Control method and system for pumped water compressed air energy storage device considering ecological flow of small power station

Abstract

The present invention discloses a control method and system for a pumped-air-pressurized energy storage device that takes into account the ecological flow of a small power station. According to the current time period, the control mode of the corresponding time period is activated. During the off-peak period, while storing energy, ecological water is released to provide the ecological flow required by the downstream river channel, thereby ensuring the self-purification capacity of the river channel. During the peak period, while releasing energy, the water storage tank of the pumped-air-pressurized energy storage device is used to store the ecological water required during the off-peak period. Not only can the pumped-air-pressurized energy storage device itself play its own energy storage role, but the energy storage device can also be used to store the ecological water required during the off-peak period during the peak period, and release the ecological water during the off-peak period to provide the ecological flow required by the downstream river channel, thereby ensuring the self-purification capacity of the river channel. Under the premise of ensuring the ecological flow of the river, the power demand issued by the power system dispatching center is supported, and the charging and discharging power of the pumped-air-pressurized energy storage during the peak and off-peak periods and the generating power of the turbine of the small hydropower station are determined.

Description

Technical Field

[0001] The present invention relates to the technical field of pumped-storage small hydropower stations, and in particular to a control method and system for a pumped-air compressed air energy storage device taking into account the ecological flow of a small power station. Background Art

[0002] Small hydropower stations are an important part of rural energy and the most mature and effective distributed energy. They are very close to the load (i.e. the end of the power grid) and do not require the construction of a large power grid for long-distance high-voltage or ultra-high-voltage transmission. They can greatly reduce line losses, save investment in power transmission and distribution construction and operating costs, and achieve a higher comprehensive energy utilization rate.

[0003] Therefore, it is urgent to transform small hydropower stations into pumped-air compressed air type, optimize the power generation potential of small hydropower stations and improve the power consumption situation at the end of the distribution network while ensuring the ecological flow of the river. Summary of the Invention

[0004] The present invention provides a control method and system for a pumped-air compressed air energy storage device that takes into account the ecological flow of a small hydropower station, which is used to solve the problem that the ecological flow of a small hydropower station is not reasonably controlled, resulting in water reduction and dehydration in the downstream river channel and a serious decline in the self-purification capacity of the river.

[0005] In a first aspect, a control method for a pumped-air energy storage device taking into account the ecological flow of a small power station is provided, comprising the following steps:

[0006] S1: Collect information about the current time period. If it is in the off-peak period, jump to step S2; if it is in the peak period, jump to step S5; if it is in other periods, the pumped water compressed air energy storage device does not work;

[0007] S2: Collect the reservoir water level of the small hydropower station and the inflow flow of the upstream river, establish a water abandonment flow model to calculate the flow discharged by the small hydropower station to avoid water abandonment; combine the flow discharged by the small hydropower station and the ecological flow demand of the river to calculate the ecological supplementary flow required to be released by the pumped gas energy storage device; establish the valve opening-flow relationship to determine the valve opening of the external circulation system of the pumped gas energy storage device during the off-peak period ;

[0008] S3: Based on the turbine output, a power storage model is established to calculate the required storage power of the pumped water compressed air energy storage device; a power-pressure storage model of the pumped water compressed air energy storage device is established to calculate the pressure corresponding to the required storage power to determine the compression ratio of the compressor. ;

[0009] S4: Valve opening of the external circulation system of the pumped water compressed gas energy storage device during the off-peak period and compressor compression ratio , control the pumped water compressed air energy storage device; if the valley period ends, return to step S1;

[0010] S5: Collect water level information of the water storage tank in the pumped water compressed air energy storage device, establish an ecological flow storage model to calculate the pumping flow of the pumped water compressed air energy storage device; establish a valve opening-flow relationship to determine the valve opening of the external circulation system of the pumped water compressed air energy storage during peak hours ;

[0011] S6: Based on the water pump output, calculate the power consumed by the pumping compressed air energy storage device; combine the current node load power and node power generation power issued by the power system dispatching center to establish the pumped compressed air energy storage power-pressure release model, calculate the working pressure of the pumped compressed air energy storage device when releasing energy, and determine the expansion ratio of the expander :

[0012] S7: Valve opening of the external circulation system based on the pumped water compressed gas energy storage device and expander expansion ratio , control the pumped water compressed air energy storage device; if the peak period ends, return to step S1.

[0013] Furthermore, in step S2, the abandoned water flow model is expressed as follows:

[0014]

[0015] Where, It is the flow rate released by small hydropower stations to avoid water abandonment; is the inflow flow of the upstream river; is the total storage capacity of the small hydropower station reservoir; is the current storage capacity of the small hydropower station reservoir, which is obtained according to the current water level of the small hydropower station reservoir, that is, referring to the water level and storage capacity curve of the small hydropower station , water level The corresponding storage capacity; is the duration of the trough period;

[0016] Valve opening of the external circulation system of the pumped water compressed gas energy storage device during the off-peak period Calculated by the following formula:

[0017]

[0018] Where, Supplementing traffic for the ecosystem; The maximum flow rate of the valve in the external circulation system of the pumped water compressed air energy storage device; The ecological flow demand of the river; is the downstream river flow.

[0019] Furthermore, in step S3, the power storage model is expressed as follows:

[0020]

[0021] Where, The storage power required for the pumped gas energy storage device; The efficiency of water discharge for power generation in pumped hydro compressed gas energy storage devices; is the water flow density; is the acceleration due to gravity; The water head for discharging water to the pumped gas energy storage device is the height difference between the water level in the storage tank and the turbine; Supplementing traffic for the ecosystem; The current node power generation capacity issued by the power system dispatching center. This power generation capacity does not include the power generation capacity of small hydropower stations and pumped compressed air energy storage. The current node load power issued by the power system dispatching center; the power generation power of the small hydropower station Calculated by the following formula:

[0022]

[0023] Where, For the power generation efficiency of small hydropower stations; The power generation head is the height difference between the water level of the small hydropower station reservoir and the turbine unit of the small hydropower station; It is the flow rate released by small hydropower stations to avoid water abandonment; It is the maximum energy storage power of the pumped gas energy storage device; It is the inflow flow rate when the power generation capacity of the small hydropower station reaches the maximum energy storage capacity of the pumped compressed air energy storage device.

[0024] Furthermore, in step S3, the power-pressure storage model of the pumped water compressed air energy storage is expressed as follows:

[0025]

[0026] Where, is the energy storage pressure; is the duration of the trough period; The storage power required for the pumped gas energy storage device; is the atmospheric pressure; is the volume of the water storage tank; is the volume of the high-pressure gas storage tank;

[0027] Compressor compression ratio Calculated by the following formula:

[0028]

[0029] Where, The power consumed by the water pump to perform the first stage of compression; The time it takes for the pump to perform the first stage of compression; It is the volume of compressed air obtained after the first stage of compression.

[0030] Furthermore, in step S5, the ecological flow storage model is expressed as follows:

[0031]

[0032] in, The pumping flow rate of the pumped compressed air energy storage device; The ecological flow demand of the river; is the duration of the trough period; is the water level in the water storage tank; is the bottom area of ​​the water storage tank;

[0033] Valve opening of the external circulation system of water pumping, compressed air and energy storage during peak hours Calculated by the following formula:

[0034]

[0035] Where, It is the maximum flow rate of the valve of the external circulation system of the pumped water compressed air energy storage device.

[0036] Furthermore, in step S6, the power-pressure release model of the pumped water compressed air energy storage is expressed as follows:

[0037]

[0038] Where, is the pumping efficiency; is the water flow density; is the acceleration due to gravity; The water head for discharging water to the pumped gas energy storage device is the height difference between the water level in the storage tank and the turbine; The pumping flow rate of the pumped compressed air energy storage device; The energy conversion efficiency of the pumped water compressed gas energy storage device when releasing energy; The amount of water stored in the expansion end water vapor tank; The node load power at the current moment issued by the dispatching center; is the power generation capacity of the small hydropower station at the current moment; The current node power generation capacity issued by the power system dispatching center. This power generation capacity does not include the power generation capacity of small hydropower stations and pumped compressed air energy storage.

[0039] Expander expansion ratio Calculated by the following formula:

[0040]

[0041] Where, is the energy storage pressure; It is the working pressure of pumped water compressed air energy storage when releasing energy.

[0042] Furthermore, in step S4, in the process of controlling the pumped gas energy storage device, the real-time ecological flow of the downstream river is collected. , the valve opening of the external circulation system of the pumped water compressed air energy storage device during the off-peak period Make corrections:

[0043]

[0044]

[0045] Where, Supplementing traffic for the ecosystem; The maximum flow rate of the valve in the external circulation system of the pumped water compressed air energy storage device; The ecological flow demand of the river; is the downstream river flow; It is the flow rate released by small hydropower stations to avoid water abandonment; It is the correction value of the discharge flow of the water storage tank.

[0046] Furthermore, in step S7, during the control process of the pumped air energy storage device, the real-time water level of the water storage tank is collected. , for the expander expansion ratio Make corrections:

[0047]

[0048]

[0049] Where, is the energy storage pressure; is the pumping efficiency; is the water flow density; is the acceleration due to gravity; The water head for discharging water to the pumped gas energy storage device is the height difference between the water level in the storage tank and the turbine; The pumping flow rate of the pumped compressed air energy storage device; The energy conversion efficiency of the pumped water compressed gas energy storage device when releasing energy; The amount of water stored in the expansion end water vapor tank; The node load power at the current moment issued by the dispatching center; The power generated by the small hydropower station at the current moment; is the increase in water level in the water storage tank, and its value is ; It is the power generation capacity of the node at the current moment issued by the power system dispatching center. This power generation capacity does not include the power generation capacity of small hydropower stations and pumped compressed air energy storage.

[0050] Furthermore, in step S7, during the control process of the pumped air energy storage device, if the water storage tank reaches the maximum storage capacity, , the water pump stops pumping water; if the air pressure in the high-pressure gas tank is atmospheric pressure , the expander, turbine and generator stop working; if the peak period ends, return to step S1.

[0051] In the second aspect, a control system for a pumped water compressed air energy storage device taking into account the ecological flow of a small power station is provided, including a sensor data acquisition module and a control module;

[0052] The data acquisition module includes a first liquid level sensor, a second liquid level sensor, a reservoir water level sensor, a pressure sensor, a first radar flowmeter, a second radar flowmeter, a third radar flowmeter, an ultrasonic flowmeter and a control module:

[0053] The first liquid level sensor is installed in the water storage tank to monitor the water level of the water storage tank; the second liquid level sensor is installed in the expansion end water vapor tank to monitor the water level of the expansion end water vapor tank; the reservoir water level sensor is installed in the reservoir of the small hydropower station to monitor the water level of the reservoir of the small hydropower station; the pressure sensor is installed in the high-pressure gas storage tank to monitor the pressure of the high-pressure gas storage tank; the first radar flowmeter is installed in the upstream river channel of the small hydropower station to monitor the inflow flow of the upstream river channel; the second radar flowmeter is installed in the river channel between the small hydropower station and the pumped gas energy storage device to monitor the flow of the downstream river channel before the ecological flow is discharged; the third radar flowmeter is installed in the downstream river channel of the pumped gas energy storage device to monitor the flow of the downstream river channel after the ecological flow is discharged; the ultrasonic flowmeter is used to monitor the ecological flow stored and discharged by the pumped gas energy storage device;

[0054] The control module includes:

[0055] a memory having a computer program stored thereon;

[0056] The processor is used to load and execute the computer program to implement the control method of the pumped water compressed air energy storage device considering the ecological flow of the small power station as described above.

[0057] The present invention proposes a control method and system for a pumped-air-pressurized energy storage device that takes into account the ecological flow of a small power station. The water storage tank of the pumped-air-pressurized energy storage device can be used to store ecological water to ensure the ecological flow of the river. During the dry season, not only can the pumped-air-pressurized energy storage device play its own energy storage role, but it can also use stored energy to supplement ecological water during peak hours, and discharge ecological water during low periods to provide the ecological flow required by the downstream river channel and ensure the self-purification capacity of the river channel; the pumped-air-pressurized energy storage device improves the electricity consumption in the terminal area of ​​the distribution network under the premise of ensuring the ecological flow of the river. During the flood season, the river flow is abundant and there is no need to reserve ecological downstream flow. The pumped-air-pressurized energy storage device can fully play its own energy storage role and fully improve the electricity consumption in the terminal area of ​​the distribution network. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0059] Figure 1 This is a control principle diagram of a pumped-air energy storage device taking into account the ecological flow of a small power station provided by an embodiment of the present invention;

[0060] Figure 2 Schematic diagram of the structure of a pumped water compressed air energy storage device provided by an embodiment of the present invention;

[0061] Figure 3 This is a typical daily pumped-water compressed-air energy storage coordinated small hydropower station output curve provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0062] To make the objectives, technical solutions, and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other implementations obtained by those of ordinary skill in the art without inventive effort are within the scope of protection of the present invention.

[0063] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "top", "bottom", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. When an element is referred to as being "fixed to" another element, it can be directly on the other element or there can also be a central element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there can be a central element at the same time. The terms "first", "second", etc., are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or order.

[0064] In order to facilitate understanding of the technical solution of the present invention, the pumped water compressed air energy storage device is first introduced. Figure 2 As shown, the pumped water compressed gas energy storage device includes a flow meter, a turbine, a generator, a water pump, an electric motor, a first water vapor tank F1 (compression end water vapor tank), a second water vapor tank F2 (expansion end water vapor tank), a compressor, an expander, a first high-pressure gas storage tank G1, a first water storage tank H1 for storing ecological water, and several valves;

[0065] The first interface of the water turbine and the first interface of the water pump are connected to the flow meter through valves respectively; the second interface of the water turbine and the second interface of the water pump are connected to the first water storage tank H1 through valves respectively; the generator is connected to the water turbine, and the electric motor is connected to the water pump;

[0066] The first water vapor tank F1, the compressor, the first high-pressure gas storage tank G1, the expander, the second water vapor tank F2, and the water pump are sequentially connected through valves to form a closed loop; the bottom of the first water vapor tank F1 and the bottom of the second water vapor tank F2 are also connected through a valve; the first water vapor tank F1 and the second water vapor tank F2 are respectively connected to the second port and the third port of the turbine;

[0067] The external circulation system composed of the water pump, the first water storage tank H1 and the turbine is used to store ecological water, discharge ecological water and generate electricity; the internal circulation system composed of the first steam tank F1, the compressor, the first high-pressure gas tank G1, the expander, the second steam tank F2, the water pump and the turbine is used to store energy and generate electricity.

[0068] During periods of low electricity demand, the pumped-water compressed air energy storage device calculates the required flow rate from the first water tank H1, combining downstream river flow information and the required ecological flow rate. The external circulation system's drain valves (valves 8, 3, and 2) are then opened, releasing the flow from the first water tank H1. The generator motor then generates electricity. Simultaneously, valves 14, 10, 6, 5, 9, 16, and 19 are opened to compress and store energy. The compressed high-pressure air is then stored in the first high-pressure air tank G1. Once energy storage is complete, valves 7, 13, and 14 are opened to balance the water levels in the first and second water vapor tanks F1 and F2.

[0069] During peak hours of electricity consumption, the pumped water compressed gas energy storage device releases energy to generate electricity. Valve 19, valve 17, valve 10, valve 4, valve 3, valve 9 and valve 13 are opened, and the expander increases the pressure to The high pressure air expands to , driving the water in the second water vapor tank F2 to flush the generator motor and generate electricity. To replenish ecological water, the external circulation system water supply valves (valve 1, valve 5, valve 8) and valve 12 are opened, and the water pump pumps water into the first water storage tank H1 for storage as ecological water.

[0070] Taking into account the high cost and difficulty of construction when a single water storage tank is too large, some preferred embodiments also include a second water storage tank H2 for storing ecological water. The third interface of the turbine is connected to the second water storage tank H2 through valves 4 and 11, and the third interface of the water pump is connected to the second water storage tank H2 through valves 6 and 11. The first water storage tank H1 and the second water storage tank H2 have the same functions and complement each other. When the capacity of a single water storage tank cannot meet the requirements, two water storage tanks can be used to store ecological water. Valve 11 has the same function as valve 8, and valve 15 has the same function as valve 12. Of course, in other embodiments, if the capacity of the two water storage tanks still cannot meet the requirements, the number of water storage tanks can be increased, such as setting three or four.

[0071] It should be noted that in this embodiment, the first interface of the turbine is the output end; the third interface of the turbine is the input end; the second interface of the turbine is the input end in the ecological flow release stage and the output end in the energy release stage. The second interface of the turbine can be selectively switched between the input end and the output end through a three-way valve. Of course, in some other embodiments, the first water storage tank and the first water vapor tank may not share a second interface to connect to the turbine. For example, the first water storage tank is directly connected to the input end of the turbine through a pipeline and a valve, and the first water vapor tank is directly connected to the output end of the turbine through another pipeline and a valve. The first interface of the water pump is the input end; the second interface of the water pump is the output end; the third interface of the water pump is the output end when storing ecological water and the input end in the energy storage stage. The third interface of the water pump implements the same principle as the second interface of the aforementioned turbine and will not be repeated here.

[0072] Furthermore, considering the high cost and construction difficulty associated with a single high-pressure gas storage tank being too large, some preferred embodiments further include a second high-pressure gas storage tank G2, which is connected to the compressor and expander via valve 18. The second high-pressure gas storage tank G2 functions identically to the first high-pressure gas storage tank G1, and valve 18 functions identically to valve 19. Of course, in other embodiments, if the capacity of two high-pressure gas storage tanks still cannot meet the requirements, additional high-pressure gas storage tanks may be added, such as to three or four.

[0073] This embodiment further includes a heat exchanger, a first interface of which is connected to the compressor, a second interface of which is connected to the first high-pressure gas storage tank G1 and / or the second high-pressure gas storage tank G2, and a third interface of which is connected to the expander. The addition of a heat exchanger allows the large amount of heat generated by the compressed air during the energy storage phase to be stored. This stored heat is then used to heat the high-pressure air released from the high-pressure gas storage tank during the energy release phase, accelerating the expansion effect.

[0074] Based on the above-mentioned pumped water compressed air energy storage device, the embodiment of the present invention provides a control method for the pumped water compressed air energy storage device taking into account the ecological flow of a small power station, such as Figure 1 As shown, the following steps are included:

[0075] S1: Collect information about the current time period If it is in the off-peak period, jump to step S2; if it is in the peak period, jump to step S5; if it is in other periods, the pumped water compressed air energy storage device does not work.

[0076] The off-peak period and peak period can be set according to the actual situation. , it is considered to be in the valley period, and the working status mark of the pumped water compressed air energy storage device is , start the valley control loop and jump to step S2; if or , it is considered to be in the peak period, and the working status mark of the pumped air energy storage device is , start the peak control loop and jump to step S5; if or , working status sign of pumped water compressed air energy storage device , the pumped air energy storage device does not work.

[0077] S2: Collect water levels of small hydropower station reservoirs and upstream river flow , establish a water abandonment flow model to calculate the flow rate discharged by small hydropower stations to avoid water abandonment ; Combined with the discharge flow of small hydropower stations and the ecological flow demand of the river , calculate the ecological supplementary flow that needs to be released by the pumped gas energy storage device ; Establish the valve opening-flow relationship to determine the valve opening of the external circulation system of the pumped water compressed gas energy storage device during the off-peak period .

[0078] The abandoned water flow model is expressed as follows:

[0079]

[0080] Where, It is the flow rate released by small hydropower stations to avoid water abandonment; is the total storage capacity of the small hydropower station reservoir; is the current storage capacity of the small hydropower station reservoir, according to the current water level of the small hydropower station reservoir Obtained, that is, referring to the water level and storage capacity curve of the small hydropower station , water level The corresponding storage capacity; The duration of the low period.

[0081] Valve opening of the external circulation system of the pumped water compressed gas energy storage device during the off-peak period Calculated by the following formula:

[0082]

[0083] Where, Supplementing traffic for the ecosystem; The maximum flow rate of the valve in the external circulation system of the pumped water compressed air energy storage device; It is the downstream river flow before ecological flow release.

[0084] S3: Based on the turbine output, a power storage model is established to calculate the required storage power of the pumped water compressed air energy storage device; a power-pressure storage model of the pumped water compressed air energy storage device is established to calculate the pressure corresponding to the required storage power to determine the compression ratio of the compressor. .

[0085] The power storage model is expressed as follows:

[0086]

[0087] Where, The storage power required for the pumped gas energy storage device; The efficiency of water discharge for power generation in pumped hydro compressed gas energy storage devices; is the water flow density; is the acceleration due to gravity; The water head for discharging water to the pumped gas energy storage device is the height difference between the water level in the storage tank and the turbine; Supplementing traffic for the ecosystem; The current node power generation capacity issued by the power system dispatching center. This power generation capacity does not include the power generation capacity of small hydropower stations and pumped compressed air energy storage. The current node load power issued by the power system dispatching center; the power generation power of the small hydropower station Calculated by the following formula:

[0088]

[0089] Where, For the power generation efficiency of small hydropower stations; The power generation head is the height difference between the water level of the small hydropower station reservoir and the turbine unit of the small hydropower station; It is the flow rate released by small hydropower stations to avoid water abandonment; It is the maximum energy storage power of the pumped gas energy storage device; It is the inflow flow rate when the power generation capacity of the small hydropower station reaches the maximum energy storage capacity of the pumped compressed air energy storage device.

[0090] The power-pressure storage model of pumped water compressed air energy storage is expressed as follows:

[0091]

[0092] Where, is the energy storage pressure; is the duration of the trough period; The storage power required for the pumped gas energy storage device; is the atmospheric pressure; is the volume of the water storage tank; is the volume of the high-pressure gas storage tank.

[0093] Compressor compression ratio Calculated by the following formula:

[0094]

[0095] Where, The power consumed by the water pump to perform the first stage of compression; The time it takes for the pump to perform the first stage of compression; It is the volume of compressed air obtained after the first stage of compression.

[0096] S4: Valve opening of the external circulation system of the pumped water compressed gas energy storage device during the off-peak period and compressor compression ratio , to control the pumped air energy storage device. Motor power consumption Drive the water pump to pump water from the second water tank to compress the air in the first water tank to the transient pressure , and then through the compressor with a compression ratio Compressed to storage pressure , stored in the high-pressure gas storage tank, realizing the conversion of electrical energy into air internal energy; if the low period ends, the water pump and compressor stop working, the valve is closed, and the process returns to step S1.

[0097] In some preferred embodiments, during the control of the pumped gas energy storage device, the real-time ecological flow of the downstream river after the ecological flow is released is collected. , the valve opening of the external circulation system of the pumped water compressed air energy storage device during the off-peak period Make corrections:

[0098]

[0099]

[0100] Where, Supplementing traffic for the ecosystem; The maximum flow rate of the valve in the external circulation system of the pumped water compressed air energy storage device; The ecological flow demand of the river; It is the downstream river flow before ecological flow release; It is the flow rate released by small hydropower stations to avoid water abandonment; It is the correction value of the discharge flow of the water storage tank.

[0101] S5: Collect water level information of the water tank in the pumped water compressed air energy storage device , establish an ecological flow storage model to calculate the pumping flow of the pumped compressed air energy storage device ; Establish the valve opening-flow relationship to determine the valve opening of the external circulation system of water pumping, compressed air storage and energy storage during peak hours .

[0102] Among them, the ecological flow storage model is expressed as follows:

[0103]

[0104] in, The pumping flow rate of the pumped compressed air energy storage device; The ecological flow demand of the river; is the duration of the trough period; is the water level in the water storage tank; is the bottom area of ​​the water storage tank;

[0105] Valve opening of the external circulation system of water pumping, compressed air and energy storage during peak hours Calculated by the following formula:

[0106]

[0107] Where, It is the maximum flow rate of the valve of the external circulation system of the pumped water compressed air energy storage device.

[0108] S6: Based on the water pump output, calculate the power consumed by the pumped gas energy storage device; combine the current node load power and node power generation power issued by the power system dispatching center to establish the pumped gas energy storage power-pressure release model and calculate the working pressure of the pumped gas energy storage device when releasing energy. , to determine the expander expansion ratio

[0109] The power-pressure release model of pumped water compressed air energy storage is expressed as follows:

[0110]

[0111] Where, is the pumping efficiency; is the water flow density; is the acceleration due to gravity; The water head for discharging water to the pumped gas energy storage device is the height difference between the water level in the storage tank and the turbine; The pumping flow rate of the pumped compressed air energy storage device; The energy conversion efficiency of the pumped water compressed gas energy storage device when releasing energy; The amount of water stored in the second water tank; The current node load power issued by the power system dispatching center; is the power generation capacity of the small hydropower station at the current moment; It is the power generation capacity of the node at the current moment issued by the power system dispatching center. This power generation capacity does not include the power generation capacity of small hydropower stations and pumped compressed air energy storage.

[0112] Expander expansion ratio Calculated by the following formula:

[0113]

[0114] Where, is the energy storage pressure; It is the working pressure of pumped water compressed air energy storage when releasing energy.

[0115] S7: Valve opening of the external circulation system based on the pumped water compressed gas energy storage device and expander expansion ratio , control the pumped air energy storage device; if the water storage tank reaches the maximum storage capacity , the water pump stops pumping water; if the air pressure in the high-pressure gas tank is atmospheric pressure , the expander, turbine and generator stop working; if the peak period ends, return to step S1.

[0116] In some preferred embodiments, during the control process of the pumped air energy storage device, the real-time water level of the water storage tank is collected. , for the expander expansion ratio Make corrections:

[0117]

[0118]

[0119] Where, is the energy storage pressure; is the pumping efficiency; is the water flow density; is the acceleration due to gravity; The water head for discharging water to the pumped gas energy storage device is the height difference between the water level in the storage tank and the turbine; The pumping flow rate of the pumped compressed air energy storage device; The energy conversion efficiency of the pumped water compressed gas energy storage device when releasing energy; The amount of water stored in the second water tank; The current node load power issued by the power system dispatching center; The power generated by the small hydropower station at the current moment; is the increase in water level in the water storage tank, and its value is ; It is the power generation capacity of the node at the current moment issued by the power system dispatching center. This power generation capacity does not include the power generation capacity of small hydropower stations and pumped compressed air energy storage.

[0120] The above embodiment provides a control method for a pumped-air-pressurized energy storage device that takes into account the ecological flow of a small power station. The water storage tank of the pumped-air-pressurized energy storage device can be used to store ecological water to ensure the ecological flow of the river. During the dry season, not only can the pumped-air-pressurized energy storage device play its own energy storage role, but it can also use energy storage to supplement ecological water during peak hours, and discharge ecological water during low periods to provide the ecological flow required by the downstream river channel and ensure the self-purification capacity of the river channel; the pumped-air-pressurized energy storage device improves the electricity consumption in the terminal area of ​​the distribution network under the premise of ensuring the ecological flow of the river. During the flood season, the river flow is abundant, and there is no need to reserve ecological downstream flow. The pumped-air-pressurized energy storage device can give full play to its own energy storage role and fully improve the electricity consumption in the terminal area of ​​the distribution network.

[0121] The embodiment of the present invention also provides a control system for a pumped water compressed air energy storage device that takes into account the ecological flow of a small power station, such as Figure 1 As shown, it includes a sensor data acquisition module and a control module;

[0122] The data acquisition module includes a first liquid level sensor, a second liquid level sensor, a reservoir water level sensor, a pressure sensor, a first radar flowmeter, a second radar flowmeter, a third radar flowmeter, an ultrasonic flowmeter and a control module:

[0123] The first liquid level sensor is installed in the water storage tank to monitor the water level of the water storage tank; the second liquid level sensor is installed in the expansion end water vapor tank to monitor the water level of the expansion end water vapor tank; the reservoir water level sensor is installed in the reservoir of the small hydropower station to monitor the water level of the reservoir of the small hydropower station; the pressure sensor is installed in the high-pressure gas storage tank to monitor the pressure of the high-pressure gas storage tank; the first radar flowmeter is installed in the upstream river channel of the small hydropower station to monitor the inflow flow of the upstream river channel; the second radar flowmeter is installed in the river channel between the small hydropower station and the pumped gas energy storage device to monitor the flow of the downstream river channel before the ecological flow is discharged; the third radar flowmeter is installed in the downstream river channel of the pumped gas energy storage device to monitor the flow of the downstream river channel after the ecological flow is discharged; the ultrasonic flowmeter is used to monitor the ecological flow stored and discharged by the pumped gas energy storage device;

[0124] The control module includes:

[0125] a memory having a computer program stored thereon;

[0126] The processor is used to load and execute the computer program to implement the control method of the pumped water compressed air energy storage device considering the ecological flow of the small power station as described above.

[0127] Specifically, the control module includes:

[0128] Time period information collection unit, used to obtain the current time period information , and sends the collected time period information to the working mode judgment unit;

[0129] The working mode judgment unit processes the time period information collected by the time period information collection unit to determine the working mode of the pumped water compressed air energy storage device in different time periods and assigns a value to the working state flag EN of the pumped water compressed air energy storage device;

[0130] Abandoned water power unit: Receives water level data of small hydropower station reservoir collected by sensors and upstream river flow data , calculate the flow rate discharged by small hydropower stations to avoid water abandonment and its generated power , and the calculated flow data Transmit to EcoFlow unit, power data Transmitted to a power storage unit;

[0131] Ecological flow unit: receives flow data transmitted by the abandoned water power unit and downstream river flow data collected by sensors , calculate the ecological supplementary flow required to be released by the external circulation system and its generated power , and the power data obtained Transmitted to a power storage unit;

[0132] Power storage unit: Receives power data transmitted by the water abandonment power unit to avoid water abandonment , the power data generated by the ecological flow transmitted by the ecological compensation unit And the power data that the power grid cannot absorb issued by the dispatch center , calculate the power required to be stored in the internal circulation system of the pumped water compressed gas energy storage , and the power data obtained Transmitted to the low-valley inner loop execution unit;

[0133] Low valley external circulation execution unit: the pumping and compressed air energy storage valve is opened, and the external circulation system valve opening , ensuring that water storage tanks replenish flow with ecological releasing water to replenish river flows;

[0134] Low valley ecological flow correction unit: Receives the real-time ecological flow of the river downstream of the pumped compressed air energy storage after the water tank is discharged, collected by the sensor ,If the river flow exceeds the river ecological threshold after discharge, the ecological flow discharged from the water storage tank is changed, and the corrected valve opening is transmitted to the valley external circulation execution unit;

[0135] Low-valley internal cycle execution unit: Based on the water tank pressure calculation model, combined with the power storage unit to calculate the power data , calculate the storage pressure of the gas tank And the compression ratio of the compressor, and the compression ratio can be adjusted through the compressor control interface ;

[0136] Ecological flow storage unit: receives the water storage information of the first water tank and the second water tank collected by the sensor, calculates the pumping flow Power consumed in pumping water to replenish the water storage tank , and the calculated power data Transmitted to the peak output unit;

[0137] Peak output unit: based on the power demand of the grid and the power generated by the small hydropower station during peak hours, combined with the power consumed by replenishing the water storage tank , calculate the output required during the peak period of pumped water compressed gas energy storage = and its corresponding pressure , used to clarify the expansion ratio when the expander expands the air in the high-pressure gas tank ;

[0138] Peak output correction unit: receives the water level information of the first water storage tank collected by the sensor, corrects the working water head of the water pump, and transmits the corrected working water head to the ecological flow storage unit.

[0139] The following uses specific application examples to compare the costs incurred by small hydropower stations with and without pumped gas energy storage devices to ensure downstream ecological flows under typical operating day time-of-use electricity prices.

[0140] The specific calculation model for the cost of ensuring downstream ecological flow for a small hydropower station with pumped gas energy storage is described as follows:

[0141]

[0142] Where, and The electricity prices are the off-peak and peak load periods respectively; 、 and They are respectively the power generation time of small hydropower stations during off-peak period, the pumping time of the peak control loop of pumped gas energy storage device, and the power generation time of the peak control loop of pumped gas energy storage device.

[0143] The installed capacity is set to 10.08MW and the storage capacity is 8.92 million The daily regulation small hydropower station is used as an example scenario, and the detailed parameters are shown in Table 1. The pumping efficiency of the pump turbine of the pumped gas energy storage device , the energy conversion efficiency of the energy storage device when releasing energy =0.7.

[0144]

[0145] During the dry season, to ensure ecological flow in the downstream river, small hydropower stations release water for power generation, at a cost of 2,019.15 yuan per day. Pumped-air storage devices replace these small hydropower stations in replenishing the downstream ecological flow, at a cost of 1,232.69 yuan per day. Compared to direct water release for power generation, these devices reduce costs by 786.462 yuan per day. Furthermore, during the flood season, when river flows are abundant and no ecological discharge reserves are required, pumped-air storage devices fully utilize their energy storage capabilities, generating a profit of 33,761.305 yuan per day through peak-valley price arbitrage.

[0146] This example selects a small hydropower station in the dry season to cooperate with pumped compressed gas energy storage to participate in the typical day grid operation and dispatch and a small hydropower station to participate in the typical day grid operation and dispatch for real-time comparison calculation. , the relevant parameters of small hydropower station are shown in Table 1.

[0147] During the evening low-load period (11:00 PM - 7:00 AM), the small hydropower station, constrained by reservoir capacity, generated 1.362 MWh of electricity to avoid abandoning water. To ensure the ecological flow requirements of the downstream river, the external circulation system of the pumped hydroelectric energy storage device released ecological flow and generated 0.769 MWh of electricity, while the internal circulation system of the pumped hydroelectric energy storage device stored this energy, totaling 2.131 MWh. During normal hours (7:00 AM - 10:00 AM and 2:00 PM - 5:00 PM), the small hydropower station generated sufficient electricity to meet the load, and the pumped hydroelectric energy storage device was inactive. During the daytime peak load period (11:00 AM - 2:00 PM and 5:00 PM - 11:00 PM), the small hydropower station discharged water at its peak, but still could not meet the load requirements. The pumped hydroelectric energy storage device released water to generate peak power, generating 1.885 MWh. Figure 3 Shown is a typical daily pumped-water compressed air energy storage coordinated small hydropower station output curve.

[0148] It can be understood that the same or similar parts of the above embodiments can be referenced to each other, and the contents not described in detail in some embodiments can refer to the same or similar contents in other embodiments.

[0149] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A control method for a pumped water compressed air energy storage device considering the ecological flow of a small power station, characterized in that: The steps include: S1: Collect the current time period information. If it is in the off-peak period, jump to step S2; if it is in the peak period, jump to step S5; If it is in other time periods, the pumped water compressed air energy storage device will not work; S2: Collect the reservoir water level of the small hydropower station and the inflow flow of the upstream river, establish a water abandonment flow model to calculate the flow discharged by the small hydropower station to avoid water abandonment; combine the flow discharged by the small hydropower station and the ecological flow demand of the river to calculate the ecological supplementary flow required to be released by the pumped gas energy storage device; establish the valve opening-flow relationship to determine the valve opening of the external circulation system of the pumped gas energy storage device during the off-peak period ; S3: Based on the turbine output, a power storage model is established to calculate the required storage power of the pumped water compressed air energy storage device; a power-pressure storage model of the pumped water compressed air energy storage device is established to calculate the pressure corresponding to the required storage power to determine the compression ratio of the compressor. ; S4: Valve opening of the external circulation system of the pumped water compressed gas energy storage device during the off-peak period and compressor compression ratio , control the pumped water compressed air energy storage device; if the valley period ends, return to step S1; S5: Collect water level information of the water storage tank in the pumped water compressed air energy storage device, establish an ecological flow storage model to calculate the pumping flow of the pumped water compressed air energy storage device; establish a valve opening-flow relationship to determine the valve opening of the external circulation system of the pumped water compressed air energy storage during peak hours ; S6: Based on the water pump output, calculate the power consumed by the pumping compressed air energy storage device; combine the current node load power and node power generation power issued by the power system dispatching center to establish the pumped compressed air energy storage power-pressure release model, calculate the working pressure of the pumped compressed air energy storage device when releasing energy, and determine the expansion ratio of the expander : S7: Valve opening of the external circulation system based on the pumped water compressed gas energy storage device and expander expansion ratio , control the pumped water compressed air energy storage device; if the peak period ends, return to step S1.

2. The control method of a pumped-air type energy storage device considering the ecological flow of a small power station according to claim 1 is characterized in that: In step S2, the abandoned water flow model is expressed as follows: ； Where, It is the flow rate released by small hydropower stations to avoid water abandonment; is the inflow flow of the upstream river; is the total storage capacity of the small hydropower station reservoir; is the current storage capacity of the small hydropower station reservoir, which is obtained according to the current water level of the small hydropower station reservoir; is the duration of the trough period; Valve opening of the external circulation system of the pumped water compressed gas energy storage device during the off-peak period Calculated by the following formula: ； Where, Supplementing traffic for the ecosystem; The maximum flow rate of the valve in the external circulation system of the pumped water compressed air energy storage device; The ecological flow demand of the river; is the downstream river flow.

3. The control method of a pumped water compressed air energy storage device considering the ecological flow of a small power station according to claim 1 is characterized in that: In step S3, the power storage model is expressed as follows: ； Where, The storage power required for the pumped gas energy storage device; The efficiency of water discharge for power generation in pumped hydro compressed gas energy storage devices; is the water flow density; is the acceleration due to gravity; The water head for discharging water to the pumped gas energy storage device is the height difference between the water level in the storage tank and the turbine; Supplementing traffic for the ecosystem; The current node power generation capacity issued by the power system dispatching center. This power generation capacity does not include the power generation capacity of small hydropower stations and pumped compressed air energy storage. The current node load power issued by the power system dispatching center; Power generation capacity of small hydropower station Calculated by the following formula: ； Where, For the power generation efficiency of small hydropower stations; The power generation head is the height difference between the water level of the small hydropower station reservoir and the turbine unit of the small hydropower station; It is the flow rate released by small hydropower stations to avoid water abandonment; It is the maximum energy storage power of the pumped gas energy storage device; It is the inflow flow rate when the power generation capacity of the small hydropower station reaches the maximum energy storage capacity of the pumped compressed air energy storage device.

4. The control method of a pumped water compressed air energy storage device considering the ecological flow of a small power station according to claim 1 is characterized in that: In step S3, the power-pressure storage model of the pumped water compressed air energy storage is expressed as follows: ； Where, is the energy storage pressure; is the duration of the trough period; The storage power required for the pumped gas energy storage device; is the atmospheric pressure; is the volume of the water storage tank; is the volume of the high-pressure gas storage tank; Compressor compression ratio Calculated by the following formula: ； Where, The power consumed by the water pump to perform the first stage of compression; The time it takes for the pump to perform the first stage of compression; It is the volume of compressed air obtained after the first stage of compression.

5. The control method of a pumped water compressed air energy storage device considering the ecological flow of a small power station according to claim 1 is characterized in that: In step S5, the ecological flow storage model is expressed as follows: ； in, The pumping flow rate of the pumped compressed air energy storage device; The ecological flow demand of the river; is the duration of the trough period; is the water level in the water storage tank; is the bottom area of ​​the water storage tank; Valve opening of the external circulation system of water pumping, compressed air and energy storage during peak hours Calculated by the following formula: ； Where, It is the maximum flow rate of the valve of the external circulation system of the pumped water compressed air energy storage device.

6. The control method of a pumped-air type energy storage device considering the ecological flow of a small power station according to claim 1 is characterized in that: In step S6, the power-pressure release model of the pumped water compressed air energy storage is expressed as follows: ； Where, is the pumping efficiency; is the water flow density; is the acceleration due to gravity; The water head for discharging water to the pumped gas energy storage device is the height difference between the water level in the storage tank and the turbine; The pumping flow rate of the pumped compressed air energy storage device; The energy conversion efficiency of the pumped water compressed gas energy storage device when releasing energy; The amount of water stored in the expansion end water vapor tank; The current node load power issued by the power system dispatching center; The power generated by the small hydropower station at the current moment; The current node power generation capacity issued by the power system dispatching center. This power generation capacity does not include the power generation capacity of small hydropower stations and pumped compressed air energy storage. Expander expansion ratio Calculated by the following formula: ； Where, is the energy storage pressure; It is the working pressure of pumped water compressed air energy storage when releasing energy.

7. The control method of a pumped water compressed air energy storage device considering the ecological flow of a small power station according to claim 1 is characterized in that: In step S4, during the control of the pumped gas energy storage device, the real-time ecological flow of the downstream river is collected. , the valve opening of the external circulation system of the pumped water compressed air energy storage device during the off-peak period Make corrections: ； ； Where, Supplementing traffic for the ecosystem; The maximum flow rate of the valve in the external circulation system of the pumped water compressed air energy storage device; The ecological flow demand of the river; is the downstream river flow; It is the flow rate released by small hydropower stations to avoid water abandonment; It is the correction value of the discharge flow of the water storage tank.

8. The control method of a pumped water compressed air energy storage device considering the ecological flow of a small power station according to claim 1 is characterized in that: In step S7, during the control process of the pumped air energy storage device, the real-time water level of the water storage tank is collected. , for the expander expansion ratio Make corrections: ； ； Where, is the energy storage pressure; is the pumping efficiency; is the water flow density; is the acceleration due to gravity; The water head for discharging water to the pumped gas energy storage device is the height difference between the water level in the storage tank and the turbine; The pumping flow rate of the pumped compressed air energy storage device; The energy conversion efficiency of the pumped water compressed gas energy storage device when releasing energy; The amount of water stored in the expansion end water vapor tank; The current node load power issued by the power system dispatching center; is the power generation capacity of the small hydropower station at the current moment; is the increase in water level in the water storage tank, and its value is ; It is the power generation capacity of the node at the current moment issued by the power system dispatching center. This power generation capacity does not include the power generation capacity of small hydropower stations and pumped compressed air energy storage.

9. The control method of a pumped water compressed air energy storage device considering the ecological flow of a small power station according to claim 1, characterized in that: In step S7, during the control process of the pumped air energy storage device, if the water storage tank reaches the maximum storage capacity , the water pump stops pumping water; if the air pressure in the high-pressure gas tank is atmospheric pressure , the expander, turbine and generator stop working; if the peak period ends, return to step S1.

10. A control system for a pumped water compressed air energy storage device taking into account the ecological flow of a small power station, characterized in that: It includes a sensor data acquisition module and a control module connected thereto; The data acquisition module includes a first liquid level sensor, a second liquid level sensor, a reservoir water level sensor, a pressure sensor, a first radar flow meter, a second radar flow meter, a third radar flow meter, and an ultrasonic flow meter; The first liquid level sensor is used to monitor the water level in the water storage tank; the second liquid level sensor is used to monitor the water level in the expansion end water vapor tank; the reservoir water level sensor is used to monitor the water level in the small hydropower station reservoir; the pressure sensor is used to monitor the pressure in the high-pressure gas storage tank; the first radar flow meter is used to monitor the flow of water in the upstream river; the second radar flow meter is used to monitor the flow of the downstream river before the ecological flow is released; The third radar flow meter is used to monitor the flow in the downstream river after the ecological flow is released; The control module includes: a memory having a computer program stored thereon; A processor for loading and executing the computer program to implement the control method of a pumped-air energy storage device taking into account the ecological flow of a small power station as described in any one of claims 1 to 9.

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