A water hammer protection method and device based on a wind, solar, water and storage multi-energy complementary system

Abstract

The present invention relates to the technical field of safe and energy-saving power generation, and discloses a water hammer protection method based on a wind, solar, water and storage multi-energy complementary system, comprising the following steps: real-time monitoring of the light intensity and wind speed of the wind, solar, water and storage multi-energy complementary system; real-time monitoring of the pressure, flow, air, equipment operating status and working status during the operation of the system; through meteorological models, hydraulic models, and real-time monitoring data, forming a water hammer protection control strategy for the entire system operation process, which is used to predict scenarios such as when wind power and photovoltaic power cannot generate electricity, normal scheduling and sudden power outages, and when pipe bursts occur. The control strategy includes early warning regulation, distributed control and pump and valve joint regulation and control, and pipe burst emergency management. The present invention can perform water hammer protection on the entire process and multiple scenarios of the wind, solar, water and storage multi-energy complementary system, thereby improving system stability.

Description

Technical Field

[0001] The present invention relates to the field of energy-saving power generation technology, and in particular to a water hammer protection method and device based on a wind, solar, and water storage multi-energy complementary system. Background Art

[0002] The wind, solar, and hydropower multi-energy complementary system is a system that integrates wind power stations, photovoltaic power stations, pumped storage power stations, and power station control equipment. The wind power stations, photovoltaic power stations, and pumped storage power stations are interconnected through power lines and controlled by power station control equipment. The system connects wind power, photovoltaic power stations, and hydropower to the power grid. Hydropower units and pump units are set up in pumped storage power stations to absorb the excess output of the wind, solar, and hydropower multi-energy system while ensuring the output of the wind, solar, and hydropower multi-energy system, thereby avoiding the waste of resources of the wind, solar, and hydropower complementary system as much as possible. For example, the Chinese patent application with publication number CN113890108A discloses a wind, solar, and hydropower multi-energy complementary system. The electricity generated by wind power and photovoltaic power generation is used for water pumping, and the water after hydropower generation is pumped back to the reservoir for storage to supplement the power shortage during peak periods.

[0003] However, since wind power and photovoltaic power generation are greatly affected by sunlight, if the weather suddenly turns cloudy and there is insufficient sunlight, or the wind speed suddenly decreases, the photovoltaic and wind power will attenuate. When the water pump units work at the same time, the power system trough will be lowered, and the water pump will suddenly stop or the water volume will suddenly change. This change will cause water hammer in the pipeline.

[0004] Currently, water hammer protection primarily addresses water hammer in pipelines caused by sudden power outages. There are no effective protection methods for water hammer caused by insufficient power output from pump units. For example, there are two methods for preventing pressure drop during hydraulic transients: injecting water into the pipeline, and injecting air into the pipeline. Water hammer protection for injecting water primarily involves surge tanks and air tanks; air valves primarily address water hammer for injecting air. Surge tanks and air tanks are expensive and difficult to operate and manage. Air valves can only inject air when the pressure in the pipeline is below atmospheric pressure, limiting their effectiveness in preventing water hammer.

[0005] Prior art CN2016110356651 discloses a device for water hammer protection of a long-distance pump water supply system, specifically disclosing:

[0006] There is a local high point in the water supply pipeline. A water hammer protection device is connected to the local high point through an inspection valve. The water hammer protection device includes a compressed air tank, a pressure reducing valve, an air valve, a gas supply pipeline, and a solenoid valve. The water hammer protection device is provided with a ventilation channel connected to the compressed air tank. The ventilation channel is connected in sequence by the pressure reducing valve, the gas supply pipeline, and the solenoid valve A, and is connected to the air valve through the solenoid valve B.

[0007] Although the prior art discloses a device for protecting water hammer in a water supply system, the following problems still exist:

[0008] The structure is simple, and in particular, automatic detection and control of water hammer protection cannot be achieved. Summary of the Invention

[0009] The technical problem solved by the present invention is to overcome the defects of the existing technology and provide a water hammer protection method based on a wind, solar, and water storage multi-energy complementary system that can automatically detect and protect against water hammer effects. It is used to meet the water hammer protection needs of various scenarios, such as when there is insufficient power but no power outage, and when a power outage occurs.

[0010] The purpose of the present invention is achieved through the following technical solutions:

[0011] S1. Real-time monitoring of the working status of the wind, solar, hydropower and storage multi-energy complementary system, wherein the working status includes the following variables: wind conditions, solar conditions, wind and solar power station operating conditions, water conditions, and hydropower station operating conditions;

[0012] S2. Establish a real-time simulation and early warning model for wind power generation, photovoltaic power generation and water pump operation; the model inputs the real-time wind speed to calculate the wind turbine output according to formula (1-1), and the input light intensity to calculate the photovoltaic output according to formula (1-2). The wind turbine output and photovoltaic output are transmitted to the water pump through the power system as the power supply load of the water pump unit. Since the distance between the wind turbine, photovoltaic panel and water pump unit is relatively close, the network loss of the power system can be ignored.

[0013]

[0014] Among them, p w is the output power of the wind turbine, v is the wind speed, ρ is the air density, R is the radius of the wind turbine impeller, C p is the wind energy utilization coefficient of the wind turbine (maximum 0.593). Furthermore, when the wind speed is less than the minimum operating wind speed and greater than the maximum operating wind speed, the wind turbine shuts down and the output power is 0. When the calculated wind turbine output power exceeds the rated power of the wind turbine, the rated power is used for output.

[0015] P v =I(G,T)·U(G,T) (1-2)

[0016] Among them, P v is the photovoltaic output, G is the light intensity, and T is the temperature.

[0017] I(G,T)=I ref +ΔI(G,T) (1-3)

[0018]

[0019]

[0020] Among them, I ref The two voltages of the photovoltaic array are reference voltage U ref The corresponding output current when SC is the short-circuit current of the photovoltaic array under reference conditions. is the temperature coefficient of current and voltage change under reference light intensity. S is the series resistance of the photovoltaic array. c is the temperature coefficient of the solar cell module. ref , G ref are the temperature and light intensity under the reference conditions, respectively. The reference conditions are (T ref =25°, G ref =1kW·m -2 ).

[0021] S3. Establish a water hammer protection strategy that will cause the wind, solar, hydro and storage multi-energy complementary system to experience power shortage and power outage under meteorological conditions;

[0022] S4. When it is monitored that the wind, solar, water and storage multi-energy complementary system cannot supply normal water to the water pump unit, select the corresponding water hammer protection method to perform water hammer protection on the wind, solar, water and storage multi-energy complementary system.

[0023] Furthermore, the wind, solar, and water storage multi-energy complementary system is provided with a hydraulically controlled ball valve, an air valve and / or an air tank, a water hammer prevention valve, and an emergency shut-off valve. The control strategy is to reduce the number of water pump startups, the opening of the hydraulically controlled ball valve, the action time of the hydraulically controlled ball valve, the use of air valves and air tanks, the use of water hammer prevention valves, and the use of one or several combinations of emergency shut-off valves.

[0024] Furthermore, the sudden abnormalities include: insufficient light and wind speed, the generated power generation is insufficient to meet the normal pumping operation of all water pumps; insufficient light and wind speed, the generated power generation cannot meet the operation of any water pump; photovoltaic, wind power or other lines fail, sudden power outage occurs and water cannot be pumped; sudden pipe burst.

[0025] Furthermore, the water hammer protection method is as follows: when the power generation of wind power and photovoltaic power generation cannot meet the minimum power for the operation of all water pumps, according to the power output power: when the wind power and photovoltaic power generation can meet the normal scheduling of at least one water pump operation, the preset control strategies such as the number of running water pump units, the opening degree and action time of the hydraulic control ball valve are triggered to perform transient process control of water hammer protection; when the wind power and photovoltaic power generation cannot meet the operation of any water pump, the control strategies such as the pump stop and the closing action time of the hydraulic control ball valve are triggered to perform water hammer early warning regulation.

[0026] Furthermore, when the wind, solar, and water storage multi-energy complementary system suddenly loses power, the turbulence and vibration caused by water hammer and pipeline backflow are prevented by controlling the fast closing and slow closing times of the hydraulically controlled ball valve.

[0027] Furthermore, the water hammer protection method further includes: automatically supplying and exhausting air through an air valve and an air tank.

[0028] Furthermore, the water hammer protection method also includes adjusting through the water hammer prevention valve, automatically opening the water discharge when the water pressure drops to the low pressure setting threshold; and continuing to discharge water when the water pressure rises to the high pressure setting threshold.

[0029] Furthermore, the water hammer protection method also includes a pipe burst protection strategy in which, when a pipe burst occurs, a pipe burst emergency shut-off valve is controlled by a transient hydraulic model to automatically cut off the upstream water flow to prevent secondary disasters.

[0030] A water hammer protection device based on a wind, solar, water and storage multi-energy complementary system includes a regulating valve arranged on the wind, solar, water and storage multi-energy complementary system, a detection device for detecting weather data at the location of the wind, solar, water and storage multi-energy complementary system, a processor of the communication connection detection device, and a transient hydraulic model arranged in the processor. The processor is communicated with the regulating valve and performs actions according to processor signals.

[0031] Furthermore, the processor includes a control module capable of presetting the opening and closing time of the regulating valve, and the control module is in communication with the regulating valve.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] In this application, by detecting weather changes such as wind speed and light, the impact of weather changes on the power generation of the wind, solar, and hydropower storage multi-energy complementary system can be judged. When the power generation of the photovoltaic plant or wind power plant is about to drop sharply, appropriate protection measures can be taken to prevent water hammer from occurring in the system.

[0034] The present invention incorporates multiple protection strategies, including pump and valve coordinated control, hydraulic ball valve opening and closing timing, air pressure control, and water pressure control. When the system encounters power shortages and sudden power outages, it provides comprehensive water hammer protection, maximizing system stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The figure is a flow chart of a water hammer protection method based on a wind, solar, and hydropower storage multi-energy complementary system;

[0036] Figure 2 This is a schematic diagram of the protection strategy principle of a water hammer protection method based on a wind, solar, and hydropower storage multi-energy complementary system;

[0037] Figure 3This is a structural schematic diagram of a water hammer protection device based on a wind, solar, and water storage multi-energy complementary system. DETAILED DESCRIPTION

[0038] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0039] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0040] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features specified as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that ordinary technicians in this field can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0041] Example 1

[0042] like Figure 1 As shown, a water hammer protection method based on a wind, solar, and water storage multi-energy complementary system is provided, comprising the following steps:

[0043] S1. Real-time monitoring of meteorological information at the wind, solar, hydropower and storage multi-energy complementary system operation site, including wind and light conditions monitoring, wind and solar power station operation monitoring, water conditions monitoring, and hydropower station operation monitoring, such as monitoring the following parameters: light intensity, wind speed parameters, water pressure, flow, equipment health status and working status during system operation.

[0044] S2. Establish a real-time simulation and early warning model for wind power generation, photovoltaic power generation, and water pump operation, feeding the information collected in S1 into the real-time simulation and early warning model in real time. The real-time simulation and early warning model uses real-time wind speed and light intensity as input to simulate the wind power and photovoltaic power generation process and the pumping process of the pump station in real time. Based on predictions of future wind speed and light intensity, it also provides real-time predictions and early warnings for the future operating status of the wind, solar, hydro, and storage multi-energy complementary system. When the wind, solar, hydro, and storage multi-energy complementary system output is insufficient and falls below the minimum load required for pump station operation, a real-time early warning is issued. If the warning is not responded to in a timely manner within the emergency action time, the water hammer protection measures of the water pump unit are triggered.

[0045] The model inputs real-time wind speed to calculate the wind turbine output according to formula (1-1), and inputs light intensity to calculate photovoltaic output according to formula (1-2). The wind turbine output and photovoltaic output are transmitted to the water pump through the power system as the power supply load of the water pump unit. Since the distance between the wind turbine, photovoltaic panel and water pump unit is relatively close, the network loss of the power system can be ignored.

[0046]

[0047] Among them, p w is the output power of the wind turbine, v is the wind speed, ρ is the air density, R is the radius of the wind turbine impeller, C p is the wind energy utilization coefficient of the wind turbine (maximum 0.593). Furthermore, when the wind speed is less than the minimum operating wind speed and greater than the maximum operating wind speed, the wind turbine shuts down and the output power is 0. When the calculated wind turbine output power exceeds the rated power of the wind turbine, the rated power is used for output.

[0048] P v =I(G,T)·U(G,T) (1-2)

[0049] Among them, P v is the photovoltaic output, G is the light intensity, and T is the temperature.

[0050] I(G,T)=I ref +ΔI(G,T) (1-3)

[0051]

[0052]

[0053] Among them, I ref The two voltages of the photovoltaic array are reference voltage U ref The corresponding output current when SC is the short-circuit current of the photovoltaic array under reference conditions. is the temperature coefficient of current and voltage change under reference light intensity.S is the series resistance of the photovoltaic array. c is the temperature coefficient of the solar cell module. ref , G ref are the temperature and light intensity under the reference conditions, respectively. The reference conditions are (T ref =25°, G ref =1kW·m -2 ).

[0054] S3. Establish a water hammer protection strategy for the wind, solar, hydropower and storage multi-energy system, assuming meteorological conditions result in power shortages and power outages. After the real-time simulation warning model activates, the transient hydraulic model is driven by the real-time simulation model's input, based on the future load process of the pumps. This model then calculates changes in flow rate and transient pressure, determines system operation, and develops a corresponding control strategy.

[0055] During the operation of a wind-solar-water storage system, the following anomalies may occur: insufficient sunlight or wind speed, resulting in insufficient power generation to support the normal pumping operation of all water pumps; insufficient sunlight or wind speed, resulting in insufficient power generation to support the operation of any water pump; failures in photovoltaic, wind power, or other lines, resulting in sudden power outages; and sudden pipe bursts. The insufficient pump output described in this invention primarily addresses the water hammer phenomenon caused by insufficient pump unit output due to minute-by-minute fluctuations in sunlight and wind speed.

[0056] For emergencies, the following methods can be used to prevent water hammer according to different situations: reduce the number of water pumps started, the opening of the hydraulically controlled ball valve, the action time of the hydraulically controlled ball valve, the air valve and air tank, open the water hammer prevention valve, and the emergency shut-off valve.

[0057] The protection strategy is to adopt an appropriate method or a combination of methods to deal with sudden abnormal conditions in the system, so as to minimize the possibility of water hammer and ensure stable system operation.

[0058] S4. When it is monitored that the wind, solar, water and storage multi-energy complementary system cannot supply normal water to the water pump unit, select the corresponding water hammer protection method to perform water hammer protection on the wind, solar, water and storage multi-energy complementary system.

[0059] Through the above method, the control strategy that best meets the actual operating conditions is adopted, thereby achieving the maximum water hammer protection purpose.

[0060] For step S4, the specific water hammer protection methods are as follows:

[0061] 1) The wind, solar and water storage systems are dispatched normally P1, and all water pumps are operating normally A1.

[0062] 2) The wind, solar and water storage systems are operating normally, but the power generation from wind and photovoltaic power generation cannot meet the minimum power requirements for all water pumps. Based on the power output:

[0063] When the wind power and photovoltaic power generation can meet the normal operation scheduling P2 of at least one water pump, the preset control strategies such as the number of running water pump units, hydraulic ball valve opening and action time are triggered to carry out water hammer protection transient process control A2.

[0064] When the wind power and photovoltaic power generation cannot meet the operation time of any water pump P3, the control strategies such as pump stop and hydraulic ball valve closing time are triggered to perform water hammer warning and control A3.

[0065] 3) When a power outage occurs due to a fault, P4. Based on the power and hydraulic monitoring parameters, the preset control strategy A4, calculated using a transient hydraulic model, is triggered. This controls the fast and slow closing times of the hydraulically controlled ball valve to prevent turbulence and vibration caused by water hammer and reverse flow in the pipeline. The air valve and air tank automatically replenish and exhaust air. When the pressure drops to a set threshold, the water hammer prevention valve automatically opens. When the pressure rises to a set threshold, the water hammer prevention valve also opens.

[0066] 4) When pipe P5 bursts, the emergency shut-off valve automatically cuts off the water flow upstream of A5 to prevent secondary disasters.

[0067] Example 2

[0068] This embodiment provides a water hammer protection method based on a wind, solar, and hydropower storage multi-energy complementary system, comprising the following steps:

[0069] S1. Real-time monitoring of meteorological information at the operation site of the wind, solar, hydropower and storage multi-energy complementary system, including light intensity and wind speed parameters, as well as water pressure, flow, equipment health status and working status during system operation.

[0070] S2. Establish a real-time simulation and early warning model for wind power generation, photovoltaic power generation, and water pump operation, feeding the information collected in S1 into the real-time simulation and early warning model in real time. The real-time simulation and early warning model uses real-time wind speed and light intensity as input to simulate the wind power and photovoltaic power generation process and the pumping process of the pump station in real time. Based on predictions of future wind speed and light intensity, it also provides real-time predictions and early warnings for the future operating status of the wind, solar, hydro, and storage multi-energy complementary system. When the wind, solar, hydro, and storage multi-energy complementary system output is insufficient and falls below the minimum load required for pump station operation, a real-time early warning is issued. If the warning is not responded to in a timely manner within the emergency action time, the water hammer protection measures of the water pump unit are triggered.

[0071] S3. Establish a water hammer protection strategy for the wind, solar, hydropower and storage multi-energy system, assuming meteorological conditions result in power shortages and power outages. After the real-time simulation warning model activates, the transient hydraulic model is driven by the real-time simulation model's input, based on the future load process of the pumps. This model then calculates changes in flow rate and transient pressure, determines system operation, and develops a corresponding control strategy.

[0072] S4. When it is monitored that the wind, solar, water and storage multi-energy complementary system cannot supply normal water to the water pump unit, select the corresponding water hammer protection method to perform water hammer protection on the wind, solar, water and storage multi-energy complementary system.

[0073] This embodiment provides a method for preventing water hammer in a wind-solar-water-storage multi-energy complementary system. Figure 3 As shown, the wind-solar-hydro-storage multi-energy complementary system is equipped with at least two water pumps 2 for pumping water from the reservoir. Wind power and photovoltaic power generation are used to supply the power required by the water pumps 2. A hydraulically controlled ball valve 3 is installed on the branch line of each water pump, and an air valve 4, a water hammer prevention valve 5, and a pipe burst emergency shut-off valve 7 are installed on the main line of the pumping pipeline.

[0074] Specifically, the system detects that weather conditions will change in four hours, with a sharp drop in sunlight intensity and consequently, a sharp decrease in photovoltaic and wind power generation. The system predicts that the power output in four hours will only be sufficient to pump water for one set of pumps. At that point, only one set of pumps 2 remains operational, while the remaining pumps 2 are shut down. After each pump 2 shuts down, the corresponding hydraulically controlled ball valves 3 for each pump set are immediately closed. Because the remaining pumps shut down in a timely manner, the remaining power remains sufficient for one pump to operate normally, allowing the system to continue pumping. Water continues to flow from the main line to the reservoir, preventing water hammer. Furthermore, because the corresponding hydraulically controlled ball valves 3 in the shut-down pump sets have been promptly closed, water hammer will not occur in the branch lines.

[0075] When the system detects that weather conditions will change in six hours, with both sunlight intensity and wind speed expected to drop sharply, and predicts that power generation will be insufficient to keep any pumps running, it shuts down all pumps 2 and closes their corresponding hydraulically controlled ball valves 3. Because the pumps stop operating early and their corresponding hydraulically controlled ball valves 3 close, water hammer will not occur in either the main or branch circuits.

[0076] The above is an adjustment method for shutting down the water pump. When it is predicted that the meteorological conditions will change, the water pump can still pump water, but it cannot meet the full load operation of the water pump. The pumping power cannot reach the maximum value and the water path in the pipeline will be reduced. At this time, it is necessary to adjust the opening of the hydraulic control ball valve 3 to meet the water hammer effect.

[0077] Example 3

[0078] The difference from Example 2 is that this embodiment provides a method for preventing water hammer during power outage. Figure 3As shown, a sudden failure in the wind and photovoltaic power generation circuits prevented the circuits powering the water pump from supplying power. Based on power and hydraulic monitoring parameters, a transient hydraulic model calculated a control strategy. This strategy rapidly closed hydraulically controlled ball valve 3 to prevent water hammer and turbulence and vibration caused by reverse flow in the pipe. Air valve 4 automatically replenished and exhausted air. When pressure dropped to a set threshold, water hammer prevention valve 5 automatically opened. When pressure rose to a set threshold, the valve also opened. For added safety, a safety relief valve 6 could also be installed. This coordinated control of valves prevented water hammer in the pipe network, preventing pipe bursts and water hammer damage to the pump.

[0079] Example 4

[0080] The difference from Example 2 is that this embodiment provides a method for preventing water hammer when a pipeline bursts suddenly. Figure 3 As shown, when a pipe bursts, water flows out from the burst pipe, and the water in the main channel cannot flow to the reservoir. Since the water pump is pumping water from a low point to a high point, the water flow suddenly stops, and the water in the high point will flow back and quickly return from the main channel. At this time, the pipe burst emergency shut-off valve 7 is urgently activated to automatically cut off the upstream water flow to prevent secondary disasters.

[0081] Obviously, the above embodiments are merely examples for the purpose of clearly illustrating the technical solutions of the present invention, and are not intended to limit the implementation methods of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A water hammer protection method based on a wind, solar, and water storage multi-energy complementary system, characterized in that: The steps include: S1. Real-time monitoring of the working status of the wind, solar, hydropower and storage multi-energy complementary system, wherein the working status includes the following variables: wind conditions, solar conditions, wind and solar power station operating conditions, water conditions, and hydropower station operating conditions; S2. Establish a real-time simulation and early warning model for wind power generation, photovoltaic power generation, and water pump operation, and establish the relationship between wind power, photovoltaic parameters, and water pump working status; S3. Establish a water hammer protection strategy that will cause the wind, solar, hydro and storage multi-energy complementary system to experience power shortage and power outage under meteorological conditions; S4. When it is detected that the wind-solar-hydro-storage multi-energy complementary system cannot supply normal water to the water pump unit, select the corresponding water hammer protection method to protect the wind-solar-hydro-storage multi-energy complementary system from water hammer; The real-time simulation early warning model inputs real-time wind speed to calculate wind turbine output and inputs light intensity to calculate photovoltaic output. The wind turbine output and photovoltaic output are transmitted to the water pump through the power system as the power supply load of the water pump unit; The calculation method of fan output is: Among them, p w is the output power of the wind turbine, v is the wind speed, ρ is the air density, R is the radius of the wind turbine impeller, C p is the wind energy utilization coefficient of the wind turbine; In addition, when the wind speed is less than the minimum operating wind speed of the wind turbine and greater than the maximum operating wind speed, the wind turbine will shut down and the output power will be 0; when the calculated output power of the wind turbine is greater than the rated power of the wind turbine, the rated power will be output; The calculation method of photovoltaic output is: P v =I(G,T)·U(G,T) Among them, P v is the photovoltaic output, G is the light intensity, and T is the temperature; I(G,T)=I ref +ΔI(G,T) (1-3) Among them, I ref The two voltages of the photovoltaic array are reference voltage U ref The corresponding output current when I SC is the short-circuit current of the photovoltaic array under reference conditions; φ, is the temperature coefficient of current and voltage change under reference light intensity; R S is the series resistance of the photovoltaic array; t c is the temperature coefficient of the solar cell module; T ref , G ref are the temperature and light intensity under the reference conditions, respectively. The reference conditions are (T ref =25°, G ref =1kW·m -2 ).

2. The water hammer protection method based on the wind, solar, water and storage multi-energy complementary system according to claim 1 is characterized in that: The wind, solar and water storage multi-energy complementary system is equipped with a hydraulically controlled ball valve, an air valve and / or an air tank, a water hammer prevention valve and an emergency shut-off valve. The water hammer protection strategy is to reduce the number of water pump startups, the opening of the hydraulically controlled ball valve, the action time of the hydraulically controlled ball valve, the use of air valves and air tanks, the use of water hammer prevention valves and the use of one or several combinations of emergency shut-off valves.

3. The water hammer protection method based on the wind, solar, water and storage multi-energy complementary system according to claim 1 is characterized in that: The wind, solar, hydropower and storage multi-energy complementary system cannot supply normal water to the water pump unit due to the following reasons: insufficient sunlight and wind speed, resulting in insufficient power generation to meet the normal pumping operation of all water pumps; insufficient sunlight and wind speed, resulting in insufficient power generation to meet the operation of any water pump; failure of photovoltaic, wind power or other lines, resulting in sudden power outage and inability to pump water; sudden pipe burst.

4. The water hammer protection method based on the wind, solar, water and storage multi-energy complementary system according to claim 1 is characterized in that: The water hammer protection method is: the power generation of wind power and photovoltaic power generation cannot meet the minimum power of all water pumps, according to the power output power: When the wind power and photovoltaic power generation can meet the normal scheduling of at least one water pump, the preset number of running pump units, hydraulic control ball valve opening and action time control strategy are triggered to perform water hammer protection transient process control; when the wind power and photovoltaic power generation cannot meet the operation of any water pump, the pump stop and hydraulic control ball valve closing action time control strategy are triggered to perform water hammer early warning regulation.

5. The water hammer protection method based on the wind, solar, water and storage multi-energy complementary system according to claim 1 is characterized in that: When the wind, solar, and water storage multi-energy complementary system suddenly loses power, the fast closing and slow closing times of the hydraulically controlled ball valve are controlled to prevent turbulence and vibration caused by water hammer and pipeline backflow.

6. The water hammer protection method based on the wind, solar, water and storage multi-energy complementary system according to claim 5 is characterized in that: Water hammer protection methods also include: automatic air replenishment and exhaust through air valves and air tanks.

7. The water hammer protection method based on the wind, solar, water and storage multi-energy complementary system according to claim 5 is characterized in that: Water hammer protection methods also include adjusting the water hammer prevention valve to automatically open the water release when the water pressure drops to the low pressure setting threshold; and continue to release water when the water pressure rises to the high pressure setting threshold.

8. The water hammer protection method based on the wind, solar, water and storage multi-energy complementary system according to claim 1 is characterized in that: The water hammer protection method also includes a pipe burst protection strategy that controls a pipe burst emergency shut-off valve through a transient hydraulic model to automatically cut off upstream water flow to prevent secondary disasters when a pipe burst occurs.

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