Electricity, commonly known as the "electric tiger", is an invisible and intangible thing that plays a big role in the lives of modern people, but it is also very dangerous. Photovoltaic power generation projects, whether distributed small power plants or centralized large land-based power plants, have certain hazards. Accidents related to PV safety are not uncommon. For various reasons, few reports have been reported before. After a photovoltaic plant at an Apple factory caught fire, there was
1. Use the Right Fuse
Electrical fires are characterized by extremely fast burning speeds, which can damage system equipment in an instant. Therefore, when an electrical fire occurs, the first thing to do is to find a way to quickly cut off the power circuit within the range of the fire. Fuses, commonly known as fuses, can quickly disconnect the circuit in the event of a short circuit to prevent greater losses.
1) The fuse should be selected with a suitable rated current. If the current is too small, it is easy to misjudge; if the current is too large, it will not play a protective role.
2) The fuse in the junction box must use a special DC porcelain structure fuse core and a corresponding fireproof and arc-proof base. The exposed fuse core and circuit board design must not be used.
2. Lightning Protection Design for Photovoltaic Systems
For solar photovoltaic power generation systems, direct lightning strikes, lightning induction, and lightning wave intrusion must be prevented. The main ways of lightning induction and lightning wave intrusion are from overhead wires, photovoltaic arrays to the incoming lines in the machine room. Lightning rods are installed in the junction box, inverter, and AC distribution box. The grounding of the photovoltaic system is also very critical. On the one hand, the system needs to be protected from lightning strikes; on the other hand, the static electricity of the equipment needs to be eliminated.
3. Precautions
1) Check whether the temperature of the equipment, cables and connectors is abnormal.
When the equipment is designed, the current carrying capacity of the copper rods, cables and connectors will have a certain reserve. During normal operation, the temperature will not be too high. You can touch the infrared layer with your hands. When the cable is aged and the insulation layer is damaged, the local temperature will increase significantly.
2) Pay attention to changes in current and voltage.
When the power generation of a certain line is significantly lower than that of other lines, but there is no shadow and the components are normal. The junction box shows low voltage and low current, and it is necessary to disconnect and check the wiring until it is completely normal.
3) Pay attention to changes in sound.
When the inverter is running, the sound of the fan is stable. When the air duct is blocked or the fan fails, the sound will change. When the cable insulation layer is damaged, the sound of metal discharge can be heard and small sparks will be generated.
4) Pay attention to color changes.
When the photovoltaic power station stops working, the equipment casing can be disassembled to check whether the color of each component has changed. If the local color of the electrical equipment changes, such as blackening, it should be tested and inspected.
5) Pay attention to changes in smell.
During the inspection, if you smell a mushy or burnt smell, stop the machine immediately for inspection.
