Street lamps installed outdoors, lightning is a very big threat. Light will lead to street lamp damage, heavy damage caused by fire or casualties, resulting in huge losses. Here, we will introduce to you about the impact of LED street lights and preventive measures.
Shenzhen MIC Photoelectric Technology Co., Ltd. through many years of research, summed up the main types of lightning:
Lightning contains enormous energy, lightning peak voltage up to 5000kv inflow, with devastating force. Will cause the following three kinds of influence:
- A huge current of rich current flows down to the ground within a few milliseconds, causing the ground potential to pick up quickly, causing a counter attack, endangering the safety of persons and equipment.
- A strong electromagnetic wave is generated by the lightning current, which is caused by a very high pulse voltage on the power line and the signal line.
- The electric apparatus produces a high heat, causing a fire or explosion accident.
2. Conducting ray
Distant thunder hit the line or generated by electromagnetic induction high voltage, by outdoor power lines and communication lines spread to buildings in the interior of the electrical equipment.
3. Induction ray
Strong electromagnetic wave between the cloud layer causes the common mode and differential mode interference, which affects the operation of electrical equipment.
4 switch over voltage
In the power supply system of inductive and capacitive load is turned on or off, the ends of the earth short circuit, power supply circuit short circuit, can in power line to generate a high voltage pulse, pulse voltage up to normal voltage of 3 to 5 times, serious damage to the device. The damage effect is similar to lightning stroke.
So we will be how to prevent the occurrence of lightning accident? Through the research of MIC photoelectric technology research laboratory, the following ways are the most effective way to prevent the destruction of the street lamp:
1. External lightning protection and internal lightning protection
Now the general LED street lamps are outside the conductor material, itself is equivalent to a lightning rod, the design must be installed on the lead line and the ground, these systems constitute an external lightning protection system. The system can avoid the LED Street due to lightning caused fire and safety accident. The internal lightning protection system is to protect the equipment from the ground and the voltage protection. The system can prevent the induction of lightning and other forms of over-voltage intrusion, causing power damage, which is not guaranteed by the external lightning protection system. The two are complementary and complement each other. Internal lightning protection system in many devices and the preceding example such as shell, and reserve the cable, metal pipeline to connect external lightning protection system or set the overvoltage protector and etc. the connectivity potential.
2. Lightning protection and other potential connection
Complete elimination of the potential difference caused by lightning, power lines, signal lines, metal pipes, etc., are to be used to protect the potential connection, the interface of the inner protection zone is also a partial and other potential connections, each part of the electric potential connection, and finally connected with the main.
3. Set lightning protection zone
LED street lamp in addition to power equipment, but also set up a number of communications equipment used to control the lights of the switch and brightness, these devices and power are required to be placed in the lightning protection zone, the protection of the area directly affected by shell. The electromagnetic field is much weaker.
4. High quality protection equipment – lightning protection module and over-voltage protection module
The lightning protection device is in the shortest time (nanosecond) will be protected by the system in the electric potential system, so that the equipment of the port and other potential. At the same time, the electric circuit of the great pulse energy generated by lightning is released to the ground, reducing the potential difference between the device’s interface end, and thus play a role in the protection of the device. MIC technology research and development team believes that the LED street lamp power module not only in accordance with the above requirements of the design but must go through rigorous testing procedures.
- With constant voltage output function or with constant current output function or both functions of the control device, should be used for GB19510.12/IEC61347-2-13 safety standards.
- The control device that only has the function of controlling the logic change of LED, flashing, color, etc., should be used for the GB19510.12/IEC61347-2-11 safety standard test.
- If a control device has the function of both of the above, it shall be tested in accordance with GB19510.12/IEC61347-2-13 safety standards.
The practice has proved that through the scientific design and strict inspection, not only can ensure that the LED street lamp system is not subject to lightning damage, and put an end to the common mode and differential mode interference of the power supply equipment.