air pollution will be critical. decades, urban planners have attempted to make sustainable efficient. However, understanding complex interactions among all factors, environment microclimates on citywide scales is a complicated challenge. Only...

Projektowanie budynków energooszczędnych staje się powszechną koniecznością, wynikającą ze względów środowiskowych, ekonomicznych i społecznych oraz z obowiązującego prawa.Na ostateczny poziom zużycia energii końcowej w budynku wpływa wiele wzajemnie uzupełniających współzależnych, rozwiązań architektonicznobudowlanych instalacyjnych

Abstract The power systems usually include a number of nonlinear receivers. Nonlinear receivers are the source disturbances generated to system in form higher harmonics. level these describes total harmonic distortion coefficient THD. Its value depends on many factors. One them deformation and change RMS supply voltage. A modern LED luminaire is receiver as well. paper presents results analysis influence voltage dimming tested current was made using mathematical model based multivariable...

Outdoor lighting is an important element in creating evening and nocturnal image of urban spaces.Properly designed constructed installations provide residents with comfort security.One way to improve the energy efficiency road installation replace electromagnetic control gear (ECG) electronic ballasts (EB).The main purpose this article in-depth comparative analysis performance HPS lamps ECG EB.It will compare their under sinusoidal nonsinusoidal voltage supply conditions for four most...