Dam rear type photovoltaic power station of earth and rockfill dam

Abstract

The invention provides an earth and rockfill dam rear type photovoltaic power station which comprises a photovoltaic array, a combiner box, an inverter, a boosting transformer and a booster station and is provided with an intelligent cleaning and irrigation system with leakage water of an earth and rockfill dam as a water source. The earth and rockfill dam rear type photovoltaic power station is arranged by utilizing a water source, equipment facilities, roads, buildings and structures of an earth and rockfill dam and is synchronously operated and maintained with the earth and rockfill dam rear type photovoltaic power station; and the generated energy is firstly supplied to engineering production and living electricity of the earth and rockfill dam and the earth and rockfill dam rear type photovoltaic power station, and the redundant generated energy is supplied to a power grid. Land and water resources can be greatly saved, and construction and production management costs of civil engineering, equipment facilities and the like of a shared part are saved; the power generation benefit of a photovoltaic power station can be increased, safe and stable operation of a power grid is facilitated, and the method has wide guidance and popularization significance.

Description

Technical Field

[0001] The invention belongs to the technical field of earth-rock dams and photovoltaic power stations of hydropower or reservoirs, and specifically relates to a photovoltaic power station behind an earth-rock dam. Background Art

[0002] Earth-rock dams are widely used in hydropower or reservoir projects due to the convenience of local material collection and construction and low investment, accounting for more than 80% of the total dam construction. At present, tens of thousands of earth-rock dams with a height of more than 15m have been built in China, and the maximum dam height has reached 295m. Due to the lack of irrigation water and facilities, the downstream dam slope usually adopts large stones, concrete and other slope protection types, which cannot be organically integrated with the natural scenery. Photovoltaic power stations need to be sited separately, separately planned, surveyed and designed, land acquisition and resettlement, construction and operation and maintenance, and special buildings (structures), roads inside and outside the site, and transmission systems. In addition, dust often accumulates on the surface of photovoltaic modules, resulting in reduced power conversion efficiency and even hot spots that damage photovoltaic modules. Therefore, a large amount of water is needed for regular cleaning. At present, manual cleaning is usually used, and the cleaning quality and efficiency are low. At the same time, photovoltaic power generation is affected by the randomness and intermittent nature of solar energy and has a large volatility. There is a lack of local consumption channels. Direct grid connection not only affects the safe and stable operation of the power grid, but also generally occurs when the power grid cannot consume photovoltaic power stations. The phenomenon that photovoltaic power stations have to be shut down leads to a high unit kilowatt investment in power stations. Summary of the invention

[0003] In view of the defects of the prior art, the present invention provides a photovoltaic power station behind an earth-rock dam, which can effectively solve the above problems.

[0004] The technical solution adopted by the present invention is as follows:

[0005] The present invention provides a photovoltaic power station behind an earth-rock dam, the photovoltaic power station behind an earth-rock dam being located behind the earth-rock dam (6); the photovoltaic power station behind an earth-rock dam mainly comprises a photovoltaic array (1), a junction box (2), an inverter (3), a step-up transformer (4) and a step-up station (5), and is provided with an intelligent cleaning and irrigation system (7) using the seepage water of the earth-rock dam (6) as a water source;

[0006] The earth-rock dam (6) is a built, under construction or newly built building; the earth-rock dam back-type photovoltaic power station is planned, constructed and operated and maintained synchronously with the newly built earth-rock dam (6); the earth-rock dam back-type photovoltaic power station utilizes the water source, equipment facilities, roads, buildings and structures of the built and under construction earth-rock dam (6) and is operated and maintained synchronously with them;

[0007] The power generated by the photovoltaic power station behind the earth-rock dam is first supplied to the engineering production and living electricity of the earth-rock dam (6) and the photovoltaic power station behind the earth-rock dam, and the surplus power is then supplied to the power grid.

[0008] Preferably, the photovoltaic array (1) comprises N photovoltaic modules (1.1) and matching photovoltaic brackets (1.2); the photovoltaic array (1) is arranged on the downstream dam body (6.1) and the slag body (6.2) behind the dam of the earth-rock dam (6), and is located above the highest water level downstream;

[0009] The buried depth of the photovoltaic support (1.2) in the downstream dam body (6.1) and the slag pile body (6.2) behind the dam meets the stability requirements of the photovoltaic assembly (1.1) and is not less than 3m.

[0010] Preferably, the surface of the downstream dam body (6.1) and the slag pile body (6.2) behind the dam is paved with soil and slope protection lawns (8);

[0011] The soil protection and slope protection lawn (8) is densely planted with perennial short cold-season grass or warm-season grass or moss according to the temperature conditions of the project, and the soil layer thickness is not less than 30 cm.

[0012] Preferably, the intelligent cleaning and irrigation system (7) is used for cleaning the photovoltaic module (1.1) and irrigating the soil and slope protection lawn (8), and comprises a seepage water collection device (7.1), a water pump (7.2), a water diversion pipeline (7.3), an automatic sprinkler (7.4) and an intelligent cleaning and irrigation scheduling platform (7.5).

[0013] Preferably, the seepage water collection device (7.1) is arranged at the foot of the slope of the earth-rock dam (6); the water diversion pipeline (7.3) is arranged between the photovoltaic arrays (1); the automatic sprinklers (7.4) are installed at intervals on the water diversion pipeline (7.3), and the water spraying direction of the automatic sprinklers (7.4) is toward the photovoltaic module (1.1); the water inlet end of the water pump (7.2) is connected to the seepage water collection device (7.1); the water outlet end of the water pump (7.2) is connected to the water inlet end of the water diversion pipeline (7.3), and the water in the seepage water collection device (7.1) is pumped to the automatic sprinklers (7.4) through the water pump (7.2) and the water diversion pipeline (7.3), and sprayed to the photovoltaic module (1.1) for cleaning, and the soil protection and slope protection lawn (8) is irrigated.

[0014] Preferably, the automatic sprinkler (7.4) has the function of adjusting the water outlet pressure and the rotation angle, and multiple or all sprinklers can be opened and closed at the same time.

[0015] Preferably, the intelligent cleaning and irrigation scheduling platform (7.5) is connected to the water pump (7.2), the automatic sprinkler (7.4) and a plurality of intelligent sensors;

[0016] The intelligent cleaning and irrigation scheduling platform (7.5) automatically senses the water level of the leakage water collection device (7.1), the finish of the photovoltaic module (1.1) and the water content of the soil protection and slope protection lawn (8) through the intelligent sensor, automatically analyzes and starts and closes the water pump (7.2) and the automatic sprinkler (7.4), and automatically controls the water outlet pressure and rotation angle of the automatic sprinkler (7.4), thereby partially or all-round cleaning of the photovoltaic module (1.1) and irrigating the soil protection and slope protection lawn (8).

[0017] Preferably, the production room (9) required for the junction box (2), the inverter (3) and the step-up transformer (4) can be arranged in combination with an observation room on the downstream slope surface of the earth-rock dam (6).

[0018] Preferably, the booster station (5) utilizes an existing booster station or switch station around the earth-rock dam (6).

[0019] Preferably, the management room (10) required for the earth-rock dam back-type photovoltaic power station can be arranged in conjunction with the duty room of the earth-rock dam (6).

[0020] The earth-rock dam back-type photovoltaic power station provided by the present invention has the following advantages:

[0021] (1) Photovoltaic power stations make full use of the water sources, buildings (structures), roads, and transmission systems of existing and under-construction earth-rock dams for layout, or plan, construct, and operate and maintain them simultaneously with newly built earth-rock dams, and uniformly carry out various tasks such as research and data collection, survey and design, and project construction management; thus, the land occupation of photovoltaic power stations that are separately planned and sited can be effectively saved, as well as the costs of separate survey and design, land acquisition and resettlement, construction, and operation and maintenance;

[0022] (2) The present invention directly utilizes the seepage water of the dam nearby. On the one hand, the photovoltaic modules can be cleaned in time to improve their power conversion efficiency. At the same time, the formation of hot spots that damage the photovoltaic modules can be avoided, thereby increasing the service life of the photovoltaic modules. Since the seepage water of the dam is automatically used for cleaning nearby, the cleaning quality and efficiency are improved. On the other hand, since the seepage water of the dam can be directly utilized nearby for irrigation, a soil-retaining slope protection lawn can be laid on the dam surface for slope protection, without the need to use large stones, concrete and other slope protection types on the dam surface. Therefore, the present invention can make the earth-rock dam better integrated into nature.

[0023] (3) The earth-rock dam back-type photovoltaic power station constructed by the present invention can greatly save land and water resources, and save the construction and production management costs of the common parts such as civil engineering, equipment and facilities;

[0024] (4) In the present invention, the photovoltaic power generation of the photovoltaic power station behind the earth-rock dam is first used to supply electricity for the production and living of the project, and is consumed on site. The excess power generation is then supplied to the power grid, thereby solving the problems of the direct grid connection of the photovoltaic power station affecting the safe and stable operation of the power grid, and the photovoltaic power station having to shut down when the power grid cannot consume the power. The present invention not only greatly increases the power generation efficiency of the photovoltaic power station, but also is beneficial to the safe and stable operation of the power grid, and has broad guiding and promotion significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic plan view of a photovoltaic power station behind an earth-rock dam according to the present invention;

[0026] Figure 2 It is the A-A section of the plan schematic diagram of the earth-rock dam back-type photovoltaic power station of the present invention;

[0027] in:

[0028] 1- PV array; 2- combiner box; 3- inverter; 4- step-up transformer; 5- step-up station; 6- earth-rock dam; 7- intelligent cleaning and irrigation system; 8- soil and slope protection lawn; 9- production building; 10- management building;

[0029] 1.1-Photovoltaic module; 1.2-Photovoltaic bracket; 6.1-Downstream dam body; 6.2-Slag pile behind the dam; 7.1-Leakage water collection device; 7.2-Water pump; 7.3-Water diversion pipeline; 7.4-Automatic sprinkler; 7.5-Intelligent cleaning and irrigation scheduling platform. DETAILED DESCRIPTION

[0030] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0031] The purpose of the present invention is to provide a photovoltaic power station behind an earth-rock dam, which makes full use of the layout of the earth-rock dam's buildings (structures), roads inside and outside the site, and the delivery system, and takes into account auxiliary systems such as lightning protection, grounding, fire protection, and communication. The seepage water of the dam is used as water for cleaning photovoltaic components and irrigation water for lawns on the dam surface and other soil and slope protection. Through reconstruction or synchronous planning, construction, and operation and maintenance, the problems of land acquisition and resettlement, water sources, and construction management of photovoltaic power stations are solved, and the overall construction and production management costs are greatly reduced; the photovoltaic power generation is first used for the project itself, and the excess is supplied to the power grid, which can solve the technical problems of insufficient power grid absorption capacity and safe and stable operation, and increase power generation efficiency.

[0032] It should be noted that the earth-rock dam referred to in the present invention generally refers to a water retaining dam built by dumping, rolling, etc. with local soil, stone or mixed materials. When the dam body material is mainly soil and gravel, it is called an earth-rock dam; when it is mainly composed of slag, pebbles, and blasted stones, it is called a rockfill dam; when both types of local materials account for a considerable proportion, it is called an earth-rock mixed dam.

[0033] refer to Figure 1 and Figure 2 The earth-rock dam behind-the-dam photovoltaic power station provided by the present invention is located behind the earth-rock dam 6; the earth-rock dam behind-the-dam photovoltaic power station mainly includes a photovoltaic array 1, a junction box 2, an inverter 3, a booster transformer 4 and a booster station 5, and is provided with an intelligent cleaning and irrigation system 7 using the seepage water of the earth-rock dam 6 as a water source;

[0034] The earth-rock dam 6 is a built, under-construction or newly-built building; the earth-rock dam back-type photovoltaic power station is planned, constructed and operated and maintained synchronously with the newly-built earth-rock dam 6; the earth-rock dam back-type photovoltaic power station utilizes the water source, equipment facilities, roads, buildings and structures of the built and under-construction earth-rock dam 6, and is operated and maintained synchronously with them;

[0035] The power generated by the photovoltaic power station behind the earth-rock dam is first supplied to the engineering production and living electricity of the earth-rock dam 6 and the photovoltaic power station behind the earth-rock dam, such as the operation of production equipment and facilities of the earth-rock dam and the photovoltaic power station, and the living electricity of management personnel, and the excess power is then supplied to the power grid.

[0036] In the present invention, the production room 9 required for the combiner box 2, the inverter 3 and the step-up transformer 4 can be arranged in combination with the observation room on the downstream dam slope surface of the earth-rock dam 6. The booster station 5 utilizes the existing booster station or switch station around the earth-rock dam 6. The management room 10 for setting up the central control room and the like required for the earth-rock dam back-type photovoltaic power station can be arranged in combination with the duty room of the earth-rock dam 6.

[0037] In the present invention, the photovoltaic array 1 includes N photovoltaic modules 1.1 and matching photovoltaic brackets 1.2; the photovoltaic array 1 is arranged on the downstream dam body 6.1 and the slag body 6.2 behind the dam of the earth-rock dam 6, and is located above the highest water level downstream; the buried depth of the photovoltaic bracket 1.2 in the downstream dam body 6.1 and the slag body 6.2 behind the dam meets the stability requirements of the photovoltaic module 1.1 and is not less than 3m.

[0038] In the present invention, since the seepage water of the earth-rock dam 6 can be used for irrigation, the surface of the downstream dam body 6.1 and the slag body 6.2 behind the dam is paved with soil-retaining and slope-protecting lawns 8; in addition, in order to ensure the utilization efficiency of the photovoltaic array 1 and avoid the adverse effects of the vegetation of the soil-retaining and slope-protecting lawns 8 on the photovoltaic array 1, the soil-retaining and slope-protecting lawns 8 are densely planted with perennial short cold-season grasses or warm-season grasses or mosses according to the temperature conditions of the project, and the soil layer thickness is not less than 30 cm.

[0039] In the present invention, the intelligent cleaning and irrigation system 7 is used for cleaning the photovoltaic module 1.1 and irrigating the soil and slope protection lawn 8, and includes a leakage water collection device 7.1, a water pump 7.2, a water diversion pipeline 7.3, an automatic sprinkler 7.4 and an intelligent cleaning and irrigation scheduling platform 7.5. The leakage water collection device 7.1, the water pump 7.2, the water diversion pipeline 7.3, and the automatic sprinkler 7.4 are connected in sequence.

[0040] Wherein: the seepage water collection device 7.1 is arranged at the foot of the slope of the earth-rock dam 6, and is used to collect the seepage water of the dam; the water diversion pipeline 7.3 is arranged between the photovoltaic arrays 1; automatic sprinklers 7.4 are installed at intervals on the water diversion pipeline 7.3, and the water spraying direction of the automatic sprinklers 7.4 is toward the photovoltaic module 1.1; the water inlet end of the water pump 7.2 is connected with the seepage water collection device 7.1; the water outlet end of the water pump 7.2 is connected with the water inlet end of the water diversion pipeline 7.3, and the water in the seepage water collection device 7.1 is pumped to the automatic sprinklers 7.4 through the water pump 7.2 and the water diversion pipeline 7.3, and sprayed to the photovoltaic module 1.1 for cleaning, and the soil protection and slope protection lawn 8 is irrigated.

[0041] Among them: the automatic sprinkler 7.4 has the function of adjusting the water outlet pressure and the rotation angle, and multiple or all sprinklers can be opened and closed at the same time.

[0042] The intelligent cleaning and irrigation scheduling platform 7.5 is connected to the water pump 7.2, the automatic sprinkler 7.4 and a plurality of intelligent sensors; the intelligent cleaning and irrigation scheduling platform 7.5 automatically senses the water level of the leakage water collection device 7.1, the smoothness of the photovoltaic module 1.1 and the moisture content of the soil-retaining and slope-protecting lawn 8 through the intelligent sensors, automatically analyzes and starts and closes the water pump 7.2 and the automatic sprinkler 7.4, and automatically controls the water outlet pressure and rotation angle of the automatic sprinkler 7.4, thereby partially or comprehensively cleaning the photovoltaic module 1.1 and irrigating the soil-retaining and slope-protecting lawn 8.

[0043] It can be seen that the present invention combines the arrangement of the soil and slope protection lawn 8 and the photovoltaic array 1 on the downstream dam body 6.1 and the slag pile body 6.2 behind the dam of the earth-rock dam 6, which can bring the following advantages:

[0044] (1) To fully utilize the land resources of the downstream dam body 6.1 and the slag pile body 6.2 behind the dam 6, and solve the problem of occupying land resources when the photovoltaic array 1 is set up alone;

[0045] (2) Through the intelligent cleaning and irrigation system 7, the leakage water of the dam is used nearby to clean the photovoltaic module 1.1 and irrigate the soil and slope protection lawn 8 at the same time. In particular, the water flow after the photovoltaic module 1.1 is cleaned is used to irrigate the soil and slope protection lawn 8, so as to realize the secondary effective utilization of the water flow and save water resources;

[0046] (3) The downstream dam body 6.1 and the slag pile body 6.2 behind the dam are enhanced in stability by laying soil and slope protection lawns 8 and inserting photovoltaic brackets 1.2, thereby also improving the stability of the installation of photovoltaic modules 1.1.

[0047] The following is a photovoltaic power station project using the technical solution of the present invention as an example and further explained in conjunction with the accompanying drawings:

[0048] In this embodiment, the earth-rock dam 6 is a rockfill dam.

[0049] A photovoltaic power station with a peak capacity of 3MW is located behind the rockfill dam of the upper reservoir of a pumped storage power station and adopts the earth-rock dam behind-dam photovoltaic power station of the present invention.

[0050] like Figure 1 and Figure 2 As shown, the earth-rock dam back-type photovoltaic power station is mainly composed of photovoltaic array 1, junction box 2, inverter 3, booster transformer 4 and booster station 5. The equipment and facilities of the newly built rockfill dam, the roads inside and outside the site and the buildings (structures) are arranged. The production room 9 required by the photovoltaic power station is arranged in combination with the observation room on the surface of the downstream dam slope of the rockfill dam. The booster station 5 uses the existing 110kV booster station of the rockfill dam project. The central control room and other management rooms 10 of the photovoltaic power station are arranged in combination with the duty room of the rockfill dam. The auxiliary systems such as lightning protection, grounding, fire protection, and communication are comprehensively considered, and planning, construction, operation and maintenance are carried out simultaneously. The power generation of the photovoltaic power station is first used for the production and living electricity of the project, and the excess power generation is then supplied to the power grid.

[0051] The surface of the downstream dam body 6.1 and the slag pile body 6.2 behind the rockfill dam uses a 30cm thick soil and slope protection lawn 8 to replace the original 60cm thick dry stone masonry. According to the temperature conditions of the project, perennial short cold-season grass is densely planted to avoid blocking the photovoltaic modules 1.1. The photovoltaic array 1 consists of 9524 monocrystalline silicon photovoltaic modules 1.1 with a single chip power of 315W and their matching photovoltaic brackets 1.2. The photovoltaic brackets 1.2 are arranged on the downstream dam body 6.1 and the slag pile body 6.2 behind the rockfill dam. They use hot-dip galvanized steel brackets with a row spacing of 1.5m and a spacing of 3.5m along the dam axis. The photovoltaic brackets 1.2 penetrate 4m below the soil and slope protection lawn 8 to meet the stability requirements of the photovoltaic modules 1.1.

[0052] The photovoltaic power station is also equipped with an intelligent cleaning and irrigation system 7, which is composed of a seepage water collection device 7.1, a water pump 7.2, a water diversion pipeline 7.3, and an automatic sprinkler 7.4 connected in sequence, and controlled by an intelligent cleaning and irrigation scheduling platform 7.5. The seepage water collection device 7.1 adopts a water collection pit, which is set at the foot of the slope of the slag body 6.2 behind the rockfill dam; the water pump 7.2 has a head of 100m, and pumps the seepage water in the water collection pit into the water diversion pipeline 7.3; the diameter of the water diversion pipeline 7.3 is DN200mm, and it is continuously arranged in the center of the front and rear rows of the photovoltaic modules 1.1 along the axis of the dam; automatic sprinklers 7.4 are arranged at intervals on the water diversion pipeline 7.3, and the top of the automatic sprinkler is slightly higher than the photovoltaic module 1.1; the intelligent cleaning and irrigation scheduling platform 7.5 is installed in the management room 10, and can automatically sense the water level of the leakage water collection device 7.1, the smoothness of the photovoltaic module 1.1 and the moisture content of the soil conservation and slope protection lawn 8 through the installed intelligent sensor, automatically analyze and start and close the water pump 7.2, automatically control the simultaneous start and close of multiple or all automatic sprinklers 7.4, and can timely adjust the water outlet pressure and rotation angle of the automatic sprinkler 7.4, and can partially or all-round clean the photovoltaic module 1.1 and irrigate the soil conservation and slope protection lawn 8.

[0053] By adopting the above technical solution disclosed in the present invention, the following beneficial effects are obtained:

[0054] (1) Photovoltaic power stations make full use of the water sources, buildings (structures), roads, and transmission systems of existing and under-construction earth-rock dams for layout, or plan, construct, and operate and maintain them simultaneously with newly built earth-rock dams, and uniformly carry out various tasks such as research and data collection, survey and design, and project construction management; thus, the land occupation of photovoltaic power stations that are separately planned and sited can be effectively saved, as well as the costs of separate survey and design, land acquisition and resettlement, construction, and operation and maintenance;

[0055] (2) The present invention directly utilizes the seepage water of the dam nearby. On the one hand, the photovoltaic modules can be cleaned in time to improve their power conversion efficiency. At the same time, the formation of hot spots that damage the photovoltaic modules can be avoided, thereby increasing the service life of the photovoltaic modules. Since the seepage water of the dam is automatically used for cleaning nearby, the cleaning quality and efficiency are improved. On the other hand, since the seepage water of the dam can be directly utilized nearby for irrigation, a soil-retaining slope protection lawn can be laid on the dam surface for slope protection, without the need to use large stones, concrete and other slope protection types on the dam surface. Therefore, the present invention can make the earth-rock dam better integrated into nature.

[0056] (3) The earth-rock dam back-type photovoltaic power station constructed by the present invention can greatly save land and water resources, and save the construction and production management costs of the common parts such as civil engineering, equipment and facilities;

[0057] (4) In the present invention, the photovoltaic power generation of the photovoltaic power station behind the earth-rock dam is first used to supply electricity for the production and living of the project, and is consumed on site. The excess power generation is then supplied to the power grid, thereby solving the problems of the direct grid connection of the photovoltaic power station affecting the safe and stable operation of the power grid, and the photovoltaic power station having to shut down when the power grid cannot consume the power. The present invention not only greatly increases the power generation efficiency of the photovoltaic power station, but also is beneficial to the safe and stable operation of the power grid, and has broad guiding and promotion significance.

[0058] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be considered as the scope of protection of the present invention.

Claims

1. Earth-rock dam back-type photovoltaic power station, characterized in that: The earth-rock dam back-type photovoltaic power station is located behind the earth-rock dam (6); the earth-rock dam back-type photovoltaic power station mainly comprises a photovoltaic array (1), a junction box (2), an inverter (3), a step-up transformer (4) and a step-up station (5), and is provided with an intelligent cleaning and irrigation system (7) using the seepage water of the earth-rock dam (6) as a water source; The earth-rock dam (6) is a built, under construction or newly built building; the earth-rock dam back-type photovoltaic power station is planned, constructed and operated and maintained synchronously with the newly built earth-rock dam (6); the earth-rock dam back-type photovoltaic power station utilizes the water source, equipment facilities, roads, buildings and structures of the built and under construction earth-rock dam (6) and is operated and maintained synchronously with them; The power generated by the photovoltaic power station behind the earth-rock dam is first supplied to the engineering production and living electricity of the earth-rock dam (6) and the photovoltaic power station behind the earth-rock dam, and the surplus power is then supplied to the power grid.

2. The earth-rock dam back-type photovoltaic power station according to claim 1, characterized in that: The photovoltaic array (1) comprises N photovoltaic modules (1.1) and matching photovoltaic brackets (1.2); the photovoltaic array (1) is arranged on the downstream dam body (6.1) and the slag body (6.2) behind the dam of the earth-rock dam (6), and is located above the highest water level downstream; The buried depth of the photovoltaic support (1.2) in the downstream dam body (6.1) and the slag pile body (6.2) behind the dam meets the stability requirements of the photovoltaic assembly (1.1) and is not less than 3m.

3. The earth-rock dam back-type photovoltaic power station according to claim 2, characterized in that: The surface layers of the downstream dam body (6.1) and the slag pile body (6.2) behind the dam are paved with soil and slope protection lawns (8); The soil protection and slope protection lawn (8) is densely planted with perennial short cold-season grass or warm-season grass or moss according to the temperature conditions of the project, and the soil layer thickness is not less than 30 cm.

4. The earth-rock dam back-type photovoltaic power station according to claim 3, characterized in that: The intelligent cleaning and irrigation system (7) is used for cleaning the photovoltaic module (1.1) and irrigating the soil and slope protection lawn (8), and comprises a seepage water collection device (7.1), a water pump (7.2), a water diversion pipeline (7.3), an automatic sprinkler (7.4) and an intelligent cleaning and irrigation scheduling platform (7.5).

5. The earth-rock dam back-type photovoltaic power station according to claim 4, characterized in that: The seepage water collection device (7.1) is arranged at the foot of the slope of the earth-rock dam (6); the water diversion pipeline (7.3) is arranged between the photovoltaic arrays (1); the automatic sprinklers (7.4) are installed at intervals on the water diversion pipeline (7.3), and the water spraying direction of the automatic sprinklers (7.4) is toward the photovoltaic module (1.1); the water inlet end of the water pump (7.2) is connected to the seepage water collection device (7.1); the water outlet end of the water pump (7.2) is connected to the water inlet end of the water diversion pipeline (7.3), and the water in the seepage water collection device (7.1) is pumped to the automatic sprinklers (7.4) through the water pump (7.2) and the water diversion pipeline (7.3), and sprayed to the photovoltaic module (1.1) for cleaning, and the soil protection and slope protection lawn (8) is irrigated.

6. The earth-rock dam back-type photovoltaic power station according to claim 5, characterized in that: The automatic sprinkler heads (7.4) have the function of adjusting the water outlet pressure and the rotation angle, and multiple or all sprinkler heads can be opened and closed at the same time.

7. The earth-rock dam back-type photovoltaic power station according to claim 5, characterized in that: The intelligent cleaning and irrigation scheduling platform (7.5) is connected to the water pump (7.2), the automatic sprinkler (7.4) and a plurality of intelligent sensors; The intelligent cleaning and irrigation scheduling platform (7.5) automatically senses the water level of the leakage water collection device (7.1), the finish of the photovoltaic module (1.1) and the water content of the soil protection and slope protection lawn (8) through the intelligent sensor, automatically analyzes and starts and closes the water pump (7.2) and the automatic sprinkler (7.4), and automatically controls the water outlet pressure and rotation angle of the automatic sprinkler (7.4), thereby partially or all-round cleaning of the photovoltaic module (1.1) and irrigating the soil protection and slope protection lawn (8).

8. The earth-rock dam back-type photovoltaic power station according to claim 1, characterized in that: The production room (9) required for the junction box (2), the inverter (3) and the step-up transformer (4) can be arranged in combination with an observation room on the downstream slope surface of the earth-rock dam (6).

9. The earth-rock dam back-type photovoltaic power station according to claim 1, characterized in that: The booster station (5) utilizes the existing booster station or switch station around the earth-rock dam (6).

10. The earth-rock dam back-type photovoltaic power station according to claim 1, characterized in that: The management room (10) required for the earth-rock dam back-type photovoltaic power station can be arranged in conjunction with the duty room of the earth-rock dam (6).

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