Photometric assessment of warm and cool white LED bulbs
- PDF / 1,118,043 Bytes
- 9 Pages / 595.276 x 790.866 pts Page_size
- 70 Downloads / 229 Views
RESEARCH ARTICLE
Photometric assessment of warm and cool white LED bulbs K. Jeykishan Kumar1
•
G. Bharath Kumar1 • R. Sudhir Kumar1
Received: 2 April 2020 / Accepted: 31 July 2020 Ó The Optical Society of India 2020
Abstract The usage of white LED has increased at a rapid rate in India for residential applications because of its various advantageous properties such as energy efficiency, low power consumption, high brightness, reliability and long lifetime compared to other conventional lamps. In this paper, photometric parameters such as CCT, CRI and luminous flux for warm white and cool white LEDs are explored. Integrating sphere was used for examining the LEDs for their performance characteristics in terms of photometric parameters. The results show that warm white LEDs have a relatively low correlated colour temperature, colour rendering index and luminous flux (lumens) compared to cool white LED bulbs. With an increase in power consumption, the efficacy, lumen output and power factor increase. In terms of high brightness, cool white LED bulbs are brighter than warm white LED bulbs, whereas in terms of power quality issues such as harmonics and power consumption, warm white LEDs are better than cool white LEDs. Keywords LED Efficacy Luminous flux Correlated colour temperature Colour rendering index Warm white Cool white
& K. Jeykishan Kumar [email protected] 1
Energy Efficiency and Renewable Energy Division, Central Power Research Institute, Bengaluru, India
Introduction It is a well-known fact that light-emitting diode lamps (LEDs) have better productivity than existing conventional lamps such as CFL and incandescent lamps. LEDs are considerably having long running hours and are pollutionfree or eco-friendly as they do not have poisonous gas like mercury in them. The main advantage of fast penetration of LEDs is due to their less power consumption, thereby making the electricity bills by half. As the power consumption of every individual increases day by day due to a greater number of advanced gadgets and household equipment, the electricity bills are shooting up higher than the earlier days. In earlier days, CFL and incandescent lamps consume higher energy such as 40 W, 60 W and 100 W, but the LEDs power consumption is 10% less in comparison with the conventional bulbs. Of course, there will be certain disadvantages. The main demerits of LEDs are harmonic distortion which causes when multiple numbers of LEDs are connected to main supply [1]. LEDs may be energy-saving component, but at the cost of making the grid stability poor. The quality of power can be compromised if more distortion is injected to it. The consumers would be the end-user of the same power which will have harmonics in them [2]. Harmonic impacts of warm white LEDs are observed to be more than the cool white LEDs when considering the residential, industrial and commercial office sectors [3]. By using a type-C goniophotometer, the study on light pattern, its distribution, candela and polar plot of individual LED, LED street l
Data Loading...
