More and more photovoltaic applications, more and more large-scale power plants, in recent years, "fish and light complement each other" this new form of photovoltaic power generation also began to be widely used in the eastern region, the upper for photovoltaic power generation, the lower for aquaculture. As long as the three-dimensional arrangement of photovoltaic panel supports above the water surface and along the banks of the fish ponds, it not only saves land, increases the economic value per unit area of ​​land, but also does not affect aquaculture at the same time as generating electricity. Complementary" features. However, compared with ordinary large-scale ground power stations, the "fish-to-light complementary" power plant also has certain difficulties. Due to the humidity and high temperature environment, water vapor is easily generated. If water vapor penetrates into the components, the conductivity of the encapsulant (ENC) increases, and the corresponding components The increase of the leakage current will cause polarization of the surface of the module, namely PID effect. Therefore, the power loss caused by the PID effect in the photovoltaic system of the module in a high humidity or high temperature environment, especially a fish-photo complementary photovoltaic system, a coastal photovoltaic system, and a photovoltaic system near the equator is more severe. PID Effect and Analysis of Formation Cause The PID effect (Potential Induced Degradation), also known as potential induced attenuation, is the packaging material of the battery components and the material on the upper surface and the lower surface thereof. Ion migration occurs under high voltage between the cell chip and its grounded metal frame, and the performance of the components is degraded. phenomenon. External possible causes: It is easy to occur in a humid environment, and the degree of activity is related to the degree of moisture. At the same time, the degree of contamination of the surface of the module by the conductivity, acidity, alkalinity, and the ion-bearing object is also related to the occurrence of the aforementioned attenuation phenomenon. So far, the formation mechanism is not yet clear, and it is speculated that the metal ions derived from the soda-lime glass are the main current-carrying medium that forms the aforementioned leakage current with the PID effect. Possible internal reasons: 1: System: Inverter grounding and the placement of components in the array determine whether the cells and components are positively or negatively biased. The actual operating conditions and research results of the power station show that if all the components between the entire middle component and the negative output terminal of the inverter are under negative bias, then the PID phenomenon closer to the output component becomes more obvious. While all components in the middle of the middle component and the positive output of the inverter are under positive bias, the PID phenomenon is not obvious. 2: Components: Environmental conditions, such as the influence of humidity, cause leakage currents. 3: Batteries: The uneven sheet resistance caused by the unevenness of the cell sheet in the cell sheet; the increased sheet resistance used to optimize the cell efficiency will make the cell sheet easier to attenuate, leading to the PID effect. Therefore, the power loss caused by the PID effect in the photovoltaic system of the high humidity environment, especially in the fish photo-complementary photovoltaic system, the coastal photovoltaic system, and the photovoltaic system near the equator is very severe. Humidity Test on PID Effect of Photovoltaic Plant Three components (F/G/H) of the same batch and the same material are selected. The components are covered with glass and covered with copper foil. The components are connected in steps. They are in 30°C, 35% RH, 30°C, and 85% RH environments. A negative pressure of 1 kV was applied and the power of the module was tested after 1 h. The power changes are shown in Table 1. The leakage current monitoring curve during the test is shown in Figure 2. From Fig.1, the leakage current of the 3 components in the 1h is increased with the increase of the humidity, but the power is almost unchanged due to the lower temperature; the H component is subjected to a 66h test at 30°C and 85% RH. The power is attenuated by 30.35, and it can be speculated that at the same component temperature, the power decay takes longer in the case of lower humidity. Anti-PID effect kit new product comes into being: PROSOL-PVOBOX PROJOY introduced a new product, the PROSOL-PVOBOX, a PID-proof device, which applies the principle of reversible PID change. At night, it imposes a positively biased voltage on the module and repairs the PID effect panel at night. Product Highlights Instantly detect the grid voltage conditions and detect the insulation resistance of photovoltaic modules and ground; The maximum DC voltage up to 1500V; Automatic and manual two voltage switching modes; Supports 1st, 2nd, and 3rd MPPT inverters, and each MPPT can be connected in series; Does not affect the structure of the original photovoltaic system, the repair effect is obvious, no additional risk; Simple installation and maintenance, convenient maintenance; compact structure, light weight, small size, and space-saving; A single system can be used in 18 units in series; working principle: The PROSOL-PVOBOX is connected in parallel with the DC input of the inverter, applying a high voltage between the negative component of the PV module and the earth (PE), and intelligent adjustments can be made based on the DC input voltage. At night, it can release the accumulated charge of the PV module during the day because of the negative bias voltage between the negative electrode and the ground, so as to repair the PV modules whose efficiency is degraded due to the PID effect. This device has the function of detecting the insulation resistance of photovoltaic modules and ground (including photovoltaic modules and inverters, the system impedance must be greater than 200kΩ) and detecting the grid voltage conditions. The PROJOY team is constantly developing and updating product lines based on the user's perspective, providing customers with corresponding solutions. After continuous efforts, it has become a global professional supplier of inverter and photovoltaic power station solutions. Lathe And Milling Machining Service,Lathe And Milling Service,Custom Lathe And Milling Service,Pricision Lathe And Milling Service Lizhi Precision Manufacturing Technology Co.,Ltd , https://www.lzautoindust.com