"Code for Wind Turbine Generators" - China Classification Society (2008)
Chapter 10 Lightning Protection System
Section 2 Protection Level and Lightning Protection Zone
10.2.1 Lightning protection design principles
10.2.1.1 Select an appropriate protection level to reduce the risk of damage to wind turbines caused by direct lightning strikes through the protection measures taken under the maximum allowable conditions. risk.
10.2.1.2 The entire wind turbine generator set is divided into several lightning protection zones according to the requirements for electromagnetic conditions, and appropriate measures should be taken for different lightning protection zones.
10.2.2 Protection level
10.2.2.1 According to the IEC 62305-1 standard, the estimated frequency of direct lightning strikes to the protected wind turbine and the allowable number of lightning strikes per year are Based on this, determine the protection level of the wind turbine and then determine the corresponding protection equipment.
10.2.2.2 Wind turbines should meet the following minimum protection levels:
(1) Wind turbines with a hub height not exceeding 60m: protection level III/IV;
(2) Wind turbines with hub height above 60m: protection level II.
If you need the full text, please leave an email on Baidu hi or visit the following address
http://www.moc.gov.cn/zizhan/zhishujigou/chuanjishe/guifanguize_DT/200804/P020080423588457254728. pdf
1. Construction process requirements for grounding devices and equipotential connections:
Steel grounding devices should be welded, and the overlap length should comply with the following regulations. Flat steel and flat steel The overlap between round steel and round steel should be 2 times the width of the flat steel, and welding should be done on no less than three sides; the overlap between round steel and round steel should be 6 times the diameter of the round steel, and welding should be done on both sides; the overlap between round steel and flat steel should be 6 times the diameter of the round steel. times, double-sided welding; when flat steel and round steel are welded to steel pipes and angle steel, in addition to welding on both sides of the contact part, round steel overlaps should also be added; the welded parts should be anti-corrosion treated. Copper grounding devices should be welded or welded. The connection between steel and copper grounding devices should be welded or tinned and bolted. The connection parts should be anti-corrosion treated. The connection of the grounding device should be reliable, and the connection should not be loose, desoldered, or have poor contact. After the construction of the grounding device is completed, the tested grounding resistance value must meet the design requirements, and the concealed engineering part should have inspection and acceptance records. The connection between the ground wire and the ground body should be welded. The connection between the protective earth wire (PE) and the grounding terminal board should be reliable, and the connection should be protected against loosening or corrosion. The connection between the ground wire and natural grounding bodies such as metal pipes should be welded. If there are difficulties in welding, clamps can be used to connect them, but they should have good electrical conductivity.safety and anti-corrosion measures.
2. The installation of surge protectors (SPDs) for power lines should comply with the following regulations:
Surge protectors (SPDs) at all levels of power lines should be installed separately on the protected areas. At the front end of the equipment power line, each terminal of the surge protector should be connected to the phase line of the same end of the line in the distribution box. The ground terminal of the surge protector is connected to the protective ground wire (PE) ground terminal board of the distribution box. The ground terminal board of the distribution box should be connected to the equipotential grounding terminal board of the lightning protection area. The connecting wires of surge protectors (SPD) at all levels should be straight and their length should not exceed 0.5m. Power line surge protectors with terminal blocks should be crimped; surge protectors with binding posts should be connected with copper noses and binding posts. The surge protector SPD should be firmly installed and its location and wiring correct. The minimum cross-sectional area of the connecting wire of the power surge protector (SPD) should comply with the requirements in the table below.
3. The installation of signal line surge protector (SPD) should comply with the following regulations:
The line surge protector SPD should be connected to the signal port of the protected equipment. The SPD output of the surge protector is connected to the port of the protected equipment. The surge protector SPD can also be installed in the cabinet, fixed on the equipment rack or on a nearby support. The SPD grounding terminal of the signal line surge protector should be connected to the local equipotential grounding terminal board in the equipment room using a copper core wire with a cross-sectional area of not less than 1.5mm2. The grounding wire should be straight. The surge protector SPD should be firmly installed and its location and wiring correct. The minimum cross-sectional area of the connecting wire of the signal surge protector (SPD) should comply with the requirements in the table below.