JPH09235720A - Discharge control device of dam and water level changeover control device thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control system which produces a stabilized water level drop speed. SOLUTION: When starting a water level changeover operation at a target water level computation/discharge quantity computation unit 8, a regulated period, which attains a water storage level (limited water level), which is a final target, is divided in a plurality of small periods, and the target water level of each small period is determined while a definite water level drop speed is being maintained. After the starting of control, the amount of discharge is determined between a current water level and a target water level of a small period. Furthermore, the amount of discharge is corrected for every correction timing. When the target water level is attained in each small period, the relation between a stored water level and a total stored water level is determined from the difference between a total amount of discharge and a total amount of in- flow in a small period, thereby renovating a stored water level/total stored water quantity table 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dam discharge control device, and more particularly to a water level shift control method for discharging water according to a constant water level decrease rate.

[0002]

2. Description of the Related Art The water level shift control of a dam is intended to improve the dam's water storage capacity in preparation for the flood season such as the rainy season and typhoons, and the target water storage by the scheduled date (regular deadline). The discharge of the dam will be controlled so that it will drop to the maximum level (limit water level).

FIG. 2 shows the relationship between the water level and the stored water volume depending on the cross-sectional shape of the dam. The dam has facilities such as a bank 21, a discharge gate 22, and the like. In the figure (a), the water level Hk at the start of the water level transition, the limiting water level He, and the inflow amount Qi during the water level transition period.
n, the discharge amount Qout. Further, 23 indicates the flooded water area F (Hk) of the dam at the water level Hk, and 24 indicates the total water storage amount V (Hk) of the dam at the water level Hk. 25 is the water level He
Area of dam water F (He), 26 is water level He
Shows the total water storage amount V (He) of the dam in. The water storage area is the water storage area at the water level.

Dams often use natural terrain, and as shown in FIG. 2B, the relationship between the water storage area and the total water storage is not constant with respect to changes in water storage level. For this reason, the total storage volume corresponding to each fixed pitch of the storage level is calculated using a model and is used as a database.

By the way, the water level transition control of the dam is defined in the "dam operational rules / detailed rules" so that the water is discharged according to a constant rate of water level drop for reasons such as safety and easiness of judging the situation. This water level lowering speed is determined in advance from the stored water level at the start of control, the final target water level, and the water level transition period.

FIG. 3 shows a processing flow of conventional water level shift control. When a water level shift control start command is input from the operator (S301), the hydraulic state of the dam is monitored (the water level and the inflow rate of the dam are measured at regular intervals), and the end condition (limit water level) Alternatively, it is determined whether or not a prescribed time limit has been established (S302). If it is the end, the timing of correcting the discharge amount is monitored (S303), and when the correction timing is reached, the discharge amount Qo from the water level Hk at that time point is monitored.
ut is calculated by Equation 1 (S304).

[0007]

[Equation 1]

However, Qout: Discharge of dam (m ³ /
s), Qin: Inflow of dam (m ³ / s), V (HK):
Total water storage of dam at water level Hk (m ³ ), V (He): Total water storage of dam at water level limit (m ³ ), Tk: Control start time or correction time, Te: Time of specified deadline . In addition,
The total water storage V is obtained by referring to the dam water level / total water storage definition table 33.

Next, the gate opening corresponding to the calculated discharge flow rate Qout is calculated, and a control command is output to the gate control device 31 (S305). As a result, the gate opening is adjusted,
Discharge according to the opening is performed. The gate opening degree is monitored by the opening degree measuring device 32, the discharge amount of the dam is calculated by using this opening degree as an input, and it is checked whether the dam equipment is operating according to the command (S306, 307). The change in the water level of the dam due to the discharge is taken in from the water level meter 33 (S308), and the dam water level is calculated (S309). The above processing is repeated every correction cycle until the end condition is satisfied.

[0010]

In the above-mentioned conventional water level shift control system, the water level, the total water level, and the water level limit at the correction start time are used first, and thereafter,
The amount of discharge at that time is determined. However, since the relationship between the dam's water level and total water storage is not linear, it may not be possible to maintain discharge according to a certain rate of water level decrease. That is, the greater the change in the water area of the dam and the greater the transition width of the water level, the more noticeable the change in the water level decrease rate.

FIG. 4 shows the time change of the water storage level by the conventional water level shift control. In the figure, limited water level He, reservoir water level Hk ₀ ~Hk ₃ of correction timing t0 to t3, the correction period T1,
A water level lowering straight line 40 according to a predetermined water level lowering speed, a water level upper limit straight line 41, a water level lower limit straight line 42, and a management water level width 43 are shown, respectively. During the water level transition period, the dam water level is controlled to be within the control water level width 43 required for hydraulic monitoring.

The water level Hk at each correction point is the water level locus 40.
When it changes to 0, the discharge amount is reviewed from the water level Hk and the limited water level He. However, the non-linear relationship between the water storage area and the stored water volume at each water level was not considered,
Since the discharge is simply calculated with the target water level as the target,
The water level lowering lines 401, 402, and 403 may deviate from the water level lowering line 40 gradually and finally exceed the water level control width 43 like Hk ₃ . In this case, since the water level shift control does not satisfy the specified condition, the water level shift control ends abnormally, and there is a problem that stable water level shift control cannot be performed.

In view of the problems of the prior art, it is an object of the present invention to provide a dam water level shift control method and a discharge control device which can stably and accurately control a constant water level drop rate.

[0014]

[Means for Solving the Problems] The above object is to provide a water level shift control method for controlling a dam gate by calculating the discharge flow rate of a dam from the measured water storage level of the dam so that the water level becomes a limit water level by a specified deadline. The specified deadline is divided into a plurality of small periods, and the target water level for each small period is set according to a certain rate of water level decrease up to the above-mentioned water level during each small period. This is achieved by repeatedly calculating the discharge amount at a predetermined correction cycle according to the difference with the water level.

The discharge amount is obtained by dividing the difference between the total water storage amount at the water level at the calculation timing and the total water storage amount at the target water level for the small period by the time from the calculation timing to the end of the small period, Further, it is characterized in that it is calculated by subtracting the inflow amount of the dam at the calculation timing.

Here, the total water storage amount is obtained by referring to a preset water storage level / total water storage table. Further, when the target water level for the small period is reached, the total water storage amount is calculated based on the difference between the total discharge amount and the total inflow amount in the small period, and the relationship between the target water level and the total water storage amount is calculated as the water storage level. -Characterized by registering in the total water storage table.

Further, if the change of the total inflow amount exceeds the predetermined range between the previous small period and the current small period, the error becomes large, so that the water level and the total water storage table are not registered. It is characterized by

In the water level shift control method of the present invention, a predetermined water level management width is set in correspondence with the constant water level lowering speed,
When the stored water level at the timing of calculating the discharge amount exceeds the water level management width, the control is interrupted.

The discharge control device for a dam, which enables application of the water level shift control method of the present invention, inputs dam information from each measuring device to calculate and manage the water level, discharge amount, inflow amount, etc. The calculation means and the start command of the water level shift control are divided into a plurality of small periods until the specified deadline, and the target water level of each small period is set according to a predetermined water level decrease rate through each small period, and the time transition. Together with the target water level / discharge rate calculating means for sequentially calculating the discharge rate in a predetermined correction cycle according to the difference between the target water level for the corresponding small period and the current storage level, and a gate corresponding to the calculated discharge rate. Gate control command output means for obtaining the opening degree and outputting it to the gate control device.

According to the present invention, the water level transition period (for example, 1 to 2 months) up to the specified deadline is divided into a plurality of small periods (for example,
Weekly), the target water level is set for each small period according to the constant water level drop rate, and the discharge control correction control during the small period is repeated. Therefore, the non-linear relationship between the water level and the total water level and fluctuation components due to dam inflow can be absorbed early, and the water level in each small period does not deviate significantly from the constant water level decrease rate, It enables safe dam discharge control within the control range.

Whenever the target water level for each small period is reached, the total stored water amount for the target water level is calculated based on the total discharge and the total inflow amount in that small period, and the stored water level / total stored water amount (H・
V) Register in the table, and perform the next water level shift control using this updated H · V table. According to this,
The accuracy of the relationship between the reservoir level and the total reservoir volume due to the topography of the dam is gradually improved from the one that includes the error due to the model, so the reliability of the discharge control device is improved.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a functional block diagram of a dam discharge control device according to one embodiment. The control device 1 is shown in the upper part of the drawing, and the dam equipment is shown in the lower part of the drawing. The dam is provided with a water level gauge 2 for measuring the water storage level, a gate 3 for discharge, a gate control device 5 for controlling the opening degree, and an opening degree meter 4 for measuring the gate opening degree.

The discharge control device 1 comprises a water level gauge 2 and an opening gauge 4
Dam information input section 6 for inputting information from measuring instruments such as
A hydraulic calculator 7, which calculates hydraulic information such as the dam's water level, discharge, and inflow, and outputs it to the data display panel 12, inputs this hydraulic information and the operator's command from the terminal device 13, A target water level / discharge amount calculation unit 8 for determining a target water level and discharge amount by referring to a stored water level / storage amount table (H / V table) 11, a gate control unit 9 for calculating a gate opening degree from the discharge amount,
It comprises a gate control command output unit 10 for outputting a gate control command to the gate control device 5.

FIG. 5 shows a processing flow of the water level shift control according to this embodiment. The operator monitors the hydraulic information of the dam and inputs a water level shift control start command when water level shift control is necessary. This control start command also includes information such as the specified deadline, the limit water level He, and the management water level width.

When the control start command is input, the target water level
The discharge flow rate calculation unit 8 takes in the stored water level Hk at the control start time Tk, divides the total time (Te-Tk) until the specified deadline Te into a plurality of small periods of i, and the water level finally reaching the restricted water level He from Hk. Target water level He for each small period i
(I) is calculated (S501). The calculated target water level He (i) for each small period is buffer-managed. The time width S1 of each small period is the same (or almost the same), and H · V
The operator can arbitrarily give an instruction while considering the data accuracy of the table 11.

Next, it is determined whether the lower limit water level He is reached and the condition for ending the water level shift control is satisfied (S502). If not, it is determined whether the correction timing T1n is reached (S503). If it is the correction timing, the current storage level Hi (T1n) is fetched from the hydraulic calculation unit 7, and the discharge amount Qout corresponding to the target water level Hei for the relevant small period is calculated by the formula 2
(S504). Here, the sampling period T1 of the hydraulic information and the correction period of the discharge amount are equal.

[0028]

[Equation 2]

However, V (T1n): total dam storage amount (m ³ ) at the start of control or at correction timing, V (Hei): total dam storage amount (m ³ ) at target storage level Hei for a short period i ,
Ti: end time (s) of period i, T1n: n-th correction timing of small period i.

The total reservoir water storage volume V (T1n), V (Hei)
The value of is obtained from the H · V table 11. If there is no definition of the corresponding water level in Table 11, it is obtained by linear interpolation from the data between two nearby points including the water level.

Next, the gate opening required to discharge the calculated discharge amount Qout is calculated, and a control command is output to the gate controller 5 (S505). Further, as a result of the discharge, it is monitored whether or not the target water storage level Hei for the small period i has been reached (S506). If the target water level has not been reached, S
The correction process of 503 to S505 is repeated.

If the end condition of S502 includes an error check of the water level shift control, for example, the current water level exceeds the control water level width, the check by this process is performed before the correction process. To do.

On the other hand, when the target water level Hei water level is reached, the total water storage amount is calculated by Equation 3 based on the discharge amount up to that point (S507).

[0034]

(Equation 3)

However, V (Hrei): total water storage amount (m ³ ) of the target water storage level Hrei set in the small period i, V (Hre)
i-1): Dam total water storage (m ³ ) at the start of control or at the time when the previous target water level was reached, Qrout: Average value of dam discharge (m ³ / s) actually discharged during a short period i, Qr
in: average value (m ³ / s) of dam inflow that actually flowed in the small period i, S1: time width of the small period i.

Next, the relationship between the total reservoir volume V (Hrei) and the target reservoir level Hrei obtained in step S507 is expressed as H.
-Register in the V table 11 (S508). After registering the table, the process returns to step S502 again, and the same processing is repeated for the target water level in the next small period.

It should be noted that due to rainfall or the like, Qri has been changed to the previous period (i-
When the change is larger than 1), the error of the total water storage amount obtained by Equation 3 cannot be ignored. Therefore, the inflow amount (Qr
The change range of i) may be set, and when it is smaller than this change range, registration in the H · V table may be performed.

FIG. 6 shows changes in the stored water level due to the water level shift control according to this embodiment. The water level lowering line 60 from the control start time Tk to the regulation deadline Te is a straight line connecting the storage water level Hk at the start time and the limit water level He which is the final target, while the water level control width 63 by the water level upper limit 61 and the water level lower limit 62. Is set. According to the water level drop straight line 60, S for a certain time
At the end time of the small period divided by 1, the target water levels 601, 602, 603 ,. . Is set. The water level locus 600 by this water level transition control is generally within the water level management width 63 according to the water level lowering straight line 60.

FIG. 6B is a partially enlarged view of the target water level 602 during a small period. In the period S1, the current water level is first set to 601 (He1), and thereafter, according to the current water level at the correction time point shown in the water level locus 600, the discharge amount Qout is calculated and the gate is calculated at the correction cycle T1 until the target water level 602 is reached. Control is performed. Two-dot chain line 601-illustrated
Reference numerals 2, 601-3 and 601-4 indicate control trajectories for the target water level at each correction time point. As described above, even if the water level at each correction timing has some deviation from the water level decrease straight line 60, since the deviation from the target water storage level is small, absorption within a small period is easy and a large deviation occurs. There is no such thing.

Further, by dividing into a small period, the relationship between the reservoir water level and the total reservoir amount can be obtained finely and accurately,
Since it can be reflected in the data of the HV table, the control accuracy can be improved, an error such as the water level management width over can be prevented, and the reliability of the system can be improved.

[0041]

According to the present invention, the water level shift control is performed by the target water level for each divided small period while maintaining the predetermined water level low overspeed and the hydraulic control width, so that the dam is safe according to the standard. Can be released. In addition, since the relationship between the water storage level and the total water storage amount is registered based on the calculation result during control, the accuracy of data is improved and highly reliable control is possible.

[Brief description of drawings]

FIG. 1 is a functional block diagram of a dam discharge control device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a cross-sectional shape of a dam, and a relationship between a water storage level, a water tank area, and a total water storage amount depending on the shape.

FIG. 3 is a processing flow chart showing conventional water level shift control.

FIG. 4 is an explanatory diagram showing a temporal change of a water storage level in a conventional method.

FIG. 5 is a processing flow chart of water level shift control according to an embodiment of the present invention.

FIG. 6 is an explanatory diagram showing a temporal change of a water storage level according to the present embodiment.

[Explanation of symbols]

1 ... Discharge control device, 2 ... Water level gauge, 3 ... Gate, 4 ... Openness gauge, 5 ... Gate control device, 6 ... Dam information input section, 7 ... Hydraulic calculation section, 8 ... Target water level / discharge rate calculation section , 9 ... Gate control unit, 10 ... Gate control command output unit, 11 ... Water storage level / total water storage (H / V) table, 12 ... Data display panel, 13
... a terminal device.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuyuki Terunuma 5-2-1 Omika-cho, Hitachi-shi, Ibaraki Hitachi Information Control System Co., Ltd. (72) Toru Shibata 5-chome, Omika-cho, Hitachi-shi, Ibaraki No. 1 Stock company Hitachi Ltd. Omika factory

Claims (8)

[Claims] 1. A water level transition control method for controlling a dam gate by calculating a discharge amount of a dam from a measured dam storage level so that a water level is reached at a specified deadline, and a method for controlling a dam gate is provided for a plurality of small periods until the specified deadline. The target water level for each small period is set according to the constant water level decrease rate up to the above-mentioned limit water level during each small period, and with the transition of time, in sequence, according to the difference between the target water level for the relevant small period and the current reservoir level. A method for controlling water level shift of a dam, characterized in that the discharge flow rate is repeatedly calculated at a predetermined correction cycle. 2. The discharge amount according to claim 1, wherein a difference between a total water storage amount at a storage level at a calculation timing and a total water storage amount at a target water level in the small period is calculated from the calculation timing and ends in the small period. Divided by the time until
Further, the dam water level transition control method is characterized by calculating by subtracting the inflow amount of the dam at the calculation timing. 3. The water level shift control method for a dam according to claim 2, wherein the total water storage amount is obtained by referring to a preset water storage level / total water storage table. 4. When the target water level of the small period is reached, the total water storage amount is calculated based on the difference between the total discharge amount and the total inflow amount in the small period, and the target water level and the A water level shift control method for a dam, characterized in that the relationship of total water storage is registered in the water level / total water storage table. 5. The method according to claim 4, wherein when the change of the total inflow amount exceeds a predetermined range between the previous small period and the current small period, registration in the water level / total water amount table is not performed. A method for controlling the water level shift of a dam. 6. The water level according to any one of claims 1 to 4, wherein a predetermined water level management width is set corresponding to the constant water level lowering rate, and when the water storage level at the discharge timing calculation timing exceeds the water level management width. A water level transition control method for a dam, characterized by interrupting control. 7. A dam facility comprising a measuring instrument such as a water level meter or a flow meter for measuring a water storage level or an inflow rate of a dam, a gate for controlling a gate for discharging a dam, and a gate control device for controlling the opening thereof. In a discharge control device for a dam that performs a water level transition control so that the water level is limited to a deadline, the dam information from the measuring device is input to store the water level, the discharge amount,
A hydraulic calculation means for calculating and managing the inflow amount, etc., and receiving the start command of the water level shift control, dividing the specified deadline into a plurality of small periods, and lowering the predetermined water level to the limited water level through each small period. The target water level for each small period is set according to the speed, and with the transition of time, the discharge level is calculated repeatedly according to the difference between the target water level for the corresponding small period and the current stored water level. A discharge control device for a dam, comprising: a flow rate calculation means; and a gate control command output means for obtaining a gate opening degree corresponding to the calculated discharge flow rate and outputting the gate opening degree to the gate control device. 8. The water storage level / total water storage table according to claim 7, wherein the relationship between the water storage level of the dam and the total water storage is renewably defined, and the total water storage at the target water level in the small period and the calculation timing. The discharge control device for a dam, wherein the total storage water amount at the water storage level is calculated by referring to the table, and the discharge amount is calculated based on the difference.