Will the continuous bad weather adversely affect the photovoltaic power station?
Summer is here, and the rainy season is here in the south.After the May Day holiday, cold air began to influence in north China, the rain gradually increased, the northeast, north China, such as local cooling over 10 ¡æ.At the same time, the south of the relatively strong rainfall also began, guangdong, guangxi and other parts of the heavy rain to heavy rain.In severe weather with strong humidity, frequent rainfall and thunderstorms, if the photovoltaic power station is not operated and maintained systematically, it is often easy to cause safety risks. How to deal with it?
In rainy weather or haze 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 power grid, when the photovoltaic power generation system cannot operate, the power of the power grid will be automatically supplemented, so there is no problem of power shortage and power failure in rainy weather and haze.
A lightning strike
Lightning is mainly divided into two kinds of hazards: direct lightning and indirect lightning.
Direct lightning protection: metal lightning conductor, including lightning rod, lightning belt and grounding device, is set up on the tall buildings to release the electric charge of the huge thunderstorm cloud.All electrical equipment in the photovoltaic system cannot protect against direct lightning.
Lightning protection: the photovoltaic system has lightning protection modules in the bus box, inverter and other electrical equipment to protect against indirect lightning strikes.The inverter has two level lightning protection and three level lightning protection, and the two level lightning protection adopts the lightning protection module, which is generally used in medium and large photovoltaic power stations. There is no higher building around the power station. The three level lightning protection adopts the lightning protection device, which is generally used in household small photovoltaic power stations with higher buildings around the power station.
Distributed photovoltaic power generation systems are equipped with lightning protection devices, normal lightning weather does not disconnect.In case of strong thunderstorm weather, it is recommended to disconnect the dc switch of the inverter or the bus box for safety and security, and cut off the circuit connection with the photovoltaic module to avoid harm caused by inductive lightning.
The operation and maintenance personnel should make the lightning protection facilities test at ordinary times to ensure the normal connection of the lightning connector, the lead wire and the grounding system, ensure the lightning protection grounding system short circuit resistance value is below 4 ohms, and regularly test the lightning protection module performance in the equipment to prevent failure, so as to ensure that the thunderstorm days will not damage the equipment.
If the roof of the photovoltaic power station is inclined, there is little need to worry about heavy rain.If it is a flat roof, it is better to consider the drainage problem when designing and installing the photovoltaic power station. It should be avoided that the photovoltaic modules will be soaked by rain water due to the relatively low bracket installation of the flat roof when there is too much rain.In addition, when inspecting after rain, do not directly touch the connection part of inverter, photovoltaic module and power supply cable with hands. Rubber gloves and rubber boots should be put on to avoid accidents.
For the qualified photovoltaic power station products purchased from reliable large manufacturers, the photovoltaic modules have passed the impact test, so generally hail will not affect the photovoltaic modules.But after the hail, routine inspections are also necessary.If the output of photovoltaic power station drops significantly or other abnormal conditions occur after the hail, the owner must timely inform the after-sales staff of the manufacturer for testing.
In the inspection of photovoltaic modules, thermal imaging is generally used to lock the heating part, or the wire breakage detector is used to check the wire breakage and the fault of the bypass diode.If the module is smashed and the power generation is obviously decreased or other abnormal conditions occur, the user shall timely inform the operation and maintenance personnel to check the photovoltaic system, and if necessary, it can be sent back to the original factory for testing, so as to timely replace the damaged photovoltaic module.
For the owners, what should they do when building a photovoltaic power station to ensure that the power generation is stable and not affected by the weather?
1, in the early period of the power plant design: the design of the photovoltaic power station, need to choose the appropriate location, such as photovoltaic power station construction in the roof, want to consider the roof fixed load, wind load and snow load, seismic load, generally in accordance with the "load code for the design of building structures", because only in this way can avoid because of the rain weather let plant damage.
2. Do a good job in installation: the installation cannot be done at will, and the installation process of the power station should be towards the south, so that it can fully receive the sunshine.The installation Angle is theoretically equal to or close to the local latitude, and the arrangement and spacing shall be determined according to the local sunlight and the size of roof structure.In addition, the selection of good equipment, in order to effectively extend the life of photovoltaic power station.
In a word, if the photovoltaic power station wants to operate stably in the continuous bad weather, it needs to do a good job according to the design standards from the aspects of design, installation and type selection, so as to prevent the damage of photovoltaic power station, make the power station easily survive the frequent rainy season, operate stably and ensure safety.