Environmental Impact Study on LED Power Supply

I. Introduction

LED power supply is an outdoor use product, from the use of street lamp power supply, and market failure analysis, environmental factors and grounding methods have a great impact on the service life of the power supply. After comprehensive statistics, the multi-mine area, water area, and open space are invalid. There are obviously more products. On the one hand, the product has the characteristics of anti-induction lightning. At the same time, the grounding condition of the LED street lamp is not easy to be damaged by lightning. Only through the LED street lamp manufacturers, LED power manufacturers and the two sides work together to make the LED street lamp power supply life to a higher level.

Second, product information and use information

2.1, MOSO LED power supply (for 50 ~ 300W constant voltage source) in the market, the amount of investment, that is, according to different power wattage statistics product shipments and failures.

50W~200W constant voltage source shipment and failure ratio:

Third, the main use failure mechanism and analysis -1

• Use the fishbone diagram to find out the cause of the failure.

– failure mechanism

Fourth, the main use failure mechanism and analysis -2

• In summary of the above, the main failures are:

– Small area analysis:

• The grid voltage is high: it is not isolated from the industrial grid, causing the voltage to rise in the middle of the night.

The maximum input voltage across the power supply specification;

– Large area analysis:

• Mainly damaged by lightning strikes.

• The grounding effect of the lamp post installation is not good, resulting in poor lightning protection effect.

Often working

– Soil environment analysis

– pole placement depth

• The grounding of the power supply ground is not good, resulting in poor lightning protection.

• The power supply protection effect is not good, resulting in poor lightning protection

The following is a detailed analysis.

V. Use failure 1: high grid voltage

3.1. The impact of grid voltage fluctuations on the use of LED power supplies.

Example: When the LED power supply is maintained, we measure/monitor the grid voltage too high in different regions.

-- Figure 1 below shows the grid voltage measured in Nanchang: up to 314VAC

-- Figure 2 below shows the grid voltage measured in Foshan City: up to 307VAC

-- Figure 3 below shows the grid voltage measured in Hefei: up to 310VAC

V. Use failure 2: high grid voltage

3.2 Case description of external leakage switch at the input end (with tripping phenomenon)

-- Guangming Avenue installed leakage switch, try 50PCS, there is 6PCS trip.

Sixth, use failure: lightning strike failure

• Lightning in the air emits a spectrum of radio waves, while overhead road lights and power lines are good antennas. This instantaneous differential mode interference voltage can also reach hundreds of volts to more than 3,000 volts, which often breaks through the electrical gaps in the electronics power circuit and can also damage the drive circuit.

• Therefore, the power supply needs to be designed for lightning protection. The lightning protection design is a system engineering, and lightning protection design is required from the power supply grid, system grounding, and power equipment. The following is a detailed analysis of lightning protection design and current status:

– Lightning failure example (our product example, characteristics of lightning disaster in China)

– Lightning strike classification

– Power supply lightning failure mechanism

– Lightning protection design for the power supply grid

– Lightning protection design for the grounding of the lamp post

– Lightning protection design of the power supply

Lightning failure: Example 1

In the waters, the proportion of lightning strikes in the open areas is more obvious, such as the Dongjiang levee (1400 sets of Dongjiang levees, and 75 lightning strikes were returned).

Lightning failure: Example 2

Higher buildings are also vulnerable to lightning strikes. Another customer of our company installed 150W advertising lights (35 meters high), installed 50PCS, and 7PCS lightning strike damage.