1 Project location of distributed photovoltaic power station
Compared with traditional thermal power stations, distributed photovoltaic power stations are quite different in terms of footprint, climate conditions, access to energy, construction, and construction, and have higher requirements and standards. Therefore, before carrying out the construction of distributed photovoltaic power plants, it is necessary to fully consider various requirements, such as climate and sunshine. First, climate requirements. In the construction and operation of distributed photovoltaic power plants, climate conditions play a crucial role. Therefore, the power station should choose some areas with relatively rich resources, and at the same time, it is necessary to collect and sort out various kinds of data in the weather station regularly to analyze and study the impact of these weather on the power station. For example, whether the temperature is too high or too low, it will greatly reduce the operating quality and efficiency of various types of equipment, and also shorten the service life of these equipment; The wind speed can speed up the heat dissipation efficiency of the equipment, and the power generation can be increased to a certain extent. However, if the wind speed is too fast, it will blow over the equipment, bringing safety risks. Some bad weather, such as heavy rain, snow, etc., will bring great damage to the equipment, greatly reducing the operating quality of the equipment and power output, and affecting the smooth and normal operation of the power station. Second, administrative requirements. Distributed photovoltaic power stations must meet the relevant national standards and requirements, meet the administrative needs, and understand the address of the power station that can be used, but also need to communicate and exchange with the planning bureau, the land bureau, determine all kinds of information, and finally should be licensed by the environmental protection department. Third, sunshine requirements. In order to give full play to the role and value of distributed photovoltaic power stations, it is necessary to ensure that the location of the power station can obtain rich solar resources. Solar energy has a certain dispersion, and the planning and construction of distributed photovoltaic power stations must fully consider the local terrain and climate conditions. The illumination in each region is divided into several different registers to ensure that direct radiation can be greater than divergent radiation, and the quality and efficiency of solar energy utilization can be maximized. Fourth, solar energy resources are stable enough. The final influencing factor of the distributed photovoltaic power stations is the stability of solar energy resources, according to the number of days of local sunshine time greater than 6h each month, compare the maximum and minimum values, and is divided into three levels, the value is less than 2 is stable, the value is greater than 2 is less than 4 is more stable, the value is greater than 4 is not stable. Fifth, the consumption of electricity. One aspect that can not be ignored in the siting process of distributed photovoltaic power stations is the power consumption situation, and the capacity of power consumption determines whether it can successfully complete the grid-connection work and prevent the phenomenon of abandoning light. After determining the address of the project, it is necessary for relevant personnel to do a good job of field investigation, timely find the problems existing in the construction site, and formulate practical solutions to avoid various safety accidents in the future construction process of the power station, which will bring greater economic losses. Collect, record, and sort out all kinds of data and information to make adequate preparations for future investigation, verification and supervision.
2. Project characteristics and workload of distributed photovoltaic power station
2.1 Engineering resources and manpower
Before the formal construction of the distributed photovoltaic power station construction, the construction personnel must fully understand the real situation of the project, such as the number of tasks, resources, and the actual situation of the construction site . Project enterprises need to pay attention to the reasonable allocation of resources and personnel, and fully consider the allocation of construction equipment. Carefully selected material suppliers to provide sufficient construction materials for the project. Strengthen the management of the construction site, hire enough technical personnel, reasonably arrange work and rest times, formulate management systems, clarify the responsibilities of personnel, enhance their professional quality, and avoid the situation of passive sabotage.
2.2 Project Construction Management
First, define the content of project management. The project management work needs to formulate a series of management measures and methods on the basis of complying with the relevant national rules and regulations. It is pointed out in the contract that the construction of the project needs to be approved and supervised by the owner. Second, clear engineering safety objectives. Project safety is crucial to avoid casualties in the construction process as much as possible, to prevent damage to equipment, to avoid traffic accidents, fire accidents, collapse accidents, etc., to minimize the probability of various safety accidents, and to build a good civilized site. Third, improve the quality of the project. For a project, its engineering quality occupies a crucial position. All construction processes should meet the relevant standards and requirements formulated by the state, the quality of the project must be above high quality, with a 100% pass rate, and the excellent rate also needs to be higher than 99%. Fourth, we need to do a good job in environmental protection. In the process of the construction of a distributed photovoltaic power station, we must pay attention to the development of environmental protection work, clear the important objectives of environmental protection, and avoid the environment around the project to the greatest extent. In the actual construction process, can not emit too many pollutants, try not to produce noise, and reduce the environmental accident rate of the construction site. Do not destroy the environmental vegetation on the construction site to avoid soil erosion on the construction site. The exhaust gas emitted by all vehicles on the construction site shall meet the relevant emission standards.
3 Equipment selection of distributed photovoltaic power stations
In the process of building a distributed photovoltaic power station, it is necessary to select the best equipment according to the actual situation of the project, so as to ensure that the power system can always maintain a good operating state. The choice of equipment needs to start from many aspects and angles. First, photovoltaic modules. At present, in China’s photovoltaic power stations, the most commonly used solar cell products photovoltaic modules have two kinds, one is amorphous silicon type, the other is crystalline silicon type. Among them, the crystalline silicon type is divided into two kinds, one is color silicon, the other is monocrystalline silicon. Compared with crystalline silicon photovoltaic resistance, amorphous silicon photovoltaic resistance in terms of efficiency, or in terms of footprint, cost, and other aspects are relatively high, so in the construction of distributed photovoltaic power stations need to choose crystalline silicon photovoltaic resistance as far as possible. Second, the inverter. In the distributed photovoltaic power station, the core equipment is the photovoltaic grid-connected inverter, whose function can convert the original direct current into alternating current. There are two main types of grid-connected photovoltaic inverters, one is a series of inverters, and the other is a centralized inverter. Centralized inverters have greater advantages in terms of price, capacity level, attack, and technology, and when the project needs a larger installed capacity, it is necessary to use centralized inverters. Third, bus box and DC cabinet. The outdoor of the distributed photovoltaic power station needs to be configured with a special photovoltaic junction box, which can greatly reduce the connection probability between the inverter and the photovoltaic array, and can also provide greater convenience for future maintenance work. To install the mixed flow on the battery bracket, each bus box needs to be connected to eight square arrays, and each eight bus box needs to be connected to a set of DC boxes, and then connected to the inverter. Fourth, cable selection. In the construction of distributed photovoltaic power stations, cables occupy a crucial position, and their costs also occupy a large proportion. To some extent, whether it is the construction method of the cable or the choice of the cable will directly affect the overall cost of the project, and it is closely related to the smooth and safe operation of the power grid. Therefore, the relevant personnel must pay attention to the choice of cable, comply with the principles of economy, rationality, and practicality, In the selection of cables need to fully consider its heat resistance, insulation, moisture resistance and corrosion resistance, but also need to carefully analyze and study the specifications of the cable. In the construction of distributed photovoltaic power stations, it is necessary to ensure the reasonable selection of various equipment to avoid the increase in construction costs and funds due to unreasonable equipment. In order to effectively reduce the cost of the project, it is necessary to pay attention to the reasonable choice of cable trench outlet mode, Outdoor processing can be adopted, and indoor installation can be used to ensure the rationality and scientific construction plan.
4 Section division of distributed photovoltaic power plants
When the distributed photovoltaic power plant carries out the formal construction phase, the relevant personnel need to pay attention to the division of the bid section. In the actual construction process, the division of the project bid section is a crucial content and one of the major decisions, which determines the success or failure of the whole project. Therefore, the relevant personnel of the power station need to comprehensively analyze and study the project duration of the project, fully understand the various bidding sections of the project, and do a good job of connecting the construction phase, which can be divided into different stages, respectively, the installation of components and electrical, the construction of the access system, the booster station and the civil construction of the photovoltaic plant area. To a certain extent, a good engineering division can ensure the quality of the project, but also ensure that each bid section achieves a good connection, maximize the construction efficiency of the project, to ensure the smooth construction of the power station.
5. Setting of project engineering organization
5.1 Clarify the job responsibilities
In a distributed photovoltaic power station, the project manager can regulate the entire project, perform various contracts, coordinate and manage the work between various departments, handle various financial situations, and deal with comprehensive affairs and departmental relations . The deputy project manager should supervise the construction of the project, understand the construction progress, assist the project manager in doing a good job in safety, and ensure the civilized construction of the project. Project technicians need to solve various problems encountered in the construction process of the project, which is also a department closest to the project, occupying a crucial position. The logistics department is responsible for some logistics affairs, including traffic, security, and human resources management. The materials department needs to analyze and study the total amount and type of materials in the project to avoid spending too much money on materials. The safety management department is responsible for the safety management of the construction site. Construction enterprises need to clarify the responsibilities of each department, so that they understand their work content, clear their responsibilities, and establish a lifelong responsibility system so that they can carry out construction in strict accordance with relevant norms and standards.
5.2 Reasonable distribution of machinery and manpower
Both the construction project manager and relevant departments need to carefully analyze the actual situation of the project, understand the duration, scale, target resource status, etc., and realize the reasonable allocation of human resources on this basis. Effectively improve the comprehensive quality of management personnel, and establish a strong executive team. Construction enterprises need to develop a detailed labor distribution plan, and reasonable distribution of machinery and equipment so that construction personnel can find their own suitable positions, and play their own role.
5.3 Pay attention to the good management of materials
In the past, China used thermal power stations, and the number of distributed photovoltaic power stations was small. Today, China has begun to implement distributed photovoltaic power stations, but the lack of more high-quality, high-quality construction personnel, the lack of specialized personnel for material management. Therefore, the construction unit needs to fully understand the actual situation of the project and realize the importance and necessity of material management. At the same time, it also needs to learn from the experience of other projects, carefully draw the relevant flow chart of material management according to the actual situation of the project, constantly optimize and improve the relevant mechanism of internal management, clarify various responsibilities, and implement the responsibility system for life. We will adopt scientific and rational management systems and models. Construction units need to build a reasonable equipment storage but also need to arrange special management personnel, do a good job of materials and equipment statistics, achieve good management of materials, reduce the cost of equipment storage, effectively improve the quality and speed of equipment installation, to the greatest extent to solve the current unit manpower shortage situation, appropriately accelerate the speed of construction. In the distributed photovoltaic power station, imperfect systems, shortage of personnel, etc. are more common problems, but also a common problem in many power stations. Therefore, the relevant personnel need to pay special attention to the above two problems, constantly optimize and improve the management system, and effectively improve the quality and efficiency of material management.
5.4 Construction scheme and technical requirements
When building a distributed photovoltaic power station, it is necessary to determine the construction plan and clarify the technical requirements. In the actual construction process, it is necessary to do a good job of roof survey, strictly according to the relevant standards and requirements promulgated by the state, a comprehensive and serious investigation of the roof of the color steel tile form, structure, access point and other content, for some do not meet the standards and requirements of the plant structure, need to be properly reinforced to ensure that the project can meet the load requirements. This requires technical personnel to have a solid knowledge base and a high technical level. After that, the relevant personnel need to pay attention to the reasonable planning and arrangement of roof components, clarify the installed capacity, pay attention to the selection and procurement of equipment, and pay attention to the choice of equipment types. Relevant personnel need to communicate and exchange with the owner to determine the correct installation position and placement of the equipment, such as switch station foundation, box inverter, etc. After that, we need to communicate and exchange with the surrounding power supply companies to determine whether the circuit can be accessed and whether it can meet the design capacity standards and sizes, and then determine the path and direction of the line, determine the construction plan according to the above situation and requirements, and draw the construction general plan.
6 Closing remarks
All in all, in the new situation, our country begins to realize the importance of sustainable development and gradually begins to build distributed photovoltaic power stations. In order to play the role of distributed photovoltaic power stations, it is necessary to do a good job in construction management, fully consider the actual situation of the construction site, clear the content and objectives of construction management, and improve the construction quality of distributed photovoltaic power stations.