With the growing global demand for clean energy, wind power as a renewable, non-polluting form of energy, has been widely used and developed. However, because wind turbines are usually installed in the open field, and the height is high, vulnerable to lightning, so wind power lightning protection has become an important part of the safe operation of wind power.

Harm of 1. Lightning Strike to Wind Turbine

Lightning may cause a variety of hazards to wind turbines, mainly including the following aspects:

1. Mechanical damage

   • Strong lightning current may cause damage to structural components such as blades and towers of wind turbines. For example, when lightning current passes through the blade, it may generate high temperature and high pressure inside the blade, causing the blade material to crack, delaminate or burn. At the same time, the lightning current may also cause mechanical damage such as deformation and cracking of the tower.
   • The shock wave generated by the lightning strike may also cause damage to the structure of the wind turbine. When a lightning strike occurs near a wind turbine, the shock wave may cause impact loads on the blades, towers and other components, resulting in structural damage.

2. Electrical damage

   • Lightning may damage the electrical system of the wind turbine, including generators, transformers, controllers and other equipment. When lightning current passes through the electrical system, it may produce overvoltage, overcurrent and other phenomena, resulting in equipment insulation damage, short circuit, burning and other faults.
   • Lightning may also cause electromagnetic interference, affecting the normal operation of the control system and communication system of the wind turbine. For example, the electromagnetic field generated by the lightning strike may interfere with the signal transmission of the sensor, causing the control system to malfunction; or interfere with the signal reception of the communication system, causing the communication to be interrupted.

3. Fire and explosion

   • In some cases, lightning strikes may cause fires and explosions in wind turbines. For example, when the lightning current passes through the oil system of the wind turbine generator set, a high temperature may be generated, causing the oil to burn; or when the lightning current passes through the battery pack of the wind turbine generator set, the battery may explode.

Lightning protection measures for 2. wind power

In order to reduce the harm of lightning strike to wind turbines, it is necessary to take a series of lightning protection measures, mainly including the following aspects:

1. External lightning protection measures

   • Install lightning receptor: install lightning receptor, such as lightning rod, lightning protection belt, etc. on the top of the wind turbine to attract lightning current and guide it to the grounding system. The height and position of the lightning receptor shall be reasonably designed according to the height, topography and other factors of the wind turbine to ensure the effective protection of the wind turbine.
   • Laying grounding grid: grounding grid is laid around the wind turbine generator set to safely lead the lightning current into the earth. The grounding resistance of the grounding grid should be as small as possible to ensure that the lightning current can be discharged quickly. The grounding grid shall be laid in accordance with relevant standards and specifications to ensure the reliability and stability of the grounding system.
   • Installation of lightning protection wires: For some wind turbines located in high thunderstorm areas, lightning protection wires can be installed on the top of the tower to intercept lightning current and guide it to the grounding system. The lightning arrester shall be installed in conjunction with the lightning receptor and grounding grid to form a complete external lightning protection system.

2. Internal lightning protection measures

   • Equipotential connection: the metal parts of the wind turbine, such as the tower, the nacelle, the blade, etc., are connected through the equipotential connection belt, so that they are at the same potential level. This prevents the lightning current from creating a potential difference between different metal parts, thereby reducing the risk of electrical damage.
   • Installation of surge protectors: surge protectors are installed in the electrical system of wind turbines to limit overvoltage and overcurrent caused by lightning strikes. The surge protector shall be selected and installed reasonably according to the characteristics and requirements of the electrical system to ensure effective protection of electrical equipment.
   • Shielding and isolation: Shielding and isolating the control system and communication system of the wind turbine to reduce electromagnetic interference caused by lightning strikes. For example, a metal shielding cover may be used to shield the control system, or optical fiber communication may be used instead of traditional cable communication, so as to improve the anti-interference capability of the communication system.

3. Operation and maintenance measures

   • Regular inspection: the lightning protection system of the wind turbine shall be inspected regularly, including the performance and status of the lightning receptor, grounding grid, surge protector and other equipment. The test contents include grounding resistance test, surge protector performance test, equipotential connection resistance test, etc. Through regular testing, problems in the lightning protection system can be found in time, and corresponding measures can be taken to repair and maintain.
   • Maintenance: regular maintenance of the lightning protection system of the wind turbine, including cleaning the dust on the lightning receptor, checking the connection of the grounding grid, replacing the damaged surge protector, etc. Maintenance work shall be carried out in accordance with relevant standards and specifications to ensure the reliability and stability of the lightning protection system.
   • Personnel training: conduct lightning protection knowledge training for wind turbine operation and maintenance personnel to improve their lightning protection awareness and emergency handling capabilities. The training content includes the hazards of lightning strikes, the principles and methods of lightning protection measures, and the detection and maintenance of lightning protection systems. Through personnel training, it can ensure that the operation and maintenance personnel can correctly operate and maintain the lightning protection system, and reduce the occurrence of lightning accidents.

In short, wind power lightning protection is a systematic project, which needs to take comprehensive measures from external lightning protection, internal lightning protection and operation and maintenance, in order to effectively reduce the harm of lightning to wind turbines and ensure the safe operation of wind power generation. With the continuous development and progress of wind power technology, wind power lightning protection technology will continue to innovate and improve, providing a more reliable guarantee for the development of clean energy.