The main customers of street lights are government units, not ordinary consumers, so it is a relatively special and relatively closed industry. From the initial sodium lamps and mercury lamps to the current LED lamps, street lamps have undergone a long development process. So far, it has been ten years. Among them, LED driver, power drive, heat dissipation technology, optical technology, etc. new breakthrough. But at the same time, there are also some problems, among which the lightning protection facilities of LED street lights are one of the problems waiting for us to solve.

A lightning strike is an electrostatic discharge phenomenon that typically carries millions of volts from a cloud to the ground or another cloud. There are four types of lightning strikes:

1. Direct lightning strike

Direct lightning strikes contain great energy, and lightning current with a peak voltage of up to 5000kv enters the ground, which has great destructive power.

2. Conduction Lightning

Distant lightning strikes the line or the extremely high voltage generated by electromagnetic induction is transmitted from the outdoor power line and communication line to the electrical equipment indoors in the building.

3. Induction lightning

Frequent discharges between clouds generate strong electromagnetic waves that cause common-mode and differential-mode interference, affecting the operation of electrical equipment.

During the transmission process of lightning, an electromagnetic field is generated in the air, which induces thousands of volts of voltage (ie, surge) to the power line and generates an induced current that is transmitted several miles away. These indirect attacks usually occur on exposed wires outdoors, such as street lights. , traffic lights, base stations and other equipment emit surges. The surge protector directly faces the surge interference from the power line at the front end of the circuit. It diverts or absorbs surge energy, minimizing surge threats to other operating circuits such as AC/DC power supply units in LED lighting fixtures.

For LED street lights, lightning generates an induced surge on the power line, and the energy of this surge will generate a surge on the wire, that is, a surge wave. The surge is transmitted through such an induction method, and a surge from the outside world The wave will generate a tip on the sine wave in the 220V power line, and this tip will enter the street light and cause damage to the LED street light circuit.

Street lights have existed for many years, why is it only now that street lights need to be installed with lightning protection products?

In fact, the high-pressure sodium lamps and traditional mercury lamps used in the past were designed with high-pressure bulbs, which themselves have the effect of lightning protection. In recent years, LED lights have gradually become popular, and LED lights require a lower power supply voltage. Usually, a power supply is used to convert alternating current into direct current to drive, which makes the lightning protection of LED street lights themselves. Therefore, it is necessary to install street lights. Necessary lightning protection products.

The importance of lightning protection for LED street lights

Since the price of LED street lights is much higher than that of traditional street lights, the government needs to invest a relatively large amount. Therefore, it is necessary to gradually recover the cost by saving electricity expenditure during operation. Then, the service life of LED lights becomes very important. If the LED light is damaged by lightning before the cost is recovered, it needs to be repaired, and the labor cost during the repair is twice as expensive as the installation.

Therefore, in the LED era, it is not only necessary to achieve the effect of saving power and money, but also to ensure that its lifespan can meet your expectations, that is, the product has a longer shelf life. In order to achieve the purpose of saving costs and ensure that the street lamps are not damaged during the investment recovery period, it is necessary to increase the reliability of the LED street lamps. This requires the installation of lightning protection products for LED street lights to maximize the economy.

Energy-saving street lights have been made in China. The defined street lamp specifications are usually visible indicators such as brightness, lighting angle, light color, power consumption, etc., but the invisible indicator of lightning protection is often ignored. Not only in the United States and European countries, but also in many countries with high lightning risk, such as Malaysia, India and other countries, the relevant standards for lightning protection testing of street lamps have been established for a long time. In our country, only coastal cities such as Hainan and Pearl River suffered more serious thunderstorms, while most inland areas were much better. Therefore, the relevant lightning protection standards for street lamps have not been introduced so far.

In the American National Standard released in 2015, three levels of lightning protection standards have been introduced, as shown in Table 1. The reason for the three levels is that there is a big difference in the situation of landslides in the east and west of the United States. The high landmine area can reach 30 to 40 times, while the low landmine area has only 1 to 2 times. Therefore, three levels of standards have been made, namely: 6kV, 10kV and 20kV. This also gives flexibility to lighting manufacturers and local governments, and local governments can decide to use corresponding standards according to the actual situation.

There are similar standards in communication base stations in China. As early as ten or twenty years ago, when mobile phones were about to become popular, there were already relevant national standards for base station lightning protection. Since the base station is mainly set on the roof or tower, the impact of this lightning strike on the base station will be great. However, due to the large differences between the north and the south of my country, the differences in the coastal and inland environments are also large, and the street lights are basically managed by each local government, specifying specifications, bidding, supervision, maintenance, etc. Therefore, there is still no comparable country. The standard is introduced.

However, with the highlighting of relevant needs in recent years, there are already national standards related to lightning protection of LED street lights under review in 2017 and 2018. Referring to the national standards of various countries in the world, if the drive power module only meets the fourth level (line-line 2kV, line-ground 4kV), it will not be enough to cope with the lightning surge threat that outdoor lighting may face. Lightning protection grade, and use professional high-quality surge protection device (SPD) products.

LONG SUN is one of the top LED lighting manufacturer in Shenzhen China, who produced lots of led street light and area light. To ensure the quality, they adopt 10kv-20kv surge protector for their led product from power surges and most distant lightning strikes etc.