How should the lightning protection grounding system of a photovoltaic box-type substation be designed to cope with complex weather conditions?
Release Time : 2026-01-22
As a key piece of equipment integrating photovoltaic power generation systems with substation functions, the lightning protection and grounding system design of photovoltaic box-type substations must fully consider the impact of complex meteorological conditions, especially extreme weather such as lightning activity, strong winds, and heavy rain, to ensure the safe and stable operation of the equipment. The design of the lightning protection and grounding system needs to comprehensively consider multiple dimensions, including direct lightning strike protection, induced lightning strike protection, grounding device optimization, equipotential bonding, selection of lightning protection equipment, equipment installation specifications, and regular inspection and maintenance, to form a complete protection system.
Direct lightning strike protection is the primary aspect of the lightning protection system. Photovoltaic box-type substations are usually located in open areas, making them vulnerable to lightning strikes. Therefore, lightning rods or lightning protection strips must be installed on the top of the substation to guide the lightning current safely to the ground. The height and protection range of the lightning rods need to be calculated based on the size of the substation and the frequency of lightning activity in the area to ensure coverage of all critical equipment. Simultaneously, down conductors should be laid openly or concealed along the building's exterior walls or supports, evenly and symmetrically, to disperse the lightning current and avoid localized overheating or mechanical damage.
Induced lightning strike protection is equally important. Electromagnetic pulses generated by lightning can enter substations through power or signal lines, damaging sensitive electronic equipment. Therefore, surge protectors must be installed at the power input terminals of AC distribution cabinets, inverters, and other equipment in the substation to provide multi-level protection for the power lines entering the equipment. For signal lines of monitoring and communication systems, signal surge protectors should be installed at the front end of the signal equipment to prevent damage from lightning-induced overvoltages. The selection of surge protectors must be matched according to the operating voltage, transmission rate, and lightning activity intensity of the equipment to ensure effective discharge of lightning energy.
The grounding device is the core component of the lightning protection system, and its design must fully consider soil resistivity, topography, and climatic conditions. Grounding electrodes can be vertically driven into the ground using materials such as angle steel, steel pipes, or round steel, and connected to form a closed grounding grid using horizontal grounding bodies such as flat steel or round steel. The burial depth of the grounding grid should be sufficient to avoid the grounding effect being affected by soil freezing in winter. In areas with high soil resistivity, grounding resistance can be reduced by replacing the soil, applying resistance-reducing agents, or using deep well grounding to ensure that lightning current can be quickly discharged into the ground. Simultaneously, the grounding device must be reliably connected to the metal components and electrical equipment casings of the substation to form an equipotential bonding network, reducing the potential difference induced by lightning.
The installation quality of lightning protection equipment directly affects its protective effect. Power surge protectors and signal surge protectors should be installed close to the protected equipment to reduce the attenuation and distortion of lightning overvoltages on transmission lines. The grounding of the lightning protection equipment should be reliably connected to the substation's grounding system to form a unified lightning protection grounding system. Furthermore, the installation of lightning protection equipment should be strictly carried out in accordance with the product manual and relevant specifications to ensure a firm and reliable connection, avoiding protection failure due to improper installation.
Regular inspection and maintenance are crucial to ensuring the long-term effective operation of the lightning protection system. A comprehensive lightning protection system maintenance plan should be developed, and regular inspections and maintenance of lightning protection facilities should be conducted, including visual inspections, electrical connection checks, and grounding resistance measurements of lightning arresters, down conductors, grounding devices, and surge protectors. Any problems and potential hazards discovered should be repaired and addressed promptly to ensure the lightning protection system is always in good operating condition.
Under complex weather conditions, the design of the lightning protection and grounding system of a photovoltaic box-type substation needs to take into account a variety of factors. Through scientific and reasonable protection measures, it can effectively resist the damage to the equipment caused by extreme weather such as lightning, strong winds, and rainstorms, and ensure the safe and stable operation of the photovoltaic power generation system.