JPS60239814A - Control method of dam - Google Patents

Abstract

PURPOSE:To attain uniform control at the time of transition to a flood, a low water level and a water famine without generating hunting by changing an objective water level in accordance with inflow volume at the control of a dam and providing the inflow volume to be a parameter with a non-sensing band width. CONSTITUTION:A water level H1 is measured by a water level detecting means 1 at a time T2 and inputted to an inflow volume calculating means 4 to find out the inflow volume Q2 on the basis of the water level H2 at a time T1 prior to the time T2 by a fixed period. Then, the inflow volume Q1 at the time of T1, the inflow volume Q2 and an inflow volume/objective water level curve 5 are inputted to an objective water level detecting means 6, and at the time of Q2>Q1, the objective water level HS2 is set up on the basis of a curve (a). The objective water level HS2 is inputted to an objective discharge volume calculating means 7 to calculate the objective discharge volume and control a gate. Said operation is executed in every fixed period and the water level is set up so as to be a regulated water level HSa when the water level reaches a flood flow rate. At the restoration of pondage, the objective water level is gradually increased in accordance with the reduction of inflow volume as shown in a curve (b) so that the dam can keep the filling state of water even at the time of a water famine. A non-sensing band width (thick line) can be formed on the basis of hysteresis characteristics and the generation of hunting is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to the control of non-tidal weirs installed in the middle and downstream of rivers.

(b), Conventional Technology A weir is a facility for taking water from a river.A weir is built on a river to stop the flow, and the water level rises, making it easier to take water.

A non-tidal weir is one of these weirs that is installed in the middle and downstream of the river, where it is not affected by the seawater level downstream.

Conventionally, for non-tidal weirs like this one, constant water level control or set flow rate control was performed when the water was low, and a control system was adopted in which the weir gate was fully opened during floods.

(C) 0 Problems to be Solved by the Invention As explained in the section of the prior art, in the past, the weir control method was different between normal low water times and flood times. When transitioning to a different time, the operator must have sufficient experience to switch the control method and operate the gates associated with this.
In addition, a means to solve the problem of having to perform target water level setting operations even when performing control to restore the water level after the end of a flood is to Calculate the inflow from the water level, set a target water level according to the inflow, lower the target water level when the inflow increases, raise the target water level when the inflow decreases, This is achieved by a weir control method that provides a dead zone width for the inflow amount, which is a parameter.

(e) 0 action According to the present invention, the inflow is calculated from the water level of the weir, the target water level is determined according to the inflow, and the curve that determines the extent to which the target water level is lowered when the inflow increases, and the inflow By using a different curve to determine the degree to which the target water level should be raised when the water level decreases, a dead band width is provided for the inflow amount, which is a parameter. Therefore, stable control can be performed without causing hunting, and flood control can be achieved. During transition, at low water level,
The effect is that the same control method can be used regardless of the time of drought.

(f), Embodiment FIG. 1 is a schematic diagram showing an embodiment of a weir control system according to the present invention.

FIG. 2 is a graph for explaining the present invention in detail.

In the figure, 1 is a water level detection means, 2 is a gate opening detection means, and 3
is the discharge amount calculation means, 4 is the inflow amount calculation means, and 5 is the inflow amount -
In the target water level curve, 6 is a target water level detection means, and 7 is a target discharge amount calculation means.

The present invention will be described in detail below with reference to the drawings.

Generally, when calculating the inflow Q to a weir, the water level of the weir is measured and calculated using the following formula.

Note that the water level of the weir at time TI is defined as Hl, and the amount of water stored when the water level is H1 is V(H1'). Similarly, let H2 be the water level of the weir at time T2, and the amount of water stored at water level H2 is V(
Hz). Moreover, q1 is the average discharge amount between time T2 and time TI.

The present invention is characterized in that when controlling a weir, the target water level is changed according to the inflow amount, and a dead zone width is provided for the inflow amount as a parameter.

When the inflow increases, the target water level is gradually lowered as the inflow increases, as shown by curve a in Figure 2, and when the inflow increases to the flood flow rate, the target water level is set to the specified water level Hsa. has been reached.

That is, at time T2, the water level H2 is measured using the water level detection means 1, and this water level H2 is manually input to the inflow amount calculation means 4, and the water level measured at time T, a certain period of time before time T2. Using H1, the inflow amount Q2 is calculated by equation 0.

Next, input the inflow amount Q1 at time T1, the inflow amount Q2 at time T2, and the inflow amount-target water level curve 5 to the target water level detection means 6, and when the inflow amount Q2 is larger than the inflow amount Q1, The target water level H52 is set according to the curve a in FIG.

Furthermore, this result is input to the target discharge amount calculation means 7 to calculate the target discharge amount and control the gate.

The opening degree of the gate is measured by the gate opening degree detection means 2,
The opening degree of this gate and the water level H2 at time T2 are manually entered into the discharge amount calculation means 3 to calculate the discharge amount q2 at time T2.

The above operations are carried out at predetermined time intervals, and when the inflow volume increases until it reaches a flood flow rate, the target water level reaches the specified water level H.
Set it so that it reaches sa.

In this case, the specified water level Hsa is the water level that the weir is specified to take at the start of a flood, and the minimum flow rate corresponding to the specified water level Hsa is defined as Qsa.

When the water level recovers, that is, when the inflow volume decreases from the flood flow rate, the target water level is gradually raised as the inflow volume decreases, as shown by the curve in Figure 2, and the weir is closed even in times of drought. Make sure to keep the water close to full.

Also, unlike the curve a when the inflow rate is increasing and the curve a when it is decreasing, it has a hysteresis characteristic, so there is a dead band width in the inflow rate as shown by the thick line in Figure 2. Hunting will not occur due to inflow calculation errors.

Effects of Ig1 Invention As explained in detail above, according to the present invention, during flood transition,
This has the great effect of being able to implement a weir control system that can handle low water levels and droughts with the same control system, and that does not cause hunting due to inflow calculation errors.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of a weir control system according to the present invention. FIG. 2 is a graph for explaining the present invention in detail. In the figure, 1 is a water level detection means, 2 is a gate opening detection means, and 3
is the discharge amount calculation means, 4 is the inflow amount calculation means, and 5 is the inflow amount -
In the target water level curve, 6 is a target water level detection means, and 7 is a target discharge amount calculation means. Kaya 1 mouth rate 2 days

Claims (1)

[Claims] In the adjustment method used for weir control, the inflow rate is calculated from the water level of the layer, the target water level is determined according to the inflow rate, and when the inflow rate increases, the target water level is lowered; A control system for a weir, characterized in that when the inflow rate decreases, the target water level is raised, and a dead zone width is provided for the inflow rate as a parameter.