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The beginning of summer has arrived, and the rainy season in the south has arrived. After the May Day holiday, the cold air began to affect the northern regions of my country, the rain gradually increased, and the local temperature in the Northeast and North China exceeded 10 °C. At the same time, heavy rainfall in the south also unfolded, with torrential to heavy rains appearing in parts of Guangdong, Guangxi and other places. In severe weather with strong humidity, frequent rainfall and thunderstorms, if the photovoltaic power station is not systematically operated and maintained, it is often easy to cause potential safety hazards. How to deal with it?

smog

In rainy weather or foggy weather, when the solar radiation is low, if the working voltage of the photovoltaic power generation system cannot reach the starting voltage of the inverter, the photovoltaic power generation system will not work. Since the grid-connected power generation system is connected to the grid, when the photovoltaic power generation system fails to operate, the electricity from the grid will be automatically replenished, so there is no problem of insufficient power and power outages in the rainy weather and smog.

lightning strike

There are two main types of lightning hazards: direct lightning strikes and indirect lightning strikes.

Protection against direct lightning strikes: Setting up metal lightning conductors to the ground on tall buildings, including lightning rods, lightning strips, and grounding devices, can release the charge of huge thunderstorm clouds. All electrical equipment in the photovoltaic system cannot be protected from direct lightning strikes.

Induction lightning protection: The photovoltaic system has lightning protection modules in electrical equipment such as combiner boxes and inverters to protect against indirect lightning strikes. The inverter has secondary lightning protection and tertiary lightning protection. The secondary lightning protection adopts lightning protection module, which is generally used in medium and large photovoltaic power stations. There are no tall buildings around the power station. The third-level lightning protection adopts lightning protection devices. It is used for household small photovoltaic power station, and there are tall buildings around the power station.

Distributed photovoltaic power generation systems are equipped with lightning protection devices, and there is no need to disconnect them in normal lightning weather. If there is a strong thunderstorm, it is recommended to disconnect the DC switch of the inverter or combiner box, and cut off the circuit connection with the photovoltaic modules, so as to avoid the harm caused by the induction lightning.

The operation and maintenance personnel should usually check the lightning protection facilities to ensure the normal operation of the lightning terminal, down-conductor and grounding system, ensure that the short-circuit resistance value of the lightning protection grounding system is below 4 ohms, and regularly check the performance of the lightning protection module in the equipment. Prevent failures, so you can ensure that the equipment will not be damaged during a thunderstorm.

rainstorm

If the roof of the photovoltaic power station is a sloping roof, there is basically no need to worry about the rainstorm. If it is a flat roof, it is best to consider the drainage problem during the design and installation of the photovoltaic power station. It should be avoided that the photovoltaic modules are soaked by rainwater due to the relatively low bracket installation of the flat roof when the rainfall is too heavy. In addition, during the inspection after rain, be sure not to directly touch the connection parts of the inverter, photovoltaic modules and power supply cables with your hands, and wear rubber gloves and rubber boots to prevent accidents.

hail

Qualified photovoltaic power station products purchased from reliable large manufacturers, photovoltaic modules have been impact tested, so generally hail will not affect photovoltaic modules. However, after the hailstorm, daily inspections are also essential. If the power generation of the photovoltaic power station drops significantly or other abnormal conditions occur after the hailstorm, the owner must promptly notify the manufacturer's after-sales personnel for inspection.

When inspecting photovoltaic modules, the thermal image is generally used to lock the heating part, or the disconnection detector is used to check the disconnection part and the failure of the bypass diode. If there is a significant drop in power generation or other abnormal conditions after the module is smashed, the user should promptly notify the operation and maintenance personnel to check the photovoltaic system, and if necessary, send it back to the original factory for inspection, so as to replace the damaged photovoltaic module in time.

For the owner, what should be done when building a photovoltaic power station to ensure stable power generation and not be affected by the weather?

1. Do a good job in the preliminary design of the power station: When designing a photovoltaic power station, it is necessary to choose a suitable location. For example, if the photovoltaic power station is built on the roof, the fixed load of the roof, wind pressure load, snow pressure load, and earthquake load should be considered. "Building Structural Load Code", because the only way to avoid damage to the power station due to rainy weather.

2. Do the installation work well: the installation cannot be done arbitrarily. The installation process of the power station should be oriented to the south, so that it can fully receive the sunlight. The installation angle is theoretically equal to or close to the local latitude, and the arrangement and spacing need to be determined according to the local sunlight and the size of the roof structure. In addition, it is necessary to choose good equipment to effectively prolong the life of photovoltaic power plants.