JPS6093179A - Flow rate controller - Google Patents

Abstract

PURPOSE:To properly handle a primary water flow, by installing a computer, which calculates a primary water flow time, to a flow rate controller in a hydraulic power plant. CONSTITUTION:A primary water flow condition is detected by a primary water flow detector 28, and a primary water flow instruction 34 is outputted. A desired value 36 of a gate opening is calculated by a computer 30 from a flow rate, to which an instruction flow rate 16 is limited by a limiter 29 according to the instruction 34, and a current water level in a water storage pond 18. When a deviation between the desired value 36 and an actual gate opening 21 exceeds an insensitive zone, a gate control instruction 22 is outputted to a motor 19 for controlling a gate. With an intake gate 12 driven, an amount 23 of water discharged from a water storage pond is controlled to a primary water flow amount 40. From the primary water flow amount 40, a current primary water flow time 51 is calculated by a computer 50. After the primary water flow time 51 has elapsed, the primary water flow instruction 34 is rendered ineffective.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a flow rate control device for performing initial water flow treatment in a hydroelectric power plant.

[Technical background of the invention and its problems]

For example, some hydroelectric power plants controlled by a water level adjustment device are equipped with a flow rate control device that performs initial water flow processing. Figure 1 shows such a hydroelectric power plant. Upstream water flows into a reservoir 1 via a river or a waterway, and this water is led to a water tank 4 through a water intake gate 2 and an unpressurized barrier 3. Furthermore, the water in the water tank 4 drives a water wheel 6 via a guide vane 5, and is guided from a discharge channel 8 to a river or a lower pond. At that time, the generator 7 generates electricity by driving the water turbine 6.

Control of this hydroelectric power plant is performed as follows. That is, the water level IO of the water tank 4 is detected by a water level detector and input to the water level adjustment device 11. On the other hand, the water level adjustment device 11 returns the guide vane opening degree 14, and the water tank water level 1
A guide vane operation command 12 is output to the guide vane 5 so that the water level is maintained at a predetermined water level. This is output under the condition of a starting command 13 for the main engine (hydraulic 2 generator) from the flow control system [15].

On the other hand, the flow rate control device 15 includes a water level detector 1 for the reservoir.
The reservoir water level 18 and command flow rate 16 detected in step 7 are input, and a gate operation command 22 for the water intake gate 2 is issued based on these. As a result, the operation motor 19 is operated, and the gate opening degree detector 20 detects the gate opening degree 21.
is detected and fed back to the flow rate control device 151. In this way, the outflow t23 of water from the reservoir 1, the inflow amount 24 of water into the water tank 4, and the outflow amount 25 of water from the water tank 4 are respectively controlled.

FIG. 2 is a characteristic diagram showing the relationship between the command flow rate 16 when performing initial water flow and the actual flow rate (initial water flow rate) 40 of water during initial water flow. n aQ is the initial water flow rate 40. Indicates the upper limit value. If the command flow rate 16 is less than or equal to ao, the command flow rate I6 is proportional to the initial water flow rate 40, and if the command flow rate 16 is greater than an, the initial water flow rate 40 is the upper limit of the initial water flow rate, as can be seen from the figure. a (held at 1). Now, if the command flow rate 16 changes from O to a+ (a+>0), the flow rate control device 15 gives a gate operation command 22 to the operation motor 19 of the water intake gate 2. This gate operation The water gate 2 opens according to the command 22 from the gate fully closed state to the gate opening according to the command flow rate 16, and the amount of water flowing out from the reservoir 1 becomes the same as the command flow 1t16.However,
In order to control the water intake gate 2 so that the commanded flow rate is 16 at this time, the following needs to be considered.

One is the change in the water tank water level lo when the water tank 4 is not very large in a hydraulic power plant, and the other is the change in the water intake gate 2 because the reservoir l and the water tank 4 are connected by the unpressurized drainage road 3.
It takes a sufficient amount of time (N water time) for the water that has passed through to flow into the water tank 4. Plants that require all of these considerations are required to operate in the following manner. Aquarium 4
is not very large, so the inflow of water is 24 and the outflow is −m−2.
5 becomes large, the change in the water tank water level lo becomes drastic, leading to an overflow or a drop in the water level, leading to the generator stopping. Therefore, when the water intake gate 2 is fully opened to 1w in response to the command flow ft16 while the gate is fully closed, the amount of water flowing out from the reservoir 1 by the water intake gate 2 is 2.
3 is below a certain value aQ.

Then, the main engine is adjusted by taking into account the landing time of the water that has passed through the water intake gate 2 to reach the water tank 4, and the time for the water tank water level 4 to stabilize so that the turbulence of the inflowing water is reduced and the water level adjustment device 11ffi can be used. Determine the startup wait time. This main engine startup waiting time is the waiting time in the trench where the main engine starts starting from the moment when the flood gate 2 starts to open from the fully closed state as 'ol, and after the main engine startup waiting time elapses, the flow rate is controlled. A start command 13 for the main engine is output from the system [15] to the water level adjustment device 11.

Then, the main engine is started by this main engine start command 13, and the water level adjustment device 11 performs wood-like operation. When the wood style operation is started, the water level adjustment device 11 drives the guide vane 5 according to the guide vane operation command 13 so that the inflow amount 24 and outflow amount 25 of water into the water tank 4 are kept constant. In this state, the water level 10 of the water tank 4 becomes stable.

Therefore, after that, the flow rate control device 15 drives the gate operation motor 19 so that the final target, the command flow rate 16 = al, is set.1.In that case, even if al-aQ is large to some extent, the water level can be adjusted without startup time. Since the device 15 drives the guide vane 5 in response to changes in the water tank water level IO, the difference between the amount of water flowing into the tank 4 24 and the amount of water flowing out 25 does not become too large. Therefore, the plant can be operated without causing problems such as overflow.

In the above process, the outflow amount 23 of water is limited when the water intake gate 2 starts to open from fully closed. Here, the initial water flow time is defined as the waiting time for starting the main engine, which includes the initial water flow, M1 water landing time, and the stability of the water system. Note that these treatments are collectively referred to as initial water flow treatment.

A schematic configuration of the flow rate control device 15 that performs this initial water flow process is shown in FIG. That is, the command flow rate 16 is O
The contents of the processing such as calculations performed during the period from when the initial water flow process is completed to when the water outflow 123 from the reservoir 1 becomes the command flow 1116 are as follows.

First, when the gate opening degree 21 is fully closed, the command flow rate is 16.
As the value becomes larger than O, the initial water flow detector 2
8, the initial water flow state is detected. When the initial water flow state is detected, the initial water flow detector 28 outputs an initial water flow command 34. Based on this initial water flow command 34, the command flow rate 16 is limited by the limiter 29, and then the gate opening target value 3 is calculated by the calculator 30 based on the initial water flow rate 40 and the reservoir water level 18 at that time.
Calculate 6. Then, the deviation between this gate opening degree target value 36 and the actual gate opening degree target value 21 is determined by the adjuster 31, and if the deviation is greater than the dead zone 32, the gate operation command 2 is determined.
2 is output to the gate operation motor 19, and the water intake gate 2 is controlled so that the outflow of water from the reservoir 1 (If) 23 becomes an initial water flow rate of 40. This initial water flow state continues for the initial water flow time 27 set in the setting device 26, and after that time, the initial water flow detector 28 detects the initial water flow processing path r, and the initial water flow command 34 Release. Upon release, the start command generator 35 issues a start command 13 for the main engine to the water level adjustment device 11.
'r Output. Then, by canceling this initial water flow command 34, the command flow rate 16 is directly input to the calculator 3o, so a new gate opening degree target value 36 corresponding to this is calculated.
The water intake gate 2 is controlled with this as the target, and the command flow rate 16
Water similar to that will flow out from reservoir 1.

By the way, the initial water flow time used here takes into account both the water landing time and the water system stabilization time, as described above. This water landing time depends on the length, slope, shape, and
It is determined by the surface condition, gravity, flow rate, etc., and the water system stabilization time is mainly determined by the shape of the tank 4, the flow rate, the tank water level, etc. Here, each value other than the flow rate and water level differs for each plant, but the plant itself hardly changes over time.

Therefore, the initial water flow time is usually determined by taking into consideration the water landing time and water system stabilization time at a certain flow rate.

Then, the time is set in the total time setting device 26.

However, in this case, it is difficult to select the flow rate to determine the initial water flow time. At flow rates other than that flow rate, the water landing time etc. differ and the timing of starting the main engine is too early or too late compared to the actual water landing time, resulting in unstable control.

In addition, in order to prevent such instability of control, there is a drawback that the initial water flow rate must be controlled at a constant flow rate, which does not allow for much margin.

[Purpose of the invention]

The purpose of the present invention is to reduce the instability of control caused by the difference in the initial water flow rate and the time difference between the main engine startup time and the actual initial water flow time, and to reduce margins such as limitations on the initial water flow rate. It is an object of the present invention to provide a flow rate control device suitable for performing initial water flow treatment without the conventional drawback of having to perform unnecessary control.

[Summary of the invention]

The present invention uses the initial water flow rate as a state quantity that completely changes the water landing time, etc., adds a new calculator that calculates the initial water flow time based on the flow rate, and uses the result of the calculator as the initial water flow time. To provide a flow rate control device suitable for performing initial water flow processing, which eliminates the deviation in timing of starting a main engine seen in the past by using it, performs stable control, and can also change the initial water flow amount.

[Embodiments of the invention]

FIG. 4 shows a configuration diagram of the flow rate control device of the present invention, and FIG. 5 shows an example of the input/output characteristics of the computing unit used in the present invention to calculate the initial water flow time.

In FIG. 4, the same components as those in FIG. 3 are designated by the same reference numerals, and their explanation will be omitted. 5o is a calculation unit for calculating initial water flow time newly added according to the present invention.

51 indicates the initial water flow time calculated by the calculator 50. Further, 150 is a flow rate control device of the present invention.

Note that this calculator 50 calculates the initial water flow amount 4o and the initial water flow time 5o.
A characteristic curve based on a mathematical formula or actual data showing the relationship with 1 is stored. Then, the computing unit 5° outputs an initial water flow time 51 corresponding to the initial water flow amount 4o, as shown in FIG.

The processing performed from the start of initial water flow until the end of control (the same flow rate as the commanded flow rate 16 is taken) will be described below with reference to FIGS. 4 and 5. First, the initial water flow detector 28 detects the initial water flow state and outputs the initial water flow command 34. Next, the command flow rate 16 is determined by the initial water flow command 34.
Flow rate with limiter 29 added to (initial water flow rate 40)
The gate opening degree target value 36 is calculated by the calculator 3o based on the reservoir water level 18 at that time. At this time, the limiter 29 (2) is configured to limit the upper limit value, so if the flow rate is less than the upper limit value, an arbitrary value can be input as total command flow [16] to perform initial water flow. In addition, if the upper limit value can be changed, the initial water flow rate can be set to any value.However, since the upper limit of the initial water flow rate is determined by the stability of the water system of each plant, the initial Water cannot be passed through.

Next, the deviation between the gate opening degree target value 36 and the actual gate opening degree 21 is calculated by the adjuster 31. If the deviation is greater than or equal to the dead zone of 32, a gate operation command 22 is output to the gate operation motor 19. Water increase game) 12 by this operation motor 19
is driven, and the outflow amount 23 of water from the reservoir 1 is controlled so as to become the initial water flow amount 40. Based on this initial water flow amount 40, the initial water flow time 51 at that time is calculated. For the calculation, an arithmetic unit 50 as shown in FIG. 5 (-) is used.

The initial water flow state is continued during this initial water flow time 51, and after that time, the initial water flow detector 28 detects the end of the initial water flow process and cancels the initial water flow command 34. When the initial water flow command 34 is canceled, the start command generator 35 outputs the main engine start command 13 to the water level adjustment device 11, and the water level adjustment device 11 controls the guide vane 5 to remove water from the water tank 4. The outflow amount 25 is made to flow according to the aquarium water level 10. At the same time, a command flow 1116 is directly input to the calculator 3°. Then, a new gate opening degree target value 36 corresponding to the command flow 1916 is calculated 111, and control is performed with this new gate opening degree target value 36 as the target.

As described above, the flow rate control device of the present invention performs initial water flow for an initial water flow time corresponding to the initial water flow amount, and outputs a start command for the main engine. This eliminates the timing lag between the main engine start-up, water landing time, and water system stabilization time that was conventionally seen, making it possible to perform stable control. Further, the initial water flow It, which was fixed in order to prevent the above-mentioned timing deviation, can be changed freely as long as it is within the constraint conditions of the water system.

In the above embodiment, only the initial water flow rate was used to calculate the initial water flow time, but in plants where the stability of the water system is considered as important or more important than the water landing time, the tank water level and the initial water flow rate, etc. : Calculate the initial water flow time using . In addition, if a specific plant has other state variables that change the initial water flow time, the initial water flow time is calculated using the state quantities.

〔Effect of the invention〕

As described above, according to the present invention, the initial water flow time is calculated based on the predetermined state quantity at that time, and the initial water flow processing and all start-up commands for the main engine are executed, so that stable control can be performed. Further, since restrictions on control such as the initial water flow amount can be reduced, a flow rate control device suitable for performing initial water flow can be provided.

[Brief explanation of drawings]

Figure 1 is a configuration diagram of a hydroelectric power plant that includes a flow rate control device that performs initial water flow processing, Figure 2 is a diagram showing the relationship between commanded flow rate and initial water flow rate, and Figure 3 is a schematic diagram of the configuration of a conventional flow rate control device. ,
FIG. 4 is a schematic diagram of the configuration of the flow rate control device of the present invention, and FIG. 5 is a characteristic diagram showing an example of input/output characteristics of a computing unit that calculates the initial water flow time. ■... Reservoir 2... Water intake gate 3... Unpressurized roadway 4... Water tank 5... Guide vane 6... Water turbine 7... Generator 8... Spillway 9...・Aquarium water level detector 1o...Aquarium water level 11...
・Water level adjustment device 12...Guide vane operation command T3
...Main engine start command 14...Guide vane opening degree 1
5... Conventional flow rate control device 16... Command flow rate 17... Reservoir water level detector 18
... Reservoir water level 19 ... Gate operation motor 20
...Gate opening degree detector 21...Gate opening degree 22...Gate operation command 23
... Amount of water flowing out from the reservoir 24 ... Amount of water flowing into the aquarium 25 ... Amount of water flowing out from the aquarium 26 ... Initial water flow time footer 27 ... Initial water flow Water time 28...Initial water flow detector 2
9...Limiter of command flow rate 30...Arithmetic unit for gate opening variation target value calculation 31...Adjuster/subtractor for deviation calculation 32...Dead band 33...Motor gate opening characteristic 34...Initial flow Water command 35...Start command creator 3
6... Gate opening target value 40... Initial water flow rate 50... Initial water flow time calculation calculator 51... Initial water flow time 150... Flow rate control device of the present invention (7317) Agent Patent attorney Kensuke Chika (and 1 other person) Figure 2 0

Claims (1)

[Claims] A flow rate control device that performs initial water flow processing in a hydroelectric power plant includes a calculation unit that calculates an initial water flow time based on a flow rate during initial water flow, and uses the initial water flow time that is the result of the calculation unit. A flow rate control device that performs initial water flow processing.