Characterization of Acoustic Resonance in a High Pressure Sodium Lamp

With the last decades, the high pressure sodium (HPS) lamp has been supplied in high frequency in order to increase the efficacy of the lamp/ballast system. However, at some given frequencies, standing acoustic waves, namely acoustic resonance (AR), might develop in the burner and cause lamp luminous fluctuation, extinction and destruction in the most serious case. As we seek for a control method to detect and avoid the lamp AR some main characteristics of the acoustic resonances in a 150W HPS lamp are presented in this paper,. The first one is the characteristic of the lamp AR threshold power, the second one is the differences between forward and backward frequency scanning effects during lamp open loop operation. Thirdly, lamp AR behaviour in closed loop operation with an LCC half bridge inverter will be presented and leads to a new point of view and a change in the choice of the AR detection method. These characteristics allow us to further understand the AR and to better control the lamp

Design of a Current Converter for the Study of the UV Emission in DBD Excilamps

This paper presents the design of a current converter to supply a DBD exciplex lamp. The structure is implemented, based on a Boost converter. An analysis in the state plane is used, to determine the stability of the converter and the values of current and voltage during the discharge phase. An electrical model of the lamp is used to simulate the non measurable variables: the gas current and the gas conductance. Finally, the relationship between the gas current and the UV emission is presented

Acoustic resonances in HID lamps: model and measurement

International audienceA finite element model including plasma simulation is used to calculate the amplitude of acoustic resonances in HID lamps in a 2D axisymmetric geometry. Simulation results are presented for different operation parameters and are compared with experimental data

Pulsed Current-Mode Supply of Dielectric Barrier Discharge Excilamps for the Control of the Radiated Ultraviolet Power

UV excimer lamps are efficient narrowband sources of UV radiation with applications in various domains. The issue of controlling the UV emission by means of the power supply associated with such lamps favors pulsed current-controlled generators. After having established the previous statements, we propose a dedicated power converter topology which implements the needed performances. The analysis of the degrees of freedom of this structure shows the capability of this pulsed supply to realize the control of both the pulses’ current energy and of the mean power transferred to the lamp. Actual experimental realizations and measurement are presented and the feasibility and the performances of the proposed solutions are established

Current-Mode Power Converter for Radiation Control in DBD Excimer Lamps

A pulsed current-mode converter specifically designed for the supply of dielectric barrier discharge excimer lamps is proposed in this paper. The power supply structure is defined on the basis of causality criteria that are justified by the structure of the lamp model. The converter operation is studied, and its design criteria are established using state-plane analysis. This converter, operating in discontinuous conduction mode, controls directly both the amplitude and the duration of the emitted ultraviolet (UV) pulses. Experimentally, the UV radiation is demonstrated to be proportional to the current injected into the gas, and the degrees of freedom offered by the control of the supply are shown to be very efficient for the active control of the UV power

Estimation of the light output power and efficiency of a XeCl dielectric barrier discharge exciplex lamp using one dimensional drift-diffusion model for various voltage waveforms

A XeCl dielectric barrier discharge (DBD) excilamp applied by pulsed and sinusoidal voltage waveforms is simulated using a 1-D drift–diffusion model. In both waveforms, the light output power depends not only on the gas mixture composition but also on the electrical parameters of each voltage waveform such as the frequency, the duty cycle, etc. At the same amplitude of the applied voltage and frequency, the light ultraviolet output efficiency of a pulsed voltage is higher than that of a sine voltage. These results obtained in this paper permit us to find out an appropriate power supply for a DBD excilamp

Acoustic Resonance Characterization and Numerical Model Including Acoustic Streaming in an HPS Lamp

This paper presents a numerical model of High Pressure Sodium (HPS) lamps including the acoustic streaming. The model is implemented in COMSOL and based on the finite elements method using a 2D axi-symmetric geometry. Moreover, a revision concerning AR experimental characterizations of HPS lamps will also be provided. The results presented in this paper will contribute to the understanding of AR phenomena and help in the electronic ballast design methods for AR avoidance

Efficiency computation of current controlled excilamps

The coupling between the power supply and a Dielectric Barrier Discharge (DBD) for UV production purposes (excilamp) is a major issue for the design of powerful and efficient UV sources. In order to improve this coupling, new power supply topologies have been developed, based on the current control of the DBD. The aim of this paper is to present the modeling results of such a control on the performances of the excilam

Predictive model of a DBD lamp for power supply design and method for the automatic identification of its parameters

An electrical model for a dielectric barrier discharge(DBD) is proposed, with the aim of its application in power supply design process. An identification method, which finds the actual value of the parameters in a model, is presented. The specific modelling of a XeCl exciplex lamp is developed, along with the identification procedure of the parameters, using a sinusoidal and a pulsed experiment. Electrical representation of the model is done in two different simulators. The applicability of the identified model is proved with different experiments. Differences between experimental and simulated waveforms are minor, encouraging the use of the model in the construction of the converter for the DBD lamp

Dielectric-Barrier-Discharge Excilamp in Mixtures of Krypton and Molecular Chlorine

International audienc