JPH02249012A - Controller for keeping water level of hydroelectric power plant constant - Google Patents

Abstract

PURPOSE:To automatically adjust the guide vane opening of a hydraulic turbine generator driving hydraulic turbine to keep the water level of a dam constant by using a water level change rate calculation circuit calculating the hourly change rate of the water level in a dam and a target opening calculation part. CONSTITUTION:A dead band circuit 17 detecting that a deviation between the set point of a target water level setter and the water level in the dam exceeded a prescribed range, the water level change rate calculation circuit 14 calculating the hourly change rate of the water level in the dam at a prescribed period, the target opening calculation part 18 calculating the target guide vane opening and a control calculation part 10 supplying a guide vane adjustment signal to a guide vane driving part 11 are installed, and the hourly change rate of the water level in the dam is calculated at every prescribed period. Then, a dam in-flow change quantity is calculated, and it is converted into the guide vane change opening from the characteristic of the hydraulic turbine to obtain the target guide vane opening. A dam flow-in quantity is controlled to be equal to a hydraulic turbine discharge quantity. Thus, the controller always adjusts the guide vane opening and controls for returning the water level to the target one, whereby the stable constant control of the water level is attained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention adjusts the amount of water discharged from a water turbine that drives a water turbine generator in a hydroelectric power plant, and adjusts the opening degree of the guide vane of the water turbine to maintain a constant dam water level. This invention relates to a water level constant control device for a hydroelectric power plant that performs adjustment.

[Conventional technology]

In dam-type power plants, automatic water level adjustment control, commonly used in run-of-river power plants, is used to maintain a constant dam water level by adjusting the opening of the guide vane of the water turbine.

The wood tone control method will be explained with reference to the block diagram shown in FIG.

When the amount of inflow 102 flowing into the dam 100 changes, the dam water level 103 changes. Deviation 1 between this dam water level 103 and the reference water level 105 set by the reference water level setting device 104
06 and the guide vane opening degree signal from the rigid restoring section 1.
According to the polarity of the deviation 109, a drive signal is given from the control unit 110 to the guide vane drive unit 11 to control the guide vane opening of the water turbine 112 so that the deviation 109 from the guide vane opening value 108 obtained through 07 is below the dead zone. adjust. By opening and closing the guide vane, the water turbine discharge amount 1
13 changes. Due to the above movements, the inflow amount is 102
The purpose of water adjustment is to make the water discharge amount 113 equal to the water discharge amount 113, and to stabilize the water by 2mm. In addition, in the case of wood tone, stable operation is achieved by providing a water level change, so-called water level droop rate, required to change the flow rate from the no-load flow rate of the water turbine to the rated flow rate.

[Problem to be solved by the invention]

However, in the conventional technique described above, the amount of water discharged by the turbine is adjusted during a certain level change called the water level droop rate, but depending on the dam, the water level is kept constant as long as it is possible to suppress the water level change as much as possible. □ may be requested. On the other hand, if wood tone is applied to reduce the water level droop rate, ripples in the dam water level and disturbances to the dam water level signal will greatly affect the guide vane opening degree, which may eventually cause hunting of the water turbine. There is a limit to reducing the drooping rate. The present invention has been made in view of the above-mentioned conventional technology, and is a constant water level control that automatically adjusts the opening degree of the guide vane of a water turbine so that the dam water level is kept constant according to the discharge amount of the water turbine generator in a dam type power plant. The goal is to provide equipment.

[Means to solve the problem]

In order to achieve the above object, the present invention includes a dead band circuit that detects when the deviation between the set value of a target water level setting device and the dam water level exceeds a predetermined range, and a dead band circuit that detects when the dam water level is inputted and the temporal change rate of the dam water level. a water level change rate calculation circuit that calculates the target guide vane opening at a constant cycle; and a control calculation unit that provides a guide vane adjustment signal to the guide vane drive unit in accordance with the difference between the guide vane opening degree signal and the guide vane opening degree signal.

[Effect]

Calculation of the temporal rate of change of the dam water level is performed every fixed period. On the other hand, the deviation between the dam water level and the 11 water mark is dead zone 1.
If it is within 11, the guide vane will not be adjusted, but if the water level deviation exceeds the dead zone 11, the amount of change in dam inflow will be calculated from the water level change rate signal and various quantities such as the dam area. Convert the amount of change from the characteristics of the water turbine to the guide vane change opening to find the target guide vane opening. Drive the guide vane open or close signal according to the deviation between the target opening and the actual guide vane opening that is fed back. The guide vane is adjusted to the target opening degree.The above movements control the dam inflow amount and the turbine discharge amount to be equal.Once the water level deviation falls to the dead zone 111, the guide vane opening degree remains constant without adjustment. As described above, when the dam water level deviates from the target water level, the guide vane opening is constantly adjusted, and by controlling the dam to return to the target water level, stable water level control can be achieved.

〔Example〕

Hereinafter, the present invention will be explained based on illustrated embodiments.

FIG. 1 is a block diagram of a constant water level control device of the present invention.

The dam water level 3 of the dam 1 changes depending on the dam inflow amount 2.

The constant water level control device also includes a target water level setter 4 in which a target water level setting value 5 is set, and a water level change rate calculation unit 14 that detects changes in the dam water level as a water level change rate 15 at regular intervals. The dead band circuit 17 is configured to provide a water level change rate 15 to the target opening calculation unit 18 when the deviation between the dam water level 3 and the target water level set value 5 exceeds a certain range.

The control unit 10 is connected to the target opening calculation unit 18, and the guide vane drive unit operates according to the polarity of the deviation 9 that makes the target opening value 19 and the guide vane opening value 8 obtained through the rigid restoring unit 7 equal. 11, and the guide vane drive unit 11 adjusts the guide vane opening degree of the water turbine 12 based on the signal.

The operation of the water level constant control device configured as described above will be explained.

Now, when the water level of the dam 1 is the same as the set value 5 set by the water mark level setter 4 of the control device, and the dam inflow amount 2 changes, the opening degree of the guide vane of the water turbine 12 remains constant. That is, since the water turbine discharge amount 13 is also constant, the dam water level 3 also changes as the dam inflow amount 2 changes. Dam water level 3
The change in the water level is detected by the water level change rate calculating section 14 at regular intervals as the water level change rate 15. In addition, when the deviation 6 between the dam water level 3 and the target water level set value 5 exceeds the dead band width set in the dead band circuit 7, that is, the water level deviation exceeds a certain range, the contact 16 closes and the water level change rate 15 changes to the target opening. It is given to the degree calculation unit 18. Next, the operation in the target opening calculation section 18 will be explained using the flowchart of FIG. 2, and FIGS. 3 and 4.

Referring to Figure 2, ``First, from the current dam water level H, use the function generator whose characteristics are shown in Figure 3 to calculate the dam basin area (dam surface area) (S) at the current water level (step 1).
00). Next, calculate the water level change rate x time x dam basin area (dam surface area), and calculate the amount of change in dam inflow (ΔQi
) is calculated (step 101). Figure 4 is a graph showing the relationship between the water discharge amount (Qo) of the water turbine and the guide vane opening (GV) of 20. Using a function generator with such characteristics, the current guide vane opening (GV) of 20 The amount of water discharged from the water turbine (Qo) is determined (step 102).

After that, the amount of change in the dam inflow amount determined in step 101 (
ΔQi) is the current water discharge amount Q from the water wheel. A target guide vane opening value (MGV) of 1.9 is determined from the discharge amount with the addition of (Step 103). In this way, the guide vane opening value 1
9 and the guide vane opening value 8 obtained through the rigid restoring part 7, the control part 10 gives a drive signal to the guide vane drive part 11 according to the polarity of the deviation 9, and adjusts the guide vane opening value 20 of the water turbine 12. Adjust. Guide vane opening degree 2
By opening and closing 0, the water turbine discharge amount 13 changes. Through the above series of operations, the dam water level H is controlled to be driven into the dead zone Il+ of the target water level.

This dead band width can be set to be smaller than the water level droop rate of the wood tone, and the guide vane opening degree is adjusted every calculation cycle of the water level change rate. Therefore, it is possible to automatically and stably maintain constant control of the dam water level in a power plant such as a dam-type power plant where water level changes are small. In the embodiment described above, the guide vane opening degree 20 is used as a feedback signal, but it is also possible to detect the water turbine discharge amount and use the discharge amount value as a feedback signal to adjust the guide vane opening degree. This method is effective when the dam water level changes significantly depending on the season.

〔Effect of the invention〕

Since the present invention has the above configuration, it is possible to automatically adjust the opening degree of the guide vane of the water turbine driven by the water turbine generator in a dam type power plant, and to stably stabilize the dam water level.

In addition, by changing the target water level setting, depending on the season,
This makes it possible to control the dam water level at a constant level.

DESCRIPTION OF SYMBOLS 10... Control part, 12... Water turbine, 13... Water turbine discharge amount, 14... Water level change rate calculation part, 15... Water level change rate, 16... Contact, 17... Dead band circuit , 18...
Target opening calculation unit, 19...Target guide vane opening value.

Claims (1)

[Claims] A dead band circuit that detects when the deviation between the set value of the target water level setting device and the dam water level exceeds a predetermined range, and a water level change rate calculation that receives the dam water level and calculates the temporal rate of change of the dam water level at a constant cycle. a target opening calculation section that calculates a target guide vane opening by adding a dam water level change rate signal during the operation of the dead band circuit; and a guide vane opening according to the difference between the target guide vane opening and the guide vane opening signal. - A constant water level control device for a hydroelectric power plant, comprising a control calculation unit that provides a guide vane adjustment signal to a vane drive unit.