Solar energy is rich in resources, widely distributed, and has broad prospects for development and utilization. As an important method of solar energy utilization, home power solar system has received attention from all over the world, expanding the new field of solar photovoltaic power generation market, and distributed household photovoltaic solar power generation has become the mainstream.

As a distributed photovoltaic power generation that is closer to people's daily life, how much do you know about the lightning protection and grounding problems of photovoltaic solar power generation systems? Lightning is the discharge phenomenon of thunderstorm clouds on the earth and buildings, which can generate strong impulse current, scorching high temperature, violent shock wave, and strong electromagnetic radiation, so it can damage buildings and electronic equipment on the discharge channel and cause property damage. even personal injury.

At present, distributed photovoltaic solar power generation systems are generally installed on the roofs of civil buildings or the roofs of industrial plants. Before the original buildings are put into use, they can be delivered after passing the inspection of the local lightning protection center. The lightning protection facilities of industrial buildings are also tested every year, so the reliability and safety of the lightning protection facilities are guaranteed to a large extent.

Although lightning is a natural disaster, in general, as long as the following three aspects are strictly , the probability of lightning strike risk can be minimized.
1. Multi-point reliable connection between the metal support of the photovoltaic support and the original lightning protection belt to form a good electrical path
The lightning energy of the direct lightning strike is quickly released to the ground through the grounding device of the original lightning protection belt, so as to protect the building and the photovoltaic modules exposed on the roof.

2. The grounding device is the basis of lightning protection
If the original building has lightning protection strips, lightning rods and other facilities, it is necessary to use a grounding resistance tester to measure the grounding resistance value. Generally speaking, if the grounding resistance value is less than 4 ohms, the original grounding can be used.

However, some facilities, such as rural houses, livestock sheds, farms, etc., do not have strict requirements for lightning protection, so new grounding devices are required. The grounding device can be constructed with grounding materials such as copper-clad steel grounding body, carbon crystal grounding electrode, and resistance reducing agent according to different geology. After completion, the grounding resistance value is less than 4 ohms, which is qualified.

3. Equipotential bonding measures
Equipotential measures include roof bracket jumper, bracket and roof metal structure connection, such as bridges for laying photovoltaic cables, inverter shells, ventilation pipes for factory reasons, air conditioning outdoor units, cooling towers, ladders and other devices.

In particular, the grounding and equipotential connection of photovoltaic power generation equipment is the top priority. In the place where the combiner box and inverter are installed, a set of equipotential grounding terminal box is added to ground the combiner box, inverter and controller. The terminals are respectively connected with the equipotential grounding terminal box with two-color grounding wire larger than 16 square meters, and the terminal box is connected with the original or new grounding device with flat steel or wires larger than 50 square meters.