JP6380722B1 - Hydroelectric power generation control system and control method - Google Patents

Abstract

  The hydraulic power generation control system includes a first step of reducing the opening degree of the guide vane below the opening degree before the load interruption when the load interruption of the hydroelectric generator is performed, and the guide vane per predetermined time than the first step. The second step of reducing the amount of change in the opening to make the opening of the guide vane smaller than that at the completion of the first step is performed to reduce the opening of the guide vane. When the rotational speed is equal to or lower than the maximum rotational speed after the start of load shedding and the water pressure change condition is satisfied, the process proceeds to the second step, and the water pressure change condition is determined within 1 second or less. That is, the rate of change of the water pressure inside at least one is equal to or greater than a predetermined threshold.

Description

  The present invention relates to a hydroelectric power generation control system and a control method.

  In hydroelectric power generation, it is known to perform so-called load shut-off that shuts off a generator that has been operating from a power system (for example, Patent Document 1).

Japanese Patent Laid-Open No. 11-287176

  In load shedding, guide vane opening control is performed in order to control the rotational speed of the water wheel after load shedding and the water pressure in the pipe of water supplied to the water wheel. In the conventional load interruption, the opening control pattern of the guide vane after the start of the load interruption is determined in advance based on measurement, simulation, and the like by a prior experimental building. However, in the conventional guide vane opening degree control pattern as in the prior art, in order to suppress the sudden change when an unintended sudden change in water pressure or the like occurs in the water pipe supplied to the turbine after the load is interrupted. It was difficult to control the opening degree of the guide vane.

  An object of the present invention is to provide a hydroelectric power generation control system and a control method that can cope with a sudden change in water pressure in a pipe of water supplied to a water turbine.

  In order to solve the above-described problems and achieve the object, a hydroelectric power generation control system according to the present invention includes a water turbine connected to a generator, a casing in which the water turbine is housed and water is allowed to flow, and the inside of the casing. A pipe for flowing water to be supplied to the casing, a guide vane that is provided in the casing and opens and closes a water channel between the pipe and the turbine, a first detection unit that detects a rotation speed of the turbine, the pipe and A second detection unit that detects a water pressure inside at least one of the casings, and a control device that controls an opening degree of the guide vane. A first step in which the opening degree of the guide vane is made smaller than the opening degree before the load is shut off; and the opening degree of the guide vane by making the amount of change in the opening degree of the guide vane per predetermined time smaller than in the first step. The above A second step of reducing the opening of the guide vane by performing a second step that is smaller than that at the completion of one step, and in the first step, the rotational speed of the water turbine is less than or equal to the maximum rotational speed after the start of load shedding And when the water pressure change condition is satisfied, the process proceeds to the second step, and the second detector repeats the detection of the water pressure at a cycle of 1 second or less, and the water pressure change condition is 1 second or less. Within a period of time, the rate of change of the increase in water pressure inside at least one of the pipe and the casing is equal to or greater than a predetermined threshold value.

  As a desirable aspect of the present invention, a signal transmission path between the control device and at least one of the first detection unit and the second detection unit includes a wireless signal transmission path.

  In order to solve the above-described problems and achieve the object, the control method of the present invention provides a rotational speed of a turbine connected to the generator and a turbine when the load is interrupted by a generator that generates electricity by hydropower. Based on a pipe for flowing water supplied into the casing in which the water is stored and a water pressure inside at least one of the casing, the water path is opened and closed between the pipe and the water turbine. A control method for controlling the opening degree of the guide vane, the first step of making the opening degree of the guide vane smaller than the opening degree before the load is interrupted, and the guide vane per predetermined time than the first step And a second step of reducing the amount of change in the opening of the guide vane so that the opening of the guide vane is smaller than that at the completion of the first step. Maximum rotation after start When the water pressure change condition is satisfied, the process proceeds to the second step, and the water pressure change condition is a water pressure inside at least one of the pipe and the casing within a time of 1 second or less. That is, the rate of change in the increase of the value becomes equal to or greater than a predetermined threshold.

  As a desirable mode of the present invention, a control device that controls the opening degree of the guide vane, a first detection unit that detects the rotational speed of the water turbine, and a second that detects water pressure inside at least one of the pipe and the casing. The signal transmission path between at least one of the detection units includes a wireless signal transmission path.

  ADVANTAGE OF THE INVENTION According to this invention, it can respond to the sudden change of the water pressure in the pipe line of the water supplied to a water turbine.

FIG. 1 is a diagram illustrating a main configuration example of a hydroelectric power generation facility to which the embodiment is applied. FIG. 2 is a schematic view of a guide vane. FIG. 3 is a schematic view of a guide vane. FIG. 4 is a diagram illustrating a main configuration of the control device. FIG. 5 is a graph showing an example of a change in the stroke of the servo motor after the load is interrupted. FIG. 6 is a graph showing an example of the relationship among the servo motor stroke, the generator voltage, the water pressure detected by the second detection unit, and the rotation speed of the water turbine when the load is interrupted. FIG. 7 is a graph showing an example of a case where the water pressure rises that deviates from the guaranteed value designed in the design. FIG. 8 is a graph showing an example in which the rate of change in the water pressure increase in a predetermined unit time is equal to or greater than a threshold value. FIG. 9 is a flowchart illustrating an example of a condition determination process regarding the transition from the second closing to the buffer closing. FIG. 10 is a flowchart illustrating an example of the flow of the first condition determination process. FIG. 11 is a flowchart illustrating an example of the flow of the second condition determination process.

  Next, embodiments will be described in detail with reference to the drawings. FIG. 1 is a diagram illustrating a main configuration example of a hydroelectric power generation facility 1 to which the embodiment is applied. The hydroelectric power generation facility 1 includes a water turbine 10, a casing 20, a pipe 30, a guide vane 60, a first detection unit 40, a second detection unit 50, a control device 70, and the like.

  The water turbine 10 is a water turbine in a form that can be adopted in hydroelectric power generation, such as a Francis turbine or a Kaplan turbine. The water turbine 10 is connected to a generator 11. As the water turbine 10 rotates, the generator 11 generates power. The generator 11 is electrically connected to a target (load) that supplies power generated by power generation by being connected to the power system 12. The electrical connection between the generator 11 and the power system 12 is provided so as to be cut off. Specifically, for example, the generator 11 and the power system 12 are electrically connected via a synchronous circuit breaker 13. The synchronous circuit breaker 13 is provided so as to be able to switch between electrical connection and non-connection between the generator 11 and the power system 12.

  The casing 20 contains the water wheel 10 and the guide vane 60 inside thereof. The casing 20 is provided so that the water W can flow inside. The casing 20 is formed so as to guide the flow of water W for rotating the turbine 10 to the turbine 10. Hereinafter, with reference to the position of the water W in the casing 20, the position where the water W supplied into the casing 20 flows may be referred to as an upstream position.

  The pipe 30 flows water W supplied into the casing 20. Specifically, the pipe 30 is provided on the upstream side with respect to the casing 20 and forms a water channel continuous with the casing 20. The water W is stored in the storage unit 31 from a water source such as a river. The water W stored in the storage unit 31 is supplied into the casing 20 via the pipe 30 and rotates the water turbine 10.

  The structure which forms the flow path through which the water W flows, such as the casing 20, the pipe 30 and the draft 21, is made using a material (for example, steel or the like) which can obtain rigidity for withstanding water pressure. The draft 21 is a tube that forms a flow path through which the water W supplied from the housing to the water turbine 10 through the guide vane 60 is discharged.

  2 and 3 are schematic views of the guide vane 60. FIG. The guide vane 60 opens and closes the water channel between the pipe 30 and the water turbine 10. Specifically, for example, as shown in FIGS. 2 and 3, the guide vane 60 includes a plurality of blade-like members 61 arranged to surround the water turbine 10. Each of the plurality of blade-like members 61 is rotatably provided. The guide vane 60 is provided so that the opening / closing and opening of the gap between the adjacent blade-like members 61 can be adjusted by the rotation of the plurality of blade-like members 61. As shown in FIG. 2, when the guide vane 60 is open, the water W supplied to the water turbine 10 flows in a gap between the blade-like members 61. In FIG. 2, the water W supplied to the water turbine 10 is schematically illustrated by arrows. In addition, when the guide vane 60 is closed as shown in FIG. 3, the blade-like members 61 are closed with no gap, and the water W does not flow.

  The first detection unit 40 detects the rotational speed of the water turbine 10. Specifically, the first detection unit 40 is, for example, an SSG (Signal Speed Generator). The SSG has, for example, a gear that rotates in conjunction with the rotation of the water turbine 10, a pickup sensor provided in the vicinity of the gear, and the like. The SSG detects the rotational speed of the water turbine 10 based on the frequency of an electrical pulse output from the pickup sensor in accordance with a change in the distance between the rotating gear teeth and the pickup sensor. The 1st detection part 40 is not restricted to SSG. For example, the rotational speed of the water turbine 10 may be detected by a tacho generator (TG) provided in the generator 11, or a permanent magnet generator (PMG) may be used. However, other methods may be used.

  The second detection unit 50 detects the water pressure inside at least one of the pipe 30 and the casing 20. The second detection unit 50 may include a pressure gauge such as a Bourdon pressure gauge or a diaphragm pressure gauge, for example, and water in the pipe 30, the casing 20 or the like by a method such as an ultrasonic flow velocity distribution measurement method. You may have an ultrasonic transducer | vibrator etc. for measuring the flow velocity of W. If the distribution of the flow velocity of the water W inside can be measured, the water pressure caused by the water W flowing at the flow velocity can be measured.

  In the present embodiment, for example, as illustrated in FIG. 1, the second detection unit 50 is provided in the pipe 30, but this is an example and the present invention is not limited thereto. The second detection unit 50 may be provided in the casing 20. Further, the second detection unit 50 may be provided in both the pipe 30 and the casing 20. In addition, a detection unit that detects the water pressure may be provided in the draft 21 in the same manner as the second detection unit 50.

  In the present embodiment, the signal transmission path between the control device 70 and at least one of the first detection unit 40 and the second detection unit 50 includes a wireless signal transmission path. Specifically, the first detection unit 40 of the present embodiment is connected to the first wireless communication unit 40a. The first wireless communication unit 40 a transmits data including information indicating the rotation speed of the water turbine 10 detected by the first detection unit 40 to the control device 70. In addition, the second detection unit 50 of the present embodiment is connected to the second wireless communication unit 50a. The second wireless communication unit 50 a transmits data including information indicating the water pressure detected by the second detection unit 50 to the control device 70. More specifically, the first wireless communication unit 40a and the second wireless communication unit 50a have a module for performing wireless communication by a mobile communication system such as LTE (Long Term Evolution), for example. Wireless communication is performed by operating.

  FIG. 4 is a diagram illustrating a main configuration of the control device 70. The control device 70 controls the opening degree of the guide vane 60. Specifically, the control device 70 includes, for example, a servo motor 71, a servo motor control unit 72, an information processing device 80, and the like.

  The servo motor 71 rotates a plurality of blade-like members 61 included in the guide vane 60 by operation. That is, according to the change in the rotation angle of the output shaft of the servo motor 71, the rotation angle of the plurality of blade-like members 61 changes. The servo motor control unit 72 controls the operation of the servo motor 71 under the control of the information processing apparatus 80. That is, the servo motor control unit 72 controls the rotation angle of the output shaft of the servo motor 71.

  The information processing device 80 is, for example, a computer having a calculation unit 81, a storage unit 82, a communication unit 83, and the like. The calculation unit 81 includes a calculation device such as a CPU (Central Processing Unit). The calculation unit 81 reads out and executes a software program from the storage unit 82, thereby performing processing according to the software program. The calculation unit 81 may acquire and refer to data stored in the storage unit 82, data transmitted via the communication unit 83, and the like during the processing.

  The storage unit 82 includes, for example, a primary storage device such as a RAM (Random access memory) and a secondary storage device such as a hard disk drive or a solid state drive. Parameters or the like temporarily generated during processing performed by the calculation unit 81 are held in the primary storage device. The software program is stored and held in the secondary storage device. The software program may be recorded on a non-rewritable storage device or medium such as a ROM (Read Only Memory).

  The communication unit 83 includes, for example, a network interface controller (NIC) that performs communication according to a predetermined standard. As the predetermined standard, for example, a so-called Internet protocol suite including a TCP / IP (Transmission Control Protocol / Internet Protocol) protocol suite can be cited, which is adopted according to the communication line N used by the control device 70 to the last. It is an example of a standard and is not limited to this. The specific contents of the predetermined standard can be changed as appropriate. The communication unit 83, the first wireless communication unit 40a, and the second wireless communication unit 50a are connected to be communicable via a public communication line N, for example.

  The storage unit 82 of the present embodiment stores, for example, a hydroelectric power generation control program 82a. The hydroelectric power generation control program 82a is a hydroelectric power generation system such as a switch of presence / absence of electrical connection between the generator 11 and the electric power system 12 by the synchronous circuit breaker 13, a rotation control of the turbine 10 based on the control of the opening degree of the guide vane 60, and the like. It is a software program related to various processes for controlling the facility 1. The hydroelectric power generation control program 82a includes a load cutoff control program 82b. The load cutoff control program 82b is a software program for controlling the opening degree of the guide vane 60 when the load cutoff that cuts off the electrical connection between the generator 11 and the power system 12 is performed.

  The information processing apparatus 80 performs various processes for controlling the hydroelectric power generation facility 1 by the calculation unit 81 reading and executing the hydroelectric power generation control program 82a. Further, the information processing device 80 reads and executes the load shedding control program 82b in order to cope with the load shedding and controls the opening degree of the guide vane 60. Specifically, when the load interruption is performed, the information processing apparatus 80 sequentially performs the first closing, the second closing, and the buffer closing to reduce the opening degree of the guide vane 60. The first closing is a step of making the opening degree of the guide vane 60 smaller than the opening degree before the load is interrupted. The second closing is a step of making the opening degree of the guide vane 60 smaller than when the first closing is completed by making the amount of change in the opening degree of the guide vane 60 per predetermined time smaller than that of the first closing. The buffer closing is a step of making the amount of change in the opening degree of the guide vane 60 per predetermined time smaller than that in the second closing so that the opening degree of the guide vane 60 becomes smaller than when the second closing is completed. The predetermined time is a time for comparing the amount of change in the opening degree of the guide vane 60 within the same time of each step (for example, first closing, second closing, buffer closing). The predetermined time may be, for example, 1 [second], a time exceeding 1 [second], or a time exceeding 0 [second] and less than 1 [second]. May be.

  FIG. 5 is a graph showing an example of a change in the stroke of the servo motor 71 after the load is cut off. In FIG. 5, the first closing time (first closing time T1), the second closing time (second closing time T2), and the buffer closing time (buffer) performed after the load cutoff timing T0. The closing time T3) is illustrated. The information processing device 80 performs first closing, second closing, and buffer closing in order to reduce the opening degree of the guide vane 60 after the load is cut off, and controls the operation of the servo motor 71 according to each step. After the load shedding is performed, the servo motor 71 is controlled so as to shift from the stroke B corresponding to the opening degree of the guide vane 60 before the load breaking to the stroke A corresponding to the opening degree of the guide vane 60 after the load breaking is completed. Is done. The opening degree of the guide vane 60 when the stroke of the servo motor 71 is the stroke A is smaller than the opening degree of the guide vane 60 when the stroke of the servo motor 71 is the stroke B.

  FIG. 6 is a graph showing an example of the relationship among the stroke of the servo motor 71, the voltage of the generator 11, the water pressure detected by the second detection unit 50, and the rotation speed of the water turbine 10 when load interruption is performed. It is. As illustrated in FIG. 6, after the load shedding is performed, the rotational speed of the water turbine 10 once increases. This is because the load (the force that acts to suppress rotation) that has been applied to the water turbine 10 from the generator 11 before the load is cut off does not work as the electrical connection between the generator 11 and the load is lost. . Further, when the opening of the guide vane 60 is reduced by controlling the stroke of the servo motor 71 from the stroke B to the stroke A, the water pressure detected by the second detection unit 50 is once increased. This is because the flow rate of the water W that can pass through the guide vane 60 decreases as the opening degree of the guide vane 60 decreases. As a result, the force for retaining the water W in the pipe 30 and the casing 20 becomes stronger than before the load is cut off, and the water pressure in the pipe 30 and the casing 20 is increased.

  The equivalent closing time Te that determines the amount of change of the opening degree of the first closing guide vane 60 per predetermined time is based on the design of the hydroelectric power generation facility 1 such as mechanical strength. For example, if the equivalent closing time Te is too long, the rotational speed of the water turbine 10 after load interruption may increase too much. If the equivalent closing time Te is too short, the water pressure in the pipe 30 and the casing 20 after load interruption may become too high. Therefore, the equivalent closing time Te is determined based on the balance between the rotational speed of the water turbine 10 and the water pressure in the pipe 30 and the casing 20. By shortening the equivalent closing time Te within a range where the balance can be achieved, the closing speed of the guide vane 60 after the load is interrupted can be further increased, and the amount of water discharged without being used for power generation after the load is interrupted is reduced. be able to. Also, by setting the second closing time T2, the amount of change in the opening degree of the guide vane 60 per predetermined time is made smaller than during the equivalent closing time Te (first closing time T1), so that the Variations in the water pressure in the tube 30 and the casing 20 can be reduced.

  The rotational speed of the water turbine 10 after the load is cut off reaches the maximum speed N during the second closing time T2, and usually decreases thereafter. Further, the water pressure detected by the second detection unit 50 reaches the maximum pressure P after the rotational speed of the water turbine 10 reaches the maximum speed N, and usually decreases thereafter.

  Note that the rotational speed of the water turbine 10 after the load is interrupted finally converges to substantially the same rotational speed as the rotational speed (rated value) before the load is interrupted. Further, the opening degree of the guide vane 60 after the load is interrupted is not completely closed, but is maintained at such an opening degree that a water flow capable of maintaining the rotational speed of the water turbine 10 after the load is interrupted is obtained.

  The maximum speed N of the rotation speed of the water turbine 10 and the maximum pressure P of the water pressure are based on the design of the hydroelectric power generation facility 1 such as mechanical strength. The second closing time T2 reaches the maximum rotational speed by saturating the rotational speed of the water turbine 10 that rises after the load is cut off, and thereafter, within the range of the value based on the guaranteed rotational speed assumed in the design. It is assumed that it is time for the rotational speed of the water turbine 10 to transition at a value lower than the rotational speed of the turbine wheel 10. The maximum speed N is a rotation speed equal to or lower than the maximum rotation speed. In addition, the second closing time T2 becomes the highest water pressure that is assumed in the design due to the saturation of the water pressure that increases after the load is shut off, and thereafter, within the range of the value based on the guaranteed value of the water pressure that is assumed in the design. It is assumed that it is time for the water pressure to change at a value lower than the water pressure. The maximum pressure P is a water pressure equal to or lower than the maximum water pressure.

  As shown in FIG. 6, the water pressure detected by the second detection unit 50 during the second closing time T2 varies after reaching the maximum pressure P and including a rise after the drop. In addition, the rotational speed of the water turbine 10 is not only simply decreased from the highest speed N, but may be increased again. The buffer closing time T3 is set so that the fluctuation of the water pressure and the re-increase of the rotation speed of the water turbine 10 are more reliably converged within a range of values based on the guaranteed value of the water pressure and the rotation speed assumed in the design. The In other words, the transition from the second closing to the buffer closing more reliably converges the fluctuation of the water pressure after passing through the highest pressure P and the re-increase of the rotational speed of the water turbine 10 after passing through the highest speed N after the start of the second closing. It is desirable to implement at the timing that is allowed. Hereinafter, a range of values based on the guaranteed value of the water pressure may be referred to as a range PA.

  Conventionally, the transition timing of each process after the load shut-off through the first closing, the second closing, and the buffer closing has been a predetermined timing starting from the timing at which the load shut-off is performed. However, in the conventional mechanism, the transition timing TA from the second closing to the buffer closing may not be a desirable timing.

  FIG. 7 is a graph showing an example of a case where the water pressure rises that deviates from the guaranteed value designed in the design. As exemplified by the fluctuation pattern PR in FIG. 7, during the second closing time T2, the water pressure may fluctuate with a height difference that is greater than the water pressure fluctuation height difference that the water pressure fluctuation planned value PI has. The water pressure fluctuation plan value is a value indicating the transition of the water pressure assumed within the range PA.

  As an example of the event when the fluctuation pattern PR occurs, there is “water flow breakup” that may occur during the second closing time T2. For example, in the process in which the water pressure decreases after reaching the maximum pressure P, the amount of water W that passes through the guide vane 60 and is supplied to the water turbine 10 decreases. For this reason, the water turbine 10 that continues to rotate while reducing the rotation speed has completely drained the water W, so that there is no water W (a state in which the water W is not discharged), and the continuity of the water flow is lost. May occur ". The flow of the water W including “divided water flow” has a larger fluctuation range of the water pressure than the continuous flow of the water W. Moreover, the fluctuation range of the water pressure may increase due to a phenomenon (reverse surge) in which the water W flowing from the water turbine 10 to the draft 21 flows backward due to a pressure difference caused by the water pressure decreasing after reaching the maximum pressure P.

  FIG. 8 is a graph showing an example when the rate of change P / Δt of the increase in water pressure in a predetermined unit time is equal to or greater than the threshold Th. Hereinafter, when the rate of change P / Δt is simply described, it indicates the rate of change P / Δt inside at least one of the tube 30 and the casing 20 in a predetermined unit time. In the example shown in FIG. 8, the change rate P / Δt is equal to or greater than the threshold Th after the timing tp at the elapsed time t during the second closing. When such a phenomenon that the rate of change P / Δt becomes equal to or greater than the threshold Th occurs, the water pressure may deviate from the range PA, such as the variation pattern PR.

  When the rate of change P / Δt becomes equal to or greater than the threshold value Th during the second closing time T2, that is, during the second closing, the difference in water pressure fluctuation can be reduced by quickly starting the buffer closing. . However, the mechanism for determining the transition timing TA from the second closing to the buffer closing at a predetermined timing as in the prior art cannot cope with the fluctuation of the water pressure when such a fluctuation pattern PR occurs. It was.

  Therefore, in the present embodiment, the information processing device 80 detects the occurrence of the variation pattern PR based on the water pressure detected by the second detection unit 50, and controls the transition timing TA from the second closing to the buffer closing. Specifically, when the first condition is satisfied and the second condition is satisfied, the process proceeds to buffer closing. The first condition is that the rotation speed of the water turbine 10 is equal to or less than the highest speed N after the start of load shedding in the second closing. The second condition is that the rate of change P / Δt is equal to or higher than a predetermined threshold (for example, threshold Th) in the second closing. That is, in the present embodiment, the second closing corresponds to the “first step”, and the buffer closing corresponds to the “second step”.

  That is, in this embodiment, if the first condition that the rotational speed of the water turbine 10 is equal to or less than the maximum speed N after the start of load shedding is satisfied in the second closing, the fluctuation of the water pressure and the rotational speed of the water turbine 10 It is treated as a time zone in which the re-rise is converged within the range of values based on the guaranteed water pressure and the rotational speed assumed in the design. In addition, even if the first condition is satisfied, the rate of change P / Δt being equal to or greater than a predetermined threshold (for example, threshold Th) can deviate from the guaranteed water pressure value that is assumed in design. Treated as a sudden change in water pressure. When the first condition and the second condition are satisfied, the height difference of the fluctuation of the water pressure can be further reduced by shifting from the second closing to the buffer closing.

  The predetermined unit time is, for example, 0.5 [seconds]. That is, the 1st detection part 40 and the 2nd detection part 50 of this embodiment repeat a detection with the predetermined unit time period of 1 second or less. The predetermined unit time is not limited to 0.5 seconds and can be changed as appropriate.

  FIG. 9 is a flowchart illustrating an example of a condition determination process regarding the transition from the second closing to the buffer closing. When the second closing is started (step S1), the calculation unit 81 performs a first condition determination process (step S2) and a second condition determination process (step S3). In FIG. 9, the process of step S3 is described after the process of step S2, but the process of step S2 and the process of step S3 are performed in parallel. When the first condition is satisfied (step S4; Yes) and the second condition is satisfied (step S5; Yes), the calculation unit 81 performs the opening degree control process of the guide vane 60 in load interruption. Is shifted from the second closure to the buffer closure, and the buffer closure is started (step S6). Specifically, the calculation unit 81 outputs a command to the servo motor control unit 72 to change the change amount per predetermined time of the stroke of the servo motor 71 from the change amount at the second closing time to the change amount at the buffer closing time. To do. The servo motor control unit 72 controls the stroke of the servo motor 71 under the control of the information processing device 80.

  On the other hand, when the first condition is not satisfied (step S4; No) or when the first condition is satisfied but the second condition is not satisfied (step S5; No), the calculation unit 81 maintains the current state. Or it waits (step S7) and transfers to the process of step S2 after predetermined unit time. Maintaining the current state means, for example, maintaining the change amount per predetermined time of the stroke of the servo motor 71 at the change amount at the time of the second closing. The standby means that the change in the stroke of the servo motor 71 is stopped and the opening degree of the guide vane 60 is not changed until the transition timing to the buffer closing comes. The standby is applied when, for example, the second closing is performed, so that the opening degree of the guide vane 60 becomes a predetermined “minimum opening degree at the second closing time”. Otherwise, status quo is applied.

  FIG. 10 is a flowchart illustrating an example of the flow of the first condition determination process. The calculation unit 81 acquires data including information indicating the rotation speed of the water turbine 10 detected by the first detection unit 40 (step S11). The calculation unit 81 determines whether the rotation speed of the water turbine 10 indicated by the information included in the data acquired in the process of step S11 is equal to or lower than the maximum rotation speed after the load is interrupted (for example, the highest speed N) (step S12). ). Specifically, the information processing device 80 determines the fastest rotation speed among the rotation speeds of the water turbine 10 indicated by the information included in the data acquired in one or more steps S11 performed after the start of load shedding. Information is held in the storage unit 82 as the maximum speed N until the load shedding is completed. In step S12, the calculation unit 81 compares the rotational speed of the water turbine 10 acquired in the latest processing of step S11 with the maximum speed N, and determines whether the speed is less than or equal to the maximum speed N after the load is interrupted. When it determines with it being below the maximum speed N after load interruption (step S12; Yes), the calculating part 81 determines with the 1st condition having been satisfied (step S13). On the other hand, when it is determined in step S12 that the speed is not less than the maximum speed N after the load is interrupted (step S12; No), that is, when the maximum rotation speed after the start of the load interrupt is acquired, the calculation unit 81 It is determined that one condition is not satisfied (step S14).

  FIG. 11 is a flowchart illustrating an example of the flow of the second condition determination process. The calculation unit 81 acquires data including information indicating the water pressure detected by the second detection unit 50 (step S21). The calculation unit 81 determines whether the water pressure indicated by the information included in the data acquired in the process of step S21 indicates the occurrence of a sudden change (step S22).

  The water pressure change condition for determining that a sudden change in water pressure has occurred is, for example, that the rate of change in water pressure (for example, the rate of change P / Δt) is within a predetermined threshold (for example, within a predetermined unit time). For example, the threshold value Th) or more. Specifically, the information processing device 80 has been acquired by at least the latest two processes among the water pressures indicated by the information included in the data acquired by the process of step S21 that is performed a plurality of times after the start of load shedding. Information on the water pressure is stored in the storage unit 82 until the load interruption is completed. That is, the information processing apparatus 80 is provided so as to be able to handle at least the water pressure acquired in the latest processing of step S21 and the water pressure acquired in the processing of immediately preceding step S21.

  The predetermined threshold value (for example, threshold value Th) is derived based on the measurement result of water pressure at the time of past load interruption, simulation of water pressure at the time of load interruption, and the like. That is, out of the rate of change P / Δt that occurs after the rotation speed of the water turbine 10 reaches the maximum rotation speed after the load is cut off (for example, the maximum high speed N) after the second closing starts, it deviates from the guaranteed value of the water pressure designed in design. The rate of change P / Δt that gives rise to the possibility of occurrence is derived in advance. The storage unit 82 stores data indicating the rate of change P / Δt that causes a possibility of deviating from the guaranteed design value of the water pressure that is assumed in the design as data that is referred to when the load shedding control program 82b is executed. doing. The calculation unit 81 treats the difference between the water pressure acquired in the latest processing of step S21 and the water pressure acquired in the processing of step S21 immediately before as the change rate P / Δt. The calculation unit 81 determines whether or not the rate of change P / Δt is equal to or higher than the rate of change P / Δt that causes a possibility of deviating from the design-guaranteed water pressure stored in the storage unit 82. Then, “determination as to whether a sudden change has occurred” is performed in the process of step S22.

  When it is determined that a sudden change has occurred (step S22; Yes), the calculation unit 81 determines that the second condition is satisfied (step S23). On the other hand, when it is determined in step S22 that no sudden change has occurred (step S22; No), the calculation unit 81 determines that the second condition is not satisfied (step S24).

  In addition, about the detection frequency of the rotational speed and water pressure of the water turbine 10, and the content of the calculation performed when determining the establishment of the first condition and the second condition can be appropriately changed. For example, the first detection unit 40 and the second detection unit 50 may repeatedly perform detection at a period of 0.1 [second]. The information processing apparatus 80 may cause the storage unit 82 to store data indicating detection results for the past one second. In addition, the calculation unit 81 calculates an average value (moving average value) of changes in the rotation speed and water pressure of the water wheel 10 in the past 1 second at intervals of 0.1 second, and calculates a value 0.5 seconds before and a recent value. The determination may be made based on the difference between the two.

  When the second detection unit 50 is provided in either the pipe 30 or the casing 20, the calculation unit 81 determines based on the water pressure detected by the second detection unit 50. When the 2nd detection part 50 is provided in both the pipe | tube 30 and the casing 20, the calculating part 81 determines based on the water pressure which both the 2nd detection parts 50 detected. That is, when the change in the water pressure detected by at least one of the second detection units 50 is a change corresponding to a sudden change, the second condition is satisfied.

  As described above, according to the embodiment, when the rotational speed of the water turbine 10 is equal to or lower than the maximum rotational speed (for example, the maximum high speed N) after the second closing, and the water pressure suddenly changes, the buffer closing can be performed. . Thereby, the height difference of the fluctuation of the water pressure can be reduced. Therefore, it is possible to cope with a sudden change in the water pressure in the pipe of the water W supplied to the water turbine 10.

  In addition, when the rate of change P / Δt becomes equal to or higher than a predetermined threshold value (for example, threshold value Th) within a time of 1 second or less, the height difference of the fluctuation of water pressure is more reliably reduced by performing buffer closing. be able to. Therefore, it is possible to cope with a sudden change in the water pressure in the pipe of the water W supplied to the water turbine 10.

  Further, when the signal transmission path between the control device 70 and at least one of the first detection unit 40 and the second detection unit 50 includes a wireless signal transmission path, all of them are wired. Compared to the above, it is possible to relax the design requirements of the transmission path between the control device 70 and the first detection unit 40 and the second detection unit 50.

  The above-described embodiment is merely an example, and can be changed as appropriate without departing from the technical features of the present invention. For example, the transmission path of the control device 70 and the first detection unit 40 and the second detection unit 50 may be a wired path.

  Second closure is not essential. That is, you may transfer to buffer closure after the first closure. In this case, the first closing corresponds to the first step.

DESCRIPTION OF SYMBOLS 1 Hydroelectric power generation facility 10 Turbine 11 Generator 12 Electric power system 13 Synchronous circuit breaker 20 Casing 21 Draft 30 Pipe 31 Storage part 40 1st detection part 40a 1st wireless communication part 50 2nd detection part 50a 2nd wireless communication part 60 Guide vane 70 Control Device 71 Servo Motor 72 Servo Motor Control Unit 80 Information Processing Device 81 Calculation Unit 82 Storage Unit 82a Hydropower Generation Control Program 82b Load Cutoff Control Program 83 Communication Unit N Communication Line W Water

Claims (4)

A turbine connected to a generator,
A casing in which the water wheel is housed and water is allowed to flow;
A pipe for flowing water to be supplied into the casing;
A guide vane provided in the casing and opening and closing a water channel between the pipe and the water wheel;
A first detector for detecting the rotational speed of the water wheel;
A second detector for detecting a water pressure inside at least one of the pipe and the casing;
A control device for controlling the opening of the guide vane,
The control device includes a first step of reducing the opening degree of the guide vane below the opening degree before the load interruption when the load interruption of the generator is performed, and the guide vane per predetermined time than the first step. A second step of reducing the amount of change in the opening of the guide vane to make the opening of the guide vane smaller than that at the completion of the first step to reduce the opening of the guide vane, In the step, when the rotational speed of the water wheel is equal to or lower than the maximum rotational speed after the start of load shedding and the water pressure change condition is satisfied, the process proceeds to the second step,
The second detector repeats the detection of water pressure with a period of 1 second or less,
The water pressure change condition is a hydraulic power generation control system in which a rate of change of water pressure inside at least one of the pipe and the casing becomes a predetermined threshold or more within a time of 1 second or less. The hydraulic power generation control system according to claim 1, wherein a signal transmission path between the control device and at least one of the first detection unit and the second detection unit includes a wireless signal transmission path. When load interruption of a generator that generates electricity by hydropower is performed, at least one of a rotation speed of a water turbine connected to the generator, a pipe for flowing water supplied in a casing in which the water wheel is stored, and the casing A control method for controlling the opening of a guide vane that is provided in the casing and opens and closes a water channel between the pipe and the water wheel, based on the water pressure inside
A first step of making the opening degree of the guide vane smaller than the opening degree before load interruption;
A second step of making the amount of change in the opening degree of the guide vane per predetermined time smaller than that in the first step to make the opening degree of the guide vane smaller than when the first step is completed,
In the first step, when the rotational speed of the water wheel is equal to or lower than the maximum rotational speed after the start of load shedding and the water pressure change condition is satisfied, the process proceeds to the second step,
The water pressure change condition is that the rate of change of the increase in water pressure inside at least one of the pipe and the casing becomes a predetermined threshold value or more within a time of 1 second or less. At least one of a control device that controls the opening degree of the guide vane, a first detection unit that detects a rotation speed of the water turbine, and a second detection unit that detects a water pressure inside at least one of the pipe and the casing; The control method according to claim 3, wherein the signal transmission path between the two includes a wireless signal transmission path.

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