JP2005330680A - Discharge rate control method and device for dam - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a discharge rate control method and a device for a dam capable of performing the optimum control of the discharge rate of the dam. <P>SOLUTION: The discharge rate control device for controlling the discharge rate by computing a target discharge rate from the water level and the opening of a gate 2 in the dam 1 and controlling the opening of the gate, comprises a computing means 6 for computing a first allowable fluctuation range to the target discharge rate for every change of a hydraulic state from a controllable point, and a control means 6 for controlling the discharge rate while changing the first allowable fluctuation range according to the hydraulic change. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a dam discharge flow rate control method and apparatus.

  The constant flow control is a control for keeping the dam gate discharge flow rate constant at a preset target discharge flow rate. The minimum control unit of the water level of the dam and the opening sensor is in units of cm so that control at an intermediate opening cannot be performed. For this reason, the control accuracy is managed within a certain range. This constant width is called an allowable fluctuation range. This allowable fluctuation range also functions as a control dead zone (play) for preventing excessive operation of the control facility and maintaining the facility.

  FIG. 5 is a conceptual diagram of the dam discharge system. In the figure, 1 is a dam, 2 is a gate for adjusting the discharge flow from the dam 1, 3 is a gate drive motor for driving the gate 2, 4 is an opening sensor for detecting the opening of the gate 2, and 5 is a dam. A water level gauge 6 for detecting the water level of the dam 1 is an arithmetic unit which receives the water level of the dam 1 and the output of the opening sensor 4 and gives a control signal to the gate drive motor 3. The gate 2 usually has a size of about several tens of meters in width and about 10 meters in height. The discharge of the dam is controlled using the gate of such a size.

The operation of the apparatus configured as described above will be described with reference to FIG. FIG. 6 is a diagram showing a transition within the allowable fluctuation range of the target discharge flow rate. In the figure, L1 is a target discharge flow rate, and L2 is an allowable fluctuation range. The target discharge flow rate L1 functions as an upper limit value of the discharge flow rate, and the allowable fluctuation range L2 functions as a lower limit value of the discharge flow rate.
a. In the initial control, the gate discharge flow rate is adjusted within the target discharge flow rate L1 and the allowable fluctuation range L2.
b. When the upper limit value L1 of the allowable fluctuation range is exceeded, readjustment is made within the allowable fluctuation range of c.
d. When the lower limit L2 of the allowable fluctuation range is exceeded, readjustment is made within the allowable fluctuation range of e.

  In order to make the gate discharge flow as close as possible to the target discharge flow, it is necessary to make the allowable fluctuation range as narrow as possible. On the other hand, when it is desired to suppress the operation frequency of the gate 2, an operation is performed in which the allowable fluctuation range is secured to some extent.

  The control method for the constant discharge control in the conventional method is based on the permissible fluctuation range, and the target value is adjusted by using a method for bringing the control result itself closer to the control target value, for example, using arithmetic means, etc. There is a technique such as closer to the value.

In addition, as a method for keeping the discharge flow rate constant in the dam, a technique for increasing the discharge flow rate to the target flow rate based on the discharge flow increase control data and maintaining the discharge flow when the target flow rate is reached is known (for example, Patent Document 1).
JP-A-9-217334 (4th page, 5th page, FIG. 1)

  However, in the conventional technology described above, the operation of a certain distance may be prohibited for facilities such as dam gates and valves for the purpose of maintaining the facilities and preventing vibrations due to minute opening discharge (minimum operation). Quantity control). In such a case, control is required to always maintain the allowable fluctuation range (play) that limits the control within the minimum operation amount by changing the allowable fluctuation range itself, but this control is not possible in the prior art. is there.

  FIG. 7 is a diagram for explaining the operation of the conventional allowable fluctuation range method. ○ in the figure is the controllable opening (controllable point) within the control range. Here, the permissible fluctuation width is indicated not by the amount but by the moved width (cm). When the water level is low, the controllable opening within the control width can be three points of 10 cm, 11 cm, and 12 cm. When the water level is middle, the controllable opening within the control range can be two points of 10 cm and 11 cm. When the water level is high, the controllable opening within the control width can be taken at only one point of 10 cm. When the water level is low, 8 tons / second can be controlled at 3 controllable points, and when the water level is medium, 9 tons / second can be controlled at 2 controllable points. When the water level is high, 10 tons / second can be controlled at one controllable point.

  The gate discharge rate in the dam has a characteristic that the change amount of the discharge rate per 1 cm of opening is small at a low water level, and the change amount is large at a high water level. For example, in FIG. 6, if the minimum operation amount of the discharge facility to be used is 2 cm, the allowable fluctuation range 1 has high accuracy with respect to the target value, but only the 1 cm operation amount width can have the allowable fluctuation range, and the minimum operation amount. The operation is as follows. In the allowable fluctuation range 2, there is a problem that the allowable range at a position where the water level is low becomes large and the control accuracy cannot be maintained.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a dam discharge control method and apparatus capable of optimally controlling a dam discharge.

  In the present invention, the method of holding the allowable fluctuation range is not the current fixed fluctuation range, but how many control points are included therein. (A) From the number of points, every change of hydraulic state The allowable fluctuation range is automatically changed. In terms of flow rate management, (b) the allowable fluctuation range obtained from the number of points is provided with a limiter based on the absolute flow rate value, and (c) whether the absolute flow rate value has priority after exceeding the limiter is obtained from the equipment maintenance point number. It is possible to set whether to give priority to the allowable fluctuation range.

  (1) The invention described in claim 1 is as follows. FIG. 1 is a flowchart showing the principle of the method of the present invention. The present invention relates to a method for calculating a target discharge from a water level and an opening of a gate in a dam, and controlling the discharge by controlling the opening of the gate. A first allowable fluctuation range with respect to the target discharge flow is calculated every time (step 1), and discharge flow control is performed while changing the allowable fluctuation width according to hydraulic changes (step 2). To do.

  (2) In the invention according to claim 2, with respect to the first allowable fluctuation range, a second allowable fluctuation range whose value is fixed is obtained as a limiter, and the fluctuation range of the discharge flow rate is the second allowable fluctuation range. The discharge control is performed so as not to exceed the width.

  (3) The invention according to claim 3 compares the first allowable fluctuation range with the second allowable fluctuation range, and performs discharge flow control using the first allowable fluctuation range according to the comparison result. And determining whether to perform discharge flow control using the second allowable fluctuation range.

  (4) The invention described in claim 4 is a discharge flow rate control device for controlling the discharge flow rate by calculating the target discharge flow rate from the water level and the gate opening degree by controlling the gate opening degree in the dam. Calculating means for calculating a first allowable fluctuation range with respect to the target discharge flow for each change of hydraulic state from the controllable point; and releasing the pressure while changing the first allowable fluctuation range according to the hydraulic change. And control means for performing flow rate control.

  (1) According to the first aspect of the invention, since the first allowable fluctuation range with respect to the target discharge rate is calculated for each change in the hydraulic state, the optimal control allowable fluctuation range that is not affected by the hydraulic change. Can always be maintained, and both control accuracy and equipment maintenance can be achieved.

(2) According to the invention described in claim 2, since the second allowable fluctuation range having a fixed value is obtained as a limiter, safety in terms of fluctuation of the discharge flow rate can be ensured.
(3) According to the invention described in claim 3, the first allowable fluctuation range and the second allowable fluctuation range are compared, and the discharge flow rate control using any of the allowable fluctuation ranges according to the comparison result is performed. Can be done.

  (4) According to the invention described in claim 4, since the first allowable fluctuation range with respect to the target discharge flow is calculated for each change of the hydraulic state, the optimal control allowable fluctuation range that is not influenced by the hydraulic change. Can always be maintained, and both control accuracy and equipment maintenance can be achieved.

  FIG. 2 is a diagram for explaining the operation of the present invention. The hardware configuration of the device of the present invention can basically be applied as shown in FIG. However, the operation of each component is different. In particular, the functions of the arithmetic device 6 are different. That is, in addition to the conventional arithmetic function, it has a function of changing the control formula (hereinafter, the arithmetic device is referred to as an arithmetic control device). In the figure, (a) shows the change in the reservoir level, (b) shows the target discharge flow rate, and (c) shows the allowable fluctuation range 1. An example is shown in which three controllable points are arranged between the target discharge flow rate and the allowable fluctuation range. Let the changes in the reservoir level be A, B, and C, respectively. When the water level is low, the arithmetic and control unit 6 obtains the allowable fluctuation range 1 from the water level, the opening of the gate 2 and the specified control accuracy.

  In this case, as shown in FIG. 2, the allowable fluctuation range 1 is set near the controllable point 10 cm with respect to the water level A. On the other hand, when the water level rises to the water level B, the arithmetic control device 6 obtains the optimum allowable fluctuation range 1 from the water level, the opening degree of the gate 2 and the designated control accuracy. As a result, the allowable fluctuation range 1 is set to a point lower than the allowable fluctuation range 1 for the water level A by Δ1. Further, when the water level rises to the water level C, the arithmetic and control unit 6 obtains the optimum allowable fluctuation range 1 from the water level, the opening degree of the gate 2 and the specified control accuracy. As a result, the allowable fluctuation range 1 is set to a point lower than the allowable fluctuation range 1 for the water level B by Δ2.

  As described above, by dynamically changing the allowable fluctuation range 1 according to the water level, the target discharge flow rate and the allowable fluctuation range are too close to each other and control becomes impossible, or the target discharge flow rate and the allowable fluctuation range are too far apart. Thus, the control accuracy is not deteriorated.

  As is clear from FIG. 2, it can be seen that the value of the allowable fluctuation range 1 changes following the change. The discharge flow between the target discharge flow at the water level A and the allowable fluctuation width 1 corresponds to, for example, 8 tons / second, and the discharge flow between the target discharge flow and the allowable fluctuation width 1 at the water level B is, for example, 9 tons. The discharge flow rate between the target discharge flow rate at the water level C and the allowable fluctuation width 1 corresponds to, for example, 10 tons / second.

  According to this embodiment, since the first allowable fluctuation range with respect to the target discharge flow is calculated for each change in hydraulic state, the optimal control allowable fluctuation range that is not affected by the hydraulic change can always be maintained. Therefore, it is possible to achieve both control accuracy and equipment maintenance.

  FIG. 3 is a diagram for explaining another operation of the present invention. (A) shows the change in the stored water level, (b) shows the target discharge flow rate, (c) shows the allowable fluctuation range 1, and (d) shows the allowable fluctuation range 2. The allowable fluctuation range 2 is fixed as shown in the figure. The thick solid line in the figure indicates the control point priority control, and the broken line indicates the allowable fluctuation range priority control. When the allowable fluctuation range 1 exceeds the allowable fluctuation range 2, it is determined whether to perform control with priority over the allowable fluctuation range or control with priority over the control point. In the case of D in the figure, discharge flow control using the allowable fluctuation range 2 is performed, and in the case of E in the figure, discharge flow control using the allowable fluctuation range 1 is performed.

According to this embodiment, since the second allowable fluctuation range having a fixed value is obtained as a limiter, safety in terms of fluctuations in the discharge flow rate can be ensured.
FIG. 4 is a flowchart showing an embodiment of the operation of the present invention. As the hardware configuration, the configuration shown in FIG. 5 is used. This control is mainly performed by the arithmetic and control unit 6 shown in FIG. First, it is checked whether hydraulic conditions (for example, water level) have changed (S1). If the hydraulic conditions have changed, the current water level is read from the water level gauge 5 (S2). Next, the opening degree information of the gate 2 is read by the opening degree sensor 4 (S3). Next, the designated control accuracy set in the system is read (S4).

  Next, an allowable fluctuation range lower limit flow rate (allowable fluctuation range 1) is calculated from the designated control accuracy (S5). Next, the allowable fluctuation range 2 set in the system is read (S6). Next, it is checked whether or not the allowable fluctuation range 1 <the allowable fluctuation range 2 (S7). If the allowable fluctuation range 1 is smaller than the allowable fluctuation range 2, the discharge flow rate control using the allowable fluctuation range 1 is performed (S8). If the allowable fluctuation width 1 <the allowable fluctuation width 2 is not satisfied, it is checked whether or not the designation has priority over the allowable fluctuation width 1 (S9). When the allowable fluctuation range 1 is prioritized, the discharge flow rate control using the allowable fluctuation range 1 is performed (S10). If the designation in step S9 does not give priority to the allowable fluctuation range, discharge flow control using the allowable fluctuation range 2 is performed (S11).

  According to this embodiment, the first allowable fluctuation range and the second allowable fluctuation range are compared, and the discharge flow rate control using any of the allowable fluctuation ranges can be performed according to the comparison result.

It is a flowchart which shows the principle of this invention method. It is operation | movement explanatory drawing of this invention. It is another operation explanatory view of the present invention. It is a flowchart which shows one embodiment of the operation | movement of this invention. It is a conceptual diagram of a dam discharge system. It is a figure which shows the transition within the allowable fluctuation range of a target discharge flow rate. It is operation | movement explanatory drawing of the conventional allowable fluctuation range system.

Explanation of symbols

1 Dam 2 Gate 3 Gate Drive Motor 4 Opening Sensor 5 Water Level Meter 6 Arithmetic Control Device

Claims (4)

In a dam, a method for calculating a target discharge from the water level and the opening of the gate by calculation, and controlling the discharge by controlling the opening of the gate,
From the controllable point, calculate the first allowable fluctuation range with respect to the target discharge flow for each change in hydraulic state (step 1),
In accordance with hydraulic changes, the discharge flow rate control is performed while changing the allowable fluctuation range (step 2).
A dam discharge control method characterized by the above.   A second allowable fluctuation range whose value is fixed with respect to the first allowable fluctuation range is obtained as a limiter, and discharge control is performed so that the fluctuation range of the discharge flow rate does not exceed the second allowable fluctuation range. A discharge control method for a dam characterized by   The first permissible fluctuation range is compared with the second permissible fluctuation range, and the discharge control using the first permissible fluctuation range is performed according to the comparison result, or the discharge using the second permissible fluctuation range is performed. 3. The method for controlling the discharge rate of a dam according to claim 2, wherein whether to control the flow rate is determined. In the dam, a discharge flow rate control device that calculates the target discharge flow rate from the water level and the gate opening amount, and controls the discharge flow rate by controlling the gate opening amount,
Calculating means for calculating a first allowable fluctuation range with respect to the target discharge flow rate for each change in hydraulic state from a controllable point;
Control means for controlling the discharge flow rate while changing the first permissible fluctuation range according to hydraulic changes;
A discharge control device for a dam characterized by comprising:

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