Lightning protection measures for distribution lines - Solutions - Huaqiang Electronic Network

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In the low-voltage distribution network, the average height of the tower is lower than that of the transmission line, and the surrounding of the line may be shielded by buildings and trees, so the chance of being hit by lightning is relatively small. However, due to the relatively low insulation level of the distribution network, the distance between the lines is small, and it is easy to trip once it is subjected to a direct lightning strike. Therefore, it is necessary to strengthen the lightning protection of the distribution network to improve the reliability of the power supply.

The basic technical measures that should be taken for lightning protection of distribution lines are:

Anti-direct lightning. In order to improve the lightning protection level of the distribution network, it is necessary to improve the lightning resistance level of the line, and use porcelain cross arm or high level insulator. Because of the large number of distribution lines, the width of the surface, and the length of the line, it is uneconomical to use a lightning protection line or a lightning rod for direct protection. Since the distribution line adopts a neutral point ungrounded system and the span is also small, the wires are easily formed into a triangular arrangement. At this time, the uppermost wire can serve as a lightning protection line. Therefore, the best way is to install a grounded protection gap at a certain distance on the insulator of the top wire.

Anti-induction lightning. Insulation weaknesses for distribution lines, such as individual metal towers, particularly tall towers, individual iron crossarms, towers with pull wires and terminal rods, should be equipped with lightning arresters for protection.

All electrical equipment on the distribution line, such as distribution transformers, circuit breakers and disconnectors, should be protected according to their importance, such as lightning arresters or protection gaps, and strive to protect the platform from lightning protection. There are no missing points.