JP3493048B2 - Operation control method of variable speed hydraulic machine in branch water system power plant. - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the operation of a variable speed hydraulic machine of a branch waterway system power plant, and more particularly to a plurality of branch pipes branched from one hydraulic pipe communicating with an upper reservoir. The present invention relates to an operation control method for a variable speed hydraulic machine among a plurality of hydraulic machines connected to each other.

[0002]

2. Description of the Related Art In recent years, pumped-storage power plants have a tendency to install a plurality of hydraulic machines such as pump turbines in order to obtain a large amount of power generation. These pump turbines have a plurality of hydraulic machines between an upper reservoir and a lower reservoir. Each is connected to a waterway. Since a great amount of civil engineering work is required to construct a water channel between the upper reservoir and the lower reservoir, one common penstock is connected to the upper reservoir to reduce this civil works cost. In many cases, a water pressure pipe is branched into a plurality of branch pipes and a pump turbine or the like is connected to these branch pipes.

FIG. 8 shows a schematic structure of the above-mentioned branch waterway system pumped-storage power plant. One common hydraulic pipe 2 is connected to the upper reservoir 1 and the hydraulic pipe 2 is branched at the lower end thereof. At point 3, it is branched into a plurality of branch pipes 4a and 4b. These branch pipes 4a and 4b are respectively pump water turbine 5
It is connected to the lower reservoir 7 via a, 5b and discharge channels 6a, 6b.

Conventionally, as hydraulic machines such as turbines, pumps, and pump turbines, constant-speed type hydraulic machines have been widely used in the past, but in recent years, due to the progress of power electronics, the rotational speed of the main engine can be controlled arbitrarily. A variable speed hydraulic machine capable of doing so is being put to practical use. An operation control method for such a variable speed hydraulic machine is disclosed in, for example, Japanese Patent Application Laid-Open No. 48-21045 or Japanese Patent Application Laid-Open No. 57-113971.

[0005]

However, in the conventional branch waterway system power plant described above, since the branch pipes of a plurality of hydraulic machines are connected to each other at a branch point, the operation state of one hydraulic machine is There is a problem that the change affects other hydraulic machines and cannot always maintain the optimum operating condition. This will be described in detail below.

When all of the hydraulic machines are in a power generating operation and one of them has a load shed or an emergency stop, the flow control guide vanes are suddenly stopped to stop the main machine of the hydraulic machine. As a result, the water pressure in the branch pipe of the hydraulic machine with the load cut off fluctuates greatly due to the water hammer phenomenon. This water pressure fluctuation propagates to the branch pipe of the adjacent hydraulic machine during power generation operation via the branch portion, which transiently changes the effective head of the hydraulic machine during power generation operation, and in particular, the rise in the branch pipe water pressure. Will increase the effective head. Furthermore, the closing of the guide vanes of the hydraulic machine with the load cut off temporarily increases the flow rate of the hydraulic machine during the power generation operation.

Due to such a temporary rise in the effective head and a rapid increase in the flow rate, the hydraulic turbine output during the power generation operation becomes excessively large, and this excessive hydraulic turbine output imposes a great burden on the generator motor. Depending on the type, there is a problem that a redundant design must be done in advance.

Similarly, during the pumping operation of all hydraulic machines,
Water pressure fluctuations also occur when one of them shuts off the input or is in an emergency stop. For this reason, the total pump head of the hydraulic machine during the pumping operation is transiently changed, and the pump total head is also decreased due to the decrease in the water pressure of the branch pipe, and the axial input of the pump becomes temporarily excessive. Such an excessive pump shaft input imposes a heavy burden on the generator motor, and there is a problem that a redundant design must be performed in advance depending on the case. Also, during pumping operation of a certain hydraulic machine,
When another hydraulic machine starts the pumping operation, this new pumping operation also increases the flow rate of the common penstock, which also increases the hydraulic friction loss in the canal, which causes the hydraulic machine to operate during the pumping operation. There is a problem that the total pump head of the pump becomes large and the pumping amount of the pump decreases. This will be described in more detail. The total head of a hydraulic machine such as a pump turbine is shown in FIG.
It is the sum of the static head between the upper reservoir 1 and the lower reservoir 7 shown in Fig. 4 plus the hydraulic loss of the canal. As the number of operating hydraulic machinery increases, the hydraulic loss of the canal increases almost in proportion to the square of the flow rate. Therefore, the start of a new pumping operation increases the total pump head of the hydraulic machine during the pumping operation, which leads to a decrease in the pumping amount of the hydraulic machine during the pumping operation.

In a pumped-storage power station, starting a new pumping operation of a hydraulic machine generally means that there is extra capacity in the electric power system. Therefore, the decrease in the pumping amount of the hydraulic machine during the above-mentioned pumping operation is It becomes a hindrance to the efficient driving of the place.
Furthermore, when some of the hydraulic machines stop operating during the pumping operation of all the hydraulic machines, contrary to the above, the flow rate of the common penstock decreases due to the stop of operation, so Friction loss is also reduced, which causes a problem that the total pump head of the hydraulic machine during the pumping operation is reduced and the shaft input of the hydraulic machine is increased. In general, shutting down a part of a plurality of hydraulic machines during pumping operation at a pumped storage power plant is
In many cases, the electric power system does not have enough reserve capacity, and therefore it is not preferable for the efficient operation of the pumped storage power station that the shaft input of other hydraulic machines increases with the stop of some hydraulic machines.

Therefore, the object of the invention described in claim 1 is to:
Branch waterway system power plant that can prevent excessive hydraulic turbine output of hydraulic machines due to fluctuations in water pressure in branch pipes that occur when a part of a plurality of hydraulic machines that are in power generation operation has a load cut off or an emergency stop Another object of the present invention is to provide an operation control method for a variable speed hydraulic machine.

A second object of the present invention is to provide a pump for a hydraulic machine, which is caused by a fluctuation in hydraulic pressure in a branch pipe that occurs when a part of a plurality of hydraulic machines during pumping operation is shut off or an emergency stop occurs. An object of the present invention is to provide an operation control method of a variable speed hydraulic machine of a branch waterway system power plant, which is capable of preventing an excessive shaft input. The object of the invention as set forth in claim 3 is to reduce the pumping amount of a hydraulic machine due to an increase in the total pump head that occurs when another hydraulic machine starts the pumping operation during the pumping operation of one hydraulic machine. An object of the present invention is to provide an operation control method of a variable speed hydraulic machine of a branch waterway system power plant that can be prevented. An object of the invention described in claim 4 is to prevent an increase in shaft input of the hydraulic machine due to a decrease in the total pump head that occurs when a part of the plurality of hydraulic machines during the pumping operation is stopped. It is an object of the present invention to provide an operation control method of a variable speed hydraulic machine of a branch waterway system power plant which can be performed.

[0012]

In order to achieve this object, the invention according to claim 1 is connected to one of a plurality of branch pipes branched from one penstock connected to the upper reservoir. A variable speed hydraulic machine and a hydraulic machine of any type connected to the remaining branch pipes, the method of controlling a variable speed hydraulic machine of a branch waterway system power plant, comprising: During power generation operation of the machine and the above-mentioned arbitrary type hydraulic machine, when the load of the arbitrary type hydraulic machine is interrupted or an emergency stop occurs, the rotation speed of the variable speed type hydraulic machine is increased to almost the maximum operating speed and guide When the vane is closed to a predetermined opening and then the water pressure fluctuation in the water channel due to the load cutoff or the emergency stop disappears, the rotation speed of the variable speed hydraulic machine and the guide vane opening are respectively set to the predetermined operating points. Return to It is characterized in that to.

According to a second aspect of the present invention, there is provided a variable speed hydraulic machine connected to one of a plurality of branch pipes branched from a single penstock communicating with the upper reservoir, and the remaining branch. In an operation control method for a variable speed hydraulic machine of a branch waterway system power plant, which comprises a hydraulic machine of any method connected to a pipe, during pumping operation of the variable speed hydraulic machine and the hydraulic machine of any method. In addition, when the input of the hydraulic machine of the above-mentioned arbitrary system is interrupted or an emergency stop is performed, the rotation speed of the variable speed type hydraulic machine is controlled to be lowered to almost the minimum operation speed, and then the water channel caused by the input cutoff or emergency stop is controlled. It is characterized in that the rotational speed of the variable speed type hydraulic machine is increased to a predetermined rotational speed when the water pressure fluctuation of (1) has almost disappeared.

According to a third aspect of the present invention, a variable speed hydraulic machine connected to one of a plurality of branch pipes branched from one hydraulic pipe communicating with the upper reservoir and the remaining branch In an operation control method of a variable speed hydraulic machine of a branch waterway power plant, which comprises a hydraulic machine of an arbitrary method connected to a pipe, the hydraulic machine of the arbitrary method during pumping operation of the variable speed hydraulic machine. When the pumping operation is started, the rotating speed of the variable speed type hydraulic machine is increased to almost the maximum operating speed in response to the establishment of priming water pressure of the arbitrary type hydraulic machine or the start of the guide vane opening control. To do. The invention according to claim 4 is a variable speed hydraulic machine connected to one of a plurality of branch pipes branched from one hydraulic pipe communicating with the upper reservoir, and the remaining branch pipes. In a method of controlling operation of a variable speed hydraulic machine of a branch waterway system power plant including a hydraulic machine of any of the above described types, during the pumping operation of the variable speed hydraulic machine and the hydraulic machine of the arbitrary method, When the operation of the arbitrary type hydraulic machine is stopped, the rotation speed of the variable speed type hydraulic machine is decreased to almost the minimum operation speed in response to the start of the guide vane closing control of the arbitrary type hydraulic machine. To do.

[0015]

According to the invention described in claim 1, when both the variable speed type hydraulic machine and the arbitrary type hydraulic machine are in a power generating operation and the load of the arbitrary type hydraulic machine is interrupted or an emergency stop occurs, the Water pressure fluctuations occur in the branch pipes of hydraulic machines. This water pressure fluctuation propagates to the branch pipe of the variable speed hydraulic machine and increases the effective head of the variable speed hydraulic machine. Also,
Closing the guide vanes of a hydromachine with a load off causes a temporary surge in the flow rate of the variable speed hydromachine. Such a temporary increase in the effective head and a rapid increase in the flow rate act in the direction of making the hydraulic turbine output of the variable speed hydraulic machine excessive.

However, in order to avoid such a situation, the variable speed hydraulic machine has its rotational speed increased to almost the maximum operating speed in response to load shedding or an emergency stop of the arbitrary type hydraulic machine. At the same time, the guide vanes are closed to a predetermined opening, thereby reducing the turbine torque and preventing temporary overpower. After that,
When the water pressure fluctuations in the water channel due to load shedding or emergency stop have almost disappeared, the rotational speed and the guide vane opening of the variable speed hydraulic machine are respectively returned to predetermined operating points.

According to the second aspect of the present invention, when the variable-speed hydraulic machine and the arbitrary-type hydraulic machine are both in pumping operation and the input of the arbitrary-type hydraulic machine is interrupted or an emergency stop occurs, the arbitrary-type hydraulic machine is Water pressure fluctuations occur in the branch pipes of hydraulic machines. This water pressure fluctuation propagates to the branch pipe of the variable speed hydraulic machine, reduces the total head of the pump, and acts to make the pump shaft input of the variable speed hydraulic machine excessive. However, in order to avoid such a situation, the variable speed hydraulic machine is controlled so that its rotational speed is lowered to almost the minimum operational rotational speed in accordance with the input interruption or the emergency stop of the hydraulic machine of any method. Prevents excessive pump shaft input. After that, when the water pressure fluctuation in the water channel due to the input interruption or the emergency stop is almost disappeared, the rotation speed of the variable speed hydraulic machine is increased to a predetermined rotation speed.

According to the third aspect of the present invention, when the hydraulic machine of an arbitrary system starts the pumping operation during the pumping operation of the variable speed hydraulic machine, the flow rate of the penstock is increased by the start of the pumping operation of the hydraulic machine of the arbitrary system. , Which increases the friction loss in the water channel, and thus increases the total pump head of the variable speed hydraulic machine during the pumping operation. This increase in the total pump head acts in the direction of reducing the pumping amount of the variable speed hydraulic machine during the pumping operation. However, in order to avoid such a situation, the variable speed hydraulic machine has its rotational speed almost reached the maximum operating speed in response to the establishment of the priming hydraulic pressure of an arbitrary type hydraulic machine or the start of the guide vane opening control. Raised to prevent a reduction in pumping.

According to the fourth aspect of the present invention, when both the variable speed type hydraulic machine and the arbitrary type hydraulic machine are in the pumping operation and the arbitrary type hydraulic machine stops operating, the flow rate of the penstock decreases. , The total pump head of the variable speed hydraulic machine is reduced. This reduction in the total pump head acts in the direction of increasing the shaft input of the variable speed hydraulic machine. However, in order to avoid such a situation, the variable speed hydraulic machine has its rotational speed lowered to almost the minimum operating speed in response to the start of the guide vane closing control of the hydraulic machine of any method. To prevent an increase in shaft input.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an operation control method for a variable speed hydraulic machine of a branch waterway power plant according to the present invention will be described below with reference to FIGS. 1 to 8. In this embodiment, the present invention is applied to the general two-branch water storage system pumped-storage power plant shown in FIG. 8. In FIG. 8, one common hydraulic pipe 2 is connected to the upper reservoir 1 and The hydraulic pipe 2 is branched into a plurality of branch pipes 4a and 4b at a branch point 3 at the lower end thereof. A constant speed pump turbine 5a and a variable speed pump turbine 5b are connected to the branch pipes 4a and 4b, respectively, and the constant speed and variable speed pump turbines 5a and 5b are connected to the discharge channel 6a, 6b
Respectively connected to the lower reservoir 7.

Constant and variable speed pump turbines 5a, 5b
When the constant speed pump turbine 5a is unloaded while both of them are in the power generation operation, the water pressure of the branch pipe 4a of the constant speed pump turbine 5a greatly changes due to a water hammer phenomenon, and an unstable state occurs. Occurs transiently. 1 (a), (b)
And (c) show the rotation speed of the constant velocity pump turbine 5a, the water pressure of the branch pipe 4a, and the guide vane opening when the load is cut off, respectively. The water pressure fluctuation of the branch pipe 4a propagates to the branch pipe 4b of the adjacent variable speed pump turbine 5b via the branch point 3. Therefore, the water pressure in the branch pipe 4b of the variable speed pump turbine 5b also fluctuates greatly as shown in FIG.

Therefore, the constant speed pump turbine 5 is measured by measuring the water pressure fluctuation of the branch pipe 4a or 4b.
1 is detected, and the rotation speed N ₀ of the variable speed pump turbine 5b during the power generation operation is continued according to the detection result.
As shown in (e) of Fig. 1, the guide vane opening is increased at the same time as the operating maximum rotation speed Nmax is increased.
As shown in, closed to 50% opening.

When a predetermined time T ₁ elapses after the load is cut off and the fluctuation in water pressure subsides, the rotational speed N of the variable speed pump turbine 5b is reduced.
As shown in (e) of FIG. 1, the max is lowered to a predetermined rotation speed, for example, the original rotation speed N ₀ , and at the same time, the guide vane opening is set to, for example, as shown in (f) of FIG. Restore the original opening. The rotation speed and the timing of returning the guide vane opening can be determined by measuring the water pressure in the branch pipe and detecting the time when the water pressure fluctuations almost disappear, or the water pressure fluctuations disappear. Since the time required to do so is substantially constant according to the waterway configuration, it is also possible to measure the time lapse T ₁ from the occurrence of load shedding and determine it by this time measurement result.

FIG. 2 is a graph showing the power generation operation characteristics of the variable speed pump turbine 5b. The variable speed pump turbine 5b normally operates on the optimum operation curve L ₁ according to the output. When the effective head operating point P ₁ of the H ₀ and rotational speed N _0, the load shedding in Josokukatachi pump turbine 5a occurs, the effective head by this load shedding is increased in transiently H _1, if variable speed If the rotation speed and the guide vane opening of the model pump turbine 5b remain unchanged, the operating point of the variable speed pump turbine 5b shifts to P ₂ and the flow rate increases.
In order to avoid such a situation, as described above, the rotation speed of the variable speed pump turbine 5b is set to the maximum operation speed Nm.
The operating point is returned to P ₁ by increasing it to ax, and the operating point is further moved to P ₃ by closing the guide vane opening to 50% opening. Thus
It is possible to avoid an increase in the flow rate of the variable speed pump turbine 5b due to the load shedding of the constant speed pump turbine 5a, and it is possible to prevent over-output of the variable speed pump turbine 5b.

FIG. 3 shows the relationship between the rotational speed per unit head of the variable-speed pump turbine 5b, the turbine torque per unit head, and the guide vane opening. The operating points P ₁ and P ₂ are shown.
And P ₃ correspond to those in FIG. 2, and the operating point P
_{In No. 1} , the hydraulic turbine torque can be decreased by transiently moving to the operating point P ₂ due to the occurrence of load shedding and then immediately moving to the operating point P ₃ . In the above description, the case where the load is cut off is described as an example. However, the same is true when an emergency stop occurs due to an equipment accident or the like.

Further, in the above description, the constant speed type and variable speed type pump turbines 5a and 5b are combined. However, the present invention is not limited to this, and a combination of a variable speed pump turbine and a variable speed pump turbine is also possible. Further, if at least one is a variable speed turbine, It is also possible to combine a turbine with a pump turbine, or a combination of a turbine and a turbine if the operation is limited to power generation.

Next, a constant speed type and a variable speed type pump turbine 5
Constant speed pump turbine 5 when a and 5b are in pumping operation
The case where the input of a is blocked will be described. As shown in FIG. 4A, when the rotation speed of the constant speed pump turbine 5a is rapidly reduced, the guide vanes of the constant speed pump turbine 5a are suddenly stopped to stop the main engine. As a result, the water pressure in the branch pipe 4a of the constant velocity pump turbine 5a greatly changes due to the water hammer phenomenon as shown in FIG. 4 (b). Due to this fluctuation of water pressure, the water pressure of the branch pipe 4b of the variable speed pump turbine 5b also largely changes as shown in FIG. 4 (c). Due to the fluctuation of the water pressure in the branch pipe 4b, the total pump head of the variable-speed pump turbine 5b during the pumping operation is transiently reduced, and the pump shaft input is temporarily excessive. Therefore, in order to avoid such a situation, the input cutoff of the constant speed pump turbine 5a is detected by measuring the water pressure fluctuation of the branch pipe 4a or 4b, and the pumping operation is being continued according to the detection result. The rotation speed of the variable-speed pump turbine 5b is decreased to the minimum operation rotation speed as shown in FIG. 4 (d). As a result, the increase in pump shaft input can be suppressed to a minimum.

When the water pressure fluctuation has subsided after a lapse of a predetermined time T ₂ from the input interruption, the rotation speed of the variable speed pump turbine 5b is changed to a predetermined rotation speed as shown in FIG. Increase to rotation speed. The timing of the increase in the rotation speed can be set, as described above, by measuring the water pressure in the branch pipe, or by measuring the elapsed time from the occurrence of load shedding. In the above description, the case where the input cutoff occurs has been described as an example. However, the same is true when an emergency stop occurs due to an equipment accident or the like.

Next, the case where the constant speed pump turbine 5a starts the pumping operation while the variable speed pump turbine 5b is in the pumping operation will be described. When the constant velocity pump turbine 5a starts the pumping operation, the flow rate of the common hydraulic pipe 2 increases, and accordingly the hydraulic friction loss of the hydraulic pipe 2 increases. As a result, the total pump head of the variable speed pump turbine 5b during the pumping operation increases, the amount of pumped water decreases, and the operating efficiency of the pumped storage power plant decreases.

Therefore, in order to avoid such a situation, when the pumping start condition of the constant speed pump turbine 5a is satisfied, for example, as shown in FIG. At the start of the guide vane opening control, or at the time of establishing the priming water pressure of the constant speed pump turbine 5a as shown in FIG. 5B, the rotation speed of the variable speed pump turbine 5b during the pumping operation is shown. As shown in (c) of 5, the operating maximum rotation speed is increased. Along with this, the pumping volume of the variable speed pump turbine 5b also increases as shown in FIG. 5 (d). Such operation control will be described from the viewpoint of hydraulic characteristics of the pump turbine using FIG.

[0031] Figure 6 shows a part of the hydraulic characteristics of the pump operation of the variable speed pump-turbine 5b, the variable speed pump-turbine 5b during pumping operation initially operating at the operating point P ₄ If the constant speed pump turbine 5a starts pumping operation after that, if the rotation speed of the variable speed pump turbine 5b is unchanged, the operating point of the variable speed pump turbine 5b is P
It moves to ₅ , and the amount of pumped water decreases. Therefore, when the rotation speed of the variable speed pump turbine 5b is increased to the operation maximum rotation speed, the variable speed pump water turbine 5 moves to the operating point P ₆ through the locus A and increases the pumping amount.

Next, a constant speed type and a variable speed type pump turbine 5
Constant speed pump turbine 5 when a and 5b are in pumping operation
The case where a stops driving will be described. During the pumping operation of the constant speed and variable speed pump turbines 5a and 5b, a stop command for the constant speed pump turbine 5a is generated, and the guide of the constant speed pump turbine 5a is generated as shown in FIG. When the vanes are closed, the hydraulic losses in the canals are reduced, the total pump head is reduced and the pump shaft input is increased. Therefore, in order to avoid such a situation, the rotation speed of the variable speed pump turbine 5b is set to the minimum operation speed as shown in FIG. 7B in response to the stop command of the constant speed pump turbine 5a. Lower to rotation speed. Along with this, the pump shaft input of the variable speed pump turbine 5b decreases as shown in FIG. 7 (c).

Such operation control will be described from the viewpoint of hydraulic characteristics of the pump turbine with reference to FIG. Let P _{5 be} the operating point of the variable speed pump turbine 5b when both the constant speed and variable speed pump turbines 5a and 5b are in the pumping operation. When the operation of the constant speed pump turbine 5a is stopped, if the rotation speed of the variable speed pump turbine 5b is not changed, the operating point of the variable speed pump turbine 5b moves to P ₄ , and the pump shaft input increases. Will end up. Therefore, as described above, the variable speed pump turbine 5a is operated in response to the stop command of the constant speed pump turbine 5a.
When the rotation speed of b is lowered to the operation minimum rotation speed, the operating point of the variable speed pump turbine 5b moves to P ₇ through the locus B, the pump shaft input decreases, and the influence on the power system is minimized. You can hold it down.

The control method during the pumping operation described above is for the combination of the constant speed type and variable speed type pump turbines 5a and 5b. However, the present invention is not limited to this, and may be a combination of a variable speed pump turbine and a variable speed pump turbine, and if at least one is a variable speed combination, Also, a combination of pumps and pumps is possible. Furthermore, the above-described embodiment is one in which the present invention is applied to a general two-branch waterway system pumped storage power plant. However, the present invention can be applied to a power plant having three or more branch pipes by connecting a variable speed hydraulic machine to at least one branch pipe.

[0035]

As is apparent from the above description, according to the invention described in claim 1, even when a part of a plurality of hydraulic machines during power generating operation is subjected to load interruption or emergency stop, the branch pipe is provided. It is possible to prevent the output of the hydraulic turbine of the hydraulic machine from being excessively large due to the fluctuation of the water pressure, and to efficiently perform the power generation operation. According to the invention described in claim 2, even when a part of the plurality of hydraulic machines during the pumping operation is shut off or an emergency stop occurs, the pump shaft input of the hydraulic machine is excessive due to the fluctuation of the hydraulic pressure in the branch pipe. Can be prevented and the pumping operation can be performed efficiently. According to the invention described in claim 3, even when another hydraulic machine starts the pumping operation during the pumping operation of a certain hydraulic machine, the reduction of the pumping amount of the hydraulic machine due to the increase of the total pump head is prevented. Therefore, the pumping operation can be efficiently performed. According to the invention described in claim 4, even when a part of the plurality of hydraulic machines during the pumping operation is stopped, the increase of the shaft input of the hydraulic machine due to the reduction of the total pump head is prevented. The pumping operation can be performed efficiently.

[Brief description of drawings]

FIG. 1 is a timing chart showing a control state during power generation operation of an embodiment of an operation control method for a variable speed hydraulic machine of a branch waterway system power plant of the present invention.

FIG. 2 is a graph showing the relationship between the rotation speed per unit head and the flow rate per unit head of the variable speed hydraulic machine.

FIG. 3 is a graph showing the relationship between the rotation speed per unit head and the torque per unit head of the variable speed hydraulic machine.

FIG. 4 is a timing chart showing the control state during the pumping operation of the above embodiment.

FIG. 5 is a timing chart showing a control state during the pumping operation of the above embodiment.

FIG. 6 is a graph showing the relationship between the total head and the shaft input or the pumping amount during the pumping operation of the variable speed hydraulic machine.

FIG. 7 is a timing chart showing the control state during the pumping operation of the above embodiment.

FIG. 8 is a schematic diagram showing a waterway of a general two-branch pumped storage power plant.

[Explanation of symbols]

1 upper reservoir 2 penstock 4a Branch pipe 4b Branch pipe 5a Constant speed hydraulic machine 5b Variable speed hydraulic machine

Claims (4)

(57) [Claims] 1. A variable speed hydraulic machine connected to one of a plurality of branch pipes branched from one hydraulic pipe connected to an upper reservoir, and an arbitrary hydraulic pipe connected to the remaining branch pipes. In a method for controlling operation of a variable speed hydraulic machine of a branch waterway system power plant including a hydraulic machine of the method, a hydraulic power of the arbitrary method is generated during power generation operation of the variable speed hydraulic machine and the hydraulic machine of the arbitrary method. When the machine has a load shedding or an emergency stop, the rotation speed of the variable speed hydraulic machine is increased to almost the maximum operating speed and the guide vanes are closed to a predetermined opening.
After that, when the water pressure fluctuations in the water channel due to the load shedding or the emergency stop have almost disappeared, the rotation speed and the guide vane opening of the variable speed hydraulic machine are respectively returned to predetermined operating points. Operation control method for variable speed hydraulic machines in hydropower stations. 2. A variable speed hydraulic machine connected to one of a plurality of branch pipes branched from one penstock communicating with the upper reservoir, and an arbitrary hydraulic pipe connected to the remaining branch pipes. In the operation control method of the variable speed hydraulic machine of the branch waterway system power plant including the hydraulic machine of the method, in the pumping operation of the variable speed hydraulic machine and the hydraulic machine of the arbitrary method, the hydraulic power of the arbitrary method is used. When the machine cuts off the input or makes an emergency stop, the rotation speed of the variable speed hydraulic machine is controlled to a minimum operation speed, and then the water pressure fluctuations in the water channel due to the cut-off of the input or an emergency stop almost disappeared. A method of controlling the operation of a variable speed hydraulic machine of a branch waterway power plant, wherein the rotational speed of the variable speed hydraulic machine is increased to a predetermined rotational speed. 3. A variable speed hydraulic machine connected to one of a plurality of branch pipes branched from one penstock communicating with the upper reservoir, and an arbitrary hydraulic pipe connected to the remaining branch pipes. In the operation control method of the variable speed hydraulic machine of the branch waterway system power plant including the hydraulic machine of the method, when the hydraulic machine of the arbitrary method starts the pumping operation during the pumping operation of the variable speed hydraulic machine. , A branching hydropower plant characterized by increasing the rotation speed of the variable speed hydraulic machine to almost the maximum operating speed in response to establishment of priming water pressure of the arbitrary type hydraulic machine or start of guide vane opening control. Variable speed hydraulic machine operation control method. 4. A variable speed hydraulic machine connected to one of a plurality of branch pipes branched from one penstock connected to the upper reservoir, and an arbitrary hydraulic pipe connected to the remaining branch pipes. In the operation control method of the variable speed hydraulic machine of the branch waterway system power plant including the hydraulic machine of the method, in the pumping operation of the variable speed hydraulic machine and the hydraulic machine of the arbitrary method, the hydraulic power of the arbitrary method is used. A branch waterway system characterized in that, when the machine stops operating, the rotational speed of the variable speed hydraulic machine is lowered to almost the minimum operating speed in response to the start of guide vane closing control of the hydraulic machine of the arbitrary method. Operation control method for variable speed hydraulic machine at power plant.