Hydroelectric power generation system

Abstract

A hydroelectric power generation system (10) is provided with: a flow path (11) through which water flows and which has a reservoir (102) on a downstream side; a power generation unit (12) which converts the energy of water (W) flowing through the flow path (11) into electric power; an electric valve (13) which adjusts a flow rate of the water (W) flowing through the flow path (11); and a control unit (14) which controls the electric valve (13) on the basis of a target value. The control unit (14) selects the target value from two or more preset setting values, and the two or more setting values include a first setting value that is greater than a maximum value of an outflow flow rate (Q2) from the reservoir (102).

Description

Hydroelectric power generation system

[0001] The present disclosure relates to a hydroelectric power generation system.

[0002] Conventionally, as a small-scale hydroelectric power generation system, there is a hydroelectric power generation system as disclosed in Patent Document 1, for example. In this hydroelectric power generation system, a generator and an electric valve are provided in a flow path connecting a storage pond such as a purification pond on the upstream side and a storage pond such as a water distribution pond on the downstream side. The generator converts the energy of the water flowing through the flow path into electric power. The electric valve adjusts the flow rate of the water flowing through the flow path. The water stored in the storage pond on the downstream side is distributed to houses, facilities, etc. Therefore, the outflow flow rate, which is the flow rate of the water flowing out from the storage pond, varies according to the usage conditions in houses, facilities, etc. In a general hydroelectric power generation system, in order to keep the water level in the storage pond constant, the electric valve is controlled so that the outflow flow rate and the inflow flow rate in the storage pond match.

[0003] Japanese Unexamined Patent Application Publication No. 2018 - 207696

[0004] However, in the above hydroelectric power generation system, since the inflow flow rate into the storage pond is controlled to match the outflow flow rate from the storage pond, the flow rate of the water supplied to the generator is limited. As a result, there is a problem that the power generation output of the generator is limited. An object of the present disclosure is to provide a hydroelectric power generation system capable of increasing the power generation amount.

[0005] The hydroelectric power generation system according to the first aspect of the present disclosure is a hydroelectric power generation system including a flow path through which water flows and having a storage pond on the downstream side, a power generation unit that converts the energy of the water flowing through the flow path into electric power, an electric valve that adjusts the flow rate of the water flowing through the flow path, and a control unit that controls the electric valve based on a target value. The control unit selects the target value from two or more preset values, and the two or more preset values include a first preset value that is larger than the maximum value of the outflow flow rate from the storage pond.

[0006] In this configuration, the flow rate of water supplied to the power generation unit is controlled by the control unit based on a target value selected from two or more setpoints. These two or more setpoints include a first setpoint that is greater than the maximum outflow rate from the reservoir. This allows for a timing where the flow rate of water supplied to the power generation unit exceeds the maximum outflow rate from the reservoir, thereby increasing the amount of power generated by the power generation unit.

[0007] The hydroelectric power generation system from the second perspective is one in which, in the hydroelectric power generation system from the first perspective, the two or more set values ​​include a second set value that is smaller than the minimum outflow rate from the reservoir. With this configuration, the set value that determines the flow rate of water supplied to the power generation unit includes a second set value that is smaller than the minimum outflow rate from the reservoir. Therefore, by allowing time to operate at the second set value, the first set value can be set to a higher value or the time to operate at the first set value can be set to a longer value, thereby making it possible to further increase the amount of power generated in the power generation unit.

[0008] In the hydroelectric power generation system of the third perspective, the control unit alternately selects the first set value and the second set value as the target value. With this configuration, the control of the electric valve can be simplified because the control is switched between two values, the first set value and the second set value. In addition, since the time spent operating at the first set value can be extended, the amount of power generated in the power generation unit can be further increased.

[0009] The hydroelectric power generation system in the fourth perspective is the hydroelectric power generation system in the second or third perspective, in which the second setting value is the minimum inflow rate of water flowing from the flow path to the reservoir. With this configuration, the second setting value can be set to the minimum value that the hydroelectric power generation system can take. This makes it possible to set the first setting value to a higher value or to set the operating time at the first setting value to a longer value, thereby making it possible to further increase the amount of power generated in the power generation section.

[0010] The fifth perspective of the hydroelectric power generation system is a hydroelectric power generation system according to any one of the first to fourth perspectives, in which the first set value is the maximum value of the inflow rate of water flowing from the flow channel into the reservoir.

[0011] This configuration allows the first setpoint to be the maximum value that the hydroelectric power generation system can take. This makes it possible to further increase the amount of power generated by the power generation unit when operating at the first setpoint.

[0012] In the sixth perspective, the hydroelectric power generation system is a hydroelectric power generation system in any one of the first to fifth perspectives, in which the control unit selects the target value from the two or more set values ​​based on the water level information of the reservoir.

[0013] This configuration makes it possible to prevent the reservoir water level from reaching an upper or lower limit. The hydroelectric power generation system in the seventh view is the hydroelectric power generation system in the sixth view, wherein the two or more set values ​​include a second set value that is smaller than the minimum outflow rate from the reservoir, and the control unit selects the first set value as the target value when the reservoir water level is below a first threshold, and selects the second set value as the target value when the reservoir water level is above a second threshold that is greater than the first threshold.

[0014] With this configuration, by using the first and second threshold values ​​when the control unit switches between the first and second setpoints, it becomes possible to increase the amount of power generated in the power generation unit while suppressing the reservoir water level from reaching the upper or lower limit.

[0015] In the hydroelectric power generation system of the eighth perspective, in a hydroelectric power generation system of any one of the first to seventh perspectives, the control unit selects the target value from the two or more set values ​​based on the passage of time.

[0016] This configuration ensures that the amount of power generated per unit time is stable, making it easier to manage the amount of power generated. The hydroelectric power generation system of the ninth perspective comprises a first power generation system and a second power generation system, each having the flow path, the power generation unit, the electric valve, and the control unit, in any one of the first to eighth perspectives, wherein when the target value of the first power generation system is greater than the maximum outflow rate from the reservoir located downstream of the flow path of the first power generation system, the target value of the second power generation system is less than the maximum outflow rate from the reservoir located downstream of the flow path of the second power generation system.

[0017] This configuration allows for stable power generation by combining the first and second power generation systems and by staggering the timing of operation at the first set value, which represents the highest power output, for both systems.

[0018] This is a schematic diagram of a water supply facility into which a hydroelectric power generation system of one embodiment has been introduced. This is an explanatory diagram for explaining the control mode of the control unit in the hydroelectric power generation system of the same embodiment. This is a flowchart of the control mode of the control unit in the hydroelectric power generation system of the same embodiment. This is an explanatory diagram for explaining the control mode of the control unit in a modified example. This is a schematic diagram of a water supply facility into which a hydroelectric power generation system of the modified example has been introduced. This is an explanatory diagram for explaining the operation of the hydroelectric power generation system of the modified example.

[0019] <Hydroelectric Power Generation System> The hydroelectric power generation system 10 will be described with reference to Figures 1 to 3. <Water Supply Facility 100> The hydroelectric power generation system 10 of this embodiment shown in Figure 1 is applied to, for example, a water supply facility 100. The water supply facility 100 includes, for example, a water treatment plant 101, a reservoir 102 located downstream of the water treatment plant 101, and a flow channel 11 connecting the water treatment plant 101 and the reservoir 102. Due to the difference in elevation between the water treatment plant 101 and the reservoir 102, water W flows from the water treatment plant 101 to the reservoir 102 in the flow channel 11. In other words, water stored in the water treatment plant 101 flows into the reservoir 102 through the flow channel 11. The reservoir 102 temporarily stores the water that flows in from the flow channel 11. The water stored in the reservoir 102 is then distributed to the target of supply 104, such as houses and buildings, via the distribution pipe 103. In the following explanation, the flow rate of water flowing into the reservoir 102 through the channel 11 will be referred to as "inflow flow rate Q1," and the flow rate of water flowing out of the reservoir 102 into the distribution pipe 103 will be referred to as "outflow flow rate Q2."

[0020] <Hydroelectric Power Generation System 10> The hydroelectric power generation system 10 is configured to include a flow channel 11 and utilizes the effective head between the water treatment plant 101 and the reservoir 102 in the water supply facility 100 as an energy source for power generation. The hydroelectric power generation system 10 comprises a flow channel 11, a power generation unit 12, an electric valve 13, and a control unit 14.

[0021] The power generation unit 12 and the electric valve 13 are provided in the flow path 11. The electric valve 13 includes a motor 15 as a drive source. The electric valve 13 is opened and closed by the drive of the motor 15 to adjust the flow rate of water W flowing through the flow path 11. The power generation unit 12 includes, for example, a water turbine provided in the flow path 11 and a generator connected to the water turbine. The power generation unit 12 converts the energy of the water W flowing through the flow path 11 into electricity. That is, the power generation unit 12 generates power in the generator by the rotation of the water turbine, which is affected by the flow of water W in the flow path 11. The electric valve 13 is provided, for example, upstream of the power generation unit 12. That is, the flow rate of water W supplied to the power generation unit 12 is adjusted by the electric valve 13. When the electric valve 13 is opened and the flow rate of water W increases, the power generated in the power generation unit 12 increases, and when the electric valve 13 is closed and the flow rate of water W decreases, the power generated in the power generation unit 12 decreases. The electricity generated in the power generation unit 12 is supplied to the recipients of the power supply, such as power transmission and distribution companies, via a power conditioner, etc. Furthermore, there is a correlation between the flow rate of water W flowing through the channel 11 (the flow rate of water W supplied to the power generation unit 12) and the inflow flow rate Q1 flowing into the reservoir 102, and the inflow flow rate Q1 increases or decreases in accordance with the increase or decrease in the flow rate of water W flowing through the channel 11.

[0022] The hydroelectric power generation system 10 includes, for example, a flow meter 16 that detects the flow rate of water W flowing through the channel 11. The flow meter 16 is installed, for example, downstream of the power generation unit 12 and detects the inflow flow rate Q1 of water that passes through the power generation unit 12 and flows into the reservoir 102. The flow meter 16 outputs the detected inflow flow rate Q1 information to the control unit 14.

[0023] <Control Unit 14> The control unit 14 controls the flow rate of water W flowing through the flow path 11 by controlling the opening degree of the electric valve 13. The control unit 14 includes, for example, a CPU (Central Processing Unit) or MPU (Micro-processor Unit) and memory. The control unit 14 performs various controls based on the program and various information stored in the memory.

[0024] The control unit 14 controls the electric valve 13 based on a target value Qg. In this embodiment, the control unit 14 selects a target value Qg from two preset set values ​​(first set value A1 and second set value A2) and performs flow rate control to bring the flow rate of water W flowing through the flow path 11 closer to the selected target value Qg. The first set value A1 and the second set value A2 are stored, for example, in the memory of the control unit 14. The control unit 14 controls the electric valve 13 by feedback control based on the difference between the detected value of the inflow flow rate Q1 input from the flow meter 16 and the selected target value Qg.

[0025] <First setting value A1 and second setting value A2> As shown in Figure 2, the first setting value A1 and the second setting value A2 are values ​​set based on the predicted value Q2p of the outflow rate Q2 of water flowing out of the reservoir 102. The predicted value Q2p of the outflow rate Q2 is data that represents the fluctuation of the outflow rate Q2 over 24 hours, predicted based on the measurement data of the outflow rate Q2 of the reservoir 102 over the past week. The first setting value A1 is set to a value greater than the maximum value Q2max of the predicted value Q2p. The second setting value A2 is set to a value less than the minimum value Q2min of the predicted value Q2p.

[0026] Furthermore, the predicted value Q2p can be a value predicted based on measurement data of the outflow rate Q2 of the reservoir 102 at the same time last year. Alternatively, the predicted value Q2p can be a value predicted based on measurement data of the outflow rate Q2 of the reservoir 102 one day prior. Additionally, the maximum value Q2max and minimum value Q2min of the predicted value Q2p can be the annual average of the maximum and minimum daily outflow rate Q2 obtained from measurement data of the outflow rate Q2 of the reservoir 102 over the past year. Furthermore, the maximum value Q2max and minimum value Q2min of the predicted value Q2p can be the maximum and minimum values ​​of the outflow rate Q2 of the reservoir 102 over the past year, respectively. Additionally, the maximum value Q2max and minimum value Q2min of the predicted value Q2p can be the maximum and minimum daily measurement data based on measurement data of the outflow rate Q2 over a predetermined period in the past (e.g., 3 years), where the temperature, weather, and whether it is a weekday or holiday are the same.

[0027] In this embodiment, the first set value A1 is the maximum value of the inflow rate Q1 of water flowing from the flow path 11 to the reservoir 102. The inflow rate Q1 is maximized, for example, when the electric valve 13 is fully open. That is, the maximum value of the inflow rate Q1 is the outflow rate Q2 when the electric valve 13 is fully open. Furthermore, the maximum value of the inflow rate Q1 is greater than the maximum value Q2max of the predicted value Q2p.

[0028] In this embodiment, the second set value A2 is the minimum value of the inflow rate Q1 of water flowing from the flow path 11 to the reservoir 102. The inflow rate Q1 is minimized, for example, when the electric valve 13 is fully closed. When the electric valve 13 is fully closed, the inflow rate Q1 is 0 [m³]. ３ / h]. In other words, the minimum value of the inflow flow rate Q1 in this embodiment is 0 [m ３ [ / h]. Also, the minimum value of the inflow rate Q1 is smaller than the minimum value Q2min of the predicted value Q2p.

[0029] The control unit 14 sets either the first set value A1 or the second set value A2 to the target value Qg based on the water level information Dw of the reservoir 102. The control unit 14 receives the water level information Dw from the water level gauge 105 installed in the reservoir 102 (see Figure 1). The water level gauge 105 detects the water level WL in the reservoir 102, and various types such as ultrasonic or float type gauges can be used.

[0030] As shown in Figure 2, when the water level WL of the reservoir 102 based on the water level information Dw falls below the first threshold WL1, the control unit 14 switches the target value Qg from the second setting value A2 to the first setting value A1. Also, when the water level WL of the reservoir 102 based on the water level information Dw falls above the second threshold WL2, the control unit 14 switches the target value Qg from the first setting value A1 to the second setting value A2. The first threshold WL1 is a preset value and is set to a value near the lower limit hmin (see Figure 1) of the water level of the reservoir 102, which is greater than the lower limit hmin (see Figure 1). The second threshold WL2 is a preset value and is set to a value near the upper limit hmax (see Figure 1) of the water level of the reservoir 102, which is less than the upper limit hmax (see Figure 1). The second threshold WL2 is a value greater than the first threshold WL1. The first threshold WL1 and the second threshold WL2 are stored, for example, in the memory of the control unit 14.

[0031] (Control Mode of Control Unit 14) Figure 3 is a flowchart showing the control mode of the control unit 14. As shown in Figure 3, in step S1, the control unit 14 selects a second set value A2 as the target value Qg and performs flow control to bring the flow rate of the water W flowing through the flow path 11 (inflow flow rate Q1) closer to the second set value A2. Here, the second set value A2 is 0 [m ３ If set to [ / h], the control unit 14 closes the electric valve 13 completely. After step S1, the control unit 14 proceeds to step S2.

[0032] In step S2, the control unit 14 determines whether the water level WL in the reservoir 102 is less than or equal to the first threshold WL1. If the water level WL is greater than the first threshold WL1 (step S2: NO), the control unit 14 repeats step S2. At this time, the electric valve 13 is kept open at the degree based on the second set value A2 selected for the target value Qg. If the water level WL is less than or equal to the first threshold WL1 (step S2: YES) in step S2, the control unit 14 proceeds to step S3.

[0033] In step S3, the control unit 14 selects a first set value A1 as the target value Qg and performs flow rate control to bring the flow rate of water W flowing through the flow path 11 (inflow flow rate Q1) closer to the first set value A1. At this point, the control unit 14 fully opens the electric valve 13 based on the first set value A1, and the inflow flow rate Q1 becomes the maximum value. After step S3, the control unit 14 proceeds to step S4.

[0034] In step S4, the control unit 14 determines whether the water level WL of the reservoir 102 is equal to or greater than the second threshold WL2. If the water level WL is less than the second threshold WL2 (step S4: NO), the control unit 14 repeats step S4. At this time, the electric valve 13 is kept open at the degree based on the first set value A1 selected as the target value Qg. In step S4, if the water level WL is equal to or greater than the second threshold WL2 (step S4: YES), the control unit 14 returns to step S1. In this manner, the control unit 14 alternately selects the first set value A1 and the second set value A2 as the target value Qg based on the water level information Dw (water level WL) of the reservoir 102.

[0035] The operation of this embodiment will now be explained. The control unit 14 selects either a first setting value A1 or a second setting value A2 as the target value Qg when controlling the electric valve 13. Here, the first setting value A1 is set to a value greater than the maximum value Q2max of the outflow rate Q2 (predicted value Q2p) from the reservoir 102. Therefore, when the first setting value A1 is selected as the target value Qg, a flow rate greater than the maximum value Q2max of the outflow rate Q2 is supplied to the power generation unit 12. As a result, compared to the conventional technology in which the electric valve 13 is controlled so that the inflow rate Q1 in the reservoir 102 matches the outflow rate Q2, it becomes possible to drive the power generation unit 12 with a larger flow rate. As a result, it becomes possible to increase the amount of power generated in the power generation unit 12. The second setting value A2 is set to a value smaller than the minimum value Q2min of the outflow rate Q2 (predicted value Q2p) from the reservoir 102. The smaller the second setting value A2, the higher the first setting value A1 can be set to, and the longer the operating time at the first setting value A1. This makes it possible to further increase the amount of power generated by the power generation unit 12.

[0036] Furthermore, the control unit 14 switches the target value Qg from the second setting value A2 to the first setting value A1 when the water level WL of the reservoir 102 falls below the first threshold WL1, and switches the target value Qg from the first setting value A1 to the second setting value A2 when the water level WL falls above the second threshold WL2. This makes it possible to prevent the water level WL of the reservoir 102 from exceeding the upper water level limit hmax and from falling below the lower water level limit hmin.

[0037] The effects of this embodiment will now be explained. (1) The flow rate of water W supplied to the power generation unit 12 is controlled by the control unit 14 based on a target value Qg selected from two set values. The two set values ​​include a first set value A1 that is greater than the maximum value Q2max of the outflow flow rate Q2 (predicted value Q2p) from the reservoir 102. As a result, there are times when the flow rate of water W supplied to the power generation unit 12 is greater than the maximum value Q2max of the outflow flow rate Q2 from the reservoir 102, making it possible to increase the amount of power generated in the power generation unit 12.

[0038] (2) The two set values ​​that determine the flow rate of water W supplied to the power generation unit 12 include a second set value A2 that is smaller than the minimum value Q2min of the outflow flow rate Q2 (predicted value Q2p) from the reservoir 102. Therefore, by setting a time for operation with the second set value A2, it is possible to set the first set value A1 to a higher value or to set a longer time for operation with the first set value A1, thereby making it possible to further increase the amount of power generated by the power generation unit 12.

[0039] (3) The control unit 14 alternately selects the first set value A1 and the second set value A2 as the target value Qg. With this configuration, the selection control of the target value Qg is a switching control between two values, the first set value A1 and the second set value A2, which simplifies the control of the electric valve 13. In addition, since the time spent operating at the first set value A1 can be extended, it becomes possible to further increase the amount of power generated by the power generation unit 12.

[0040] (4) The second set value A2 is the minimum value of the inflow rate Q1 of the water W flowing from the flow path 11 into the storage pond 102. According to this configuration, the second set value A2 can be set to the minimum value that the hydroelectric power generation system 10 can take. As a result, the first set value A1 can be set to a higher value or the operation time at the first set value A1 can be set longer, so that the power generation amount in the power generation unit 12 can be further increased.

[0041] (5) The first set value A1 is the maximum value of the inflow rate Q1 of the water W flowing from the flow path 11 into the storage pond 102. According to this configuration, the first set value A1 can be set to the maximum value that the hydroelectric power generation system 10 can take. As a result, the power generation amount in the power generation unit 12 when operating at the first set value A1 can be further increased.

[0042] (6) The control unit 14 selects the target value Qg from the first set value A1 and the second set value A2 based on the water level information Dw of the storage pond 102. According to this configuration, it is possible to suppress the water level WL of the storage pond 102 from reaching the water level upper limit hmax or the water level lower limit hmin.

[0043] (7) When the water level WL of the storage pond 102 is below the first threshold value WL1, the control unit 14 selects the first set value A1 as the target value Qg, and when the water level WL of the storage pond 102 is above the second threshold value WL2 which is larger than the first threshold value WL1, the control unit 14 selects the second set value A2 as the target value Qg. According to this configuration, by using the first threshold value WL1 and the second threshold value WL2 in the switching between the first set value A1 and the second set value A2 by the control unit 14, while suppressing the water level WL of the storage pond 102 from reaching the water level upper limit hmax or the water level lower limit hmin, it is possible to make the operation time at the first set value A1 as long as possible. For this reason, the power generation amount in the power generation unit 12 can be further increased.

[0044] <Modification example> The hydroelectric power generation system 10 of the present disclosure may be in a form other than the above-described embodiment, for example, a modification example shown below, or a combination of at least two non-contradictory modification examples.

[0045] ・In the above-described embodiment, the control unit 14 selects the target value Qg from the first set value A1 and the second set value A2 based on the water level information Dw of the storage tank 102. However, it is not particularly limited to this, and the selection mode of the target value Qg of the control unit 14 can be appropriately changed according to the configuration of the water supply facility 100 and the like. For example, as shown in FIG. 4, the control unit 14 may select the target value Qg from the first set value A1 and the second set value A2 based on the passage of time. In the example shown in FIG. 4, when the elapsed time of the operation at the first set value A1 reaches the first set time T1 set in advance, the control unit 14 switches the target value Qg from the first set value A1 to the second set value A2. Further, when the elapsed time of the operation at the second set value A2 reaches the second set time T2 set in advance, the control unit 14 switches the target value Qg from the second set value A2 to the first set value A1. The control unit 14 repeats the switching control between the first set value A1 and the second set value A2 described above. According to such control, since the power generation amount of the power generation unit 12 per unit time is stabilized, the management of the power generation amount becomes easy. Further, according to such control, since the control unit 14 alternately selects the first set value A1 and the second set value A2 as the target value Qg, the selection control of the target value Qg becomes a switching control between two values of the first set value A1 and the second set value A2. Therefore, the control of the motor-operated valve 13 can be simplified. Note that the first set time T1 and the second set time T2 may be set to the same value. Further, the first set time T1 may be set to a value smaller or larger than the second set time T2.

[0046] ・The hydroelectric power generation system 10 in the above-described embodiment may be changed to, for example, the hydroelectric power generation system 10A shown in FIG. 5. The hydroelectric power generation system 10A includes a first power generation system E1 and a second power generation system E2. The first power generation system E1 and the second power generation system E2 are respectively provided in two water supply facilities (the first water supply facility 201 and the second water supply facility 202).

[0047] The first water supply facility 201 and the second water supply facility 202 each have the same configuration as the water supply facility 100 in the above embodiment. That is, the first water supply facility 201 and the second water supply facility 202 each include a water treatment plant 101, a reservoir 102, and a flow path 11, etc. The water stored in the reservoirs 102 of the first water supply facility 201 and the second water supply facility 202 is distributed to the target recipients 104 such as houses and buildings.

[0048] The first power generation system E1 and the second power generation system E2 each have the same configuration as the hydroelectric power generation system 10 of the above embodiment. That is, the first power generation system E1 and the second power generation system E2 each have the same flow path 11, power generation unit 12, electric valve 13, control unit 14, and flow meter 16 as the hydroelectric power generation system 10 of the above embodiment. The first power generation system E1 and the second power generation system E2 can send and receive signals between their respective control units 14. Each control unit 14 in the first power generation system E1 and the second power generation system E2 selects a target value Qg from a plurality of set values ​​(for example, first set value A1 and second set value A2) based on the water level information Dw of the reservoir 102 or the passage of time.

[0049] Figure 6 shows the control modes in the control units 14 of the first power generation system E1 and the second power generation system E2. In the following description, the target value Qg in the first power generation system E1 will be referred to as the first target value Qg1, and the maximum value that the first target value Qg1 can take will be referred to as the maximum value Qg1max. For example, if the first target value Qg1 is selected from either the first setting value A1 or the second setting value A2, the maximum value Qg1max of the first target value Qg1 will be the first setting value A1. Similarly, the target value Qg in the second power generation system E2 will be referred to as the second target value Qg2, and the maximum value that the second target value Qg2 can take will be referred to as the maximum value Qg2max. For example, if the second target value Qg2 is selected from either the first setting value A1 or the second setting value A2, the maximum value Qg2max of the second target value Qg2 will be the first setting value A1. Furthermore, in the following explanation, the outflow rate Q2 from the reservoir 102 in the first power generation system E1 will be referred to as the first outflow rate Q2a, and the outflow rate Q2 from the reservoir 102 in the second power generation system E2 will be referred to as the second outflow rate Q2b.

[0050] As shown in Figure 6, when the first target value Qg1 in the first power generation system E1 is greater than the maximum value Q2amax of the first outflow rate Q2a, the second target value Qg2 in the second power generation system E2 is less than the maximum value Q2bmax of the second outflow rate Q2b. For example, when the first setting value A1 is selected as the first target value Qg1 in the first power generation system E1, the second setting value A2 is selected as the second target value Qg2 in the second power generation system E2.

[0051] Furthermore, when the first target value Qg1 in the first power generation system E1 is smaller than the maximum value Q2amax of the first outflow rate Q2a, the second target value Qg2 in the second power generation system E2 is larger than the maximum value Q2bmax of the second outflow rate Q2b. For example, when the second setting value A2 is selected as the first target value Qg1 in the first power generation system E1, the first setting value A1 is selected as the second target value Qg2 in the second power generation system E2. Note that the maximum values ​​Q2amax and Q2bmax of the first outflow rate Q2a and the second outflow rate Q2b are predicted values ​​based on past data, etc., similar to the predicted value Q2p of the outflow rate Q2 in the above embodiment.

[0052] According to the control configuration shown in the example in Figure 6, by combining the first power generation system E1 and the second power generation system E2, and by staggering the timing of operation at the first setpoint A1 (a value greater than the maximum value Q2max of the outflow rate Q2) for both systems, stable power generation becomes possible. In Figures 5 and 6, the hydroelectric power generation system 10A is given as an example configuration that includes two power generation systems (first power generation system E1 and second power generation system E2), but the hydroelectric power generation system 10A is not limited to this and may include three or more power generation systems.

[0053] In the above embodiment, the first set value A1 was set to the maximum value of the inflow flow rate Q1. However, it is not limited to this, and the first set value A1 can be set to a value other than the maximum value of the inflow flow rate Q1, as long as it is greater than the maximum value of the outflow flow rate Q2 Q2max.

[0054] In the above embodiment, the second setting value A2 is set to the minimum value of the inflow flow rate Q1, but it is not limited to this, and the value of the second setting value A2 can be changed within a range smaller than that of the first setting value A1.

[0055] In the above embodiment, the number of setting values ​​(first setting value A1 and second setting value A2) that the control unit 14 can select as the target value Qg is two, but the number of setting values ​​that the control unit 14 can select as the target value Qg may be three or more.

[0056] The control unit 14 may be configured as a circuit including: 1) one or more processors that execute various processes according to a computer program (software); 2) one or more dedicated hardware circuits, such as application-specific integrated circuits (ASICs), that execute at least some of the various processes; or 3) a combination thereof. The processor includes a CPU and memory such as RAM and ROM, and the memory stores program code or instructions configured to cause the CPU to execute processes. Memory, or computer-readable media, includes any available media that can be accessed by a general-purpose or dedicated computer.

[0057] ・Although embodiments of the hydroelectric power generation systems 10 and 10A have been described above, it should be understood that various modifications to the form and details are possible without departing from the spirit and scope of the hydroelectric power generation systems 10 and 10A as described in the claims.

[0058] 10, 10A...Hydroelectric power generation system, 11...Flow path, 12...Power generation unit, 13...Electric valve, 14...Control unit, 102...Reservoir, A1...First setpoint, A2...Second setpoint, Dw...Water level information, E1...First power generation system, E2...Second power generation system, Q1...Inflow rate, Q2...Outflow rate, Q2max...Maximum outflow rate, Q2min...Minimum outflow rate, Q2a...First outflow rate (outflow rate), Q2amax...Maximum first outflow rate, Q2b...Second outflow rate (outflow rate), Q2bmax...Maximum second outflow rate, Qg...Target value, Qg1...First target value (target value), Qg2...Second target value (target value), WL...Water level, WL1...First threshold, WL2...Second threshold.

Claims

1. A hydroelectric power generation system (10) comprising: a channel (11) through which water flows and which has a reservoir (102) downstream; a power generation unit (12) that converts the energy of the water flowing through the channel into electricity; an electric valve (13) that adjusts the flow rate of the water flowing through the channel; and a control unit (14) that controls the electric valve based on a target value (Qg), wherein the control unit selects the target value from two or more preset set values ​​(A1, A2), and the two or more set values ​​include a first set value (A1) that is greater than the maximum value (Q2max) of the outflow rate (Q2) from the reservoir.

2. The hydroelectric power generation system according to claim 1, wherein the two or more setting values ​​include a second setting value (A2) that is smaller than the minimum outflow rate (Q2min) from the reservoir.

3. The hydroelectric power generation system according to claim 2, wherein the control unit alternately selects the first set value and the second set value as the target value.

4. The hydroelectric power generation system according to claim 2 or 3, wherein the second set value is the minimum value of the inflow rate (Q1) of water flowing from the flow path into the reservoir.

5. The hydroelectric power generation system according to any one of claims 1 to 4, wherein the first set value is the maximum value of the inflow rate (Q1) of water flowing from the flow path into the reservoir.

6. The hydroelectric power generation system according to any one of claims 1 to 5, wherein the control unit selects the target value from the two or more set values ​​based on the water level information (Dw) of the reservoir.

7. The hydroelectric power generation system according to claim 6, wherein the two or more setting values ​​include a second setting value (A2) which is smaller than the minimum outflow rate (Q2min) from the reservoir, and the control unit selects the first setting value as the target value when the water level of the reservoir is less than or equal to a first threshold (WL1), and selects the second setting value as the target value when the water level of the reservoir is greater than or equal to a second threshold (WL2) which is greater than the first threshold.

8. The control unit selects the target value from the two or more set values ​​based on the passage of time, the hydroelectric power generation system according to any one of claims 1 to 7.

9. A hydroelectric power generation system according to any one of claims 1 to 8, comprising a first power generation system (E1) and a second power generation system (E2), each having the flow path, the power generation unit, the electric valve, and the control unit, wherein when the target value (Qg1) of the first power generation system is greater than the maximum value (Q2amax) of the outflow rate (Q2a) from the reservoir located downstream of the flow path of the first power generation system, the target value (Qg2) of the second power generation system is less than the maximum value (Q2bmax) of the outflow rate (Q2b) from the reservoir located downstream of the flow path of the second power generation system.

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