Author: Site Editor Publish Time: 2022-06-16 Origin: Site
Building a solar photovoltaic power station is a very time-consuming and labour-intensive project, and the slightest carelessness may have an impact on the subsequent operation of the plant. So today we are going to introduce some of the problems in the construction of solar PV power stations, such as the impact on buildings, the environment and the power grid.
I. The impact on the building load-bearing
1. The construction of solar photovoltaic power station does not affect the original structure of the building, the original function of the building, the characteristics of the envelope structure, the shape and façade of the building does not change.
2. PV power station is installed on the roof of the concrete structure, the design bearing capacity of the building is about 200Kg/㎡, while the load of the PV power station is about 30Kg/㎡², the use of solar energy applications are safe, reliable and do not affect the aesthetics of the building.
3. The PV power station uses the self-weight of the foundation to fix the square array, without damaging the waterproof layer of the roof, the heat insulation layer and the heat preservation layer, etc.
II. Impact on the environment
1. Solar photovoltaic power generation does not produce any waste gas, waste water, waste residue and other waste.
2. There are no rotating parts in the process of operation and no noise pollution is produced.
3. The principle of photovoltaic power generation is the photovoltaic effect, the solar cell modules produce direct current under the condition of light, after a certain series-parallel aggregation connected to the grid-connected inverter, converted into 50HzAC230V/400V power, there is no high frequency alternating current in the whole process of power generation and conversion, no electromagnetic radiation, no harm to human body.
4. Solar power station cable laying using the original pipeline and bridging, generally no additional laying of lines, even if the laying of lines involved, is also used to conceal the structure, not to damage the original building and the environment.
5. Solar power stations are maintenance-free or maintenance-free, and the operation of the station is unattended.
III. Impact of solar power stations on the grid
Safety of grid-connected photovoltaic power stations
(1) The "islanding effect" refers to the phenomenon that power generation equipment remains as an isolated source of power supply to the load in the event of a power loss in the grid. The "islanding effect" is a major safety hazard for equipment and personnel, and is reflected in the following two aspects: on the one hand, when maintenance personnel stop supplying power to the grid and carry out maintenance on power lines and power equipment, if the inverter of the grid-connected solar power plant continues to supply power, it will cause injuries and fatalities to maintenance personnel; on the other hand, when a grid fault causes a power outage, if the grid-connected solar power plant continues to supply power to the load, it will cause an accident. On the other hand, if the grid-connected inverter continues to supply power when a power outage is caused by a grid fault, once the grid is restored, there may be a large difference in phase between the grid voltage and the output voltage of the grid-connected inverter, which will generate a large inrush current in this instant, thus damaging the equipment.
(2) Anti-islanding protection PV grid-connected inverters generally adopt two "islanding effect" detection methods, including passive and active detection methods. The passive detection method refers to the real-time detection of the amplitude, frequency and phase of the grid voltage, when the grid loses power, it will generate a jump signal in the parameters of the grid voltage amplitude, frequency and phase, through the detection of the jump signal to determine whether the grid loses power; the active detection method refers to the generation of a small interference signal to the grid parameters, through the detection of the feedback signal to determine whether the grid loses power, one of the methods is by measuring One of the methods is by measuring the value of the harmonic voltage generated by the harmonic current output from the inverter at the grid connection point, so as to obtain the grid impedance to make a judgement, when the grid loses power, there will be a large change in the grid impedance parameters, so as to determine whether there is a grid loss.