Optimization for Spectral and Power Characteristics of Bicolour LED Driver

LED-powered luminaires have the ability to offer cutting-edge features like temperature adjustment and color management. Color shift creates discomfort in human eyes. So it is essential to design a LED driver which will precisely control the color parameters of the LED driver. Precise control of color parameters like CRI, CCT, color intensity is very complex and challenging. This paper describes the nonlinear optimization methodology for the design of blended LED light sources. This paper presents the methodology that enables LED strings regarding various parameters, e.g. high color rendering index (CRI) and high luminous efficacy of a blended bi-color (namely red CCT-2500K and blue CCT-9000K) LED driving system. Due to the applied optimization, the obtained CRI is maintained 98.03%. The overall luminous intensity depends upon the combined luminous flux which depends upon the current control of both LED sources. These optimized LED currents ensure the desired CCT. The achieved luminous efficacy is 90% at two optimal peak wavelengths 601 nm and 426 nm respectively. Power loss is minimized by frequency optimization. At the same time power parameters i.e. low THD and high P. F. is also maintained. The nonlinear optimization is verified in Ltspice simulations and experimentally for two different luminaire strings.