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Innovative solutions for acoustic resonance characterization in metal halide lamps

Metal halide lamp is one kind of the most compact high-performance light sources. Because of their good color rendering index and high luminous efficacy, these lamps are often preferred in locations where color and efficacy are important, such as supermarkets, gymnasiums, ice rinks and sporting arenas. Unfortunately, acoustic resonance phenomenon occurs in metal halide lamps and causes light flicker, lamp arc bending and rotation, lamp extinction and in the worst case, arc tube explosion, when the lamps are operated in high-frequency bands. This thesis takes place in the context of developing electronic ballasts with robust acoustic resonance detection and avoidance mechanisms. To this end, several envelope detection methods such as the multiplier circuit, rectifier circuit, and lock-in amplifier, are proposed to characterize fluctuations of acoustic resonance. Furthermore, statistical criteria based on the standard deviation of these fluctuations are proposed to assess acoustic resonance occurrence and classify its severity. The proposed criteria enable classifying between no acoustic resonance and acoustic resonance cases based upon either a two-dimensional plane, a histogram or a boxplot. These analyses are confirmed by the study of spectral variations (variations of the spectral irradiance and colorimetric parameters) as well. Standard deviations and relative standard deviations of these variations are also correlated with the presence of acoustic resonance. The results from this study show that whatever voltage envelope variations or spectral variations are significantly influenced by acoustic resonance phenomena. A set of metal halide lamps from different manufacturers and with different powers are tested in our experiments. We concluded that our designed multiplier and rectifier circuits for acoustic resonance detection have the same sensitivity as the lock-in amplifier, paving the way for the implementation of this function directly into the ballast circuit board.

Identiferoai:union.ndltd.org:univ-toulouse.fr/oai:oatao.univ-toulouse.fr:20219
Date24 January 2018
CreatorsLei, Fang
ContributorsInstitut National Polytechnique de Toulouse - INPT (FRANCE), Laboratoire Plasma et Conversion d'Energie - LAPLACE (Toulouse, France)
Source SetsUniversité de Toulouse
LanguageEnglish
Detected LanguageEnglish
TypePhD Thesis, PeerReviewed, info:eu-repo/semantics/doctoralThesis
Formatapplication/pdf
Rightsinfo:eu-repo/semantics/openAccess
Relationhttp://oatao.univ-toulouse.fr/20219/

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