JPS6044514B2 - Hydroelectric power plant operation control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an operation control method for a hydroelectric power plant that has an intermediate reservoir between an upper power plant and a lower power plant that is shared by both power plants.

In a hydroelectric power plant, a power station is constructed between an upper reservoir and a lower reservoir, and power generation or pumping operation is performed by utilizing the head or lift formed by the water level difference between the two reservoirs.

However, if it is difficult to construct a power plant in the required location due to topographical or geological problems, or if the head or lift is too high to be applied to only one power plant, an upper reservoir may be used. By installing an intermediate reservoir at the point where the head or head is divided into two between the lower reservoir and the lower reservoir, and placing separate power plants above and below the reservoir, each power plant can share the water from the intermediate reservoir. Electric power generation or water pumping operations are performed. Each of the power plants arranged in this manner influences the operation of equipment at the other power plant through the water level of the intermediate reservoir, etc. Particularly when the water storage capacity of the intermediate reservoir is small, the water level changes easily due to equipment operation, so the degree to which they are influenced by each other becomes stronger. Therefore, it becomes an important issue how to operate the equipment of each power plant, which is mutually susceptible to each other, from the viewpoint of safety and economy.

This is an extremely important issue, especially for pumped storage power plants with complex operation modes. On the other hand, considering the necessity and location difficulties of pumped storage power plants for the purpose of load adjustment at nuclear power plants or thermal power plants, there is a tendency to increase the construction of pumped storage power plants that share intermediate reservoirs. Generally, the operating state of equipment such as water turbines, pumps, and pump water turbines is controlled by controlling the opening degree of guide vanes attached to each equipment to adjust the flow rate. Therefore, to explain the outline of the waterway system of a hydroelectric power plant that shares the above-mentioned intermediate reservoir with reference to Fig. 1, an intermediate reservoir 3 is added between the upper reservoir 1 and the lower reservoir (including the river) 2. An upper power station 4 and a lower power station 5 are separately arranged above and below the power station. The upper power plant 4 is connected to the upper reservoir 1 and the intermediate reservoir 3 by an inlet water channel 6 and an outlet water channel 8, respectively, and the lower power plant 5 is connected to the intermediate reservoir by an inlet water channel 7 and an outlet water channel 9, respectively. 3 and the lower reservoir 2. A feature of such a hydroelectric power plant is that the upper power plant 4 and the lower power plant 5 are connected to the intermediate reservoir 3 through waterways 8 and 7, respectively, so that they share the water there and also share the water between the upper and lower power plants. H1, which is obtained by dividing the head or head H between 2 and 2 into two.
and H2, respectively. In other words, the operating conditions of the equipment in the upper power station 4 and the lower power station 5 are influenced by the operating conditions of the equipment in the other power station by measuring the water level x of the intermediate reservoir 3. In power plants that share such intermediate reservoirs, when controlling the opening of the guide vanes of equipment depending on the water level, conventionally, changes in the water level in each reservoir are understood as the head or lift acting on each equipment, and these are Therefore, this is a method in which the guide vane opening degree is controlled for each machine.

In other words, conventional operation control. The method will be explained below with reference to FIG. The water level x of the intermediate reservoir 3 is detected by the water level detector 11, and the subtractor 13, which constitutes the operation control system of the upper power station 4 and the lower power station 5, respectively.
15. The subtracters 13 and 153 calculate the difference between the water levels y and z detected by the water level detector 10 of the upper reservoir 1 and the water level detector 12 of the lower reservoir 2, respectively, and the water level X of the intermediate reservoir 3, Water level difference y-X,z respectively
The guide vane control device 14 of the upper power plant and the guide vane control device 1 of the lower power plant 5 use −x as the main control signal.
6, and each power plant was controlled independently from each other. Therefore, when operating equipment at each power plant based on such conventional control methods, even if the water level in the intermediate reservoir becomes abnormal, the head or head of each equipment will be within the operating tolerance range. If so, the operation will continue, and in some cases, an abnormal situation such as overflow or shortage of water may occur in the intermediate reservoir, which is extremely dangerous for the equipment and the waterway.

Furthermore, depending on the water level of the intermediate reservoir, the operation of equipment may be restricted, so in the case of pumped storage power plants in particular, it is necessary to respond quickly and maneuverably in response to complex power demand relationships. It becomes difficult to operate certain equipment. The present invention provides water level and water level changes in the intermediate reservoir in a hydroelectric power plant where water turbines, pumps, or pump-turbine equipment are in a relationship where each other is susceptible to the influence of the other by sharing water in the intermediate reservoir. A method for controlling the operation of a hydroelectric power plant, which maintains the water level of an intermediate reservoir within a safe range by controlling a water wheel or a pump-turbine depending on its speed, and allows each power plant equipment to be operated safely and economically. The purpose is to provide

In order to achieve the above object, the present invention provides an intermediate reservoir in the middle of a waterway system that connects the upper reservoir and the lower reservoir, an upper hydroelectric power plant between the upper reservoir and the intermediate reservoir, and an intermediate reservoir and the lower reservoir. In a hydroelectric power plant where a lower hydroelectric power plant is installed between 1 and 2, the magnitude and direction of the water level change rate in the intermediate reservoir are detected, and the magnitude and direction of the water level change rate in the intermediate reservoir can be detected to prevent the intermediate reservoir from falling into an abnormal situation in a short period of time. If the water level is below the predetermined value, the main control signal according to the water level difference between the upper and intermediate reservoirs will control the guide vane opening of the upper power plant to an appropriate opening, and The guide vane opening degree of the lower power station is controlled to the appropriate opening degree using the main control signal according to the water level difference in the power station.
On the other hand, when the magnitude of the water level displacement speed exceeds a specified value set to prevent the intermediate reservoir from falling into an abnormal situation for a short time, auxiliary control is carried out in proportion to the magnitude of the water level displacement speed and corresponding to its direction. The signal controls the opening of the guide vanes of either or both of the upper and lower power plants to control the amount of water flowing into and out of the intermediate reservoir, thereby keeping the water level in the intermediate reservoir below a specified value. This allows the equipment at each power plant to be operated safely. Next, the relationship between the flow rate used by each power plant and the displacement rate of the intermediate pond water level will be explained.

First, the upper power station 4 and the lower power station 5 simultaneously perform power generation operation, and the upper power station 4 generates a power generation flow rate QTl based on the head H1, or the lower power station 5 generates a power generation flow QTl based on the head H2.
A case will be described in which the power generation water turbine operation is performed under the conditions of the power generation flow rate QT2. Each power generation flow rate QTl
The relationship between QT9 and the flow rate ΔQT flowing into or out of the intermediate reservoir 3 is as follows (flow continuity equation).
On the other hand, the displacement speed of the water level X of the intermediate reservoir 3, that is, the amount equivalent to the first derivative value of the water level
If A is the effective horizontal cross-sectional area of the intermediate reservoir 3 at a position corresponding to water level x, the following equation holds true.

Also, by substituting equation (1) into equation (2), the following equation is obtained.

Here, the units of each quantity are as follows. QTl, QT2
~ΔQT: [Dlsec]x: [m]Δx/Δt:
[M, Sec] A: [d] From this, the water level displacement speed Δx/Δt of the intermediate reservoir 3 is detected, and the direction of the water level displacement, that is, the positive or negative of Δx/Δt is detected. The magnitude relationship of QT2 can be easily given.

If we assume that the operation is currently in a state where the relationship between each power generation flow is Q, l> Q, 2, then Δx/Δt>0, and the intermediate reservoir 3
Then, the amount of water corresponding to ΔQT will increase per unit time, and the water level x will rise with time. On the other hand, the relationship between each power generation flow rate is QTl
〈Assuming that it is operated in the state of QT2, ∆x/∆t<
0, and in the intermediate reservoir 3, the amount of water corresponding to ΔQa is lost per unit time, and the water level x decreases with time. In either case, when the capacity of the intermediate reservoir 3 is small, the water level X changes quickly. Next, a configuration diagram of an embodiment of the present invention shown in FIG. 3 will be explained.

In FIG. 3, the water level x of the intermediate reservoir 3 is determined by the water level detector 11.
and is transmitted to subtracters 13 and 15 that constitute the operation control systems of power plants 4 and 5, respectively. The subtractor 1
3 and 15, the water level detector 10 of the upper reservoir 1
, the difference between the water levels y and z respectively detected by the water level detector 12 of the lower reservoir 2 and the water level x of the intermediate reservoir 3 is determined, and the water level difference y-X. ．． z-x is applied as a main control signal to the guide vane control device 14 of the upper power plant 4 and the guide vane control device 16 of the lower power plant 5, so that the power plants 4 and 5 can be controlled independently of each other. do. In the control device of the present invention, the water level difference y−X. ．． In addition to the main control signal consisting of z - x, the directionality and magnitude of the displacement speed of the intermediate pond water level x are detected, and this is configured to be provided to the guide vane control devices 14 and 16 as an auxiliary control signal. .

17 is an auxiliary control signal generation section provided for this purpose.

FIG. 4 is a detailed configuration diagram of the auxiliary control signal generation section. First, a signal of the water level x of the intermediate pond 3 is given to the differentiating circuit 18, which detects the displacement speed Δx/Δt of the water level x, which is further introduced into the polarity discriminator 19 to determine the increasing direction (+Δx/Δt).
However, it is determined whether it is in the decreasing direction (-Δx/Δt). Furthermore, an output signal level detector 20 of this polarity discriminator 19
and when the magnitude exceeds a predetermined value to prevent the intermediate reservoir from falling into an abnormal situation in a short period of time, the signal Δx/Δt is sent to the guide vane control device 14 or 16. An auxiliary control signal Xdl or Xd2 proportional to the magnitude is provided. Reference numeral 21 denotes a changeover switch that switches the auxiliary control signal circuit according to the power generation operation and the pumping operation.

Note that 22 and 23 operate when the auxiliary control signals Xdl and Xd2 are extremely large and may impede the plant operation if the operation continues, and they respectively cause an emergency stop of the power plant equipment 7 or issue an alarm. It is an anomaly detector that detects Next, the operation of the present invention will be explained.

The upper power station 4 and the lower power station 5 are running power generation at the same time, and the flow rate relationship of each power station is temporarily QTl>QT2.
Let's consider the case where the state is f. The polarity discriminator 19 detects the positive polarity Δx/Δt from the relationship of equation (3) through the differentiation circuit 18, and if the magnitude is less than the specified value determined by the level detector 20, the auxiliary control is performed. Signal Xd
l is not transmitted. After all, the guide vane control device 14
, 16 are appropriate guide vane opening degrees A that are preset for the water level difference, as illustrated in FIG.
In the state of , each water level difference y−X. ．． It is independently controlled under the z-x control signals. In this case, since the magnitude of the water level displacement rate Δx/Δt of the intermediate reservoir 3 is less than the specified value, it is clear from the relationship in equation (3) that the flow rate ΔQT (=QTl−QT2) flowing into or out of the intermediate reservoir 3 is a small value. As a result, the water level of the intermediate reservoir 3 is maintained within a safe range that does not cause abnormal situations such as overflow or shortage in a short period of time. However, when the magnitude of Δx/Δt exceeds the specified value, the level detector 20 detects Δ
A positive auxiliary control signal Xdl having a magnitude proportional to x/Δt is transmitted to the guide vane control device 14. In the guide vane control device 14, as illustrated in FIG. 5, the guide vane opening degree A is adjusted by Δa depending on the magnitude of the auxiliary control signal Xdl. The equipment of the power plant 4 is operated with the guide vane opening being j-Δa, which is smaller than the opening for a given water level difference y-x. In this way, in the upper power plant 4, the auxiliary control signal 1d1
As a result, the operation of the equipment is controlled with the guide vane slightly opened, and the power generation flow rate QTl gradually decreases. Therefore, the flow rate relationship at each power plant is the initial QTl〉Q
By bringing QTl closer to QT2 from T2, QTl=
This will lead to a transition to state Q.2.

This reduces the value of Δx/Δt from the relationship in equation (3) above, and shifts the water level of the intermediate reservoir 3 to a safe area.
It means to make. In the above process, auxiliary control chaos signal Xd
If l is extremely large, the abnormality detector 22 controls to stop the equipment in the upper power plant 4, thereby rapidly reducing the power generation flow rate Q1. Next, consider a case where the flow rate relationship of each power station is Q, l and the power generation operation state is QT2.

In this case, since Δx/Δt of negative polarity is detected, this auxiliary control signal
Control is performed on the equipment of the lower power station 5. In the above explanation, when the auxiliary control signal Xdl is output, the opening degree of the guide vanes of the upper power station 4 is narrowed by the function of the guide vane control device 14, but conversely, the guide vane control device 16 is operated. The guide vane opening degree of the lower hydroelectric power plant 5 may be opened by

Similarly, when the auxiliary control signal Xd2 is output, instead of narrowing down the guide vane opening of the lower hydroelectric power station 5, the guide vane opening of the upper power station 4 may be increased. Further, the guide vane openings of the upper power station 4 and the lower power station 5 may be controlled at the same time. Next, upper power station 4
Pumping operation is performed at the same time in the upper power station 4 and the lower power station 5, and in the upper power station 4, the pumping flow rate Q,l is performed under the pumping head H1, and in the lower power station 5, the pumping flow rate QP2 is performed under the pumping head H2. Let us consider the case where the water pump is operating in each state.

In the case of pumped storage operation, it is the opposite of the case of power generation operation mentioned above.
In the intermediate reservoir 3, the inflow flow rate is the pumped water flow rate QP2 of the power station 5, and the outflow flow rate is the pumped water flow rate QPl of the upper power station 4.

Therefore, in the previous equation (3), even when QTl is replaced by QPl and QT2 by QP2, when QPl>QP2, the rate of change in the water level of the intermediate pond becomes Dx/Dt<O, which means a decrease in the water level, and QPl When Q, 2, Dx/Dt>0, which means the water level is rising.During pumping operation, the selector switch 21 is switched from the power generation side to the pumping side.

By this switching, when the output of the level detector 20 is negative (Dx2), the output signal is introduced into the guide vane control device 14 of the upper power station 4, and conversely, DXl is introduced into the guide vane control device of the lower power station 5. 16 will be introduced. That is, in the case of this pumping operation, as in the case of the above-mentioned power generation operation, the displacement rate Δx/Δ of the water level
t and the displacement direction are detected by a polarity discriminator 19 through a differentiation circuit 18 as a common control signal to the equipment of the upper power station 4 and lower power station 5, and the magnitude of the displacement speed Δx/Δt is detected by a level detector 20. If the water level exceeds a predetermined value, the level detector 20 transmits the auxiliary control signal of Δx/Δt to each of the guide vane control devices 14 and 16 according to the polarity, so that the direction of displacement of the water level Δx/Δ
When t<0, that is, QPl>QP2, the equipment in the upper power plant 4 controls the guide vane opening in the closing direction to perform partial opening operation, or the equipment is stopped by operating the alarms 22 and 23. By controlling QPl to QP
2 to slow down the value of Δx/Δt to maintain the water level x in a safe region. Next, the displacement direction Δx/Δt of water level
〉0, that is, Q, KQ, 2, the equipment of power plant 5 is controlled in conjunction with the displacement speed of water level Maintain water level X in a safe area. In the case of this pumping operation as well, when the auxiliary control signal Xdl is output, the guide vane opening of the lower hydroelectric power station 5 may be controlled to be opened instead of narrowing the guide vane opening of the upper hydroelectric power station 4.

Similarly, when the auxiliary control signal Xd2 is output, the guide vane opening of the upper hydraulic power station 4 may be controlled to be opened instead of narrowing down the opening of the guide vane of the lower hydraulic power station 5. Further, the guide vane openings of the upper power station 4 and the lower power station 5 may be controlled at the same time. As explained above, according to the present invention, between the upper power station and the lower power station,
The water level of the intermediate reservoir shared with each other is maintained in a safe area without falling into an abnormal state, and the upper power plant and the lower power plant can be safely connected.

In addition, if the water level displacement speed of the intermediate reservoir is below the specified value,
Since the upper power plant and the lower power plant can be optimally controlled, it is also possible to improve the overall operating efficiency of the hydroelectric power plant.

[Brief explanation of drawings]

Fig. 1 is a conceptual diagram showing a hydroelectric power plant having an intermediate reservoir to which the present invention is applied, Fig. 2 is a conceptual diagram showing a conventional operation control method of a hydroelectric power plant, and Fig. 3 is an embodiment of the present invention. FIG. 4 is a block diagram showing an example of the auxiliary control signal generation section in FIG. 3, and FIG. 5 is a characteristic diagram showing the relationship between the water level difference and the guide vane opening. 1...Upper reservoir, 2...Lower reservoir, 3...Intermediate reservoir, 4...Upper hydroelectric power plant, 5...Lower hydroelectric power plant power plant, 10, 11, 1
2... Water level detector, 14, 16... Water mouth control device, 17... Auxiliary control signal creation section, 22
, 23... Abnormality detector.

Claims (1)

[Claims] 1 An intermediate reservoir is installed in the middle of the waterway system connecting the upper reservoir and the lower reservoir, and an upper hydroelectric power station is installed between the upper reservoir and the intermediate reservoir, and a lower hydroelectric power station is installed between the intermediate reservoir and the lower reservoir. At a hydroelectric power plant, the magnitude and direction of the water level displacement speed of the intermediate reservoir are detected, and the magnitude and direction of the water level displacement speed are determined to be below a specified value set to prevent the intermediate reservoir from falling into an abnormal situation in a short period of time. If so, the guide vane opening degree of the upper power plant is controlled to an appropriate opening degree using a main control signal according to the water level difference between the upper reservoir and the intermediate reservoir, and the main control signal according to the water level difference between the intermediate reservoir and the lower reservoir. The guide vane opening degree of the lower power station is controlled to an appropriate opening degree, and when the magnitude of the water level displacement speed exceeds a specified value set to prevent the intermediate reservoir from falling into an abnormal situation in a short time, The amount of water flowing into and out of the intermediate reservoir is controlled by controlling the guide vane opening degree of either or both of the upper power station and the lower power station using an auxiliary control signal that is proportional to the magnitude of the water level displacement speed and corresponds to its direction. A method for controlling the operation of a hydroelectric power plant, characterized in that: