Performance characteristics of LED drivers

According to the power consumption rules of the power grid and the characteristic requirements of the LED drive power supply, the following points should be considered when selecting and designing the LED drive power supply:
1. High reliability Especially like the drive power supply of LED street lights, installed at high altitude, maintenance is inconvenient, and the cost of maintenance is also large.

2. High efficiency LED is an energy-saving product, and the efficiency of driving power supply is high. For power installation, the structure of the LED drive power supply in the luminaire is particularly important. Because the luminous efficiency of the LED decreases with the increase of the LED temperature, the heat dissipation of the LED is very important. The efficiency of the power supply is high, its power consumption is small, and the heat generation in the lamp is small, which reduces the temperature rise of the lamp. It is beneficial to delay the light decay of LED.

3. High power factor Power factor is the load requirement of the power grid. Generally, there are no mandatory indicators for electrical appliances below 70 watts. Although the power factor of a single consumer with little power has little impact on the power grid, everyone lights up at night, and the same kind of load is too concentrated, which will cause more serious pollution to the power grid. For 30 watts ~ 40 watts LED drive power supply, it is said that in the near future, there may be certain index requirements in terms of power factors.

4. Drive mode There are two kinds of common use: one is a constant voltage source for multiple constant current sources, and each constant current source independently supplies power to each LED. In this way, the combination is flexible, and the failure of one LED does not affect the work of other LEDs, but the cost will be slightly higher. The other is direct constant current power supply, LED series or parallel operation. Its advantage is that the cost is a little lower, but the flexibility is poor, and it has to solve the problem of a certain LED failure and does not affect the operation of other LEDs. These two forms coexist for a period of time. The multi-channel constant current output power supply mode will be better in terms of cost and performance. Maybe it's the mainstream direction in the future.

5. Surge protection The ability of LED to resist surges is relatively poor, especially the ability to resist reverse voltage. It was also important to strengthen protection in that regard. Some LED lights are installed outdoors, such as LED street lights. Due to the start-up of the grid load and the induction of lightning strikes, various surges are invaded from the grid system, and some surges will cause LED damage. Therefore, the LED drive power supply should have the ability to suppress the intrusion of surges and protect the LED from being damaged.

6. Protection function In addition to the conventional protection function of the power supply, it is best to increase the negative feedback of LED temperature in the constant current output to prevent the LED temperature from being too high.

7. Protection of lamps and lanterns installed outside, the power structure should be waterproof and moisture-proof, and the shell should be sun-resistant.
8. The life of the drive power supply should be adapted to the life of the LED.

9. To meet the requirements of safety regulations and electromagnetic compatibility.　With the increasing application of LEDs, the performance of LED drive power supplies will be more and more suitable for LED requirements.