News

Your location：

Two effects affecting the normal operation of photovoltaic modules

Categories:Company news
Author:
Origin:
Time of issue:2021-09-09
Views:0

(Summary description)Photovoltaic modules are the most important equipment in photovoltaic power generation. In the process of daily installation, operation and maintenance, if there are special circumstances, it will cause the hot spot effect and potential induced attenuation effect (PID) of photovoltaic modules and cause losses to the majority of owners. Therefore, we should pay attention to controlling the photovoltaic power station during installation and daily maintenance of the power station to avoid these two effects.

Two effects affecting the normal operation of photovoltaic modules





Two effects affecting the normal operation of photovoltaic modules

Categories:Company news
Author:
Origin:
Time of issue:2021-09-09
Views:0

Information

Photovoltaic modules are the most important equipment in photovoltaic power generation. In the process of daily installation, operation and maintenance, if there are special circumstances, it will cause the hot spot effect and potential induced attenuation effect (PID) of photovoltaic modules and cause losses to the majority of owners. Therefore, we should pay attention to controlling the photovoltaic power station during installation and daily maintenance of the power station to avoid these two effects.

1、 Hot spot effect

The shielded solar cell module in a series branch will be used as a load to consume the energy generated by other illuminated solar cell modules. The shielded solar cell module will generate heat at this time, which is the hot spot effect.

This effect can seriously damage the solar cell. Part of the energy generated by solar cells with light may be consumed by shaded cells. The hot spot effect may only be caused by a piece of bird droppings.

In order to prevent the solar cell from being damaged due to the hot spot effect, it is best to connect a bypass diode between the positive and negative poles of the solar cell module in parallel to avoid the energy generated by the lighting module being consumed by the shielded module. When the hot spot effect is serious, the bypass diode may break down and burn the module

2、 PID effect

Potential induced attenuation effect is that under the action of high voltage for a long time, there is leakage current between glass and packaging materials, and a large number of charges snipe on the surface of the battery, which worsens the passivation effect of the battery surface, resulting in the performance of the module lower than the design standard. When the PID phenomenon is serious, it will cause a component power attenuation of more than 50%, thus affecting the power output of the whole string. PID is most likely to occur in coastal areas with high temperature, high humidity and high salinity.

After the PID effect, some batteries have high resistance, which is mainly caused by the following three aspects:

First, the system design reason: the lightning protection and grounding of photovoltaic power station is realized by grounding the component frame at the edge of the square array, which causes a bias between a single component and the frame. The higher the bias voltage of the component, the more serious the PID phenomenon occurs. For p-type crystalline silicon module, through the inverter negative pole grounding with transformer, eliminating the positive bias of the module frame relative to the battery will effectively prevent the occurrence of PID phenomenon, but the inverter negative pole grounding will increase the corresponding system construction cost;

The second reason is the PV module: the external environment of high temperature and humidity makes the leakage current form between the battery and the grounding frame, and the leakage current channel is formed between the packaging material, back plate, glass and frame. Changing the insulating film ethylene vinyl acetate (EVA) is one of the ways to realize the anti PID performance of components. Under the condition of using different EVA packaging film, the anti PID performance of components will be different. In addition, the glass in photovoltaic modules is mainly calcium sodium glass, and the influence of glass on the PID phenomenon of photovoltaic modules is still unclear;

The third reason is the battery: the uniformity of the battery block resistance, the thickness and refractive index of the antireflection layer have different effects on the PID performance. Among the above three aspects causing PID phenomenon, the component PID phenomenon caused by the potential difference between the component frame and the internal component in the photovoltaic system is recognized by the industry, but the mechanism of the component PID phenomenon in the two aspects of components and cells is not clear, and the corresponding measures to further improve the anti PID performance of components are still unclear.

Scan the QR code to read on your phone

Previous: None

Next: Analysis of advantages and disadvantages of monocrystalline silicon, polycrystalline silicon and amorphous silicon cells

Previous: None

Next: Analysis of advantages and disadvantages of monocrystalline silicon, polycrystalline silicon and amorphous silicon cells

Relevant information

Two effects affecting the normal operation of photovoltaic modules

2021-09-09

Analysis of advantages and disadvantages of monocrystalline silicon, polycrystalline silicon and amorphous silicon cells

For those who have just joined the photovoltaic industry, I think it is necessary to tell you the difference between monocrystalline silicon cells, polycrystalline silicon cells and amorphous silicon cells. If there is anything inappropriate, please forgive me.

2021-09-09

How to avoid those potential safety hazards in the photovoltaic anti islanding device market

As an important safety guarantee for photovoltaic maintenance, anti islanding devices are also required by local power grid companies to install anti islanding devices in photovoltaic grid connected public transformer area.

2021-09-09