Hydroelectric power generation device and control method

Abstract

To provide a hydraulic power generation device and a control method for efficiently performing dust removal processing.SOLUTION: A hydraulic power generation device 100 includes a water turbine 1, a power generator 3 that generates power by rotating the water turbine 1, and a control device 8. The control device 8 periodically acquires the amount of power generated by the power generator 3, periodically acquires the rotation speed of the water turbine 1, calculates a first value based on the previously acquired amount of power generation and the amount of power generation acquired this time, calculates a second value based on a difference value between the previously acquired rotation speed and the rotation speed acquired this time, and determines whether to perform the dust removal process for removing dust from the water turbine 1 on the basis of the first value and the second value.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a hydroelectric power generating device and a control method. [Background technology]

[0002] A hydroelectric power generation device is a device that uses the kinetic energy of flowing water to generate electricity. The main components of a hydroelectric power generation device are a water wheel that rotates when exposed to the flow of water, a generator that is connected to the water wheel and converts the rotational energy into electrical energy, and a control device that controls the output of the generator and the water wheel. Foreign objects (such as garbage, water plants, branches, strings, etc.) that drift to the generator from upstream can become entangled in the water wheel and cause a decrease in the amount of electricity generated. Therefore, measures against foreign objects are important in hydroelectric power generation. For example, it is preferable to install a device that removes foreign objects upstream of the water wheel. However, for small hydroelectric power generation devices that are small and can be easily installed in waterways, it is difficult to use large-scale dust removal equipment because it increases costs.

[0003] Patent Document 1 discloses a hydroelectric generator that performs a dust removal process. The dust removal process is a process that removes foreign matter by repeatedly stopping and rotating the blades of the water turbine. Patent Document 1 discloses that the dust removal process is performed when the amount of power generated by the hydroelectric power generation device falls below a threshold value. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-90892 A Summary of the Invention [Problem to be solved by the invention]

[0005] The flow rate of water at the location where the hydroelectric power generation device is installed may change. For example, if the flow rate decreases, the amount of power generated may decrease even if no foreign objects are entangled in the water turbine. In this case, the hydroelectric power generation device may perform unnecessary dust removal processing even though the need for dust removal is low.

[0006] The present invention has been made to solve the above-mentioned problems, and has an object to provide a hydroelectric power generation device and a control method that efficiently perform dust removal processing. [Means for solving the problem]

[0007] According to an aspect of the present disclosure, a hydroelectric power generation device includes a water turbine, a generator that generates power by rotation of the water turbine, and a control device. The control device periodically acquires the amount of power generated by the generator. The control device periodically acquires the rotation speed of the water turbine. The control device calculates a first value based on the amount of power generated last time and the amount of power generated this time. The control device calculates a second value based on the rotation speed last time and the rotation speed currently acquired. The control device then determines whether to perform a dust removal process to remove dust from the water turbine based on the first value and the second value.

[0008] According to another aspect of the present disclosure, a control method is a method for controlling a hydroelectric power generation apparatus including a water turbine and a generator that generates electricity by rotation of the water turbine. The control method includes acquiring an amount of electricity generated by the generator, acquiring a rotation speed of the water turbine, calculating a first value based on the amount of electricity generated last time and the amount of electricity generated this time, calculating a second value based on the rotation speed last time and the rotation speed currently acquired, and determining whether to perform a dust removal process to remove dust from the water turbine based on the first value and the second value. Effect of the Invention

[0009] According to the present disclosure, dust removal processing can be carried out efficiently. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a hydroelectric power generation device. [Diagram 2] FIG. 2 is a diagram illustrating an example of a hardware configuration of a control device. [Diagram 3] FIG. 4 is a waveform diagram for explaining the operation of the dust removal brake. [Figure 4] FIG. 4 is a diagram illustrating an example of a control map. [Diagram 5] FIG. 2 is a functional block diagram of a control device. [Figure 6] 10 is a flowchart showing a dust removal determination process of the control device. [Figure 7] 13 is a flowchart of a dust removal process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding device components are designated by the same reference numerals, and description thereof will not be repeated.

[0012] [Example of hydroelectric power generation device configuration] Fig. 1 is a diagram showing a configuration example of a hydroelectric power generation device 100. In the example of Fig. 1, the hydroelectric power generation device 100 has a water turbine 1, a generator 3, an AC / DC (Alternate Current / Direct Current) converter 4, a voltage maintenance device 5, a rotation speed detector 6, a power generation amount detector 7, a control device 8, a grid-connected inverter 10, and a dust removal brake 12.

[0013] The water turbine 1 rotates due to the force of the flowing water acting on the water turbine 1. A generator 3 is connected to the water turbine 1. The generator 3 generates electricity by converting the rotational energy of the water turbine into electrical energy. The generator 3 is, for example, a three-phase synchronous generator that outputs three-phase AC. Note that in this embodiment, a case will be described in which the generator 3 is a three-phase synchronous generator, but the type of the generator 3 is not limited. Any type of generator, such as a three-phase induction generator or a DC generator, can be used as the generator 3 in combination with a control device corresponding to the type of generator.

[0014] The AC power generated by the generator 3 is output to the AC / DC converter 4. The AC / DC converter 4 converts the AC power generated by the generator 3 into DC power and outputs it to the intermediate nodes NM (NM+ and MN-). The voltage maintenance device 5 maintains the voltage of the intermediate node NM. The voltage maintenance device 5 is, for example, a secondary battery or a capacitor. Note that the voltage maintenance device 5 may also be a device capable of maintaining other voltages, such as a power generation device. The grid-connected inverter 10 converts the DC power converted by the AC / DC converter 4 into a predetermined AC power and outputs it.

[0015] The rotation speed detector 6 detects the rotation speed of the water turbine 1 in a predetermined time S1 (for example, 1 minute). The rotation speed detector 6 detects the rotation speed periodically (for example, every 5 minutes). Since the rotation speed detector 6 detects the rotation speed in the predetermined time S1 in this way, it may be expressed as detecting the rotation speed of the water turbine 1. The power generation detector 7 detects the amount of power generated (amount of generated electric power) generated by the generator 3 in a predetermined time S2 (for example, 1 minute). The power generation detector 7 acquires, for example, a power generation current value in the generator 3 and a power generation voltage value in the generator 3. Then, the power generation detector 7 detects the amount of power generated by multiplying the power generation current value and the power generation voltage value. The power generation detector 7 detects the amount of power generated periodically (for example, every 5 minutes). Note that the predetermined time S1 and the predetermined time S2 may be the same or different. Typically, the rotation speed and the amount of power generated are detected simultaneously. The rotation speed detected by the rotation speed detector 6 and the amount of power generated by the power generation detector 7 are input to the control device 8.

[0016] The control device 8 causes the dust removal brake 12 to perform a dust removal process for the water turbine 1. The dust removal process is a process for removing foreign objects (such as garbage, water plants, branches, strings, etc.) entangled in the water turbine 1. The control device 8 determines whether or not to perform the dust removal process based on the rotation speed from the rotation speed detector 6 and the power generation amount from the power generation amount detector 7.

[0017] The dust removal brake 12 is typically a mechanical brake that converts kinetic energy into heat through friction. The dust removal brake 12 is, for example, an electromagnetic brake or a disk brake. In this embodiment, the dust removal brake 12 increases or decreases the rotation speed of the water turbine 1 or stops the rotation by increasing or decreasing the braking force. As a modified example, the rotation speed of the water turbine 1 may be increased or decreased or the rotation may be stopped by increasing or decreasing the load on the generator 3.

[0018] [Control device hardware configuration] Fig. 2 is a diagram showing an example of a hardware configuration of the control device 8. Referring to Fig. 2, the control device 8 has, as main components, a CPU (Central Processing Unit) 160, a ROM (Read Only Memory) 162, a RAM (Random Access Memory) 164, a HDD (Hard Disk Drive) 166, and a communication I / F (Interface) 168. The components are connected to each other via a data bus.

[0019] The communication I / F 168 is connected to the rotation speed detector 6, the power generation detector 7, and the dust removal brake 12. The control device 8 acquires the rotation speed from the rotation speed detector 6 via the communication I / F 168. The control device 8 also acquires the power generation amount from the power generation detector 7 via the communication I / F 168. The control device 8 also transmits a dust removal signal to the dust removal brake 12 via the communication I / F 168. The dust removal signal is a signal for causing the dust removal brake 12 to execute dust removal processing.

[0020] ROM 162 stores programs executed by CPU 160. RAM 164 can temporarily store data generated by execution of the programs in CPU 160 and data input via communication I / F 168. RAM 164 can function as a temporary data memory used as a working area. HDD 166 is a non-volatile storage device. Instead of HDD 166, a semiconductor storage device such as a flash memory may be adopted.

[0021] The program stored in ROM 162 may be stored in a non-transitory recording medium and distributed as a program product. Alternatively, the program may be provided by an information provider as a so-called product program that can be downloaded via the Internet or the like. The control device 8 reads the program provided from the recording medium or via the Internet or the like. The control device 8 stores the read program in a predetermined storage area (for example, ROM 162). The CPU 160 can execute various processes by executing the program.

[0022] [About dust removal brakes] FIG. 3 is a waveform diagram for explaining the operation of the dust removal brake 12. The dust removal brake 12 executes a switching process multiple times (three times in the example of FIG. 3) during the execution time T. The switching process is a process of switching an electromagnetic brake (not shown) installed on the water turbine 1 between ON and OFF. The process of turning the electromagnetic brake ON is a process of stopping the rotation of the water turbine 1. The process of turning the electromagnetic brake ON may also be a process of decelerating the rotation of the water turbine 1. The state in which the process of turning the electromagnetic brake OFF is executed is a state in which the electromagnetic brake is not activated (i.e., a state in which the water turbine 1 rotates by the force of flowing water). Hereinafter, as shown in FIG. 3, the time when the electromagnetic brake is turned ON is also referred to as the "first set time t1", and the time when the electromagnetic brake is turned OFF is also referred to as the "second set time t2".

[0023] [Control Map] Next, the control map will be described. The control device 8 uses the control map to determine whether or not to perform dust removal processing. Fig. 4 is a diagram showing an example of the control map. The horizontal axis of this control map indicates the differential rotation speed ΔN, and the vertical axis indicates the differential power ΔP.

[0024] Here, the differential power ΔP will be explained. As described above, the control device 8 periodically acquires the amount of power generated by the hydraulic turbine 1. The differential power ΔP is a value calculated by subtracting the amount of power acquired this time from the amount of power acquired previously (the amount of power most recently acquired). The differential power ΔP corresponds to the "first value" in this disclosure. The differential power ΔP is the amount of change in the amount of power.

[0025] Next, the differential rotation speed ΔN will be described. As described above, the control device 8 periodically acquires the rotation speed of the water turbine 1. The differential rotation speed ΔN is a value calculated by subtracting the rotation speed acquired this time from the rotation speed acquired previously (the rotation speed most recently acquired). The differential rotation speed ΔN corresponds to the "second value" in this disclosure. The differential rotation speed ΔN is the amount of change in the rotation speed.

[0026] In the control device 8, a graph L is shown. The graph L is defined so that the larger the differential rotation speed ΔN, the larger the differential power ΔP. The graph L shows, as an example, a threshold value for the differential power ΔP. When the differential power ΔP is equal to or greater than the threshold value shown in the graph L, the control device 8 decides to perform the dust removal process. On the other hand, when the differential power ΔP is less than the threshold value shown in the graph L, the control device 8 decides not to perform the dust removal process.

[0027] Next, this graph L will be described. As shown in Fig. 4, a case where the value of the power difference ΔP is ΔP1 will be described. ΔP1 is assumed to be a value approximately in the middle of the expected range of the power difference ΔP (i.e., ΔP1 is a relatively large value). A case where ΔP1 is a relatively large value is a case where the amount of power generation has decreased relatively significantly.

[0028] In this case, when the differential rotation speed ΔN is a small value ΔN1, the control device 8 decides to execute the dust removal process. When the differential rotation speed ΔN is a small value (when the differential rotation speed ΔN is ΔN1), the rotation speed of the water turbine 1 has not changed much. When the rotation speed of the water turbine 1 has not changed much but the differential power ΔP is of a certain magnitude, there is a high possibility that a foreign object has become entangled in the water turbine 1. This is because, if a foreign object becomes entangled in the water turbine 1, the torque of the water turbine 1 will not be properly transmitted to the generator 3, and the expected amount of power will not be generated. Therefore, the control device 8 executes the dust removal process to eliminate this cause.

[0029] On the other hand, when the differential rotation speed ΔN is a large value ΔN2, the control device 8 decides not to perform dust removal processing. When the differential rotation speed ΔN is a large value (when the differential rotation speed ΔN is ΔN2), this is when the rotation speed of the hydraulic turbine 1 has decreased significantly. When the rotation speed of the hydraulic turbine 1 has decreased significantly and the differential power ΔP is of a certain magnitude, it is highly likely that the amount of power generation has decreased significantly due to a decrease in the amount of water flow (in other words, it is unlikely that the amount of power generation has decreased significantly due to foreign matter being entangled in the hydraulic turbine 1). Therefore, in this case, the control device 8 decides not to perform dust removal processing.

[0030] [Control device function block diagram] Fig. 5 is a functional block diagram of the control device 8. In the example of Fig. 4, the control device 8 has an acquisition unit 82, a processing unit 84, a control unit 86, and a storage unit 88. The acquisition unit 82 periodically acquires the amount of power generation from the power generation amount detector 7. Furthermore, the acquisition unit 82 periodically acquires the number of rotations from the rotation speed detector 6. The acquired amount of power generation and number of rotations are output to the processing unit 84.

[0031] The processing unit 84 calculates the differential power ΔP by subtracting the power generation amount acquired this time from the power generation amount acquired last time. Also, the processing unit 84 calculates the differential rotation speed ΔN by subtracting the rotation speed acquired this time from the rotation speed acquired last time.

[0032] The processing unit 84 stores the currently acquired power generation amount in the memory unit 88 for the process of calculating the next differential power ΔP. Then, when calculating the next differential power ΔP, the processing unit 84 uses the currently acquired power generation amount (i.e., the power generation amount stored in the memory unit 88) as the previously acquired power generation amount. Similarly, the processing unit 84 stores the currently acquired rotation speed in the memory unit 88 for the process of calculating the next differential rotation speed ΔN. Then, when calculating the next differential rotation speed ΔN, the processing unit 84 uses the currently acquired rotation speed (i.e., the rotation speed stored in the memory unit 88) as the previously acquired rotation speed.

[0033] The processing unit 84 determines whether or not to perform dust removal processing based on a control map (see FIG. 4), the differential rotation speed ΔN, and the differential power ΔP. The control map is stored in the memory unit 88. The processing unit 84 outputs the determination result to the control unit 86. Note that instead of using the control map, a function that uses the differential rotation speed ΔN and the differential power ΔP as arguments may be used. The processing unit 84 determines whether or not to perform dust removal processing using this function.

[0034] When the decision result from the processing unit 84 is to execute the dust removal process, the control unit 86 outputs a dust removal signal to the dust removal brake 12 to execute the dust removal process of the dust removal brake 12. On the other hand, when the decision result from the processing unit 84 is to not execute the dust removal process, the control unit 86 does not execute the dust removal process (does not output a dust removal signal).

[0035] [Control device flow chart] 6 is a flowchart showing the dust removal determination process of the control device 8. The dust removal determination process is executed every time a predetermined time has elapsed. In step S2, the control device 8 acquires the rotation speed N1 (the current rotation speed). Next, in step S4, the control device 8 stores the rotation speed N1 in the memory unit 88. The stored rotation speed N1 is used as the previous rotation speed N0 in the next dust removal determination process.

[0036] Next, in step S6, the control device 8 acquires the power generation amount P1 (the current power generation amount). Next, in step S8, the control device 8 stores the power generation amount P1 in the storage unit 88. The stored power generation amount P1 is used as the previous power generation amount P0 in the next dust removal determination process.

[0037] Next, in step S10, the control device 8 calculates the difference rotation speed ΔN by subtracting the currently acquired rotation speed N1 from the previously acquired rotation speed N0. That is, the control device 8 calculates the difference rotation speed ΔN by calculating N0-N1. The previously acquired rotation speed N0 is the rotation speed stored in step S4 of the previous dust removal determination process.

[0038] Next, in step S12, the control device 8 calculates the power generation difference ΔP by subtracting the power generation amount P1 acquired this time from the power generation amount P0 acquired last time. That is, the control device 8 calculates the power generation difference ΔP by calculating P0-P1. The power generation amount P0 acquired last time is the power generation amount stored in step S8 of the previous dust removal determination process.

[0039] Next, in step S14, the control device 8 refers to the control map based on ΔN and ΔP to determine whether or not to perform dust removal processing. Next, in step S16, if it is determined that the dust removal processing is to be performed (YES in step S16), the process proceeds to step S18. On the other hand, in step S16, if it is determined that the dust removal processing is not to be performed (NO in step S16), the dust removal determination process ends.

[0040] 7 is a flowchart of the dust removal process in step S18. In step S32, the control device 8 clears a built-in counter. This counter is a counter for measuring the number of times the electromagnetic brake is repeatedly turned on and off. Next, in step S34, the control device 8 outputs a dust removal signal so that the dust removal brake 12 generates a braking force (brake ON). After that, in step S36, the control device 8 waits in the brake ON state for a first set time t1 (for example, 1 to 10 seconds).

[0041] Next, in step S38, the control device 8 stops outputting the dust removal signal (brake OFF). As a result, the control device 8 sets a command signal SB that can prevent the dust removal brake 12 from generating a braking force. After that, in step S40, the control device 8 waits in the brake OFF state for a second set time t2 (for example, 1 to 10 seconds).

[0042] Next, in step S42, the control device 8 increments the counter. Then, in step S44, it is determined whether the count value of the counter has reached an upper limit value (a set number of times of repeated increase and decrease). In the example of Fig. 3, the upper limit value is 3 times. In step S44, if the count value has not yet reached the upper limit value (NO in step S44), the process returns to step S34.

[0043] On the other hand, in step S8, if the count value reaches the upper limit value (YES in step S44), one dust removal operation ends, and the process returns to the dust removal determination process in FIG.

[0044] Conventional hydroelectric power generation devices perform dust removal processing when the amount of power generation falls below a threshold value. However, the water flow rate at the location where the hydroelectric power generation device is installed may change. For example, when the flow rate decreases, the amount of power generation may decrease even if no foreign objects are entangled in the water turbine. In this case, a problem may occur in which the hydroelectric power generation device performs unnecessary dust removal processing even if the need for dust removal processing is low.

[0045] Therefore, the control device 8 in this embodiment periodically acquires the amount of power generated by the generator 3. Then, the control device 8 calculates the differential power ΔP (first value) between the previously acquired amount of power generation P0 and the currently acquired amount of power generation P1. The control device 8 also periodically acquires the rotation speed of the water turbine 1. Then, the control device 8 calculates the differential rotation speed ΔN (second value) between the previously acquired rotation speed N0 and the currently acquired rotation speed N1.

[0046] As shown in Fig. 4, when the differential rotation speed ΔN is small (for example, when the differential rotation speed ΔN is ΔN1 (see Fig. 4)), if ΔP is ΔP1, there is a high possibility that a foreign object is entangled in the water turbine 1. Therefore, in this case, the control device 8 executes a dust removal process.

[0047] On the other hand, when the differential rotation speed ΔN is large (for example, when the differential rotation speed ΔN is ΔN2 (see FIG. 4)), and ΔP is ΔP1, there is a high possibility that the amount of power generation has decreased significantly due to a decrease in the amount of water flowing into the water turbine 1. Therefore, in this case, the control device 8 does not execute the dust removal process.

[0048] In this way, the control device 8 refers to the control map based on the differential power ΔP and the differential rotation speed ΔN to determine whether or not to perform dust removal processing. Therefore, the control device 8 can determine whether or not to perform dust removal processing by considering not only the amount of change in the amount of power generation but also the flow rate to the hydraulic turbine 1. Therefore, the control device 8 can determine whether or not to perform dust removal processing more precisely than in the past, and as a result, the dust removal processing can be performed efficiently.

[0049] In addition, in the conventional hydroelectric power generation device, the dust removal process is performed when the amount of power generation falls below the threshold value. Therefore, the dust removal process is also performed when the amount of power generation falls due to a decrease in the flow rate to the hydroelectric turbine when no foreign object is entangled in the hydroelectric turbine. Therefore, in the conventional hydroelectric power generation device, unnecessary dust removal process is performed. Therefore, the unnecessary dust removal process consumes power to operate the dust removal brake 12, resulting in a loss of power generation. In addition, the unnecessary dust removal process causes the hydroelectric turbine 1 to stop, resulting in a loss of power generation. In contrast, the hydroelectric power generation device 100 of the present embodiment can suppress the execution of the dust removal process when the amount of power generation falls due to a decrease in the flow rate to the hydroelectric turbine when no foreign object is entangled in the hydroelectric turbine. Therefore, since the unnecessary dust removal process can be suppressed, the loss of power generation described above can be reduced, and power generation efficiency can be improved.

[0050] Moreover, the control device 8 determines whether or not to perform the dust removal process based on a threshold value based on the differential rotation speed ΔN (i.e., the threshold value shown by graph L in Fig. 4) and the first value. Therefore, since whether or not to perform the dust removal process can be determined by threshold value judgment, the process of determining whether or not to perform the dust removal process can be made relatively simple.

[0051] In the control map of Fig. 4, the threshold value is set to be larger as the differential rotation speed ΔN (second value) is larger. When the differential power ΔP (first value) is equal to or larger than the threshold value, the control device 8 decides to execute the dust removal process. On the other hand, when the differential power ΔP is less than the threshold value, the control device 8 decides not to execute the dust removal process. Therefore, by using the threshold value judgment according to the differential rotation speed ΔN, it is possible to more precisely decide whether or not to execute the dust removal process.

[0052] 3, the dust removal process includes a process of varying the rotation speed of the water turbine 1 or a process of stopping the rotation of the water turbine 1. Therefore, the control device 8 can remove foreign matter from the water turbine 1 without providing a separate device for removing foreign matter.

[0053] [Other embodiments] (1) In the control map of FIG. 4 (hereinafter also referred to as the "first control map"), a configuration has been described in which the larger the differential rotation speed ΔN, the larger the differential power ΔP. However, a second control map may be used in which the larger the differential rotation speed ΔN, the smaller the differential power ΔP. The manager of the hydroelectric power generation device 100 need only decide whether to use the first control map or the second control map depending on the structure of the hydroelectric turbine 1 and the location where the hydroelectric turbine 1 is installed, etc.

[0054] (2) In the hydroelectric power generation device according to the above embodiment, the first value (difference power ΔP) is calculated by subtracting the power generation amount acquired this time from the power generation amount acquired last time. However, the method for calculating the first value may be another method. For example, the control device 8 may calculate the first value (difference power ΔP) by subtracting the power generation amount acquired last time from the power generation amount acquired this time. Furthermore, the control device 8 may calculate the first value by dividing the power generation amount acquired last time by the power generation amount acquired this time.

[0055] In addition, in the hydroelectric power generation device of the above embodiment, a configuration has been described in which the second value (differential rotation speed ΔN) is calculated by subtracting the currently acquired rotation speed from the previously acquired rotation speed. However, the method for calculating the second value may be another method. For example, the control device 8 may calculate the second value (differential rotation speed ΔN) by subtracting the previously acquired rotation speed from the currently acquired rotation speed. Also, the control device 8 may calculate the second value by dividing the previously acquired rotation speed by the currently acquired rotation speed. When these modified examples are adopted, the control map and the like are appropriately modified so as to achieve the above-mentioned effects.

[0056] Although the embodiment of the present invention has been described above, the above-mentioned embodiment can be modified in various ways. The scope of the present invention is not limited to the above-mentioned embodiment. The scope of the present invention is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims, such as the equivalents thereof. [Explanation of symbols]

[0057] 1 water turbine, 3 generator, 4 converter, 5 voltage maintenance device, 6 rotation speed detector, 7 power generation detector, 8 control device, 10 grid-connected inverter, 12 dust removal brake, 82 acquisition unit, 84 processing unit, 86 control unit, 88 memory unit, 100 hydroelectric power generation device, 162 ROM, 164 RAM.

Claims

1. The waterwheel and A generator that generates electricity by rotation of the water turbine; a control device; The control device includes: Periodically acquiring the amount of power generated by the generator; The rotation speed of the water turbine is periodically acquired; Calculating a first value based on the previously acquired amount of power generation and the currently acquired amount of power generation; Calculating a second value based on the previously acquired number of revolutions and the currently acquired number of revolutions; The hydroelectric power generation device determines whether or not to perform a dust removal process for removing dust from the water turbine based on a threshold value based on the second value and the first value.

2. The control device includes: Calculating the first value by subtracting the currently acquired amount of power generation from the previously acquired amount of power generation; Calculating the second value by subtracting the currently acquired number of revolutions from the previously acquired number of revolutions; the larger the second value, the larger the threshold value; The control device includes: determining to perform the dust removal process when the first value is equal to or greater than the threshold value; The hydroelectric power generation apparatus according to claim 1 , wherein it is determined not to perform the dust removal process when the first value is less than the threshold value.

3. The hydroelectric power generation apparatus according to claim 1 or 2, wherein the dust removal process includes a process of varying a rotation speed of the water turbine or a process of stopping rotation of the water turbine.

4. A method for controlling a hydroelectric power generation device including a water turbine and a generator that generates electricity by rotation of the water turbine, Obtaining an amount of power generated by the generator; Obtaining the rotation speed of the water turbine; Calculating a first value based on a previously acquired amount of power generation and a currently acquired amount of power generation; Calculating a second value based on the previously acquired number of rotations and the currently acquired number of rotations; A control method comprising: determining whether or not to perform a dust removal process for removing dust from the water turbine based on a threshold value based on the second value and the first value.

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