中文摘要：

通常获得白光LED的高光视效能（K）往往是以降低其显色指数（Ra）为代价的,本文在固定相关色温（CCT）为3 000±10 K下,通过调配三基色白光LED光谱参数来寻求K和Ra的最佳平衡。模拟结果表明：当三基色白光LED的3个峰值波长分别为467、550和618 nm,半高宽（FWHM）分别为30、71和23 nm以及相对光功率配比为1.00∶1.90∶4.90时,白光LED的K为391 lm/W,Ra为92.6,这是目前低色温拟合所得到的最佳结果。分析了白光LED光谱参数对CCT、K和Ra的影响,选择合适的光谱参数可以实现指定低CCT下的LED光谱功率分布（SPD）,但同时需兼顾K和Ra的最佳平衡。

英文摘要：

Luminous efficacy of radiation（K） and color-rendering index（Ra） are two important parameters of LEDs.Generally,high luminous efficacy of radiation is obtained at the sacrifice of color-rendering index.The requirement of correlated color temperature（CCT） differs for various application environments.Considering the fixed CCT of 3 000 ± 10 K,we adjusted spectrum parameters of the tri-color white LEDs,such as peak wavelength,full width at half maximum（FWHM） and relative optical power ratio,to obtain the optimum balance between luminous efficacy of radiation and color-rendering index.It turns out that with peak wavelength at 467 nm,550 nm and 618 nm,FWHM at 30 nm,71 nm and 23 nm,relative optical power ratio at 1.00∶1.90∶4.90,we achieve K=391 lm/W and Ra=92.6.Afterwards,further study was performed i.e.,the impact of spectrum parameters on CCT,luminous efficacy of radiation and color-rendering index.Results show that suitable spectrum parameters exert tremendous influence upon the obtainment of low specified CCT of spectral power distribution（SPD） of LEDs,while the optimum balance between K and Ra should be taken into account simultaneously.