JPS63113181A - Operation control method at pumped storage power station shutdown - Google Patents

Abstract

PURPOSE:To enable quick and proper interrupt control in shutting down each machine under parallel operation for pumping and power generation by turning each machine to a parallel-off condition when an input/output difference or a difference between power received by a pumping-up machine and output from a power generating machine has reached a predetermined level. CONSTITUTION:Pump input 8, hydraulic turbine output 9 and pump shutdown instruction 10 are inputted to an operation device 11. And an input/output difference 12 is compared with a set value DELTAP, and when the difference 12 is equal to or less than -DELTAP, a hydraulic turbine guide vane is subjected to an opening operation. When the absolute value of the difference 12 is less than DELTAP, a hydraulic turbine and a pump are put to a parallel-off condition 14 and the hydraulic turbine guide vane is turned to closure 15. On the other hand, a pump guide vane starts a close operation 46 according to the pump shutdown instruction 10, the hydraulic turbine comes to a rest 17 and the pump also comes to a rest 18. When the difference 12 is equal to or longer than DELTAP, the hydraulic turbine guide vane gives a close operation 19. According to the aforesaid constitution, the pump and the hydraulic turbine prevent the fluctuation of an electric power to a system and enable quick and proper interrupt control.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Field of Application) The present invention relates to a method for controlling the operation of a pumped storage power plant, and particularly relates to a method for controlling the operation of a pumped storage power plant, and particularly to a method for controlling the operation of a pumped storage power plant that has a pump turbine or a pump and a water turbine under its control. This invention relates to a method for controlling the operation of a machine when it is stopped.

(Prior art) It has been considered to perform pump operation and water turbine operation at the same time in a branch water pumped storage power plant (Japanese Patent Laid-Open No. 6O-3048
1) However, no control method has been announced so far regarding how to stop it.

In a pumped storage power plant equipped with a synchronous generator that performs power generation operation and a synchronous motor that performs pumping operation, it is conceivable to use the same stopping method as in the case of only conventional pumps, but in this case, As illustrated in FIG. 6(a), the pump stop command starts the closing operation of the pump guide vane opening 1 or the water turbine guide vane opening 2, and the guide vane reaches the preset opening. At time T2, the electric motor is disconnected from the system and the water turbine guide vanes are closed. In this case, the pump rotation speed 3 and the water turbine rotation speed 4 change as shown in the same figure (b), and the pump human power 5, the water turbine output 6, and the input/output difference 7 between the pump and the water turbine change as shown in the figure (b).
c), and the water turbine is disconnected from the system at time T3.

In such control, operation is controlled regardless of the synchronous motor and synchronous generator that are operating at the same time.

(Problems to be solved by the invention) By the way, pumped storage power plants can
It is constructed for the purpose of maintaining the balance of electricity supply and demand by generating electricity or pumping water. Therefore, it is necessary to operate according to the output or input required by the power system.

When operating a pumped storage power plant with a water turbine, the output can be easily adjusted by changing the guide vane opening.
During pump operation, even if the guide vane opening degree is changed, the input hardly changes due to the inherent characteristics of the pump-turbine and the pump, making it impossible to accurately respond to the input required by the power system.

In other words, when stopping the pump, control is started from approximately the maximum human power value of the pump supplied from the system, the guide vane is closed, and the pump system is closed with the guide vane fully open or at a previously set opening close to fully open. Because disassembly is performed from the beginning, it has a large impact on the system. Furthermore, the conventional technology has the disadvantage that it is not possible to control the difference in input and output to the system of the pumped storage power plant at the time when the pumps are disconnected.

Therefore, the purpose of the present invention is to prevent power fluctuations in the grid, suppress transient rotational increases when hydraulic machines are stopped, minimize water pressure fluctuations in penstocks, and stop hydraulic machines quickly and accurately. An object of the present invention is to provide a method for controlling operation during stoppage.

[Structure of the invention]

(Means for Solving the Problems) The present invention has been devised against the background as described above. When stopping each machine from an operating state in which pumping operation by the pump and power generation operation by the water turbine are performed in parallel, the pumping operation machine receives power from the grid, and the generator operation machine inputs the power supplied to the grid. The guide vane opening degrees of the pumping storage operating machine and the generating operating machine are controlled so as to reduce the output difference with gradual changes, and the input/output difference is sufficiently small relative to the system capacity, and the disconnection causes a large voltage to be applied to the grid. The pumping storage operating machine and the generating operating machine are disconnected from the system when a predetermined value is reached within a range that does not cause fluctuations or frequency fluctuations, and the guide vane openings of the pumping storage operating machine and the generating operating machine are adjusted. It is characterized by reaching full throttle.

(Function) According to the method of the present invention configured as described above, the pump-turbine or the pump and the water-turbine are simultaneously operated with the input/output difference to the arbitrarily selected system, and the pump-turbine or the pump being operated is The water turbines can be quickly controlled to stop each hydraulic machine by preventing power fluctuations to the grid, suppressing transient rotational increases when the hydraulic machines are stopped, and minimizing water pressure fluctuations in the penstock. Can be done accurately.

(Embodiment) FIG. 1 shows an example of a sequence diagram of control according to the present invention.

The pump power 8 and the water turbine output 9 are input to the arithmetic unit 11 along with the pump stop command 10. Pump input 8 and water turbine output 9
The input/output difference 12 is compared with a preset value ΔP as shown in FIG. 2, and if the input/output difference is less than 1 ΔP, the water turbine guide vane is opened 13. Further, if the absolute value of the input/output difference is smaller than ΔP, the water turbine and the pump are disconnected from the system (14), and the water turbine guide vanes are closed (15).

On the other hand, in response to the pump stop command 10, the pump guide vane starts a closing operation 16. As a result, the water wheel stopped17,
The pump also stops 18.

FIGS. 3(a) to 3(c) show temporal changes in the GV opening degree, rotation speed, and input/output difference in the control according to the present invention.

Note that when the input/output difference is greater than or equal to ΔP, the guide vane of the water turbine performs a closing operation 19.

As is clear from this figure, if the pump input side and the water turbine power generation side are connected when the pump and the water turbine are disconnected from the system, the rotational speeds of both machines will be decelerated synchronously. In addition, in Fig. 4, 20 is a water wheel, 21 is a pump, and 2
2 is a synchronous generator, 23 is a synchronous motor, 24, 25.26
．． 27°28 indicates a switch.

In the method of the present invention having such a configuration, when the switches 27 and 28 are opened at time T2 in FIG. 3 and the pumps and turbines are uncoupled, the synchronous motor 23 and the synchronous generator 22 are If they are connected in parallel by the switch 26, both machines will rotate synchronously, and as shown in FIG.
After that, the guide vanes of the water wheel and the pump are closed, so that the pump and the water wheel are decelerated synchronously.

Further, as illustrated in FIG. 5, a branch pipe 31. Branch 32,
A pump 34 and a water turbine 3 are installed between these branch pipes and the lower pond 33.
5. Install these pumps.

A generator 36 and an electric motor 37 were connected to each of the water turbines.

By performing the stop control as shown in Fig. 3 at the branch water pumped storage power plant, the branch pipe 31 due to the stop control of hydraulic machinery is
．． By superimposing the rising water pressure wave 38 and the falling water pressure wave 39 in the penstock 30, it becomes possible to reduce changes in water pressure in the penstock 30.

That is, as described above, in the method of the present invention, as shown in the sequence diagram of FIG.
When a command to stop the pump and water turbine is received at , the pump guide vane 1 starts a closing operation. At this time, since the input/output difference is smaller than 1 ΔP, the water turbine guide vane 2 performs an opening operation.

On the other hand, since the pump and the water turbine are connected in parallel, and both machines are connected in parallel to the system, their rotation speed of 3°4 is the same as the time T2.
It remains constant until

Pump guide vane closing 1, pump guide vane opening 2
Therefore, the input/output difference quickly becomes zero.

Even if both machines are disconnected at this point, the impact on the grid is almost negligible. On the other hand, the branched penstocks 31 and 3
It is safe to assume that the lengths of 2 are generally approximately equal, so
As shown in Fig. 5, the transient water pressure change caused by the sudden closure of the guide vane is caused by a water pressure rising wave 38 and a water pressure falling wave 39 on the penstock 3.
0 almost simultaneously, the pressure change in the pressure wave 40 inside the penstock 30 is significantly small. In reality, the propagation speed of sound waves underwater is about 1000 m/s, and even though the difference in length between the branch penstocks 31 and 32 is 1000 m,
The transmission time difference of the pressure waves to the branch point is about 1 sec, and the effect of the water pressure change phenomenon due to the superposition of the pressure waves 38 and 39 can be fully realized.

〔Effect of the invention〕

As described above, pumps and water turbines are controlled to stop in a short time based on freely set input/output differences, without affecting the system, without increasing rotation speed, and with water pressure changes kept to a minimum. can.

[Brief explanation of the drawing]

Fig. 1 is a sequence diagram of the present invention, Fig. 2 is an example of stop control of a pumped storage power plant, Fig. 3 is a graph of the operation of the pump of the present invention, and Fig. 4 is an example of stop control to which the present invention is applied. 4 is a power system diagram, FIG. 5 is a system diagram illustrating a branch water pumped storage power plant, and FIG. 6 is an explanatory diagram of the water hammer phenomenon. is an explanatory diagram of the setting input/output difference Δp. 1... Pump guide vane opening degree, 2... Water wheel guide vane, 20... Water turbine, 21... Pump, 22...
Synchronous generator, 23...Synchronous motor, 24.25,26
゜27.28...Switch, 29...Kamiike, 30...
・Water penstock, 31. 32... Branch water penstock, 33...
・Lower pond, 34...Waterwheel, 35...Pump, 36...
・Electric motor, 37... Generator.

Claims (1)

[Claims] 1. In a pumped-storage power plant in which a pump-turbine or a pump and a water-turbine are under its control, each machine is When stopping the pumping storage operating machine and the generating operating machine, guide the pumping storage operating machine and the generating operating machine so that the input/output difference between the power that the pumping storage operating machine receives from the grid and the power that the generating operating machine supplies to the grid is gradually reduced. The pumping operation is started when the vane opening degree is controlled and a predetermined value is reached, as long as the input/output difference is sufficiently small relative to the system capacity and the disconnection does not cause large voltage fluctuations and frequency fluctuations to the system. 1. A method for controlling the operation of a pumped storage power plant during stoppage, the method comprising disconnecting the pumping storage operating machine and the generating operating machine from the system, and fully closing the guide vane openings of the pumping storage operating machine and the generating operating machine. 2. After disconnecting the pumping storage operating machine and the generating operating machine from the grid,
2. The method for controlling the operation of a pumped storage power plant during stoppage according to claim 1, characterized in that the motor input side of the pumped storage operating machine and the generator output side of the generator operating machine are connected. 3. Before disconnecting the pumping storage operating machine and the generating operating machine from the grid,
2. The method for controlling the operation of a pumped storage power plant during stoppage according to claim 1, characterized in that the motor input side of the pumped storage operating machine and the generator output side of the generator operating machine are connected.