Effects of dimming 150 W ceramic metal halide lamps on efficacy, reliability and lifetime

Abstract

Dimming high-intensity discharge (HID) lamps is often proposed as part of energy management schemes for lighting installations. However, the impacts of dimming on HID lamp performance are not well characterised. The impacts of operating 150W ceramic metal halide discharge (CMH) lamps for prolonged periods (up to 11 000 h) at reduced powers have been quantified. CMH lamps of 150W operated at 100W and 76W showed no significant differences in lumen maintenance, survival and colour rendering index compared to similar lamps operated at the rated power for the same time. The experiments confirm that the concept of dimming CMH lamps can be employed in roadlighting schemes, such as NumeLiTe, without detrimental consequences on lamp performance.

An Overview of the Impact of Dimming Metal Halide Discharge Lamps

“…Operating the lamps under the constraints shown in Table 4 should not adversely impact the uniformity as the scheme always provides the maintained illuminance. Note: a Based on values reported in [24] LLMF = Lamp lumen maintenance factor V. RELIABILITY EFFECTS The detailed study by Guest et al [24] confirms that operating 150 W ceramic metal halide lamps for prolonged periods (>11,000 h) at reduced powers using suitable ballasts does not have a detrimental impact on lamp survival nor lamp lumen maintenance. Similarly, the colour rendering properties of these lamps when measured at rated power are unaffected by operation at reduced powers for prolonged periods.…”

“…Kettlitz et al [22] illustrate changes in arc centre temperatures and radial temperature profiles on lamps specifically designed for diagnostic measurements. The effects of dimming a group of 150 W ceramic metal halide lamps on efficacy, reliability and lifetimes is outline in [23] and described in detail in a subsequent publication [24]. Contributions by Shi et al [25]- [27] detail the changes in spectral power distribution, colour temperature and colour rendering properties with input power for 70 W (CCT 4000 K) and 150 W (CCT 3000 K & 4000 K) ceramic metal halide lamps.…”

A high-frequency half-bridge driving circuit topology for HID lamps

“…In public lighting, metal halide lamps enjoy a satisfactory colourrendering property, and high-pressure sodium lamps are favourably characterized by high light penetration. [1][2][3][4] Currently, highintensity discharge (HID) lamps of these types are widely used for urban roads, factories, and shopping malls. [5][6][7][8] However, most inductive ballasts in middle and high power lamps suffer from the disadvantages of high energy consumption and low power factors.…”

Digital control of low-frequency, small-wattage, high-intensity discharge lamps

“…Low-frequency square wave (LFSW) ballasts are widely used to drive HID lamps, because acoustic resonances in highfrequency electronic ballasts will likely cause device instability. [3][4][5][6][7] Typically, an analogue circuit is selected to control the traditional LFSW electronic driving circuit. The analogue control method needs to detect the lamp voltage and lamp current and, subsequently, analogue signal processing is conducted by following a lamp power control scheme.…”