JPS6128108A - Control system of open waterway - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a control system for open channels, and is particularly suitable for open channels that have long-distance, gentle slopes, long flow delay times, and large storage effects. Regarding.

[Background of the invention]

Conventional multi-stage open channel control generally involves constant water level control, and it takes time for the flow to reach the end of the channel until the flow conditions in the entire channel are stabilized. On the other hand, it is theoretically possible to reduce the time required for stabilization to only one stage of flow time by simultaneously controlling the control devices installed in each waterway section.

However, in order to achieve this, it is necessary to perform safe control that takes into account the changes in the flow condition after the flow control at Cape Gozen, in order to take the timing of each control device. A method had not been developed.

[Purpose of the invention]

An object of the present invention is to solve the above problems and stabilize the flow condition of the entire waterway in a short time. The purpose is to provide a control method.

[Summary of the invention]

In controlling a multistage open channel, in order to quickly obtain stable flow conditions in all channel sections, the present invention adopts a control method that focuses on the amount of channel storage. In other words, by bringing the storage amount in each waterway section to an appropriate amount according to the target flow rate in a short time, it is possible to quickly reach a steady inequality state. A series of control methods were devised, including a method for calculating the temperature and a method for correcting when the predicted value and the actual value differ.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4. Figure 1 shows the functional configuration of one channel section in a multi-stage open channel. In this figure, the predicted demand value is 1, and the canal storage amount is 12.
Using the operation planning unit 2, the target flow rate 3 passing through the gate is determined. The control calculation unit 6 calculates the water storage volume 12 for each channel section and the gate opening degree 7 for each facility using unsteady flow hydraulic calculation or unsteady flow hydraulic calculation from this flow rate, waterway status 4, and facility conditions 5, and calculates the water storage amount 12 for each waterway section and the gate opening degree 7 for each facility. Control each control device simultaneously from a location.

On the other hand, the observed flow rate through the gate 8. The water level 9 above and downstream of the gate is monitored by the demand change estimating unit 10, and if the demand amount 12 is significantly different from the predicted demand value 1, the estimated demand amount 11 is sent to the control calculation unit 6 and the gate is opened. Perform degree 7 correction. Next, each control step will be specifically explained.

In order to stabilize the flow situation early, the operation planning department 2
As shown in the figure, a method will be adopted that takes into account the amount of water stored in the waterway.

That is, in step 21, the demand forecast value and the waterway storage amount v1.
I is input, and the required flow rate for each gate is calculated in step 22 from the demand forecast value.

Next, in step 23, the storage volume V 2 N in a steady state after the demand change is calculated for each downstream channel section of each gate, and until the storage volume adjustment time T set in step 24, V 2 N is calculated. The capacity of the difference between Vt++ and Q is the steady required flow rate Q,
Add to. In other words, the time t after control is (1
), the flow rate passing through the gate is expressed as equation (2). or,
Similarly, when the condition of equation (3) is satisfied, equation (4) is used.

0≦t<T...(1)Q
,,=Q,+Σ(V2.-V,,)/T-(2
)t≧T...(3)
Q□=Q, ・・・
(4) Here, Q: Steady required flow rate at the Nth gate Q: By determining the gate flow rate so that it is greater than the target flow rate through the gate at the Nth gate, a steady state at a predetermined flow rate can be quickly achieved. This contributes to reducing the time required for transient abnormal water level conditions, especially in diversion works located midway through waterways.

The control calculation unit 6 determines the gate opening degree to obtain the flow rate determined by the operation planning unit 2. A simple method is to control the gate flow rate at a constant rate, but since the time constant of the channel flow condition is large, it is expected that the gate will hunt and frequent gate operations will be required. Therefore, consider application of the control method shown in FIG. 3, for example. In other words, after inputting the target flow rate passing through the gate from the operation planning section 2, the set water level upstream of the gate, and the initial values of the facility conditions for calculating the gate flow rate in step 31, in step 32, unsteady flow calculation is performed for each downstream channel section of each gate. The water level downstream of the gate and the storage volume V1 in the gate sewage section are determined by
Find N. In step 33, the opening degree that satisfies the target flow rate through the gate is determined using the gate flow rate formula from the gate upstream set water level, the gate downstream water level just found, and facility conditions.

An example of the demand change estimation section 10 is shown in FIG. Step 4
Input the initial value (demand forecast value Q,) in step 1, and proceed to step 42.
At step 43, the flow rate passing through each gate and the water level upstream and downstream of the gate are constantly observed using measuring instruments, and based on changes in flow conditions, the estimated demand amount Q1. In particular, if the three-type model described in the earlier Japanese Patent Application No. 58-27561 is used as a simple method for unsteady flow hydraulic calculations, online control by a control computer can be further facilitated. In step 44, this estimated demand quantity Qtw and demand forecast value Q are determined. If this difference exceeds the demand quantity error tolerance K, the estimated demand quantity Q1□ is transmitted to the control calculation unit 6 in step 45 and is used as an index for changing the gate opening degree control value.

〔Effect of the invention〕

According to the present invention, when gate control is performed when demand changes, the control is performed in consideration of the balance of the amount stored in the waterway, so there is an effect of shortening the time until the flow condition of the entire waterway becomes stable. Furthermore, since the condition of the waterway is constantly monitored and the predicted demand value is compared, appropriate corrections can be made in response to sudden changes in demand, which has the effect of increasing safety.

[Brief explanation of the drawing]

FIG. 1 is an overall functional configuration diagram of an embodiment of the control method according to the present invention, FIG. 2 is a flowchart of processing in the operation planning section, and FIG. 3 is a flowchart of processing in the control calculation section.
FIG. 4 is a flowchart of processing in the demand change estimation section. 1... Demand amount forecast value, 2... Operation planning department, 3...
Target flow rate for passing through the gate, 4... Channel status (water level/flow rate)
, 5...Facility conditions, 6...Control calculation section, 7...Gate opening degree, 8...Gate passing flow rate, 9...Gate upper/downstream water level. 10... Demand change estimation unit, 11... Demand estimation amount, 1
2Z1 Figure Z Figure 3 Figure 4

Claims (1)

[Claims] 1. A first step of formulating an operation plan, a second step of performing control calculations, and a second step of estimating demand changes in a single-stage or multi-stage open channel separated by check gates. A control method for an open channel characterized by controlling a plurality of gates simultaneously by the step of step 3. 2. The open channel of item 1, wherein the first step is to calculate the storage amount in the waterway by hydraulic calculation, and perform a calculation to add the difference in the storage amount before and after the demand change to the gate flow rate in advance. control method. 3. The second step above is to find the steady flow condition after the demand change using unsteady non-uniform flow (unsteady flow) calculation, and calculate the opening degree of each gate based on this hydraulic condition. The first feature is the open channel control method. 4. The third step is to constantly monitor the difference between the predicted value and the actual demand, and in the event of an abnormality, request the control calculation unit to correct the gate opening, and estimate the actual demand using a simple unsteady flow calculation by a computer. 1. The open channel control method according to item 1, characterized in that: