Three aspects of LED street lamp heat dissipation
Through practical applications, it is demonstrated that high-power LED street lights have the advantages of energy saving, environmental protection, long life, adjustable brightness and color temperature, and high color rendering. With the maturity of LED technology and the continuous improvement of efficiency, LED solid-state lighting is the trend and the best solution for energy saving. The energy-saving characteristics of the LED street lamp lighting system are mainly determined by the LED chip and power supply. However, the LED chip and the power module are integrated together, and the space is generally small and the heat dissipation is poor. The LED chip and the power supply are heating elements, which makes the ambient temperature higher. Therefore, this article reduces the ambient temperature by improving the heat dissipation conditions of the LED street lamp system, increasing the luminous efficiency of the LED and the efficiency of the power supply, so that the LED power supply and the life of the LED chip can be matched, and real energy saving, environmental protection and long life can be realized.
Let's talk about the main three aspects of research content:
1. Experimental research on the thermoelectric relationship of high-power LED street lamps. Taking the high-power LED street lamp with the connection mode first in series and then parallel as the object, the experiment researches the relationship between the power distribution and the temperature distribution under the two power supply modes of constant current and constant voltage. Build an experimental platform for the research on the thermoelectric relationship of LED street lamps and analyze the experimental results. From the results, it is known that under constant current conditions, there is an obvious linear relationship between the LED junction temperature and the forward voltage, which verifies the voltage drop characteristics of the LED, and you can try to measure the junction temperature of the LED with a large current, which is different from the traditional small current measurement. . Compared with constant voltage drive, the total output power of the power supply is more stable in constant current drive. However, due to uneven temperature distribution among multiple LEDs, the corresponding power distribution is constrained by each other. Form a vicious circle. Therefore, the design of heat dissipation balance is of great significance to the improvement of the overall quality of high-power LED street lights.
2. Optimized design of high-power LED street lamp radiator. Taking a company’s 150W high-power LED street lamp as the research object, the thermal resistance network model of the profile radiator is established, and the radiator meeting the heat dissipation requirement is theoretically designed. On this basis, the Icepak thermal analysis software is used to optimize the design. The rationality of the existing radiator design is verified, and the theoretical calculation results are relatively consistent with the optimized results, indicating that theoretical calculations are an important part of the radiator design. Combining software optimization can reduce R&D costs, shorten R&D cycles, and improve R&D efficiency.
3. High-power LED street lamp power module heat dissipation design. Based on the design of the high-power LED power supply circuit, the heat flow path and related thermal resistance are analyzed, and the shortest heat flow path is taken as the goal, two power cooling devices are designed structurally. Aiming at the narrow space for heat dissipation of the power supply, the miniature heat pipe is tried to be used for the heat dissipation of the LED power module. The results show that the two schemes can meet the thermal design requirements of electronic equipment, and the heat dissipation performance of the device using micro heat pipes is about 5℃ better than the other scheme.
