A. Chammam

Effect of a pulsed power supply on the spectral and electrical characteristics of HID lamps

Results of spectral and photometric measurements are presented for pulsed power operated high intensity discharges (HIDs). This investigation is related to the application of a pulsed power supply for pile driving of HID lamps. Specifically, we are interested in controlling the spectral response radiation of visible and ultraviolet (UV) lines for tertiary treatment of water using UV radiation. Simulations based on a physical model of the lamps were conducted. These results relate to the radial temperature, line intensity and electrical properties (voltage, power and conductivity). Good agreement has been found between the results of the simulations and the experimental findings.

Behaviour of a high pressure sodium lamp fed by a pulsed power supply

The aim of this paper is to present the colorimetric and photometric results for a pulsed power supply operated high pressure sodium (HPS) lamp. Especially, we are interested in controlling the spectral response radiation of the yellow D line. This sodium D line is composed of two spectral components, one at 589.6 nm and the other at 589.0 nm. The pulsed power supply is a driver for the HPS lamp based on the application of a low frequency (50 Hz) square current waveform through the lamp with one or more pulses on each half cycle. A description is given of the physical modeling of the arc’s behaviour. Experimental results obtained from our laboratory power supply for a 400 W HPS lamp supplied at 50 Hz and simulations are shown.

Dimming control by variation of the switching frequency for high-intensity discharge lamps

In this paper, a high-frequency dimmable electronic power supply for the high-pressure sodium lamp is presented. The method includes a full bridge rectifier generating a dc-link voltage and a half bridge inverter to generate a frequency swept lamp power signal to drive the lamp while avoiding acoustic resonance. A dimming technique for a resonant circuit electronic ballast based on a variable frequency is introduced. In addition, the ability in the dimming range is demonstrated by experiments and simulation in order to verify the performance of the proposed circuit. A dimming range from 100% to 50% has been achieved. The efficiency is always higher than 89% and the ballast can accurately follow a fixed dimming plan.

Study of the influence of additive on the radiative properties of a HgTℓI high pressure discharge

This paper deals with radiation transfer in a cylindrical high pressure HgTlI discharge for which local thermodynamic equilibrium can be assumed. The discrete ordinates method (DOM) is used to solve the radiative transfer equation. Calculations of concentration profiles of all species have been performed using a parabolic temperature profile and a constant mercury/thallium ratio throughout the discharge tube. The influence of thallium in HgTlI discharges on the spectroscopic parameters such as the spectral intensity, the radiative flux and the net emission coefficient is studied. A comparison of the calculated thallium line shapes with the measured ones shows good agreement.

HID lamps under low frequency square wave operation: Experimental Evaluation of Dimming effects

In this paper, the dimming effects on the photometric and electric characteristics of high intensity discharge lamps supplied by a low frequency square waveform are evaluated. For this evaluation an electronic ballast is presented. The ballast consists of a current source, AC/DC converter and a full-bridge inverter. The electronic supply provides to the lamp a different form of current excitation (square waves with variable short drops). Dimming control and the characteristics of low frequency operated high intensity discharge lamps are described. The lamp is represented in a simulation by its conductance model and coupled to its electronic power supply. Experimental results are shown and compared with the simulation. A dimming range from 100% to about 60% has been achieved.

Behaviour of a high-intensity discharge lamp fed by a high-frequency dimmable electronic ballast

The main advantages of high-frequency electronic ballasts for high-intensity discharge lamps are high luminous efficacy, small size, lightweight and longer lifetime. This is why high-intensity discharge lamps operating at high frequency are widely used. This paper proposes an approach for designing resonant circuit electronic ballasts controlled by frequency variation for high-intensity discharge lamps. The proposed technique including an AC/DC rectifier, a power factor correction circuit and a DC/AC half bridge inverter. These electronic ballasts offer a wide range of dimming controls and can avoid acoustic resonance. However, under dimming, the electric and photometric characteristics of the lamp change. In order to study these effects under the process of dimming, this work studies the lamp properties by varying both lamp power and operating frequency.

Frequency dimmable electronic ballast for a 250W HPS lamp

In this paper, a simple circuit is proposed to achieve ability in dimming range, and to reduce the number of electronic components in the drive circuit, which helps to reduce its cost. Detailed analysis and design of a dimmable electronic-ballast high intensity discharge lamp circuit with frequency control are presented. A dimming technique for resonant circuit electronic ballast based on a variable frequency is introduced. Dimming is successfully accomplished and simulation results and experimental results are presented on high-frequency control electronic ballast.

Dimmable electronic ballast for HPS lamp operating in LF

In this paper we present the study, design and realization of a low frequency dimmable electronic ballast controlled by a microcontroller of a dimmable electronic ballast on micro controller. Indeed, it is with short current drop (which can be variable). We are interested in controlling the spectral radiation response in the of the spectrum , especially d-lines. A comparison between simulations and measurements of HPS lamps confirms the agreement between the model and the experiment.

Assessment of the effect of a pulsed power supply on the HgTlI lamp

The objective of this work is to study the influence of a pulsed power supply on the energy efficiency of high-intensity discharge lamps in comparison with a pseudo-continuous ballast. The results presented in this paper concern the dynamic behaviour of discharges in mercury vapour doped with thallium iodide. The acquisition of the arc current, arc voltage and spectral radiation enables us to investigate the influence of the pulsed power supply on the electrical characteristics of the lamp such as the behaviour of the lamp conductance and spectral radiance. The analysis of the 577 nm mercury line’s response to the current pulse excitation allowed us to identify several phases. Good agreement has been found between simulation and experimental results.

A study of the impact of a High Pressure Sodium (HPS) lamps on power quality

Discharge lamps based on plasma emitting light are the most important electric light sources. They are used in virtually all areas of modern lighting technology and they are produced in wide range of powers with different levels of luminous efficacy. The main concern of lighting systems is their impact on power quality. The study proposed in this work is to measure power factor and harmonic disturbances generated by a 250W HPS lamp with magnetic ballast. An experimental setup is carried out to study the harmonic impact of large scale deployment of HID lamp. In addition, results obtained for these lamps are compared with those obtained for Compact Fluorescent Lamps (CFLs) widely used by electricity consumers in modern lighting and a simulation is also conducted using conductance model of High Intensity Discharge lamp.