亚洲 欧美 图片 自拍 视频

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          Thoughts on the efficiency of LED general lighting system

          With the rapid growth of the world economy, the global energy shortage is getting worse. Among the total energy consumption, lighting electricity accounts for about 20% of the total, and is still growing. Therefore, light efficiency is one of the most important indicators for general illumination sources.

          The lighting system's efficacy depends on the light source, optical lens or reflector, and ballast or drive circuitry. Among the various new light sources, the most noticeable are semiconductor light-emitting diodes (LEDs). Especially white LEDs, which have the potential advantages unmatched by general light sources in terms of light efficiency (theoretical light effect 350 lm/W) and lifetime, and are facing the possibility of breakthrough. LEDs are widely used in indicators, signal lights, displays, decorative lights and other fields. Among them, the most promising applications are large-scale general lighting applications. However, LED is still at a high price, and cost factors have restricted the widespread application of high-power LEDs. At the same time, the existing light efficiency of high-power white LEDs is about 90-100 lm/W, which is not obvious compared with traditional light sources. In addition to improving LED efficacy, we can also increase the efficiency of LED lighting systems through optical and electrical design.

          About system light efficiency

          High light efficiency means energy saving for the country, which means saving money for the user, that is, the same illuminance can be achieved with a lower wattage light source.

          In fact, the user is concerned with the illuminance of the area (space) that is actually illuminated. Therefore, the concepts related to the efficiency of the lighting system are: light source efficacy, luminaire efficiency and light utilization (Figure 1).

          Light source efficacy = total luminous flux / total power;

          Luminaire efficiency = luminous flux of the luminaire / luminous flux of the source;

          Light utilization = luminous flux/source luminous flux within the effective area required to be illuminated.

          Therefore, the efficiency of the illumination system is: system efficacy = source efficiency X-ray utilization = driver efficiency X-ray efficacy X-ray utilization. Since the efficiency of the driver is generally about 90%, the difference of various types of light sources is not large, so this paper mainly analyzes and discusses the light efficiency and light utilization.

          Light source efficacy

          First, analyze the light source effect.

          The light source efficacy can be expressed as:


          亚洲 欧美 图片 自拍 视频
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