High-pressure Sodium Vapor Research Articles

Street lighting maintenance management system based on fuzzy logic

PurposeThis research was carried out in response to the need to find new alternative ways of maintaining public lighting with high pressure sodium vapor lamps. The objective was to develop a public lighting maintenance management system based on fuzzy logic that guarantees maximum energy efficiency and is economically feasible.Design/methodology/approachA preliminary study was carried out on the complaints due to failures of public lighting for three years in the municipality of Camagüey, Cuba, determining the failure rate of each control and the time between failures, a statistical evaluation of the time between failures was carried out identifying that this variable responds to a Weibull distribution, the membership functions of the proposed four linguistic variables and the rule base for their fuzzy sets were created, obtaining as output linguistic variable the mass replacement and cleaning time.FindingsThe fuzzy logic maintenance model developed is effective in making better use of the useful life of high-pressure sodium vapor lamps, increasing the time between maintenance operations of mass lamp replacement and mass cleaning of luminaires up to 8 and 9 years, without compromising the required lighting levels and energy efficiency.Originality/valueThe literature contains very few references to the use of condition-based maintenance in this type of system, so a novel approach by a robust heuristic model of street lighting condition-based maintenance management driven by data is proposed, the model integrates through fuzzy logic all the factors that influence the progressive deterioration of these installations and maintenance actions that guarantee compliance with the established service quality standards, with the maximum energy efficiency that is economically justified.

Study of LED Retrofit Lamps in HSPV Luminaires Based on Photometric Method for Road Lighting

Energy reduction is a great challenge in road lighting applications. Replacing high-pressure sodium vapor (HPSV) with light-emitting diodes (LED) is a viable approach to reducing energy consumption. However, a total replacement can incur a significant capital cost. This study aims to investigate the effects on light distribution by replacing HPSV lamps with LED lamps in HPSV luminaires using Light Intensity Distribution (LID) curve measurement and Backlight, Uplight and Glare (BUG) rating evaluation to reduce the adoption costs. While LED lamps have high illumination rates, the structural differences from HPSV lamps can affect the LID curve and original lighting design. Therefore, it is crucial to study photometric dispersion after retrofitting light sources. Both lamps were installed into similar HPSV luminaires to assess photometric performance using goniophotometer measurements. The HPSV lamp outperforms the LED lamp in terms of luminous flux (11.13%) and light intensity (7.69%), whereas the LED lamp outperforms the HPSV lamp in terms of efficacy rating (68.67%) and wattage used (47.61%). The findings indicate that retrofit LED luminaires have an LOR of 46.77% lower than the HPSV luminaires. The light distribution pattern is maintained but reduced to 40 to 50% for the main usable light angles. The reduced performance is caused by the lamp structure, which occupies a large area inside the luminaire housing, obstructing proper light distribution. Although overall energy consumption is reduced, similar illumination levels cannot be maintained. These outcomes can assist authorities and manufacturers with alternative methods of reducing costs while maintaining lighting levels.

Improved Public Lighting at the University of São Paulo - Brazil

The University of São Paulo (USP) transitioned the roadway lighting technology at the University called Armando de Salles Oliveira (USP-CUASO campus) from High-Pressure Sodium Vapor Lamps (HPSVL) and Metal Halide Lamps (MHL) to the Solid-State Lighting (SSL). So, this paper presents and discusses the outcomes of the lighting installations and the depreciation of light output from luminaires installed at the Institute of Energy and Environment (IEE) at USP using field data collected over two years (2018–2023). The analysis incorporates aspects related to corrective maintenance, predominantly performed last year, necessitated by the end of the useful life of components such as electronic drivers (66%), 50 W LEDi modules (17%) and others (17%). The failure rate of the sampled luminaires in the IEE area increased from 10% to 28% between August 2021 and January 2023.

Spotlight on Eupeodes americanus: Oviposition and fertility under HPS- and full spectrum LED-extended photoperiod in northern greenhouses

In northern temperate regions, high-pressure sodium vapor (HPS) or light-emitting diode (LED) lights for supplemental lighting in winter greenhouses are used to extend the photoperiod and increase plant production. These different greenhouse light treatments influence crop pests and their natural enemies. In this study, different greenhouse light treatments were evaluated for their effect on the green peach aphid, Myzus persicae (Sulzer, 1776) (Hemiptera: Aphididae) and its predator the American hoverfly, Eupeodes americanus (Wiedemann, 1830) (Diptera: Syrphidae). In particular, the development of M. persicae and the oviposition and egg hatchability of E. americanus were studied under three light treatments in winter greenhouse: 1) short photoperiod of natural sunlight, and extended photoperiod using either 2) full spectrum LED or 3) HPS lights. The results showed that both extended photoperiod treatments significantly increased M. persicae population growth by 103–130 %, after 12 days compared to short photoperiod of sunlight. Compared to the winter short photoperiod of sunlight, extending the photoperiod did not affect the oviposition of female hoverflies in terms of fecundity, fertility, and niche use (i.e., position of eggs on the plant). Nevertheless, extended photoperiod significantly increased the egg hatchability of E. americanus by 9 % (HPS) and 16 % (LED) compared to short photoperiod of sunlight. This treatment had the highest proportion of unhatched eggs (13 %). Finally, LED lights decreased the proportion of unhatched eggs by 71 % compared to HPS lights. This study, therefore, confirms the potential of the American hoverfly as a biological control agent in winter greenhouses, both with or without artificial light.

Study of the Harmonic Analysis of the High-Intensity Discharge Lamps

The high-intensity discharge (HID) lamp, mainly the high-pressure sodium vapor lamp and the MH lamp are the most common lamps used in public lighting purposes in Indian context, despite of the fact that uses of light emitting diodes are becoming common nowadays. The aim of this paper is to study the harmonic content in these high-power lighting networks. These light sources have been chosen because of their high power and another component, known as the igniter, which is connected to the circuit and whose effect can be studied. The study presented in this paper is completely based on measurements, including the harmonic analysis. Different combinations of ballasts and lamps have been chosen to perform the experiment. The main results show that high-pressure sodium vapour (SON) lamps have a much higher harmonic content in the lamp voltage and supply current waveforms as compared to the metal halide (MH) lamps. Results also indicate that lamp voltage harmonic contains significant amount of higher order harmonics, and its waveform is much distorted than the supply current or the ballast waveform. Furthermore, the percent of total harmonic distortion (THD) content is higher. These results will guide the future designer to select a light source from the point of view of the harmonic content in the lamp voltage, ballast voltage, and the supply current.

Comparative Analysis of High-Pressure Sodium Vapor Luminaires with LED Luminaires in Tunnel Illumination

Nowadays, some roads pass through underground tunnels due to technical inadequacy and high economic costs in constructing highways, railways, and pedestrians. Tunnels are opened to pass through obstacles on the route (mountain, hill, etc.) to force the driver, disturb him, reduce the ramps that could endanger safety depending on nature’s state, and shorten travel distances. In this way, number of tunnels along with the road increases, and illuminating these tunnels with different characteristics varies day and night. Tunnel illumination calculations and applications are essential as good tunnel illumination ensures the same flow of comfort, speed, and safety as on the approaching road. Moreover, with the advancement of tunnel technology, many types of equipment are used inside and outside the tunnel, and electricity needs vary according to these types of equipment. In this research, the importance of tunnel illumination was discussed and comparative illumination analysis in 8 August tunnel in Bitlis was conducted. Illumination for the Bitlis 8 August tunnel was done using luminaires with high-pressure sodium vapor lamps, and the grid was used to generate all the energy required. In this study, the energy used by the Bitlis 8 August tunnel for illumination was obtained from the accurate data and the results were compared with the initial situation when the same system was installed using light emitting diode (LED) illumination technology.

Light-Emitting Diode (LED) versus High-Pressure Sodium Vapour (HPSV) Efficiency: A Data Envelopment Analysis Approach with Undesirable Output

Road lighting is essential to ensure the safety and comfort of its users, especially in preventing accidents and aiding visual tasks. The monumental shift from conventional road lighting technology to light-emitting diode (LED) lighting is driven by energy efficiency, associated cost savings, and environmental concerns in the road lighting system. This study aims to investigate the performance of LED in substitution for high-pressure sodium vapour (HPSV) road lighting in Penang Bridge, Malaysia using the Data Envelopment Analysis (DEA), a frontier-based optimisation approach, by modelling energy, cost, and environment together, as none of the previous studies has included energy, cost, and environmental concerns together in one model. The LED renewable energy industry that promotes zero carbon emissions has the potential to establish an affordable, clean, and carbon-free energy system for road lighting, especially in rural areas.

Comparative Analysis of Lighting Installations Used in Road Illumination

As the demand for electrical energy increases daily, it has become inevitable to use electrical energy more efficiently and economically. To reduce foreign dependency in energy in our country, various steps are taken to bring the areas where energy is used under the focus and to bring the existing systems to a better level with technology. 20 % of the energy consumed in our country is used in illumination. The share of road illumination is high illumination. Besides, since the control and observability of the road illumination inside the external illumination are easy, it is easier for countries to work in this field. New generation technologies are rapidly adopted, followed, and applied in our country. Light sources and luminaires used in road illumination have constantly changed with technology. High-pressure sodium vapor lamps are primarily used in road illumination in our country. In addition, LED luminaires, which are considered a new generation illumination technology, have startedto find wide use in this market. A comparative analysis of luminaires with high-pressure sodium vapor lamps and LED luminaires used in road illumination was made in this study. DIALux program was used to compare these analyses.

An EEG based comparative study on driver's performance under the influence of metal halide and high pressure sodium lighting

For the last few decades the most favored light sources for road lighting designs are the Metal Halide (MH) and High Pressure sodium vapor (HPS). The use of LED has been increased profoundly in the recent time in different road lighting applications. One of the most important characteristics that differentiate both the light sources is their color. Although the spectral power density of both MH and HPS light sources contains peaks at different wavelengths throughout the visible spectrum but the color produced by the MH sources is mainly blue-white color and by the HPS sources are yellow. Recent study had shown that detection of object by the road users are highly influenced by lamp type (Biswas et al., 2018; Rea, 2013, 2014; Boyce Peter, 2014; Rea et al., 2010; Morante, n.d.). A comparative behavioral study along the performance analysis is thus very important from the driver’s point of view under the spectrum of these two light sources. In this research work the behavioral and detailed performance analysis study of a subject driving a vehicle in a simulated road lighting condition illuminated by HPS and MH light sources has been conducted. The driver’s time response along with electroencephalography (EEG) study was conducted to investigate the probable temporal processes and significant differences in the distribution of brain waves for detection of object located at on-axis (foveal). The results are compared for both the types of lamps and it has been found that metal halide lamps have better human cognitive performance.

Short Free-Standing Pole LED Luminaire and Lens Design for Road Lighting

Road luminaries are required to provide the luminance specified in the standards according to the road characteristics. For this reason, the light from the light source should be directed according to the desired conditions. While the range of minimum average road surface luminance recommended for different classes of road are provided; at the same time, it is desirable to be economical. In this study, a freeform lens and LED luminaire design with high luminous efficacy, low glare and uniform luminance distribution with a height of 1.5 m and a distance of 7 m between poles were designed for M3 road standards. First of all, lens design was made by using optical and illumination design software. Also, lens manufacturing and luminaire production were made as a result of the success of the design simulation test. The success of the LED luminaire in providing CIE standards has been measured on the designed road. In addition, the advantages and disadvantages have been determined by comparing with High Pressure Sodium Vapor (HPS) lamps.

Responses of mixed light-emitting diode ratios on vegetative, flower regulation, and stalk elongation of cut chrysanthemum (Dendranthema grandiflora Tzvelev)

A Greenhouse experiment on the study of responses of mixed light-emitting diode ratios in cut chrysanthemum (Dendranthema grandiflora Tzvelev) was conducted at the Department of Floriculture and Landscape Architecture, Tamil Nadu Agricultural University, Coimbatore during 2019-20. The experiment was laid out in Randomized Block Design with three replications. The treatment comprises of seven varied light-emitting diode irradiance levels viz., L1 – 100% White; L2 – 100% Red; L3 - 80% Red + 20% Blue; L4 – 80% Red + 20% Far-red; L5 – 75% Blue + 25% Far-red; L6 – 60% Red + 20% Blue + 20% Far-red; L7 - High pressure sodium vapour lamp (as check) in Salvador and Pusa Centenary varieties. The results revealed that the growth in terms of height of the chrysanthemum at critical stages was maximum (48.88 cm in Salvador and 41.92 cm in Pusa Centenary) under the light irradiance of B75FR25 (L5) during the peak vegetative stage and registered maximum leaf area. Highest internodal length up to 3rd leaf of 1.07 cm was registered in sodium vapour lamp irradiance (L7) and 1.39 cm in 100% Red irradiance (L2). The early flower bud emergence (39 days in Salvador and 50 days in Pusa Centenary) was observed in B75Fr25 spectral irradiance (L5). The highest total cut stem yield per square meter (42.65 in Salvador and 41.99 in Pusa Centenary) was registered in R80B20. The study revealed that blue LEDs combined with Far-red promoted early flowering and inhibited stem elongations. Red and Blue wavelength increased the total leaf area and registered improved flower yield.

Influence of Light Spectra on the Production of Cannabinoids

In recent years, more attention has been paid to cannabis from both medical and political points of view. This study investigates the influence of 5 different light spectra on the active substance content in THC-poor hemp of the Alessia chemotype II variety. The focus is on comparing conventional growing under metal halide lamps with growing under high-pressure sodium (HPS) vapor lamps with regard to different spectra of LED lighting modules. Growing was carried out in 10 growing boxes under controlled and mostly identical conditions for all boxes. The photoperiod during the vegetative phase was 18 h light and photosynthetic photon flux density ∼520 μmol⋅m⁻² s⁻¹. The flowering phase was 12 h light and ∼540 μmol⋅m⁻² s⁻¹. During the experiment, CO₂, temperature, and humidity were measured and logged. Additionally, weekly measurements of chlorophyll, electric conductivity of the fertilizer, activity measurement (salt content) of the soil, and pH value of the soil were checked. The content of cannabinoids was measured by high-performance liquid chromatography (HPLC). Plant height and growth were monitored during the whole experiment by cameras taking pictures every 30 min and loading them onto a cloud storage platform. Cannabinoid content was measured using HPLC. Plant wet weight was determined at the end of the experiment and showed that plants under the high pressure lamp treatment had less flower weight than those under the LED treatment. In conclusion, it could be shown that certain LED spectra can considerably increase the amount of cannabinoids with respect to conventional illumination (HPS).

Assessment of public lighting systems considering mesopic vision

The objective of this research was to evaluate public lighting systems installed in a concrete pathway considering the effects of mesopic vision. The light sources evaluated were high-pressure sodium vapour, metal halide and LED. The quantitative evaluation was based on in-situ measurements of the illuminance and luminance levels and computer simulations. The qualitative aspect included the application of questionnaires to local users. It was found that the energy savings could be up to 53% when replacing metal-halide lamps with LEDs. As for the qualitative analysis, the LED lamp was the one that received the best evaluation, followed by the metal halide and finally the high-pressure sodium vapour. The LED provided a greater sense of security to people, although the illuminance level provided was 31% less than that of the sodium vapour lamp. The research confirmed the effects of mesopic vision, i.e. when light sources with higher S/P (Scotopic/Photopic) ratio were used, the luminous perception and efficiency of the systems increased. Based on the analysis performed, it was noticed that the use of LEDs to light a concrete pathway was the best option in terms of energy savings and safety.

Assessment of Electric and Magnetic Fields Exposures for Different Types of Street Lights

The use of solid-state lightings using energy saving lights such as light emitting diodes (LEDs), High Pressure Sodium Vapour (HPSV) and induction light in the illumination has represented a major technological breakthrough in recent years. Several recent studies focus on the development and performance of energy saving street lighting systems such as LED, induction etc. These modern lamps use electronic ballasts contain a switching power supply circuit typically operate in the range of 20kHz to 60kHz to achieve low power consumption in which may cause interference to communication equipment as well as health effect to human body, which is not an issue in traditional electromagnetic 60Hz ballasts. This paper investigates the electromagnetic and electric field exposure to human body from three street lights systems; LED, HPSV and Induction lights. The electromagnetic and electric field measurement are conducted in the laboratory that represents a controlled environment in which free from external factors or interferences. The electromagnetic and electric field exposure measurements are conducted using the Aaronia SPECTRAN hand held spectrum analyzer model NF-5030 on five streetlights from three different types in accordance to MS2230-2009 standard. The results presented in this paper can be utilized as references for measurement in open space that may have some interferences from other sources as well.

A Case Study for Tunnel Lighting Lifetime Account

A lighting device is required to provide minimum lighting level during the operating time. Contamination on lighting device causes luminous flux to be lost in lamp and structural imperfections to be formed on the surface of optical elements. This deficiency in the performance of lighting makes maintenance of lighting devices necessary. This effect formed by the common effect of various parameters and implemented periodically is called maintenance factor. Maintenance factor varies by lighting system, environmental conditions and features of luminaires. In this study, calculation of maintenance factors by years and change of lighting levels by different maintenance factors have been analyzed for high-pressure sodium vapour luminaries in tunnel lighting. Accordingly, increasing the maintenance factor used as multiplier in performance calculations will decrease the energy consumed. Therefore, increasing the Maintenance Factor increases the lighting efficiency.

A design methodology for acoustic resonance-free, high-frequency, dimmable electronic ballast for high-pressure sodium-vapour lamps

This paper presents a methodology to design acoustic resonance-free, high-frequency, dimmable electronic ballasts for high-pressure sodium vapour (HPSV) lamps having a range of rated wattage (70–400 W). After estimation of the ‘quiet window’ of an HPSV lamp, the proposed iterative algorithm is able to determine the acoustic resonance-free driving frequencies of a design ballast corresponding to 50%–100% power level. On the other hand, a developed wattage and voltage independent HPSV lamp model facilitates finding the required electrical characteristics of HPSV lamps without performing laboratory experimentation. Using the estimated driving frequencies of a design ballast and the synthesized electrical characteristics of the lamp, the design circuit parameters of an electronic ballast are determined. Performance evaluation of the designed ballasts, carried out on the Matlab–Simulink platform, indicates several important attributes, viz. higher power control accuracy (deviation ≤3.69%), near-unity lamp power factor (≥0.98), lower lamp current crest factor (<1.7) and lower lamp current total harmonic distortion (≤12.63%). Results establish the effectiveness of the proposed design methodology to design lightweight and compact electronic ballasts for HPSV lamps with less effort than conventional design practice.

A Loss-Free Resistor-Based Versatile Ballast for Discharge Lamps

This paper presents a versatile ballast for discharge lamps, whose operation is based on the notion of a loss-free resistor (LFR). The ballast consists of two stages: (1) a boost converter operating in continuous conduction mode (CCM) and exhibiting an LFR behavior imposed by sliding-mode control; and (2) a resonant inverter supplying the discharge lamp at high frequencies. Thanks to this mode of operation, the power transferred to the lamp is regulated by the LFR input resistance, allowing successful ignition, warm-up, nominal, and dimming operation of a range of discharge lamps, with no need for complex regulation schemes based on lamp models. The versatility of the ballast has been experimentally proven for both conventional and electrodeless discharge lamps. Tests include induction electrodeless fluorescent (IEFL), high-pressure sodium (HPS) vapor, and metal-halide lamps.

PRODUCTIVITY OF THE GREENHOUSE TOMATO CULTURE IN THE LONG TURNOVER IN THE NORTH

The data on the greenhouse tomato culture productivity in the long turnover (February November) without application of artificial light are presented. The plants were grown using small-volume hydroponic technology on mineral wool in the industrial greenhouse of LLC "Prigorodny" (Syktyvkar, 61° 40′35″N, 50° 48′35″E). Tomato seeds (hybrid Starbuck F1) were sown in early December 2016. The seedlings were illuminated for 19 h daily with the high-pressure sodiumvapor reflector lamps (HPSV-400W / REFLUX) with an installed power of 130 W/m2. In early February 2017 plants at the age of 4245 days were transferred to the greenhouse and grown at density of 2 plants per square meter under natural lighting conditions. The dependence between the light intensity at leaf level and the natural light entering the greenhouse was studied. In spring sunny days, the light intensity at the level of the upper leaves did not exceed the 450500 μmol quanta/m2s, and in cloudy weather was 2-3 times lower. It was found that the saturation of leaf CO2-uptake by light took place at intensity of 800-1000 μmol quanta/m2s. The leaves formed under light deficiency had lowered photosynthetic activity (near 3 μmol СО2/m2s). The maximal productivity of tomato culture was observed during maximum light levels and sunny period (June-July). The average value of tomato productivity was about 34 kg/m2. The data show the possibility of producing commercial tomato yield in the first light zone without artificial lighting, which significantly reduces production costs.

Erasing day/night differences in light intensity and spectrum affect biodiversity and the health of mammals by confusing the circadian clock

The beneficial effect of sunlight on all forms of life has been well-known to human cultures worldwide throughout history. However, the importance of darkness for survival, successful reproduction and the overall fitness of all organisms is fully appreciated only by physiologists and environmental biologists. Seasonal variations in environmental conditions (i.e., rainfall, temperature, barometric pressure, food availability) significantly affect reproduction and survival but they are of little predictive value. In contrast, daily fluctuations in light levels and the light spectrum are less dramatic in their impact on life, but were highly predictable throughout evolution. Natural selection has thus favored a strategy of monitoring a day’s length as a predictor of changes in external conditions by the development of the molecular circadian clock, which is sensitive to changes in light/darkness during the day and night. Well-synchronized circadian clockwork ensures that behavioral and physiological processes fluctuate with the daily solar cycle and programs the seasonal changes in physiology via the transduction of the photoperiod into hormonal messages. During the last two decades, energy-efficient lighting technology has shifted from “yellow” high-pressure sodium vapor lamps to new “white” light-emitting diodes (LEDs). As a consequence, nighttime light pollution increased, and the sharp difference between day and night has been erased in many parts of the world, which threatens animal ecology and human health. Studies on humans, laboratory mammals and wildlife suggest that the physiological costs of living under artificial light at night (ALAN) may be due to the disruption of circadian and circannual timing. This overview summarizes the recent findings on the effect of the blurred day/night difference on the circadian clock, nighttime melatonin secretion and photoperiodic changes in mammals and suggests that the gradual decline of fitness due to the increasing ALAN measured in the human population may contribute to the changes in mammalian biodiversity in nature.

Cermet Solder for High-Pressure Sodium-Vapor Lamps

A new composition of cermet solder for high-pressure sodium-vapor lamps is proposed. This cermet solder will make it possible to attain lamp service life to 12,000 h with high specific electric load and considerably improve the quality and significantly expand the practical applications of the lamps manufactured.