Led lighting has the characteristics of energy saving, environmental protection, long service life and wide application, and is an important component of energy saving and environmental protection industry. With the continuous breakthrough of technology, the increasing emergence of energy-saving effects and the country’s vigorous promotion of energy-saving and environmental protection industries, indoor LED lighting has replaced incandescent lamps and fluorescent lamps into thousands of households.
Outdoors, street lighting consumes huge amounts of electrical energy. As a major energy consumer, driven by the current concept of energy conservation and environmental protection, LEDs with high efficiency, energy saving, long service life and high color rendering index have become a new generation of energy-saving light sources. LED street lights work in harsh outdoor environments and have high performance requirements for drive power.
First, the current situation of LED street light drive power supply life analysis
As the power supply for LED lighting, LED driving power can convert the external primary energy into the secondary energy required by LED. It is the core component of LED lighting, and its quality has an important influence on the reliability of LED lighting. Sex is also a key factor in the life of LED lighting fixtures.
Through the tracking and detection of high-power LED street lamps, some LED lamps have been in failure. Through the analysis of the fault, we found that the proportion of LED drive power damage is as high as 90%. Although the theoretical life of LED street lamps is as long as 50,000 hours (13.7 years), the life of the drive circuit is short, about 12,000 hours (3 years). The drive power becomes a short board that limits the service life of LED street lights. In addition, due to the requirements of waterproof and dustproof conditions, the LED street lamp driving power supply is generally packaged inside the product, which brings inconvenience to the maintenance of the LED street lamp, and the cost of replacing the driving power source is high. Therefore, improving the service life of the LED street lamp driving power supply, reducing its maintenance cost, and improving the maintenance convenience will greatly improve the actual service life and value of the LED street lamp.
Second, the solution
The input current of the LED driving power source includes alternating current and direct current, and the output current is generally a constant current that can change the voltage with the forward voltage of the LED. Therefore, the electronic components required in the driving power source generally have a capacitor, a resistor, an inductor, and the like. It is very clear in the industry that if there is an electrolytic capacitor in the LED driver circuit, its life depends mainly on the electrolytic capacitor. There is a well-established approximation of the life of electrolytic capacitors: the temperature doubles for every 10 degrees drop in temperature. For example, an electrolytic capacitor with a nominal 105-degree Celsius life of 2000 hours has a service life of approximately 32,000 hours at 65 degrees Celsius. The LED street lamp workplace is outdoor. In today’s global warming environment, the surface temperature in most parts of China has exceeded 70 degrees Celsius in summer. Under such conditions, the average life of electrolytic capacitors has been less than 15,000 hours.
At present, the driving power source and electrolytic capacitor in the high-power LED street lighting are soldered on the circuit board, and the entire electrical part is packaged inside. When the electrolytic capacitor is damaged and other electrical components are intact, the entire driving power supply will be replaced, which is a great waste. As long as the junction temperature of the LED lamp chip reaches the required temperature, the life of the LED lamp bead is nearly 50,000 hours, but the driving power of almost all LED street lamps is damaged early. At present, the warranty time of LED street light is generally three years. If it is used for 12 hours per day and 365 days a year, it only uses less than 14,000 hours, and only 22,000 hours for 5 years. This is quite different from the life of 50,000 hours of LED chip lights. Even though the intelligent control controls the energy saving and reduces the power and the life is relatively extended, the life is still shorter than that of the LED chip.
In order to save resources and improve the utilization of the drive power and the overall life, a modular design method can be adopted. Electrolytic easy to damage electrical components as an accessory separate from the circuit board, not directly mounted on the circuit board, using a casing to package all relevant vulnerable components into a modular electrical connector, through each The connector group is connected to each electrolytic capacitor seat in the circuit board by a circuit board or a line. When the electrolytic capacitor reaches the service life, only the module connector needs to be replaced, and the driving power source can be used again. In the normal service life of the LED chip light, it is only necessary to replace the module connector twice under normal conditions, which can make the overall life of the LED street lamp 50,000 hours become a reality. Moreover, the modular connector can be connected to the circuit board through the relevant circuit, and the waterproof and dustproof sunscreen design can be installed at a larger place, and can be easily replaced, without the need for working at height, so as to replace the ordinary household lamp. Convenience.
The problem of LED driver power failure cannot be completely avoided, and the modular design has already become the trend of the day. If the driver power supply can solve the maintenance problem by modular plugging, it will be welcomed by users; modularization is adopted by all manufacturers. After the design, by standardizing the relevant interfaces, the replacement of the LED street lamp driving power supply is as simple as the replacement of the conventional lighting source, and the LED street lamp driving power source that restricts the key factors in the development of the LED lighting industry will be greatly developed.