1. Advantages of grid-connected solar photovoltaic power generation
The grid-connected solar photovoltaic power generation can not only effectively control the emission of energy utilization pollutants, but also not produce large noise, and meet the national energy consumption reduction standards. Generally speaking, it has the advantages of less pollution, good energy consumption control, obvious environmental protection effect and high safety. The solar energy itself is rich in energy, which solves the worry of the shortage of photovoltaic power generation operation resources and expands the space of adjustment and control. The application of grid-connected solar photovoltaic power generation operation technology takes the power grid as the carrier, directly introduces the system electric energy, and the energy storage device runs accordingly. In this way, not only can the battery usage be strictly controlled, but also the power generation cost can be reduced, and more ideal comprehensive benefits can be obtained for solar photovoltaic power generation. According to the actual situation of grid-connected solar photovoltaic power generation, distributed access is adopted to create favorable conditions for the implementation of the principle of adapting to local conditions, which can be automatically connected to the grid and flexibly withdrawn. This effectively relieves the overload pressure of the power system, timely adjusts the peak power consumption of the grid, and optimizes the power system from the aspects of stability and reliability.
2. Construction technology of grid-connected solar photovoltaic power generation
2.1 Construction Process
The construction process of solar photovoltaic grid-connected power generation mainly includes three aspects. First, civil construction and photovoltaic panel installation; The second is electrical engineering construction; The third is scientific debugging. First, civil construction and photovoltaic panel installation treatment. First of all, scientific measurement of the civil pile foundation is carried out, the line treatment is completed, and the pouring construction begins after preparation for construction. Secondly, install relevant steel members; Finally, the photovoltaic modules are installed according to the requirements of solar photovoltaic grid-connected construction. Second, electrical engineering construction. First install the junction box, lay the cable in time, and install the inverter after grounding treatment; Secondly, arrange the threading pipe and determine the position of the switch station before entering the bridge link. Immediately install switching-station related equipment, such as high and low voltage distribution box, arc suppression coil, automatic operation device, reactive power compensation and protection device. All installation processing must be carried out in accordance with the requirements of the design drawing to ensure the correct installation sequence and smooth completion of the construction process. For automatic control panel cabinets and other equipment in electrical engineering, communication and quality inspection must be done before ordering to ensure the operation quality of electrical engineering equipment. Third, scientific debugging. Carry out debugging and inspection of the installed equipment, especially the regulation of photovoltaic grid-connected, to prepare for the subsequent operation of solar photovoltaic grid-connected power generation. In photovoltaic grid-connected commissioning, it specifically involves voltage transformers, insulators, vacuum load switches, current transformers and isolation switches, etc., in the way of static experiments, to ensure that the commissioning objects are in normal running state. In addition, it is necessary to carry out the inspection of the primary circuit connection line and the secondary circuit connection line, and scientifically verify the measuring instrument. Taking the test debugging of the voltage transformer as an example, the winding is measured first, followed by the AC voltage resistance test and the measurement of the DC resistance of the winding, the wiring group of the voltage transformer is checked again, and the error measurement is finally carried out. This ensures the normal operation of the voltage transformer.
2.2 Process of photovoltaic grid-connected power generation
2.2.1 Accurate pay-off and positioning.
In the process of grid-connected solar photovoltaic power generation, pay-off and positioning are the first links. First determine the datum point, through the optical theodolite to complete, determine the datum point determine the completion of positioning; Secondly, adjust the positioning, refer to the actual obstacles around the appropriate expansion and correction; Finally, according to the requirements of photovoltaic grid-connected power generation, flexibly change the pole, lifting pole, etc., and re-calibrate the foundation longitudinal and transverse.
2.2.2 Fabrication and Installation of steel components Fabrication and installation of steel components is one of the key links.
During the installation of photovoltaic modules, a fixed rooting structure is involved. The main frame of this structure is steel members. The steel component has wide coverage, more installation points and large engineering quantity. According to the characteristics of the photovoltaic grid-connected structure, the construction drawings of steel components were scientifically designed, and the scientific layout of the steel frame was installed after passing the examination. Ensure that all installation steps are completed in accordance with the specified standards to minimize rework. In addition, pay attention to the processing of steel components, especially small pieces galvanized, must choose a professional steel structure unit. Implement the integrated implementation mode of production and installation to ensure the installation process and control the installation quality. Welding ray inspection of steel components is carried out actively, especially in the jointing area. Formulate effective anticorrosive treatment scheme to improve the anticorrosive properties of steel components.
2.2.3 Installing Panels and Supports The installation of panels and supports shall be carried out after the installation of steel components.
According to the installation specification, the edge pressing block is applied to effectively connect the panel and form the overall structure of the panel. Before the installation of the panels, the quality acceptance shall be qualified before the approach. While ensuring the quality of the panels, the surface smoothness and gap inspection shall be paid attention to, and the surface area of the panels shall be measured. All parameters are consistent with the installation standards. In the collocation of panels, pay attention to the safety of the panels, and handle them lightly during the installation. Adjust the installation surface of the panel to ensure that the positions of both ends of the panel can be adjusted flexibly. After both ends are firmly handled, keep the cable in tight state, and then adjust the fluctuation of the solar panel. Timely expansion of wiring processing, to ensure accurate connection of positive and negative terminals, do a good job of wiring reinspection.
2.3 Effective commissioning of grid-connected power generation
In the commissioning of grid-connected power generation, the first step is to adjust the initial state of various electrical equipment according to the commissioning process. The second step, a comprehensive analysis of grid-connected power generation related data, a series of design data such as photovoltaic power generation system and distribution cabinet, etc., to prepare for grid-connected power generation commissioning. The third step is to optimize the grid-connected photovoltaic power generation technology. Through the adjustment of the connector load, the grid-connected power generation basic system is improved, and all kinds of equipment are repaired regularly to ensure that the output current of the grid-connected power generation system is consistent with the power grid generation through the integration of the inverter.
