Application of photovoltaic pumping inverter system in desert control and highway pumping drip irrigation project

Most of the northern regions of China are in desertification zones. Severe desertification not only affects the operational stability and normal service life of transportation routes, but also seriously affects the environment of surrounding areas, especially Beijing. We hope that our company can help local governments carry out anti-sand forest work, effectively improve the operating environment of economic lifelines such as transportation routes in desert areas, and build anti-sand forests to create a " green barrier" for economic activities, production and life in Beijing and northern regions.

In order to prevent the erosion of the road by wind and sand, grass grids were used throughout the desert highway to protect the normal passage of the desert highway in the early stage of its construction. This road protection project is time-consuming, labor-intensive, costly and has a short service life. Therefore, establishing permanent green shelter forests along the desert highway has become the best choice for preventing and controlling sand on the desert highway.

Shenzhen Tianyuan New Energy Co., Ltd. is a professional manufacturer in the field of " photovoltaic water pump dedicated inverter " and " photovoltaic pumping system integrated application " technology. After the system operation test under different climates in the north and south of China, the independent photovoltaic pumping system can meet the planting requirements of desert highway sand-proof forests without causing any pollution to the environment. Shenzhen Tianyuan New Energy Co., Ltd. has a full range of business activities including R&D, manufacturing, sales and service. Dr. Xu Zheng, the company's technical leader, helped the local government build the Xinjiang Had area highway sand-proof forest photovoltaic pumping irrigation system project as early as 2001. The system has been running so far and is in good condition.

This series of products was invited to participate in the Technology Achievement Exhibition of the Ministry of Science and Technology at the 10th China International High-Tech Achievements Fair held in Shenzhen in October 2008 , and achieved complete success. During the High-Tech Fair, Tianyuan New Energy Company and its products received attention from local government agencies at all levels and domestic and foreign manufacturers, who were very optimistic about the company's mature technology and huge industrialization prospects. Tianyuan New Energy also won the "Innovative Enterprise Award" and "Excellent Project Award for Achievement Transformation" awarded by the High-Tech Fair Organizing Committee.

2. System Introduction:

Shenzhen Tianyuan New Energy Co., Ltd.'s " photovoltaic pumping system" consists of a solar cell array, a photovoltaic pumping inverter and a water pump, which is simple and easy to use. In order to reduce construction and operation costs, reduce operation and maintenance work, and improve system reliability, the system abandons the batteries that must be used in conventional photovoltaic systems but cause serious environmental pollution, and does not use power storage equipment, which reduces the initial construction cost and later maintenance cost, and reaches the standard of zero environmental pollution.

Independent solar pumping systems have broad application prospects for solving ecological problems such as drinking water for people and livestock in remote areas, and irrigation of agriculture and shelterbelts. For water pumps driven by AC motors, an inverter controller is required to convert the DC power output by the solar cell array into the three-phase AC power required to drive the motor; the dynamic maximum power point tracking function is used to adjust the output frequency in real time according to the light intensity to ensure the maximum power output of the system. It has the advantages of simple structure, high reliability, good dynamic characteristics, and low cost.

This project combines the research of solar water-pumping drip irrigation test system for anti-sand forest on desert highway in Had area of ​​Xinjiang. The operation results after eight years show that the system has good dynamic response characteristics and maximum power point tracking effect; the special inverter for water pumping has excellent technical indicators, stable performance and high reliability. So far, there are no similar products at home and abroad, and the product technology is in the world's leading position.

System composition

1. Photovoltaic array It is composed of multiple photovoltaic modules connected in series and parallel, which absorbs solar radiation energy and converts it into electrical energy to provide power for the entire system.

2. Control inverter 'Pumping special inverter' controls and regulates the operation of the system, converts the DC power from the solar array into AC power, drives the water pump, and adjusts the output frequency in real time according to the change of sunshine intensity to achieve maximum power point tracking. This special inverter has excellent technical indicators, stable performance and high reliability. All technologies are independently developed by the company and can fully meet the power supply requirements of asynchronous AC motor water pumps of different powers in the market.

3. Water Pumps The water pumps are driven by three-phase AC motors to draw water from deep wells or rivers, lakes and other water sources, and inject it into water storage tanks / pools, or directly connect to irrigation systems and fountain systems. Depending on the actual system requirements and installation conditions, different types of water pumps, such as centrifugal pumps, axial flow pumps, mixed flow pumps or deep well pumps can be used.

III. Overview of Target Project

Aiming at lawn planting, highway sand control forest maintenance, desert control and other purposes, this paper analyzes the real case data of solar water pumping drip irrigation system in the desert sand control forest of the Hade area of ​​Xinjiang in 2001. And its operation and successful application effect in the ecological project of Taklimakan Desert Highway in Xinjiang over the years, gives the test curves of solar energy intensity and daily water pumping time and inverter frequency and flow, and several pictures of desert ecological infiltration irrigation planting, and makes a brief economic analysis of solar water pumping.

1. Design and construction of solar pumping station

In order to solve the water problem in desert shelterbelt planting, we designed a solar pumping system with a single unit capacity of 15KW .

The main technical parameters of PS15000 photovoltaic water pump system are as follows:

The highway anti -sand forest water pumping system and drip irrigation system have been operating normally for 8 years. The station was completed in September 2001. The construction site is located at the northern end of the desert highway. 116 km The still water level of the well at the intersection of Hade Highway 24 meters , dune height 45 meters , water mineralization 28 mg / L.

2. Test curve

Relationship between time intensity and flow rate ( September 28 , 2002 ​ ​ , temperature 2 8 ℃ ）

410 509 674 754 799 752 616 461 30 square array plane light intensity ( w/m2 )

680 725 782 808 801 781 721 659 620 Direct light intensity ( w/m2 )

Time intensity and flow rate diagram

3. Relationship between time and water output

Time and water output diagram

4. Relationship between frequency and time of pumping inverter

Frequency and time of special inverter for pumping

5. Planting Effect

Based on the natural environment along the Tarim Desert Highway , the selection of plant species should pay special attention to the characteristics of plant salt tolerance, drought tolerance, cold tolerance, high temperature tolerance, wind erosion and sand burial resistance, etc. According to the previous research results and the successful experience of the existing projects, three excellent sand-fixing shrub species, Calligonum mongolicum, Tamarix chinensis and Haloxylon ammodendron, are selected as plant species. However, when selecting species of Tamarix, special attention should be paid to the differences in salt tolerance and soil adaptability of different species. Fast-growing Tamarix species with many branches and flowers are selected on tall sand dunes, and Tamarix species with strong salt tolerance, such as Steel Hair and Short Hair, are selected in areas with high soil salt content and high groundwater mineralization.

Comparison of the final effects of grass grid and photovoltaic pumping system

Grass grid Vegetation

Final effect comparison chart

6. Comparison of irrigation modes

Irrigation mode is divided into flood irrigation, usually land 400m ³ / acre, the desert is definitely not suitable for flood irrigation, and there is no data on water consumption per acre. 120m3 / mu, infiltration irrigation 80 m3 / mu, and the irrigation cycle is 5-7 days. Infiltration irrigation has low evaporation, and not only does it synchronize water supply with crop root development, it also saves 1/3 of water compared to drip irrigation . The system pipes are not easily aged, fissioned, or damaged by humans or other rodents. The service life is three times that of the drip irrigation system, and the surface does not form crusts. The comprehensive indicators are higher than those of the drip irrigation system. (Figure 13 )

Drip irrigation and infiltration irrigation comparison chart

VII. Economic Analysis

According to the statistics of the first four years of operation, if the equipment depreciation period is set at 20 years, the water consumption of the desert forest belt will be about 50 yuan per mu, or about 0.4 yuan per square meter, per year, calculated at cost price.

Everyone knows that the roots of desert plants often coexist with a fungus with great medicinal value, such as Cistanche deserticola. If the construction of sand-proof forests is combined with the cultivation of medicinal materials, it will produce good economic benefits and be very beneficial to the sustainable development of shelterbelt construction.

Cistanche deserticola growing in the desert

8. Brief Conclusion

Over the years, the solar pumping station has been running well, with high stability and reliability, and no failures. The growth of crops also fully proves that the solar pumping station is running very well. Solar pumping planting is very successful and has great promotion and application value. It can completely replace traditional fuel pumps, reduce fuel and professional maintenance personnel costs, and achieve zero environmental pollution.