Intelligent Photovoltaic Connection Box Solves Three Difficulties Puzzling the Photovoltaic Industry

Publish Time:2019/8/15   Views:2789

Everything looks normal, doesn t it? Each panel (which is actually different in nature) is arranged side by side, unconditionally and indiscriminately, hand in hand, like a soldier who obeys orders, even if it is not suitable. Is there anything wrong with this arrangement?
Firstly, the voltage of each photovoltaic panel is not high, only tens of volts, but the voltage of two photovoltaic panels in series is about 1000V. When the power generation system encounters fire, even if firefighters can disconnect the bus circuit circuit switch, the whole system is still very dangerous, because only the current in the circuit is turned off, because the battery panels are connected with each other by connectors, the system voltage to the ground is still 1000V, when inexperienced firefighters hold high-pressure water guns. When spraying water to these power boards as high as 1000V to extinguish the fire, because the water is conductive, huge voltage difference is directly loaded on the firefighters through the water column, and the disaster occurs.
Secondly, the output characteristics of each photovoltaic panel are inconsistent, such as current, voltage and optimal operating point. With the long-term outdoor use of photovoltaic systems and natural aging, this inconsistency will become more and more obvious. The characteristics of series power generation conform to the "barrel effect". That is to say, the total power generated by a series of panels depends more on the output characteristics of the weakest panels in the series, so it is very important to save the "weak" and make the "weak" not drag the "team" behind.
Third, solar panels are most afraid of shading (these shading factors are often tree shade, bird droppings, dust, chimneys, foreign bodies, etc.), so they are usually installed in sunny places, but in distributed roof power generation systems, owners often consider the beauty and harmony of the overall building and courtyard building structure. It will evenly lay the panels on the whole roof, although some parts of the roof will cause shadows. Sometimes, owners are not very aware of the serious impact and harm of shadows on the panels. Investigations have found that they often say, "That s nothing, it s just a shadow." However, the actual situation is not optimistic, because when the panel is shaded, it will induce the start of bypass protection elements (usually diodes) in the junction box behind the panel. The DC current of up to 9A in the battery string will be loaded on the bypass devices instantaneously, which will produce more than 100 degrees of high temperature in the junction box. Temperature has little effect on the battery board and junction boxes in a short time, but if the shadow effect is not eliminated for a long time, it will seriously affect the service life of junction boxes and battery boxes.