JPH04104307A - Control method for dam discharge rate - Google Patents

Abstract

PURPOSE:To prevent the excess discharge of a total discharge rate or a discharge lack so as to improve reliability and safety by continuously switching the discharge rate between fine adjustment and rough adjustment gates. CONSTITUTION:A target discharge rate distribution circuit 83 distributes a total target discharge rate Qm into the target discharge rate Qmf of the fine adjustment gate 41 and the target discharge rate Qmr of the rough adjustment gate 42 in accordance with a maximum possible discharge rate Qmfm decided in a decision circuit 86 and a present discharge rate Qo. When the distribution of the target discharge rate for respective gates terminates, the discharge control parts 84 and 85 of respective gates generate necessary gate start signals df and fr from the distributed target discharge rates Qmf and Qmr and present gate openings Pf and Pr. Thus, gate driving devices 61 and 62 are controlled to set the discharge rates of respective gates to become the target values Qmf and Qmr. When an inflow rate Qin continuously increases and a flowing water level of dam Hu exceeds the upper limit of a dam water level maintenance area [Hs], the target discharge rate Qm is increased again. Thus, the flow rate can be controlled without the discontinuous change of opening and the disturbance of control owing to the difference of gate opening/closing time and gate friction can be prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for controlling the discharge amount at a weir installed in a river, and in particular, a method for finely adjusting the amount by using an overflow gate.
The present invention relates to a weir discharge flow rate control method suitable for weirs that perform rough adjustment with underflow gates.

[Conventional technology]

At river weirs, flow rate control is performed for river use and safety management. Figure 3 shows the structure of the weir, which is mainly composed of a flow rate adjustment mechanism, in which the amount of discharge from the outlet 3 is determined according to the amount of inflow Qin from the inlet 2 into the pocket of the weir 1.
t is controlled. This control is performed by controlling the respective opening degrees of a fine adjustment gate 41 that finely adjusts the flow rate by overflow and a coarse adjustment gate 42 that coarsely adjusts the flow rate by underflow. An example of this conventional control method is JP-A-641
4621, as shown in FIG. 4(a). That is, when the total target discharge amount Qm increases with time as shown in the figure, the target discharge amount Qmf of the fine adjustment gate follows the total target discharge amount Qm, and Q m f becomes the maximum value Q.
mfm (maximum possible discharge amount of the fine adjustment gate), transfer this to the target discharge amount Qmr of the coarse adjustment gate, set the target discharge amount Qmf of the fine adjustment gate to O, and change the total target discharge amount Qm again. Follow me on Qmf. Conversely, when the total target discharge amount Qm decreases with time, Fig. 4 (a)
Performs control that follows the time axis in reverse.

[Problem to be solved by the invention]

Because the coarse adjustment gate has a larger structure than the fine adjustment gate,
When a change in the target discharge amount is applied, the time required for the gate opening to actually change in response to the change is shorter with the coarse adjustment gate, so it is less time consuming than with conventional control methods. When the target discharge amount is instantaneously shifted between two gates, the fine adjustment gate is still open at the time when the coarse adjustment gate has completed changing the gate opening in response to the shift I-. It is in the middle of a change and the completion of that change is delayed.

As a result, transient over-discharge or under-discharge to the downstream occurs,
There is a possibility of posing a danger to fields, golf courses, and other facilities in the downstream riverbed, as well as anglers on sandbars. There was also the problem that it caused fluctuations in the water level downstream.

In addition, when shifting the target discharge amount between gates, the fine adjustment gate always changes the opening degree corresponding to the maximum discharge amount, so the mechanical friction of the gate itself becomes large, especially when water is flowing out. Since large changes in the opening angle are repeated many times, mechanical friction of the fine adjustment gate has become a major problem.

An object of the present invention is to prevent over-discharge or insufficient discharge downstream due to a shift in the discharge amount between the fine adjustment gate and the coarse adjustment gate, thereby improving control stability and downstream safety. The object of the present invention is to provide a radix flow control method that can reduce mechanical friction of a regulating gate.

[Means to solve the problem]

The above purpose is to change the total target discharge amount by increasing (or decreasing) the target discharge amount of the fine adjustment gate while keeping the target discharge amount of the coarse adjustment gate constant as the total target discharge amount increases (or decreases). The first control mode realizes The target discharge amount of the coarse adjustment gate is increased (or decreased) so that the target discharge amount of the gate is decreased (or increased) and the change in the target discharge amount of the two gates matches the change in the total target discharge amount. Continuing the control in the second control mode and the second control mode, when the target discharge amount of the fine adjustment game 1~ reaches 0 discharge amount (or maximum possible discharge amount), the control in the first control mode is executed again. This is achieved by repeating this control, and by providing a mechanism that sets the maximum possible discharge amount of the fine adjustment gate to be smaller as the total target discharge amount increases.

[Effect]

Of course, during the execution of the first control mode and the second control mode,
Even when switching between the two modes, there is no discontinuous change in the target discharge amount of each gate, so the discharge amount is controlled by the difference between the gates in the time required for the gate opening to follow the change in the target discharge amount. This does not occur, and stable control and downstream safety can be improved. Furthermore, since the target discharge amount of each gate does not change discontinuously, the amount of operation of each gate is smaller than that of the conventional technology, and the mechanical friction of the gates can be reduced. Furthermore, when the total target discharge amount increases significantly during a water outflow, by setting the maximum possible discharge amount of the fine adjustment gate to a smaller value as the total target discharge amount increases, the change in the opening degree of the fine adjustment gate becomes smaller. Since the flow rate adjustment is mainly performed by the coarse adjustment gate, the mechanical friction of the fine adjustment gate can be further reduced.

〔Example〕

An embodiment of the present invention will be described below. FIG. 5 is a block diagram showing an embodiment of a weir control system to which the method of the present invention is applied, in which the fine adjustment gate 41 and the coarse adjustment gate 42 are
As shown in the figure. The upstream water level HU and downstream water level HL of these weirs are determined by the weir upstream water level gauge 51 and the weir downstream water level gauge 52.
filter circuit 8 in the weir control system 8
1, where noise components are removed. The next control amount calculation circuit 82 inputs the weir upstream water level HU, and this value is a predetermined weir downstream water level maintenance area [HS] (the predetermined range H1 to H2 of the water level is abbreviated in this way)
If the weir upstream water level HU deviates from the above maintenance area [
Hs] is calculated.

In addition, the current discharge amount calculation circuit 87 calculates the current discharge amount Q out from the noise-removed upstream and downstream water levels HU rHL and the output of the opening meter 71.72 of each gate, which will be described later, and calculates the current discharge amount Q out from the upstream and downstream water levels HU rHL from which noise has been removed and the output of the opening meter 71.72 of each gate, which will be described later. The possible discharge amount Q m f m is determined by the determination circuit 87 . Target discharge amount distribution circuit 83
is the maximum possible discharge amount Qmfm determined by the determination circuit 87
, the total target discharge amount Q according to the current discharge amount Q out
m is distributed between the target discharge amount Qmf of the fine adjustment gate 41 and the target discharge amount Qmr of the coarse adjustment gate 42. The coarse adjustment gate discharge control section 84 and the fine adjustment gate discharge control section 85 perform gate control to the gate drive devices 62 and 61 of each gate 42 and 41 from each target discharge amount Qmr and Q m f and the opening degree signal of each gate. Ask for a signal.

Next, the operation of the above embodiment will be explained. In FIG. 5, the control amount calculation circuit 82 first determines that if the weir upstream water level HU detected by the weir upstream water level gauge 51 and noise removed by the filter circuit 81 is within a preset weir water level maintenance area [Hsl, , since no control is required, the total target discharge amount Qm is not output. When the weir downstream water level HU signal exceeds the upper limit H2 of the weir water level maintenance area [Hs] due to an increase in the inflow amount Q in from upstream, the weir upstream water level I (to return U to the weir water level maintenance area [Hs] Find the control amount ΔQ, and calculate the current discharge amount Q o u
t is added to the total target discharge amount 0m command, and the command is sent to the target discharge amount distribution circuit 83. When this total target discharge amount Qm is input, the target discharge amount distribution circuit 83 first sends a calculation start command S to the maximum possible discharge amount determination circuit 86 of the fine adjustment gate.

Fig. 2 shows the processing of the maximum possible discharge amount determination circuit 86 of the fine adjustment gate, and the water output correspondence coefficient is set to = O to 1 for the value between O of the target discharge amount Qm and the maximum discharge amount of the weir. is determined in advance, and by multiplying this by the fine adjustment gate collapse flow rate (the flow rate flowing through this gate when the fine adjustment gate is fully open), the maximum possible discharge flow rate of the fine adjustment gate for each flow rate range can be determined. Create a table.

FIG. 1 is a flowchart showing the flow rate distribution method in the target discharge rate distribution circuit 83, which is a feature of the present invention, and the maximum possible discharge rate determination circuit 86 completes the creation of a table of the maximum possible discharge rate of the fine adjustment gate for each flow rate. First, step 101
Flow rate Q when switching the gate discharge direction. −0,Q□,
. . . is determined by referring to the table created in the process shown in FIG. This is the flow rate for switching the fine adjustment gate maximum possible discharge amount Qmfm in the table created above, as shown in FIG. 4(b). + Q21 Q41 . . ., and the flow rates at these intermediate points are Q engineering, Q3. ...... In the next step 102, the input total target discharge amount Q
Q2n and Q2n+I (n
is an integer), it is a positive distribution direction, and Qzn++ and Q
The time between zn+2 is defined as the reverse allocation direction. Then, depending on this result, the process branches at step 103, and when the distribution is correct, the process proceeds to step 104, where the target discharge amount Q of the rough adjustment gate is determined.
m r is kept constant at the current rough adjustment gate discharge amount (the gate opening is not changed), and the target discharge amount of the fine adjustment gate is made to follow the change in the total target discharge amount Qm. That is, Qm r =constant, Qm f =Qm-Qm r . In addition, in the case of reverse distribution, in step 105, the target discharge amount Qmf of the fine adjustment gate is decreased from the maximum possible discharge amount Q m f m at that time according to the total target discharge amount Qm, and the target discharge amount of the coarse adjustment gate is Q m r is set so that the total flow rate becomes the total target discharge amount Qm. That is, Qm f =Qm f m-Qm Qmr=Qm-Qmf. Qm for Qm shown at the bottom of FIG. 4(b)
The broken line characteristics of f and Qmr indicate the above distribution method.

When the distribution of the target discharge amount to each gate is completed, the discharge control unit 84.85 of each gate controls the distributed target discharge amount Qm f
+ Qm r and the current gate opening degree Pf.

Necessary gate activation signals df and dr are created from Pr, and the gate drive devices 61 and 62 are controlled thereby so that the discharge amount of each gate becomes its target value Qmf and Qmr.

The inflow amount Q j, n continues to increase, and the water level upstream of the weir H
When υ exceeds the upper limit of the weir water level maintenance area [Hs], the target discharge amount Qm is increased again. This situation is shown in Figure 4(b).
The diagram shows the horizontal axis as time t and the vertical axis as target discharge amount Qm (when Qm increases in proportion to time), and the fine adjustment gate is in the opening direction (at the time of positive distribution). Close direction (
(at the time of reverse distribution) is repeated until both gates reach their target discharge amount,
Therefore, flow rate control is performed without discontinuous changes in opening degree, and control disturbances and gate friction due to differences in gate opening/closing times can be prevented. The same holds true when the inflow amount Qin decreases with time, and the above effect remains the same, only with the control characteristics having the time axis reversed in FIG. 4(b). In addition, by making the maximum possible discharge amount Qmfm of the fine adjustment gate become smaller as the total target discharge amount Qm increases, the fine adjustment gate opening/closing operation amount due to a large increase in the inflow amount Q in at the time of water outflow can be reduced. This also prevents mechanical friction of the gate.

〔Effect of the invention〕

According to the present invention, by continuously switching the discharge amount between the fine adjustment gate and the coarse adjustment gate, over-discharge or insufficient discharge of the total discharge amount can be prevented, reliability and safety are improved, and gate opening/closing is achieved. The reduction in the amount of movement has the effect of reducing the amount of mechanical friction on the gate, and as the amount of discharge increases, the opening/closing range of the fine adjustment gate can be reduced to reduce mechanical friction caused by frequent opening and closing during water outflow. This has the effect of reducing the amount of friction.

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing an example of the gate discharge amount distribution processing method which is a feature of the present invention, FIG. 2 is a diagram showing fine adjustment gate maximum discharge amount determination processing, and FIG. 3 is a diagram showing the weir and gate. , Fig. 4(a) and (b) are diagrams showing the discharge flow control characteristics of the conventional method and the method of the present invention, and Fig. 5 is a block diagram showing an example of a weir control system to which the method of the present invention is applied. It is. 1... Weir, 41... Fine adjustment gate, 42... Coarse adjustment gate 1-183... Target discharge amount distribution circuit, 86...
・Fine adjustment gate maximum discharge amount determination circuit. Representative Patent Attorney Tadashi Akimoto Figure 1 Figure 3 (a)

Claims (1)

[Claims] 1. Determining the total target discharge amount from the water level detection value on the upstream side of the weir, and transmitting the total target discharge amount to a first gate for coarse adjustment and a second gate for fine adjustment provided on the weir. In the weir discharge flow rate control method of controlling the gate opening degrees of the first and second gates so as to achieve the distributed target discharge volume, when the total target discharge volume is increasing (or decreasing). said increase (or decrease) in
a first control mode in which a change in the target discharge amount of the second gate is controlled to be equal to a change in the total target discharge amount while keeping the target discharge amount of the first gate constant; mode, the total target discharge amount continues to increase (or decrease), and the target discharge amount of the second gate increases to its maximum (
or minimum) Once the possible discharge amount is reached, the second
The target discharge amount of the gate decreases (or increases) at the same rate as the increase (or decrease) of the total target discharge amount, and the sum of the target discharge amount of the first gate and the second gate is equal to the total target discharge amount. When the target discharge amount of the second gate reaches its minimum (or maximum) possible discharge amount by continuing the second control mode, the control mode shifts to the first control mode again. A weir discharge flow rate control method characterized by repeatedly performing the following steps. 2. A maximum possible discharge amount setting means is provided for setting the maximum possible discharge amount of the second control gate to a smaller value in stages as the total target discharge amount increases. Weir discharge flow rate control method.