Today, the proportion of photovoltaic power generation stations in the power system is increasing. With the promotion of photovoltaic power plants, the relevant photovoltaic knowledge has also been popularized. The role of photovoltaic power generation island-preventing devices is as follows: What are the specific protection configuration functions? Let's learn together.
Today, the share of photovoltaic power stations in the power system is increasing, not only for centralized large-area photovoltaics, but also for distributed small photovoltaic power stations. From the very beginning, the northwest region gradually expanded to North China, South China, and most of China's fields. The construction site has been gradually moved closer to the villages and cities where deserted people, neighbors and mountainous areas have gathered.
For small photovoltaic power plants, there should be the ability to rapidly monitor islands and immediately disconnect from the grid. For large and medium-sized photovoltaic power stations, the public power grid relay protection device must ensure that the photovoltaic power station is cut off when the utility grid fails. The photovoltaic power station may not be equipped with island protection. The island power protection capability of the medium-sized photovoltaic power station that accesses the user's internal power grid is established by the dispatching power department. Based on this regulation, a large number of distributed photovoltaic power stations must be equipped with anti-islanding protection devices.
Photovoltaic power generation anti-islanding device
The main function of anti-isolating devices for photovoltaic power generation in substations is to disconnect the network point switches in case of faults, to avoid unnecessary personnel casualties caused by the construction and maintenance of personnel on the line, and to avoid abnormal operation of the photovoltaic power station due to the failure of the power grid, causing damage to the power station. Impact.
Photovoltaic anti-isolating device protection configuration function has the following
1. Low-frequency protection: When the frequency is between 35HZ and 65HZ, and once it is above the low-frequency value, the low-frequency protection can be started. The low-frequency protection action will return immediately after 200ms.
2, over-frequency protection: When the frequency is higher than the fixed value protection start.
3, low voltage protection: action when the voltage is lower than the fixed value.
4, over-voltage protection: when the voltage is higher than the fixed value action.
5. Joint jump: Supports the side jump of the substation, that is, when the substation side jump command is received, delay the exit of the trip and cut the grid switch of the station.
6, frequency mutation: When the frequency fluctuation value exceeds the set value, protection action.
According to the actual situation and local specific requirements, under normal circumstances, large and medium-sized photovoltaic power stations can be installed anti-islanding protection, but also can not be installed, but when the fault must be able to quickly and accurately cut off the grid switch. Mainly in large and medium-sized photovoltaic power stations are built with substations, the station has a relatively complete microcomputer protection device, when the fault occurs, the corresponding computer protection will be timely and accurate action, photovoltaic power generation anti-islanding devices sometimes in the power station as A backup protection exists. For distributed photovoltaic power plants, because of the relatively small installation capacity and low-voltage grid connection, there is generally no substation. For this reason, and in order to ensure the safety of the power grid, according to local requirements, there are generally anti-islanding devices for photovoltaic power generation, simultaneous devices, and power quality monitoring.
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advantage
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Disadvantage
The fatigue strength is poor, stress cracking easily occurs, and the wear resistance is poor. Poor resistance to solvents, not resistant to strong alkalis, oxidizing acids, amines and ketones, soluble in chlorinated hydrocarbons and aromatic solvents, and prone to hydrolysis and cracking in water for a long time.
pc film classification
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