JP2019161811A - Hydraulic power generating system - Google Patents

Abstract

To provide a hydraulic power generating system that can prevent water from being retained over a long period in a flow-dividing passage provided with a second flow rate adjusting part.SOLUTION: A control unit (60) controls the second flow rate adjusting part (40) to cause a drainage operation of draining water in the second flow-dividing passage (12) to be executed.SELECTED DRAWING: Figure 3

Description

The present invention relates to a hydroelectric power generation system.

  In the hydroelectric power generation system of Patent Document 1, a main pipe (first branch flow path) and a bypass pipe (second branch flow path) are connected in parallel to the main pipe. The main pipe is provided with a water wheel (hydraulic machine), and the bypass pipe is provided with an electric valve (second flow rate adjusting unit). In principle, the main water flows through the main pipe and is used to rotate the turbine. The rotational power of the water turbine is used for power generation by the generator.

JP-A-2006-118207

  In the bypass pipe, for example, if the motor-operated valve is closed or opened for a long time, the water in the bypass pipe is stagnated. As a result, for example, in a system targeting waterworks, the chlorine concentration of water may fall below a specified concentration. Thereafter, when the motor-operated valve is opened and water with a reduced chlorine concentration is sent downstream, the supply target may not be able to satisfy the reference value of the chlorine concentration. In addition, when the water in the bypass pipe is stagnated, there is a possibility that bacteria or mold in the water will propagate, scale components may be generated due to adhesion of water components, and pipes may be corroded.

  An object of the present disclosure is to provide a hydroelectric power generation system that can suppress water stagnation over a long period of time in a branch flow path in which a second flow rate control unit is provided.

  The first aspect is the hydraulic machine (31) provided in the first branch channel (11) of the first branch channel (11) and the second branch channel (12) connected in parallel to the main channel (10). ) And a generator (32) coupled to the rotating shaft (33) of the hydraulic machine (31), and a second flow rate controller (30) provided in the second branch channel (12). A flow rate adjustment unit (40); and a control unit (60) for controlling the first flow rate adjustment unit (30) and the second flow rate adjustment unit (40), wherein the control unit (60) includes the second flow rate adjustment unit (40). The hydraulic power generation system is characterized in that a drainage operation for discharging water from the second branch flow path (12) is executed by controlling the flow rate adjusting unit (40).

  In the first aspect, the water in the second branch channel (12) can be quickly discharged by executing the draining operation for discharging the water in the second branch channel (12). For this reason, it can suppress that water stagnates over a long period in the 2nd distribution channel (12).

  A second mode is the first mode, wherein the control unit (60) sets the total flow rate of the main channel (10) to be equal to or less than the maximum flow rate of the first branch channel (11) in the drainage operation. Is a hydroelectric power generation system characterized by

  According to a third aspect, in the first or second aspect, the control unit (60) includes an indicator indicating that the second branch channel (12) is in a non-water-passing state, and a second branch channel (12). It is a hydroelectric power generation system that determines whether or not the drainage operation needs to be started based on at least one of indices indicating a state in which only a small flow rate flows.

  According to a fourth aspect, in the first or second aspect, the control unit (60) determines whether or not the drainage operation needs to be started based on an index indicating the water quality in the second branch channel (12). This is a hydroelectric power generation system.

  According to a fifth aspect, in any one of the first to fourth aspects, the control unit (60) determines whether the drainage operation needs to be completed based on the integrated flow rate of the second branch flow path (12). It is a hydroelectric power generation system characterized by judging.

  In a sixth aspect according to any one of the first to fifth aspects, the control unit (60) supplies water in an amount equal to or greater than an entire capacity of the second branch channel (12) in the draining operation. It is a hydroelectric power generation system characterized by discharging from the second branch passage (12).

  In a seventh aspect according to any one of the first to sixth aspects, the controller (60) does not execute the draining operation when the main flow path (10) is in a non-water-permeable state. Is a hydroelectric power generation system characterized by In the seventh aspect, in the drainage operation, all the water in the second branch channel (12) can be discharged from the second branch channel (12).

  In an eighth aspect according to any one of the first to seventh aspects, the control unit (60) controls the first flow rate adjustment unit (30) in the drainage operation, thereby controlling the first flow rate control unit (30). It is a hydroelectric power generation system characterized by lowering the flow rate of a branch channel (11).

  In the eighth aspect, even if the flow rate of the second diversion channel (12) increases in the drainage operation, the total flow rate of the main flow channel (10) is greatly increased in order to reduce the flow rate of the first diversion channel (11). The increase can be suppressed.

  A ninth aspect is any one of the first to eighth aspects, wherein the control unit (60) does not execute the drainage operation when the generated power of the generator (32) is greater than a predetermined value. This is a hydroelectric power generation system characterized by this.

  In the ninth aspect, it is possible to prevent the generated power from being significantly reduced due to the drainage operation under a situation where the generated power is large.

FIG. 1 is a schematic configuration diagram of a hydroelectric power generation system according to an embodiment. FIG. 2 is a block diagram showing a schematic configuration of the controller. FIG. 3 is a timing chart for explaining the operation of the hydroelectric power generation system. FIG. 4 is a schematic configuration diagram of a hydroelectric power generation system according to Modification 4 of the first condition. FIG. 5 is a timing chart according to Modification 4 of the first condition. FIG. 6 is a timing chart according to Modification 1 of the second condition. FIG. 7 is a timing chart according to Modification 2 of the second condition. FIG. 8 is a schematic configuration diagram of the hydroelectric power generation system according to the first control. FIG. 9 is a timing chart according to the first control. FIG. 10 is a timing chart according to the second control. FIG. 11 is a timing chart according to the third control.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following embodiments are essentially preferable examples, and are not intended to limit the scope of the present invention, its application, or its use.

<< Embodiment of the Invention >>
FIG. 1 is a schematic configuration diagram of a hydroelectric power generation system (20) of the present invention. The hydroelectric power generation system (20) is applied to a water channel (C) through which water flows.

<Waterway>
The water channel (C) of this embodiment is applied to the water supply. For example, a storage tank is provided on the upstream side of the water channel (C), and a water receiving tank is provided on the downstream side of the water channel (C) (not shown). In the water channel (C), water flows due to a drop between the storage tank and the water receiving tank.

  The water channel (C) includes one main pipe (10) which is a main flow path, and a main pipe (11) and a bypass pipe (12) connected in parallel to the main pipe (10). The main pipe (10) includes an upstream pipe (10a) on the upstream side of the main pipe (11) and a downstream pipe (10b) on the downstream side of the main pipe (11). The main pipe (11) constitutes a first branch channel in which the first flow rate adjusting part (30) is provided. The bypass pipe (12) constitutes a second branch passage in which the motor operated valve (40) is provided. The bypass pipe (12) of the present embodiment is a detour for water to bypass the water turbine (31), for example, when the generator (32) is abnormal. Here, when the generator (32) is abnormal, power generation is stopped due to a power failure or instantaneous voltage drop in the power system (E), or the generator (32), converter (34), grid-connected inverter (62 ) And other equipment failures (electrical disconnection and mechanical burn-in).

<Hydropower generation system>
As shown in FIG. 1, the hydroelectric power generation system (20) includes a first flow rate adjustment unit (30), a second flow rate adjustment unit (motor valve (40)), a first flow meter (21), a second flow meter ( 22), a controller (60), and a grid interconnection inverter (62). The first flow rate adjuster (30) includes a water turbine (31), a generator (32), and a converter (34).

<Watermill>
The water wheel (31) is a hydraulic machine provided in the water channel (C). The water turbine (31) is provided in the main pipe (11). The water wheel (31) includes a casing and an impeller accommodated in the casing (not shown). The shaft center part of the impeller is connected to the generator (32) via the rotating shaft (33). In the water wheel (31), the impeller and eventually the rotating shaft (33) rotate due to the water flow in the casing.

<Generator>
The generator (32) generates power by being rotationally driven by the water turbine (31). The generator (32) includes, for example, a permanent magnet embedded rotor and a stator having a coil.

<converter>
The converter (34) adjusts the torque of the generator (32) based on a command from the controller (60). Thereby, the flow volume (1st flow volume (Q1)) of the water of a main pipe (11) is adjusted.

<Motorized valve>
The motor operated valve (40) is a second flow rate adjusting unit provided in the water channel (C). The motor operated valve (40) is connected to the bypass pipe (12). The motor-operated valve (40) adjusts the water flow rate (second flow rate (Q2)) of the bypass pipe (12). The motor-operated valve (40) is configured so that its opening degree can be adjusted in multiple stages between a fully closed state in which the bypass pipe (12) is fully closed and a fully open state in which the bypass pipe (12) is 100% open. Is done. By controlling the motor operated valve (40), the flow rate and pressure of the bypass pipe (12) change. That is, the motor-operated valve (40) can also be referred to as a valve for adjusting the pressure.

<First flow meter and second flow meter>
The first flow meter (21) is provided in the main pipe (11). The 1st flow meter (21) constitutes the 1st flow rate acquisition part which detects thru / or measures the flow (the 1st flow (Q1)) of the water which flows through the main pipe (11). The 2nd flow meter (22) constitutes the 2nd flow volume acquisition part which detects thru / or measures the flow (water flow (Q2)) of the water which flows through a bypass pipe (12). The first flow rate acquisition unit and the second flow rate acquisition unit do not necessarily detect each flow rate directly. For example, the first flow rate acquisition unit and the second flow rate acquisition unit include characteristics of the water turbine (31) (a database (characteristic map) including operating points, torque, generated power, and other characteristics of the water turbine (31) to the generator (32)). Thus, each flow rate can be estimated.

<controller>
As shown in FIG. 2, the controller (60) (control unit) includes a first control unit (70) and a second control unit (80).

<First control unit>
The first control unit (70) controls the first flow rate adjustment unit (30). As a general rule, the first control unit (70) performs flow rate control to bring the total flow rate of the main pipe (10) close to the target value. In this embodiment, this target value is determined by the request of the supply target to which water is supplied from the main pipe (10). A flow rate command value (Q *) corresponding to this target value is input to the first control unit (70).

  The first controller (70) is configured using a microcomputer and a memory device storing a program for operating the microcomputer. The first controller (70) includes a flow controller (71), a torque controller (72), and a PWM controller (73).

  The flow rate controller (71) receives the first flow rate (Q1) detected by the first flow meter (21) and the flow rate command value (Q *) that is the target value. The flow controller (71) calculates a torque command value (T *) for converging the first flow rate (Q1) to the flow command value (Q *).

  A torque command value (T *) that is a control target of the generator (32) is input to the torque controller (72). The torque controller (52) calculates a voltage command value according to the torque command value (T *).

  The PWM controller (73) performs PWM control of the switching element of the converter (34) based on the voltage command value output from the torque controller (72). Thereby, the first flow rate (Q1) converges to the flow rate command value (Q *).

<Second control unit>
A 2nd control part (80) controls the motor operated valve (40) which is a 2nd flow volume adjustment part. When the condition (abnormal condition) indicating the abnormality of the generator (32) is satisfied, the second control unit (80) of the present embodiment performs a bypass operation in which the water of the main pipe (10) bypasses the water turbine (31). The motorized valve (40) is controlled so that A 2nd control part (80) will control a motor operated valve (40) so that the drainage operation which discharges the water of a bypass pipe (12) may be performed, if the 1st condition is satisfied. A 2nd control part (80) will control a motor operated valve (40) so that drainage operation | movement may be complete | finished, if 2nd conditions are satisfied.

  The second control unit (80) is configured using a microcomputer and a memory device in which a program for operating the microcomputer is stored.

  The second control unit (80) includes a first determination unit (81), a second determination unit (82), and a valve control unit (83).

  A 1st determination part (81) determines the necessity of execution of bypass operation based on abnormal conditions. For example, the first determination unit (81) is determined based on the current value of the converter (34) connected to the generator (32). When the abnormal condition is satisfied, the first determination unit (81) outputs a command for executing the bypass operation to the valve control unit (83).

  A 2nd determination part (82) determines the necessity of the start of drainage operation | movement based on 1st conditions. When the first condition is established, the second determination unit (82) outputs a command for executing the drainage operation to the valve control unit (83. The second determination unit (82) drains based on the second condition. When the second condition is satisfied, the second determination unit (82) outputs a command for ending the drainage operation to the valve control unit (83).

  The valve control unit (83) controls the opening degree of the motor-operated valve (40) based on the commands output from the first determination unit (81) and the second determination unit (82) (details will be described later).

<System interconnection inverter>
As shown in FIG. 1, the grid-connected inverter (62) includes a plurality of switching elements that constitute an inverter unit. DC power from the converter (34) is input to the grid interconnection inverter (62). In the grid interconnection inverter (62), DC power is converted into AC power by switching a plurality of switching elements. The AC power generated by the grid interconnection inverter (62) is supplied (reverse power flow) to the power grid (E).

  The power conversion circuit including the converter (34) and the grid interconnection inverter (62) has a function of controlling the torque of the generator (32) and the power generated by the generator (32). Any other method may be used as long as it has a function that can be supplied to the device. For example, in the power conversion circuit, the grid interconnection inverter (62) and the converter (34) may be integrated, and a matrix converter may be employed.

<Operation of hydroelectric power generation system>
The operation of the hydroelectric power generation system (20) will be described. The hydroelectric power generation system (20) of the present embodiment is configured to be able to perform normal operation, bypass operation, and drainage operation.

<Normal operation>
The normal operation is an operation of generating power with the generator (32) and bringing the first flow rate (Q1) close to the target value. In normal operation, in principle, the motor-operated valve (40) is fully closed. Therefore, the water in the upstream pipe (10a) flows only through the main pipe (11) and is sent from the downstream pipe (10b) to a predetermined supply target. In addition, although mentioned later for details, you may open | release a motor operated valve (40) by a very small opening degree in normal operation | movement. In the main pipe (11), the water turbine (31) is rotationally driven by the water flow, and the generator (32) generates power. At this time, the first flow rate (Q1) is adjusted to the target value (Q *) by controlling the generator (32) by the first control unit (70). In normal operation, since the bypass pipe (12) is closed, the first flow rate (Q1) is equal to the total flow rate (QT) of the main pipe (10). Therefore, in normal operation, the total flow rate (QT) of the main pipe (10) is substantially adjusted to the target value (Q *). As a rule, the target value (Q *) is set below the maximum flow rate of water flowing through the main pipe (11).

<Bypass operation>
The bypass operation is an operation for sending water to the supply target even when the generator (32) is abnormal. The bypass operation is executed when the generator (32) is abnormal. Specifically, for example, it is assumed that power generation is stopped due to an instantaneous voltage drop in the power system (E). In this case, an abnormal condition is established in the first determination unit (81), and the motor-operated valve (40) is opened at a predetermined opening. Thereby, the water of the upstream pipe (10a) is sent to the downstream pipe (10b) via the bypass pipe (12). That is, in the bypass operation, the water of the main pipe (10) bypasses the water turbine (31) of the main pipe (11). Therefore, the water of the main pipe (10) can be reliably sent to a predetermined supply target.

<Draining action>
The draining operation is an operation for suppressing water from remaining in the bypass pipe (12) for a long period of time. In normal operation, the target value (Q *) of the main flow rate (QT) of the main pipe (10) is less than or equal to the maximum flow rate of the main pipe (11) (more specifically, the maximum operating range of the water turbine (10)) It is also executed when the flow rate is below.

  In the normal operation described above, the bypass pipe (12) is closed by the motor-operated valve (40). For this reason, in the bypass pipe (12), the water in the inside is stagnated. If the water in the bypass pipe (12) stagnates for a long time, the chlorine concentration of this water will decrease. Thus, when the chlorine concentration of water falls below a specified value, in the subsequent bypass operation, water having a very low chlorine concentration is sent to the supply target. In this case, there is a possibility that the quality of water to be supplied cannot temporarily satisfy the reference value. Therefore, in the hydroelectric power generation system (20) of the present embodiment, the drainage operation is forcibly executed in order to prevent water from stagnation over a long period of time in the bypass pipe (12).

  The 2nd determination part (82) of this embodiment performs determination of 1st conditions based on the parameter | index which shows that a bypass pipe (12) is a non-water-permeable state. As this index, a signal indicating that the motor-operated valve (40) is in a closed state is used. A first set time (Ts1) is set in advance in the second determination unit (82). The second determination unit (82) determines that the drainage operation needs to be started when the time during which the motor-operated valve (40) is closed reaches the first set time (Ts1). Here, the first set time (Ts1) is a predetermined time smaller than the specified time (Td). The specified time (Td) is the time required for the chlorine concentration of the water to fall below the specified value due to the stagnation of water in the bypass pipe (12), and changes according to the temperature and the chlorine injection amount.

  The second determination unit (82) of the present embodiment determines the second condition based on the execution time of the drainage operation. A second set time (Ts2) is set in advance in the second determination unit (82). In the drainage operation, the second determination unit (82) determines that the drainage operation needs to be terminated when the execution time of the drainage operation reaches the second set time (Ts2).

  For example, as shown in FIG. 3, it is assumed that the normal operation is performed again after the bypass operation is performed. In this case, the motor-operated valve (40) is closed at the start t1 of normal operation. When the first set time (Ts1) elapses from time t1 and reaches time t2, the second determination unit (82) determines that the drainage operation is necessary. As a result, the valve control unit (83) opens the motor-operated valve (40) at a predetermined opening, and the draining operation is started.

  In the drainage operation, the water in the upstream pipe (10a) flows through both the main pipe (11) and the bypass pipe (12). In the main pipe (11), since water passes through the water turbine (31), power is continuously generated in the generator (32). At the same time, when the bypass pipe (12) is in a water-permeable state, the water remaining in the bypass pipe (12) is discharged to the downstream pipe (10b). Thereby, the chlorine concentration of the water of a bypass pipe (12) rises.

  In the drainage operation, the motor-operated valve (40) is controlled such that the total drainage amount (Ve) of water discharged from the bypass pipe (12) is equal to or greater than the total volume (VT) inside the bypass pipe (12). Here, the total volume (VT) depends on the opening of the motor-operated valve (40) (that is, the second flow rate (W2)) and the time for opening the motor-operated valve (40) (that is, the second set time (Ts2)). Can be adjusted. Thus, all the water of a bypass pipe (12) can be reliably discharged | emitted to the exterior of a bypass pipe (12) by making total drainage volume (Ve) more than total volume (VT).

  In the drainage operation, the motor-operated valve (40) is controlled so that the total flow rate (QT) (QT = Q1 + Q2) of the main pipe (10) is less than the maximum flow rate of the main pipe (11). In order to reduce the total flow rate (QT), the opening degree of the motor-operated valve (40) may be made relatively small and the execution time of the drainage operation may be lengthened. Moreover, although mentioned later for details, it is also possible to perform control which reduces total flow volume (QT) by reducing the flow volume (1st flow volume (Q1)) of a main pipe | tube (11).

  In the drainage operation, if the total flow rate (QT) becomes excessively large, dirt attached to the inner wall of the main pipe (10) may peel off and flow out to the supply target. In this case, the quality of water to be supplied may be temporarily deteriorated. On the other hand, in the drainage operation, such a problem can be avoided by limiting the total flow rate (QT) of the main pipe (10) to the maximum flow rate of the water turbine (31) or less.

  When the motor-operated valve (40) is closed at the end of the drainage operation t3, the normal operation is resumed. Then, when the first set time (Ts1) elapses from the time point t3, the drainage operation is performed again.

  As described above, in this embodiment, the draining operation is performed at an interval (first set time (Ts1)) shorter than the specified time (Td). Thereby, it can prevent reliably that the chlorine concentration of the water stagnated in a bypass pipe (12) is less than a regulation value. As a result, even if the bypass operation is subsequently performed, it is possible to prevent the quality of water to be supplied from falling below the reference value.

-Effect of the embodiment-
In the present embodiment, the controller (60) controls the motor-operated valve (40) that is the second flow rate adjusting unit to execute a draining operation for forcibly discharging the water in the bypass pipe (12). Since the draining operation is executed in preference to the normal operation, it is surely executed regardless of the target value (Q *) of the normal operation. Thereby, it is possible to suppress water from remaining in the bypass pipe (12) for a long time.

  If water stays in the bypass pipe (12) for a long time, the chlorine concentration of the water will fall below the specified value. In addition, there are problems such as the growth of fungi and molds in the water, the formation of scales due to the fixation of components in the water, the corrosion of piping in the water, and the occurrence of rust. On the other hand, in this embodiment, the water in the bypass pipe (12) is forcibly discharged as appropriate, so that such a problem can be solved.

  In this embodiment, it is determined whether or not the drainage operation needs to be started based on an index indicating that the bypass pipe (12) is in a non-water-passing state (that is, the motor-operated valve (40) is in a closed state). . For this reason, the drainage operation can be surely performed before the motor-operated valve (40) is in the closed state before the water stays in the bypass pipe (12) for a long time.

  In the present embodiment, the controller (60) discharges water from the bypass pipe (12) in an amount equal to or larger than the entire capacity (total volume (VT)) of the bypass pipe (12) in the draining operation. For this reason, in one drain operation, all the water of a bypass pipe (12) can be discharged, and the water quality in a bypass pipe (12) can be improved.

<< Modification of the first condition >>
The first condition for determining whether or not the drainage operation needs to be started may be modified as follows.

<Variation 1 of the first condition>
The indicator indicating that the bypass pipe (12) is in a non-water-permeable state may be data relating to a known operation plan of the water channel (C). That is, this data includes information indicating at what time / time the bypass pipe (12) is in a non-water-permeable state. Therefore, the 2nd determination part (82) can perform drainage operation at a suitable timing by determining the necessity of drainage operation execution based on this data.

<Modification 2 of the first condition>
The indicator indicating that the bypass pipe (12) is in a non-water-passing state may be the second flow rate (Q2) of the bypass pipe (12). For example, when the second flow rate (Q2) of the bypass pipe (12) is continuously zero and this time reaches the first set time (Ts1), the drainage operation is executed.

<Modification 3 of the first condition>
The necessity of starting the drainage operation may be determined using an index indicating a state in which the bypass pipe (12) flows only at a minute flow rate. That is, for example, in normal operation, even when the motor-operated valve (40) has a very small opening, water is stagnated (does not flow sufficiently) in the bypass pipe (12), so that the chlorine concentration of the water decreases or bacteria There is a possibility that the growth of molds and molds is promoted, the components in water are fixed and scales are generated, and the pipes are corroded or rusted. That is, the motor-operated valve (40) of the bypass pipe (12) has a minute opening that can cause such a problem, and the second flow rate (Q2) of the bypass pipe (12) is a minute flow rate that causes such a problem. In such a case, it is necessary to execute the draining operation.

  Therefore, for example, a signal indicating a state in which the motor-operated valve (40) has a minute opening is used as an index indicating a state in which the bypass pipe (12) flows only at a minute flow rate. For example, when this state reaches a predetermined time longer than the first set time (Ts1), the draining operation is started.

  Note that, as the determination of the first condition, both an index indicating that the bypass pipe (12) is in a non-water-permeable state and an index indicating a state where the bypass pipe (12) flows only with a minute flow rate may be used. Similarly to the first condition modification 1 and the first condition modification 2 described above, the index indicating the state in which the bypass pipe (12) flows only at a minute flow rate may be data relating to a known operation plan. It may be the second flow rate (Q2) of the bypass pipe (12).

<Modification 4 of the first condition>
The 2nd determination part (82) of a controller (60) may determine the necessity of a drainage operation start using the parameter | index which shows the water quality of a bypass pipe (12). For example, as shown in FIG. 4, the bypass pipe (12) is provided with a water quality measuring unit (50) for measuring the water quality in the bypass pipe (12). In FIG. 4, the water quality measuring unit (50) is arranged on the upstream side of the motor-operated valve (40) in the bypass pipe (12), but it may be arranged on the downstream side of the motor-operated valve (40). The water quality measurement unit (50) is, for example, a chlorine concentration meter that measures the chlorine concentration of water, a conductivity meter that measures the electrical conductivity of water, and a sensor that measures other water quality indicators.

  As shown in FIG. 5, when water is stagnated in the bypass pipe (12) in normal operation, the chlorine concentration of this water gradually decreases. Along with this, the chlorine concentration (D) detected by the water quality measurement unit (50) decreases. In this example, in the normal operation, when the detected chlorine concentration (D) reaches a predetermined first value (D1), the first condition is satisfied and the drainage operation is executed. This first value (D1) is, for example, a value that is the same as or larger than the reference value of the chlorine concentration that is acceptable for drinking water.

  In this way, the water quality of the bypass pipe (12) is directly detected, and the drainage operation is executed based on the detection result. The deterioration of water quality can be avoided reliably.

<Modification 5 of the first condition>
The second determination unit (82) of the controller (70) may determine whether or not to start the drainage operation based on the integrated flow rate of the bypass pipe (12) for a predetermined time. Specifically, for example, an integrated value (integrated flow rate (QI)) of the second flow rate (Q2) of the bypass pipe (12) is obtained every predetermined time (Ts3) shorter than the above-described specified time (Td). . This integrated flow rate (QI) may be calculated based on the second flow rate (Q2), or may be directly measured by an integrated flow meter. Then, when the predetermined time (Ts3) has elapsed and the integrated flow rate (QI) at this time (Ts3) is smaller than the predetermined value, the drainage operation is executed. Thereby, it can avoid reliably that the water of a bypass pipe (12) stagnates. On the other hand, when the predetermined time (Ts3) has elapsed and the integrated flow rate (QI) at this time (Ts3) is greater than the predetermined value, the drainage operation is not performed and the time (Ts3) is counted again.

  In this example, the drainage operation should be performed at an appropriate timing while taking into account the amount of water discharged from the bypass pipe (12) when the motorized valve (40) of the bypass pipe (12) is opened instantaneously. Can do.

<< Modification of the second condition >>
The second condition for determining whether or not to end the drainage operation may be modified as follows.

<Modification 1 of the second condition>
For the determination of the second condition, an integrated flow rate of water drained from the bypass pipe (12) during the draining operation may be used. That is, the 2nd determination part (82) of a controller (60) determines the necessity of completion | finish of drainage operation | movement based on the parameter | index which shows the integrated flow rate of a bypass pipe (12).
In the example of FIG. 6, the integrated value (integrated flow rate (QI)) of the flow rate (second flow rate (Q2)) of the bypass pipe (12) is obtained from the start of the drainage operation. This integrated flow rate (QI) may be calculated based on the second flow rate (Q2), or may be directly measured by an integrated flow meter. In this example, when the integrated flow rate (QI) reaches a predetermined value (I1), the draining operation is terminated and the normal operation is started. This predetermined value (I1) is a value equal to or larger than the total volume (VT) inside the bypass pipe (12). The predetermined value (I1) is preferably equal to the total volume (VT).

  In this example, the entire amount of water stagnated in the bypass pipe (12) can be reliably discharged in the drainage operation. Further, when the integrated flow rate (I) is made equal to the total volume (VT), water stagnated in the bypass pipe (12) can be discharged without excess and deficiency, and the execution time of the drainage operation can be minimized.

<Modification 2 of the second condition>
In this example, when the motor-operated valve (40) of the bypass pipe (12) is opened with a small opening in normal operation, the drainage operation is performed in consideration of the integrated flow rate of the second flow rate (Q2) at this time. Is. For example, as shown in FIG. 7, it is assumed that the motor-operated valve (40) is opened with a very small opening degree in normal operation. In this case, the integrated flow rate (I) increases even in normal operation. In the draining operation, when the integrated flow rate (I) further increases and the integrated flow rate (I) reaches a predetermined value (I1), it is determined that the second condition is satisfied. That is, in this example, the second condition is determined based on the integrated flow rate from the start of the normal operation to the end of the drainage operation. If it does in this way, execution time of drainage operation can be made shorter than modification 1 of the 2nd condition mentioned above.

<Modification 3 of the second condition>
The 2nd determination part (82) of a controller (60) may determine the necessity of completion | finish of drainage operation | movement using the parameter | index which shows the water quality of a bypass pipe (12). That is, as shown in FIG. 4, the bypass pipe (12) is provided with the water quality measurement unit (50) described above. As shown in FIG. 5, in the drainage operation, when the water in the bypass pipe (12) is discharged, the chlorine concentration (D) gradually increases. In the draining operation, when the detected chlorine concentration (D) reaches a predetermined second value (D2), the second condition is established and the draining operation is executed. The second value (D2) is larger than the first value (D1).

《Other control examples of drainage operation》
For the draining operation, the following control examples may be adopted.

<First control>
The second controller (80) of the controller (60) may control the motor-operated valve (40) so that the drainage operation is not performed when the main pipe (10) is in a non-water-permeable state. As shown in FIG. 8, for example, in the water channel (C), an opening / closing mechanism (15) is provided upstream of the main pipe (10). The opening / closing mechanism (15) is an opening / closing valve capable of opening and closing the main pipe (10). In principle, the open / close mechanism (15) can be switched between open and closed regardless of the operation of the hydroelectric power generation system (20).

  For example, a signal indicating the open / close state of the open / close mechanism (15) is input to the controller (60) of the hydroelectric power generation system (20). The 2nd control part (80) of this example accept | permits execution of drainage operation, when the main pipe (10) is a water flow state. The second control unit (80) prohibits execution of the drainage operation when the main pipe (10) is in a non-water-permeable state.

  Specifically, it is assumed that the first condition is established when it is determined that the main pipe (10) is in the water-passing state as shown at time t1 in FIG. In this case, a 2nd control part (80) opens a motor operated valve (40), and performs drainage operation | movement. On the other hand, it is assumed that the first condition is established when it is determined that the main pipe (10) is in the non-water-permeable state, as shown at time t2 in FIG. In this case, the second control unit (80) does not open the motor-operated valve (40) even if the first condition is satisfied, and prohibits execution of the draining operation. In this case, after the time point t2, at the time point t3 when it is determined that the main pipe (10) is again in the water passing state, the motor-operated valve (40) is opened and the draining operation is performed.

  As described above, in this example, the draining operation is not performed when the vehicle is in a non-water-permeable state. For this reason, although the motor-operated valve (40) was opened, the problem that water does not actually flow through the bypass pipe (12) can be avoided. And in the drainage operation | movement of the following water flow state, the water of a bypass pipe (12) can be discharged | emitted reliably.

<Variation 1 of the first control>
The first control may be performed based on data relating to a known operation plan of the water channel (C). That is, this data includes information indicating at which time / time the main pipe (10) is in a water-permeable state and a non-water-permeable state. Based on this data, the controller (60) performs the drainage operation so as to avoid the non-water-permeable state of the main pipe (10).

<Modification 2 of the first control>
The determination of whether the main pipe (10) is in a water passage state or a non-water passage state may use an index other than the opening / closing state of the opening / closing mechanism (15). For example, it can also be determined by detecting the flow rate (water flow state) and pressure of the water channel (C).

<Second control>
The second controller (80) of the controller (60) may control the generator (32) so as to reduce the flow rate (first flow rate (Q1)) of the main pipe (11) in the drainage operation. Specifically, the generator (32) may be controlled so that the total flow rate (QT) of the main pipe (10) is maintained at the target value even when the normal operation is shifted to the drainage operation.

  For example, as shown in FIG. 10, it is assumed that the drainage operation is performed at time t1. In this case, the second control unit (80) opens the electric valve (40) at a predetermined opening. As a result, the second flow rate (Q2) increases by ΔQ. On the other hand, a 1st control part (70) controls a generator (32) so that 1st flow volume (Q1) may be made small at the start of execution of drainage operation. In this example, the first flow rate (Q1) is decreased by ΔQ in the drainage operation. In this way, even if the second flow rate (Q2) increases in the drainage operation, the total flow rate (QT) does not change significantly. Thereby, also in drainage operation, the total flow rate (QT) can be brought close to the target value (Q *) or can be maintained as it is.

  In the drainage operation, for example, if the opening degree of the motor-operated valve (40) is made relatively small and the execution time of the drainage operation is lengthened, the reduction width ΔQ of the second flow rate (Q2) becomes small. Accordingly, in the drainage operation, the increase width (that is, ΔQ) of the first flow rate (Q1) is also reduced. Therefore, from the viewpoint of suppressing fluctuations in the total flow rate (QT), it is preferable that the opening degree of the motor-operated valve (40) for the draining operation is relatively small and the execution time of the draining operation is relatively long.

<Third control>
The second control unit (80) of the controller (60) may control the motor-operated valve (40) so that the drainage operation is not performed when the generated power of the generator (32) is larger than a predetermined value. In the hydroelectric power generation system (20), the power generated by the generator (32) may fluctuate. For example, this is a case where the target value (Q *) of the total flow rate (QT) of the channel (C) changes systematically or the power demand of the generator (32) changes. The generated power (P) of the generator (32) is proportional to the cube of the first flow rate (Q1). For this reason, if the drainage operation is executed while the power generation (P) of the generator (32) is relatively large, the first flow rate (Q1) will decrease, and the power generation (P) will decrease significantly. There is a possibility. Therefore, in this example, when the generated power (P) is larger than the predetermined value (P1), the drainage operation is prohibited. After that, when the generated power (P) falls below the predetermined value (P1), the drainage operation is executed. Is done. In addition, you may use another parameter | index (1st flow volume (Q1) etc.) as a parameter | index which shows generated electric power (P).

  For example, it is assumed that the first condition is satisfied when the generated power (P) is equal to or less than a predetermined value (P1) at time t1 in FIG. In this case, a 2nd control part (80) opens a motor operated valve (40), and performs drainage operation | movement. On the other hand, it is assumed that the first condition is satisfied when the generated power (P) is larger than a predetermined value (P1) as shown at time t2 in FIG. In this case, the second control unit (80) does not open the motor-operated valve (40) even if the first condition is satisfied, and the execution of the draining operation is prohibited. In this case, after the time point t2, at the time point t3 when the generated power (P) becomes equal to or less than the predetermined value (P1), the motor-operated valve (40) is opened and the draining operation is performed.

  As described above, in this example, the drainage operation is not performed under conditions where the generated power (P) is relatively large. For this reason, it can suppress that generated electric power falls significantly resulting from drainage operation.

<Modification of third control>
The third control may use data relating to a known operation plan of the water channel (C) and the generator (32). That is, this data includes information indicating the target value (Q *) of the main (10), the target generated power of the generator (32), and the like. Based on this data, the controller (60) causes the drainage operation to be performed so as to avoid a period in which the generated power (P) is greater than the predetermined value (P1).

<< Other Embodiments >>
About the said embodiment, it is good also as following structures.

  The above-described embodiment, each modification example of the first condition, each modification example of the second condition, and other control examples may be appropriately combined within a possible range.

  In the embodiment described above, the generator (32) is controlled so that the total flow rate (QT) or the first flow rate (Q1) of the main pipe (10) approaches the target value. However, the hydroelectric power generation system (20) may be such that the pressure downstream of the main pipe (10) or the pressure downstream of the main pipe (11) approaches the target value. In this case, in each of the above-described examples, the first flow rate (Q1) is replaced with the pressure of the main pipe (11) (first pressure (p1)), and the second flow rate (Q2) is replaced with the pressure of the bypass pipe (12) (first pressure). The same control can be performed by substituting 2 pressures (p2). Here, the first pressure (p1) and the second pressure (p2) do not necessarily have to be directly measured by a sensor or the like, but the operating point, torque, generated power, etc. of the turbine (31) to the generator (32). It can also be estimated from a database (characteristic map) including the characteristics of

  The first flow rate controller (30) may be two or more hydraulic machines (31) connected in series to the main pipe (11). The first flow rate control unit (30) may be at least one hydraulic machine (31) connected in series to the main pipe (11) and at least one electric valve (40).

  The main pipe (11) (first branch flow path) provided with the first flow rate adjusting unit (30) is not necessarily one, and two or more main pipes (11) are connected in parallel to the main pipe (10). May be.

  The second flow rate adjusting unit may be two or more motor-operated valves (40) connected in series to the bypass pipe (12). Further, the second flow rate adjusting unit (40) does not have to be a motor-operated valve (40), and may have any configuration as long as the flow rate (strictly including pressure) of the bypass pipe (12) can be adjusted.

  For example, the second flow rate adjustment unit (40) may be at least one hydraulic machine (water turbine) connected to the generator. This is because, similarly to the above-described water turbine (31), by controlling this hydraulic machine, the bypass pipe (12) can be made into a non-water-permeable state, a minute flow rate, or a water-permeable state.

  Moreover, the 2nd flow volume control part may be the structure which connected the at least 1 motor operated valve and the at least 1 hydraulic machine in series. Also in this case, the bypass pipe (12) can be in a non-water-permeable state, a minute flow rate, or a water-permeable state by controlling the electric valve and the hydraulic machine in cooperation.

  The number of bypass pipes (12) (second branch flow path) provided with the second flow rate adjusting unit (40) is not necessarily one, and two or more bypass pipes (12) are arranged in parallel with the main pipe (10). You may connect to. In the embodiment described above, the principle is that the main pipe (11) (first branch flow path) is in a water-flowing state during the drainage operation. However, the main pipe (11) may be in a non-water passing state during the draining operation. Moreover, the main pipe (11) should just be in a water-passing state at least either before the draining operation or after the draining operation.

  While the embodiments and modifications have been described above, it will be understood that various changes in form and details are possible without departing from the spirit and scope of the claims. In addition, the above embodiments and modifications may be appropriately combined or replaced as long as the functions of the subject of the present disclosure are not impaired. In addition, the descriptions “first”, “second”, “third”, etc. described above are used to distinguish words / phrases to which these descriptions are given, and the number and order of the words / phrases are limited. There is no limitation.

  The present invention is useful as a hydroelectric power generation system.

10 Main pipe (main flow path)
11 Main pipe (first branch flow path)
12 Bypass pipe (second branch flow path)
30 1st flow control part 32 Generator 40 Electric valve (2nd flow control part)
60 controller (control unit)

Claims (9)

A hydroelectric power generation system targeting a water channel (C) in which a first branch channel (11) and a second branch channel (12) are connected in parallel to the main channel (10),
A first flow rate adjustment unit (30) having a hydraulic machine (31) provided in the first branch passage (11) and a generator (32) connected to a rotating shaft (33) of the hydraulic machine (31). When,
A second flow rate controller (40) provided in the second branch channel (12);
A control unit (60) for controlling the first flow rate adjustment unit (30) and the second flow rate adjustment unit (40);
The said control part (60) controls the said 2nd flow volume adjustment part (40), and performs the waste_water | drain operation | movement which discharges | emits the water of the said 2nd branch flow path (12), The hydroelectric power generation system characterized by the above-mentioned. In claim 1,
The said control part (60) makes the total flow volume of the said flow path (10) below the maximum flow volume of the said 1st branch flow path (11) in the said drainage operation | movement, The hydroelectric power generation system characterized by the above-mentioned. In claim 1 or 2,
The control unit (60) includes at least one of an index indicating that the second branch channel (12) is in a non-water-permeable state and an index indicating a state where the second branch channel (12) flows only with a minute flow rate. The hydroelectric power generation system is characterized in that it is determined whether or not the drainage operation needs to be started based on the above. In claim 1 or 2,
The said control part (60) determines the necessity of the start of the said drainage operation | movement based on the parameter | index which shows the water quality in the said 2nd branch flow path (12), The hydroelectric power generation system characterized by the above-mentioned. In any one of Claims 1 thru | or 4,
The said control part (60) determines the necessity of completion | finish of the said drainage operation | movement based on the integrated flow volume of the said 2nd branch flow path (12), The hydroelectric power generation system characterized by the above-mentioned. In any one of Claims 1 thru | or 5,
The control unit (60), in the drainage operation, discharges an amount of water equal to or greater than the entire capacity of the second branch channel (12) from the second branch channel (12). . In any one of Claims 1 thru | or 6,
The control unit (60) does not execute the drainage operation when the main channel (10) is in a non-water-permeable state. In any one of Claims 1 thru | or 7,
In the drainage operation, the control unit (60) controls the first flow rate adjustment unit (30) to reduce the flow rate of the first diversion channel (11). In any one of claims 1 to 8,
The control unit (60) does not execute the drainage operation when the generated power of the generator (32) is larger than a predetermined value.

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