The summer has arrived, and the rainy season in the south has arrived. After the May Day holiday, cold air began to affect the northern part of China, and the rain gradually increased, and the local temperature in Northeast China and North China exceeded 10 °C. At the same time, heavy rainfall in the south has also started, and heavy rains and heavy rains have occurred in parts of Guangdong and Guangxi. Under the severe weather of strong humidity, constant rainfall and thunderstorms, if the operation and maintenance of photovoltaic power plants are not systematically carried out, it is easy to cause safety hazards. How to deal with them?

Smog

Rainy weather or fog and haze, the case of low solar radiation, photovoltaic power generation system operating voltage if it is not inverter starting voltage, 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 is unable to operate, the grid's electricity will be automatically replenished, so there is no shortage of power and power outage in the rainy weather and smog.

Lightning strike

Lightning is mainly divided into two types of hazards: direct lightning strikes and indirect lightning strikes.

Direct lightning protection: Set up metal lightning protection grounding conductors on tall buildings, including lightning rods, lightning protection belts and grounding devices, which can release the huge thunderstorm cloud layer charge. All electrical equipment in a photovoltaic system is not protected against direct lightning strikes.

Protection of inductive lightning: 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 two-level lightning protection and three-level lightning protection. The second-level lightning protection adopts lightning protection module. It is generally used for medium and large-scale photovoltaic power stations. There are no high-rise buildings around the power station, and lightning protection devices are used for three-level lightning protection. It is used in small-scale photovoltaic power plants for household use, and there are high buildings around the power station.

Distributed photovoltaic power generation systems are equipped with lightning protection devices, and normal lightning weather does not need to be disconnected. If there is a strong thunderstorm, for safety insurance, it is recommended to disconnect the DC switch of the inverter or the combiner box to cut off the circuit connection with the PV module to avoid the hazard of the induced lightning.

The operation and maintenance personnel should normally check the lightning protection facilities to ensure the normality of the lightning receptor, the down conductor and the grounding system, and ensure that the short circuit resistance of the lightning protection grounding system is below 4 ohms, and the performance of the lightning protection module in the equipment is periodically checked. Prevent failures, which will ensure that thunderstorms will not damage the equipment.

Rainstorm

If the roof of the PV power plant is installed as 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 when designing and installing the PV power station. When the rainfall is too large, the installation of the flat roof is relatively low, so that the PV modules are soaked by rain. In addition, during the inspection after the rain, do not directly touch the connection between the inverter, the PV module and the power supply cable by hand, and wear rubber gloves and rubber boots to prevent accidents.

Hail

Photovoltaic modules are tested for impact from qualified photovoltaic power plants purchased from reliable large manufacturers, so hail will not affect PV modules. However, after the hail, daily inspections are indispensable. If the photovoltaic power station has a significant drop in power generation or other abnormal conditions after the hail, the owner must notify the factory after-sales personnel to conduct the test.

When inspecting a photovoltaic module, the thermal imaging portion is generally used to lock the heat generating portion, or the disconnection detector is used to check the disconnection portion and the bypass diode failure. If the power generation is significantly reduced or other abnormal conditions occur after the component is smashed, the user should promptly notify the operation and maintenance personnel to check the PV system, and if necessary, return it to the original factory for testing, so as to replace the damaged PV module in time.

For the owners, what can be done to build a photovoltaic power station to ensure stable power generation and weather resistance?

1. Do the early design of the power station: When designing the photovoltaic power station, you need to choose a suitable location. For example, if the photovoltaic power station is built on the roof, it should be considered that the roof fixed load, wind pressure load, snow pressure load, and seismic load are generally "Building Structure Load Specification", because this is the only way to avoid damage to the power station due to rain and rain.

2, do the installation work: the installation can not be arbitrary, the installation process of the power station should be southward, so that it can fully accept the sun's light. The installation angle is theoretically equal to or close to the local latitude, and the arrangement and spacing need to be combined with the local sunshine and roof structure dimensions. In addition, we must choose good equipment to effectively extend the life of photovoltaic power plants.

All in all, in order to stabilize the photovoltaic power station in the continuous bad weather, it is necessary to design according to the design, installation and selection, in order to prevent the damage of the photovoltaic power station, and let the power station easily pass the season of frequent rain. Steady operation and security.