Calculation of Inclination Angle and Power Generation of Oblique Single Axis Photovoltaic Tracking System Based on PVsyst

“Taking the Baotou photovoltaic power station project as an example, the oblique single-axis tracking system used in this project is calculated based on PVsyst, and the power generation is calculated for the first year and 25 years.

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Taking the Baotou photovoltaic power station project as an example, the oblique single-axis tracking system used in this project is calculated based on PVsyst, and the power generation is calculated for the first year and 25 years.

Project overview of solar energy resources

Baotou Photovoltaic Power Station Project is located in Qingshan Village, Wudangzhao Town, Shiguai District, Baotou City, with a construction capacity of 100 MWp and site coordinates

It is about 40°08′N～40°41′N, 110°7′E～111°58′E, the altitude is about 1400 m, and the terrain slope is between 20° and 60°.

The main terrain of the factory area includes idle land left over after the overall relocation of the village, as well as destroyed farmland, woodland and barren hills; large areas of ruins formed by open-pit coal mines that have been mined or closed; large amounts of coal produced due to coal mining The coal gangue hill formed by gangue washing covers an area of ​​about 13.3 km2. The project site is very rich in solar energy resources, and the total annual radiation value of the whole district is gradually increasing from the northeast to the southwest. The annual radiation value of Baotou is between 1400 and 1750 kWh/m2, and the annual sunshine hours are between 2700 and 3300 h.

Calculation of adjustment inclination of single-axis tracking system

This project adopts the oblique single-axis tracking system with adjustable inclination angle, and uses PVsyst software to obtain the adjustment angles of 2 adjustments a year, 4 adjustments a year, and 6 adjustments a year through statistical analysis, and calculate 2 adjustments a year , Adjust 4 times a year, adjust 6 times a year, and fix the total monthly radiation on the surface of the module from January to December. Through statistical analysis, it can be seen that the total daily irradiation on the surface of the module adjusted 4 times a year is 0.68% higher than that of the module adjusted twice a year, followed by the total daily irradiation of the module surface adjusted 6 times a year compared to 4 times a year The amount increased by 0.14%; at the same time, it can be seen that after the optimal adjustment times are reached, the adjustment times are increased, and the increase in the total daily irradiation amount on the surface of the module becomes smaller and smaller.Considering comprehensively, choosing a solution that is adjusted 4 times a year is the most economical[1].

In summary, this project adopts a plan of adjustment 4 times a year, and the adjustment angle and time are shown in Table 1.

Table 2 lists the total daily radiation on the surface of the modules for each month of the year when the inclination angle of the photovoltaic array ranges from 0° to 60°. The dark color indicates the maximum value of the total daily radiation on the surface of the module from January to December at different inclination angles. This calculation takes 4 adjustments a year as an example; the 12 months are classified and the months with close inclination angles are classified as one adjustment period, and the adjustment time is 1 time from November to February of the following year, 3 to 4 1 time per month, 1 time from May to August, and 1 time from September to October; accumulate the irradiation amount at several angles corresponding to each adjustment cycle, and the angle corresponding to the maximum accumulated amount of irradiation is The best angle for this adjustment cycle.

Tracking system power generation calculation

The power generation calculation of photovoltaic power generation system generally needs to be completed with the help of software. The software that is currently used more is RETScreen, Meteonorm, PV*SOL, PVsyst, etc.[2]. This project uses the international general software PVsyst, for continuous adjustment, you can refer to the oblique single-axis tracking system model in PVsyst, and set the inclination angle of the oblique single-axis tracking system 4 times to simulate the adjustable scheme.

1) The model is shown in Figure 1 when the east-west inclination angle is 60°.

2) Modeling of components and inverters. The single crystal component model used is established by PVsyst, as shown in Figure 2. The inverter model is shown in Figure 3.

Through the simulation, it can be concluded that the power generation of the oblique single-axis tracking system with adjustable inclination angle is calculated according to the adjustment 4 times a year. When the inclination angle of the east-west direction is 60°, the power generation in January, February, November, and December is selected; When the east-west inclination angle is 15°, select the power generation in May, June, July, and August; when the east-west inclination is 38°, select the power generation in March and April; when the east-west inclination is 46 °, select the power generation in September and October[3].

In summary, it can be concluded that the overall power generation of the project in the first year and 25 years is shown in Table 3. It can be seen from Table 4 that the 100 MWp-scale photovoltaic power station has a power generation capacity of 192,673,300 kWh in the first year, a total power generation capacity of 432,897,700 kWh in 25 years, and an average power generation capacity of 17,315,91 million kWh in 25 years.

Concluding remarks

This article introduces the application of PVsyst software in the design of photovoltaic power plants with the help of specific projects, and analyzes in detail the inclination angle and power generation calculation method of the oblique single-axis tracking system, which can be used as a reference for the economic analysis of the later project.