Thermal management of multiple LEDs for high-power lighting applications

Abstract

Power LED lighting has suffered from substantial heat generated, leading to significant performance degradation. Consequently, achieving an optimal distribution of LEDs is essential to ensure high luminance efficiency. Implementing effective thermal treatment is important to prevent any potential degradation in the performance of the LED lighting system. Optimizing the arrangement of individual LEDs is a promising approach to mitigating heat accumulation issues. In this paper, we propose a reasonable approach to obtaining the optimal distribution of LED lighting systems under DC biasing and PWM operating conditions. The thermal analysis simulation was performed based on the theoretical assumption to evaluate the thermal distribution of a single LED. Thermal analysis was conducted on an LED lighting system with 20 LEDs, and the distance between LEDs ranged from 4 mm to 24 mm. The simulated analysis showed that the maximum temperature could be controlled from 65.1 ℃ to 58.7 ℃. We discussed the optimum arrangement of LEDs and how heat generated by an LED influences the system. In addition, the LED lighting was operated in PWM mode to mitigate the thermal issues. The relationship between luminance efficiency and operation condition is discussed. Thus, the luminance efficiency improved from 114.8 lm/W to 126.8 lm/W, and the thermal relaxation time was no longer than 0.013 s. The process of determining the optimal distance between LEDs was very effective in achieving an optimized power operating condition and LEDs distribution in the module for a compact volume and enhanced performance.