1. Project location of distributed photovoltaic power station
Compared with traditional thermal power stations, distributed photovoltaic power stations have relatively high requirements and standards in terms of land area, climate conditions, energy acquisition and construction. Therefore, before the construction of distributed photovoltaic power stations, various requirements, such as climate and sunshine, need to be fully considered.
First, climate requirements. Climate conditions play a crucial role in the construction and operation of distributed photovoltaic power stations. Therefore, some areas with relatively rich resources should be selected for the power station. Meanwhile, various kinds of data in the weather station should be collected and sorted out regularly to analyze and study the impact of these meteorological conditions on the power station. For example, whether the temperature is too high or too low, it will greatly reduce the operation quality and efficiency of all kinds of equipment, but also shorten the service life of these equipment; The wind speed can speed up the heat dissipation efficiency of the device and increase the power generation to a certain extent. But if the wind speed is too fast, it will blow over the equipment, bringing safety risks. Some bad weather, such as rainstorm and blizzard, will bring great damage to the equipment, greatly reduce the operation quality and power output of the equipment, and affect 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 various administrative requirements, know the address that can be used to establish the power station, and also need to communicate and exchange with the planning bureau and the land bureau, determine all kinds of information, and finally get the permission of the environmental protection department.
Third, sunshine requirements. In order to give full play to the role and value of distributed photovoltaic power station, it is necessary to ensure that the location of the power station can obtain abundant solar resources. Solar energy has a certain degree of dispersion, the planning and construction of distributed photovoltaic power stations must fully consider the local terrain and climate conditions. The illumination in each area is divided into several different registers to ensure that the direct radiation can be greater than the divergent radiation, so as to maximize the utilization quality and efficiency of solar energy.
Fourth, solar energy resources are stable enough. The ultimate influencing factor of distributed photovoltaic power station is the stability of solar energy resources. Based on the number of local days with sunshine duration greater than 6h per month, the maximum value and minimum value are compared and divided into three levels. If the value is less than 2, it is stable; if the value is greater than 2 and less than 4, it is relatively stable; if the value is greater than 4, it is not stable.
Fifth, the consumption of electricity. One aspect that cannot be ignored in the location selection process of distributed photovoltaic power station is the power consumption situation. The capacity of power consumption determines whether it can complete the grid connection successfully and prevent the phenomenon of light abandonment. After the location of the project is determined, relevant personnel should be able to do a good job in field investigation, timely find the problems existing in the construction site, and formulate feasible solutions to avoid various safety accidents in the future construction process of the power station, which will bring great 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, the construction personnel must have a comprehensive understanding of the real situation of the project, such as the amount 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 give full consideration to 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, reasonable arrangement of work and rest time, formulate management system, clear responsibilities of personnel, enhance their professional quality, avoid the situation of slack work.
2.2 Project construction management
First, define the content of project management. Project management needs to formulate a series of management measures and methods on the basis of complying with relevant national rules and regulations. It is pointed out in the contract that the construction of the project needs to be agreed and supervised by the owner. Second, clear project safety objectives. Project safety is very important. It is necessary to avoid casualties in the construction process as far as possible, prevent damage to equipment, avoid traffic accidents, fire accidents and collapse accidents on the construction site, minimize the probability of various safety accidents, and build a good civilized site. Third, improve project quality. 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 100 percent of the qualified rate, good rate also needs to be higher than 99 percent. Fourth, we need to do a good job in environmental protection. In the process of the construction of distributed photovoltaic power station, it is necessary to pay attention to the development of environmental protection work, clarify the important objectives of environmental protection, and avoid the environment around the project being greatly affected to the greatest extent. During the actual construction process, excessive pollutants should not be discharged, and noise should not be generated as far as possible to 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. Exhaust gas emitted by all vehicles at the construction site shall meet relevant emission standards.
3. Equipment selection of distributed photovoltaic power station
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 running state. The selection of equipment needs to proceed from many aspects and angles.
First, photovoltaic modules. At present, in photovoltaic power station in our country, there are two kinds of solar cell products photovoltaic module, one kind is amorphous silicon type, and another is crystalline silicon type. Among them, crystalline silicon is divided into two kinds, one is color crystalline silicon, the other is monocrystalline silicon. Compared with crystalline silicon type photovoltaic resistance, amorphous silicon type photovoltaic resistance is relatively high in terms of efficiency, land area and cost, so it is necessary to choose crystalline silicon type photovoltaic resistance as far as possible in the construction of distributed photovoltaic power station.
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 mainly two kinds of grid-connected photovoltaic inverters, one is the series inverter, the other is the centralized inverter. Centralized inverter has great advantages in price, capacity grade, attack and technology. When the engineering needs a large installed capacity, it is necessary to use centralized inverter.
Third, the confluence box and DC cabinet. The outdoor of the distributed photovoltaic power station needs to be configured with photovoltaic special junction box, which can greatly reduce the probability of connection between the inverter and the photovoltaic square, but also can provide greater convenience for the future maintenance work. A mixed flow direction is installed on the battery bracket. Each bushing box needs to be connected to eight square arrays, and each eight bushing boxes need 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 station, cable occupies a crucial position, and its cost also occupies a large proportion. To some extent, both the construction mode and the choice of 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 selection of cables, comply with the principle 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 of construction costs and funds caused by unreasonable equipment. In order to effectively reduce the cost of the project, we need to pay attention to the reasonable choice of cable trench outlet, outdoor processing can be used, the use of indoor installation, to ensure the rationality and science of the construction scheme
4. Section division of distributed photovoltaic power stations
When the distributed photovoltaic power station carries out the formal construction phase, relevant personnel need to pay attention to the division of the bid section. In the actual construction process, the division of project bid section is one of the most important content, but also one of the major decisions, to determine the success or failure of the whole project. Therefore, relevant personnel of the power station need to comprehensively analyze and study the project duration, fully understand each bid section of the project, and do a good job in connection. The construction stage can be divided into different stages, including installation of components and electricity, construction of access system, booster station and civil construction of photovoltaic plant. To some extent, good engineering division can ensure the quality of the project, but also ensure that each section of the good connection, maximize the construction efficiency of the project, ensure the smooth construction of the power station.
5. Setting of project engineering organization
5.1 Define the job responsibilities
In a distributed photovoltaic power station, the project manager can control the entire project, perform various contracts, coordinate and manage the work among various departments, handle various financial situations, and deal with comprehensive affairs and departmental relations. The deputy project manager shall supervise the construction of the project, understand the construction progress, assist the project manager to do a good job in safety, and ensure the civilized construction of the project. Project technicians need to solve various problems encountered in the process of project construction, which is also the closest to a department of engineering, occupying a vital position. The logistics department is responsible for some logistics affairs, including traffic, security, 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 can understand their work content, clarify their responsibilities, establish a lifelong responsibility system, so that they can carry out construction in strict accordance with the 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, objectives, resources, 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 make detailed labor distribution plan, reasonable distribution of machinery and equipment, so that construction personnel can find suitable for their own posts, play their role.
5.3 Attach importance to good management of materials
In the past, thermal power stations were used, and the number of distributed photovoltaic power stations was small. Nowadays, we begin to implement distributed photovoltaic power stations, but lack a lot of construction personnel with high quality and high accomplishment, lack of special personnel to manage materials. Therefore, the construction unit needs to fully understand the actual situation of the project, realize the importance and necessity of material management, but also need to learn from the experience of other projects, according to the actual situation of the project carefully draw the relevant flow chart of material management, constantly optimize and improve the relevant mechanism of internal management, clarify the responsibilities, implement the responsibility system for life. We will adopt scientific and rational management systems and models. Construction units need to build a reasonable storage of equipment, and at the same time need to arrange special management personnel, do a good job in the statistics of materials and equipment, realize good management of materials, reduce various costs 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 distributed photovoltaic power stations, imperfect system and shortage of personnel are relatively common problems, which are also common problems in many power stations. Therefore, relevant personnel need to pay special attention to the above two problems, constantly optimize and improve the management system, effectively improve the quality and efficiency of material management.
5.4 Construction scheme and technical requirements
When constructing a distributed photovoltaic power station, it is necessary to determine the construction scheme and clarify the technical requirements. In the process of actual construction, the need to do a good job of roof survey, strictly according to the relevant standards and requirements issued 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, And this requires technical personnel to have a solid knowledge base, with a higher level of technology. After that, the relevant personnel need to be able to pay attention to the reasonable planning and arrangement of roof components, clear installed capacity, pay attention to the selection and purchase of equipment, pay attention to the choice of equipment type. Relevant personnel need to communicate and exchange with the owner to determine the correct installation and placement of 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. After that, we can 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, under the new situation, our country begins to realize the importance of sustainable development and gradually starts to build distributed photovoltaic power stations. In order to give full play to the role of distributed photovoltaic power station, it is necessary to do a good job in construction management, give full consideration to the actual situation of the construction site, define the content and objectives of construction management, and improve the construction quality of distributed photovoltaic power station.
