JPS63212773A - Transient operation control method for branch aqueduct pumped storage power station - Google Patents

Abstract

PURPOSE:To prevent the electric power fluctuation in an electric power system by detecting the rotating speed or voltage of a failed machine, controlling to close guide vanes, and dissociating the failed machine from the electric power system. CONSTITUTION:When an emergency stop protective device 13 is operated, if the detected value of the rotating speed or voltage of a failed machine is outside an allowable range, the failed machine is dissociated 76. At the same time, a command is sent to a function generator 65 on the sound machine side, the sound machine is also dissociated 77, and guide vanes 70, 71 are closed and inlet valves 72, 73 are closed to stop the failed machine and the sound machine. Accordingly, the electric power fluctuation on an electric power system is reduced.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Field of Application) The present invention is directed to a branch channel pumped storage power plant where water turbine power generation operation and pump pumping operation are performed simultaneously. A transient axis control method for a branch waterway pumped storage power plant that smoothly disconnects the accidental aircraft from the power system while suppressing disturbances to the power system and effects on the waterway system when an accident occurs on one of the aircraft. Regarding.

(Prior Art) In recent years, hydroelectric power plants have generally been constructed as pumped storage power plants that have a function not only for supplying electricity but also for recovering surplus power during low loads.

As illustrated in FIG. 5, this pumped storage power plant consists of a plurality of (in this example, two
The branch pipes 3a and 3b of the main pipe are branched, and the lower ends of these branch pipes are connected to pump-turbines, pumps, or water turbines (hereinafter referred to as pump-turbines) 4a and 4b, and the discharge pipe sides of these pump-turbines are connected to the lower ends of these branch pipes. It is often constructed as a branch water pumped storage power plant in which the downstream side of the branch pipes 5a and 5b connected to the lower pond 7 is connected to the lower pond 7 via a common spillway 6.

In Fig. 5, 8a and 8b indicate generator motors, generators, or electric motors (hereinafter referred to as generator motors) that are directly connected to the pump water turbines 4a and 4b, and their power terminals receive power via local lines 9a and 9b. It is connected to system 10. Motive for migraine 8a.

8b has a rotational speed detection device 11 and a voltage detection device 1, respectively.
2 and an emergency stop protection device 13 are installed,
Local line 9a * 9b has power grid 10
Output detection devices 14a and 14b are attached to detect the input from and the output to the power system.

The above pump-turbine 4a, 4b (hereinafter referred to as pump-turbine 4a, 4
If it is common to b, the suffixes a and b are removed and the common code 4 is displayed. The same applies to other symbols. )
A guide vane is installed in the guide vane, and its control is performed by a device illustrated in FIG.

That is, the guide vane opening detector 21 detects the opening of the guide vanes 20 rotatably arranged and supported around the pump water turbine 40 launch (not shown), and the rotational speed of the generator motor 8 is detected by the rotational speed detection. It is detected by the device 11.

The output of this rotation speed detection device and the output of the output setting device 22 are guided to the governor calculation section 23 to calculate an appropriate guide vane opening degree, and the output and the guide vane opening degree detector 2
1 is input to the comparator 24 to find the deviation between the two, and this deviation signal is amplified by the amplifier 25, and then the servo motor (
(not shown) and controls the opening degree of the water port of the guide vane 20 in conjunction with it.

In a branch channel pumped storage power plant configured as a double series, when the frequency of the power system 10 decreases, the guide vane opening command value from the governor calculation unit 23 is changed in the opening direction in order to recover the frequency. The output of the pump water turbine 4 is increased. Moreover, when the frequency of the power system 10 increases, the guide vane opening degree command value is increased in the closing direction, contrary to the above, and the output of the pump water turbine 4 is decreased.

By the way, in the power generating operation of a pump-turbine, the output can be adjusted by changing the guide vane opening, but in the pump-pumping operation of a pump-turbine, even if the guide vane opening is changed, the Due to its inherent characteristics, the input hardly changes and cannot appropriately respond to the input required by the power system.

Therefore, in pumped storage power plants with multiple pump turbines,
One or more pump turbines are operated for pumping water,
The difference between the input power and the power required by the power system is offset by operating the remaining pump turbines to generate power.
A method has been proposed to match the input value of the entire pumped storage power plant with the power system required input value (Japanese Patent Laid-Open No. 129478/1983).
issue).

As mentioned above, it is known that pump pumping operation and water turbine power generation operation are performed in parallel in a branch channel pumped storage power plant equipped with multiple pump turbines, but there is currently no control method that takes into account how to stop them. I can't find it there.

For example, as shown in FIG. 7, during pump pumping operation 30, an emergency stop 1- or a sudden stop protection device is triggered due to a drop in the frequency of the power system, an undervoltage in the generator motor, or a low oil pressure in the pressure oil tank. When the operation 31 is performed, the matching unit 32 satisfies the AND condition, the parallel circuit breaker is opened 33, the speed governor is opened 34, and the inlet valve is closed 35, and the field circuit breaker is opened 36 and the guide vane is fully closed 37. , passes through the joint part 38, and if the rotational speed of the pump turbine is equal to or lower than the specified value 39, the AND condition of the joint part 40 is satisfied, the main engine is stopped by the brake operation 41, and then the stop of the main engine is confirmed 42. A control method in which brake release 43 is performed is known.

In addition, as shown in Fig. 8, if a weak point pin (not shown) is cut off due to foreign matter getting caught between the guide vanes of the pump-turbine during pump pumping operation or hydroturbine power generation operation,
The weak point pin breakage detection relay (a) turns on, and after a predetermined time lag, the weak point pin breakage stop relay (b) turns on, and the guide vane (d) begins to close from its previous proper opening, causing the guide vane to close. It is also known to turn off the circuit breaker (c) when both the inlet valve (d) and the inlet valve (e) reach a specified opening degree, disconnect the main engine from the power system, and then stop the main engine.

In the control methods shown in Figures 7 and 8, appropriate consideration is given to the disconnection and stop timing of the pump-turbine from the power system during pump pumping operation.
The water turbine generator operating machine that is in simultaneous operation will be controlled to stop regardless of the operating state of the pump pumping operating machine.

(Problems to be Solved by the Invention) As mentioned above, pumped storage power plants are designed to maintain the power supply and demand balance in the power system by performing water turbine generation operation or pump pumping operation according to the power system supply and demand conditions. Since it is constructed, it is required to operate according to the output and input required by the power grid.

However, in a branch channel pumped-storage power plant where multiple pump-turbines are connected to a branch pipe connected to one penstock, some of the pump-turbines are operated for pumping, and all or part of the remaining pump-turbines are operated. When a water turbine is in power generation operation, if an accident occurs in one of the pump turbines during pump pumping operation or water turbine power generation operation and the emergency stop or sudden stop protection device is activated, the conventional control method Because the main engine was stopped by quickly closing the guide vanes and inlet valves of the operating machine or the pump pumping machine, it was not possible to control the difference in input and output power between the power grid and each main engine. Since the system rapidly shifts to closed control on its own, there is concern that vibration and water pressure fluctuations may have an adverse effect on the strength of the hydraulic machine, and especially if the hydraulic excitation frequency matches the natural frequency of the penstock or branch pipe, resonance may occur. There was a risk that this phenomenon would occur and the pipelines etc. would be exposed to damage.

(Object of the Invention) The present invention has been made to eliminate the above-mentioned drawbacks in the background art. In a place where some of the pump-turbines are operated for pumping water and other pump-turbines are operated for power generation, if it becomes necessary to stop the pump-turbines for some reason, the power to the power system is interrupted. Transient for branch channel pumped-storage power plants that prevents oscillations, suppresses transient rotational increases when pump-turbines are stopped, and quickly and reliably stops each pump-turbine while minimizing water pressure fluctuations in the penstock pipeline. The purpose of the present invention is to provide a method for controlling operation.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above-mentioned object, the transient operation control method of a branch channel pumped storage power plant according to the present invention provides a method for controlling transient operation of a branch channel pumped storage power plant. In a branch channel pumped-storage power plant consisting of several branch pipes, with a pump-turbine or a water turbine and a pump connected to each branch pipe, some of the pump-turbines or pumps perform pumping operation, and all or part of the remaining pumps operate. If an accident occurs on either side of the pump pump operation machine or the water turbine generator operation machine during steady operation when the water turbine or the water turbine power generation operation is being carried out simultaneously in parallel, the rotational speed and voltage of the accident machine is detected, and if one or both of them are within the allowable values, a control signal is transmitted to the accident aircraft to close the guide vane or inlet valve, and the control signal is also transmitted to the healthy aircraft to stop the pump pumping. Controlling the closing of the guide vanes or inlet valves of the sound machine in parallel so that the relative input/output difference between the power that the driving machine receives from the power system and the power that the water turbine generator driving machine supplies to the power system does not suddenly change; After the guide vanes or inlet valves of the accident aircraft and the sound aircraft reach a predetermined small opening or full opening, the accident aircraft and the sound aircraft are disconnected from the power system and stopped.

(Function) In the device of the present invention configured as described above, the state value of the rotational speed or voltage is input to the function generator and compared with a set value (tolerable value) set and stored in advance.
On condition that the input value is below the allowable value and the signal from the emergency stop protection device is input to the function generator, a signal is output to close the inlet valve and guide vane of the accident aircraft. At the same time, the signal from the function generator of the accident aircraft is manually input to the function generator of the healthy aircraft, and the relative input/output difference is compared with the tolerance value, and the input/output relative difference is within the tolerance value. A control signal is output, and the guide vane and inlet valve begin to close in parallel with the accident aircraft. During the shutdown operation of the accident aircraft and the healthy aircraft, the healthy aircraft will be controlled to shut down gradually to prevent sudden changes in the relative difference between input and output to the power system, and the accident aircraft will have its guide vanes or inlet valves open to the specified small or full opening. When this happens, it will be disconnected from the power grid and shut down.

(Example) Next, an example in which the present invention is applied to a branch water pumped storage power plant having the same configuration as that shown in FIG. 5 will be described.

In FIG. 1, the output of the rotational speed detection device 11 is converted into a signal through the signal conversion device 50, and then guided to the matching section 52 together with the setting value from the rotational speed setting device 51, and the deviation value is a function of the accident aircraft side. The signal is input to the generator 53. The output of the voltage detecting device 12 also passes through the signal converting device 54 and is led to the matching section 56 together with the set value from the voltage setting device 55, and the deviation value is inputted to the function generating device 53.

The signal from the emergency stop protection device 13 is also transferred to the signal conversion device 57.
The signal is input to the function generator 53 via the .

If the signal from the signal converter 50.54 is within a preset tolerance value, the function generator 53 directs the signal to the inlet valve and guide vane controller 58, subject to the presence of a signal from the emergency stop protection device 13. produces an output.

On the other hand, the outputs of the output detection device 14 and the human power detection device 15 are also converted into signals through signal conversion devices 60 and 61, respectively, and then a relative difference between input and output is calculated in a combination unit 62. This input/output relative difference is compared with the setting value from the input/output relative difference setting device f64 in the matching section 63, and the deviation value thereof is input to the function generating device 65 on the healthy machine side. Function generator 6
5 is an inlet valve and guide vane control device 6 on the condition that there is an input from the function generator 53 and the coupling part 63.
It produces an output towards 6.

Inlet valve and guide vane controls 58,66 are PID
It consists of an arithmetic unit, a converter, a governor, a servo motor, etc. (all not shown), and a function generator 53 or 65
When a signal is input from the guide vanes 70, 71,
When the inlet valve is instructed to close (72.73) and the guide vane or inlet valve reaches the predetermined small opening or full opening (74.75), the accident aircraft is destroyed.

After all aircraft were disconnected from the power grid 76.77, they were stopped 78.
Make it 79.

In the branch water pumped storage power plant configured as described above, if the emergency stop protection device 13 is activated due to an internal failure of the main transformer, a drop in oil pressure in the pressure oil tank, a rise in temperature of the bearing, or breakage of the guide vane, etc. , a signal indicating this is input to the function generator 53 via the signal converter 57.

The function generator 53 compares and calculates whether or not the detected value of the rotational speed or voltage of the accident aircraft is within a preset allowable value based on the signal input from the emergency stop protection device 13, and determines whether the detected value is within the allowable value. If it is within the value, the inlet valve and guide vane control device 58 are activated by the output signal from the function generator 53, and the guide vane closing 70 and Muro valve closing 72 operations are performed without disconnecting the accident aircraft from the power system. Start.

On the other hand, the output signal of the function generator 53 is also input to the function generator 65 of the healthy machine, and on condition of this input, the function generator 65 generates an output signal such that the relative input/output difference between the healthy machine and the accident machine does not change suddenly. Inlet valve and guide vane control device 6
6. The inlet valve and guide vane control device 66 controls the opening of the inlet valve and guide vane.
Closing speed control 71.73 is the closing operation on the accident aircraft side 70.72
and = IIli lines.

When the guide vane or inlet valve of the accident aircraft reaches a specified small opening or full opening, the accident aircraft is disconnected 76 from the power system and brought to a halt 78. At the time of this disconnection, the absolute input and output values of the accident aircraft have become sufficiently small, so the impact on the power system is extremely small.

In addition, controlling a healthy machine so that the relative input-output difference does not change suddenly means that the difference between the water pumped by the pump pump operation machine and the water turbine flow rate of the water turbine generator operation machine is small, as shown in Figure 2. , the difference between the water pressure rising wave 81 of the water turbine generator operating machine and the water pressure decreasing wave 82 of the pump pumping operating machine is also small.

Usually, branch pipes 3a and 3b in a branch water pumped storage power plant
Since the path lengths of are almost the same, these water pressure rising waves 81
and the water pressure drop wave 82 are superimposed and synthesized in substantially the same phase, and the water pressure fluctuation of the pressure wave 83 propagating in the penstock pipe 2 is small. As a result, the main engine is kept under stable conditions by matching the hydraulic excitation frequency caused by water pressure fluctuations and the vibration frequency of the hydraulic pipe 2 or the branch pipes 3a and 3b, that is, by avoiding the occurrence of resonance phenomena. It can be stopped with .

Note that at the time of disconnection of the power system for the generator motors ga and 8b, the opening degrees of the guide vanes and inlet valves of the pump pump operation machine and the water turbine generator operation machine are at the specified small opening or fully open state, and the amount of water pumped and the flow rate of the water turbine are are both small, so even if the pumps are disconnected from the series, the increase in rotation of the pump pumping operation machine and the water turbine generator operation machine can be suppressed to a small extent, and the ineffective discharge of water from the water turbine generator operation machine can also be suppressed to a minimum.

In FIG. 1, when the emergency stop protection device 13 is activated and a stop command is issued to the accident aircraft, the function generator 53 determines whether the rotational speed and voltage of the accident aircraft are within allowable values. However, if either or both of the rotational speed voltages exceeds the permissible value, the accident aircraft is immediately decoupled 76 as shown in FIG. 3 (corresponding to claim 2). A command is also sent to the function generator 65 on the healthy machine side, and the healthy machine is also immediately decoupled 77. After that, the guide vanes of the accident machine and the healthy machine are closed 70, 71 by the inlet valve and guide vane control devices 58, 66. , inlet valve closed 72.73
to stop as

In this way, if the impact of the accidental aircraft on the power grid exceeds the allowable value, the impact on the power system can be suppressed by disconnecting the healthy aircraft as well as the accidental aircraft from the power grid at the same time. .

FIG. 4 shows another embodiment of the method of the present invention (claim 3).
When the emergency stop protection device 13 is activated and a command to stop the accident aircraft is issued, the function generator 53 determines whether the rotation speed or voltage of the accident aircraft is below the allowable value. If one or both of them exceed the allowable value, a command is sent from the function generator 53 to the function generator 65 to immediately disconnect the healthy machine 77, and after that, the inlet valve and guide After the accident aircraft and the healthy aircraft are stopped in parallel by the vane control devices 58 and 66, and the guide vanes or inlet valves of the accident aircraft become slightly open or fully open 74,
The accident aircraft is disarranged 76 and stopped 78.

In this example, if the rotational speed or voltage of the accidental machine exceeds the allowable value, the healthy machine whose rotational speed and voltage are almost equal to those of the power grid is first disconnected from the power grid, and the faulty machine is closed to the no-load opening level. After closing, it is disconnected from the power grid, so power fluctuations in the power grid can be kept to a minimum.

[Effects of the Invention] As described above, in the transient operation control method for a branch channel pumped storage power plant of the present invention, if an accident occurs on either side of the pump pumping operation machine or the water turbine generator operation machine during steady operation, In this case, the rotational speed and voltage of the accident aircraft are detected, and if one or both of them are within the allowable values, a control signal is transmitted to the accident aircraft, and the guide vane or inlet valve is controlled to close, and the control signal is The system also controls the closing of the guide vanes or inlet valves of healthy machines to prevent sudden changes in the relative input/output difference between the power that the pump pump operating machine receives from the power grid and the power that the water turbine generator machine supplies to the power grid. In parallel, after the guide vanes or inlet valves of the accident aircraft and the sound aircraft reach a predetermined small opening or full closure, the accident aircraft and the sound aircraft are disconnected from the power system and stopped. Therefore, in the event of an accident, there is little power fluctuation in the power system, and water pressure fluctuations associated with shutdown operations are also small, so it is possible to prevent adverse effects on pipes, etc., and to perform stable shutdown operations.

Furthermore, even when the voltage or rotational speed of the accidental aircraft exceeds a permissible value, the same effect as described above can be obtained by selecting the timing for disconnecting the accidental aircraft or healthy aircraft from the power system.

[Brief explanation of the drawing]

Fig. 1 is a control block diagram showing an embodiment of the present invention, Fig. 2 is an explanatory diagram of the water hammer phenomenon in a branch channel pumped storage power plant to which the present invention is applied, and Figs. 3 and 4 are respectively in accordance with the present invention. Fig. 5 is a schematic diagram showing the schematic configuration of a branch water pumped storage power plant, Fig. 6 is a block diagram explaining its control method, and Figs. 7 and 8 show conventional operation. 3 is a block diagram and a sequence diagram illustrating a control method. FIG. 1... Upper pond, 2... Penstock, 3 a, 3
b, 5 a *5b...branch pipe, 4a, 4b...
・Pump turbine, 6... Spillway, 7... Lower pond, 8a,
8b... Generator motor, 9a, 9b... Local line, 10... Power system, 11... Rotation speed detection device, 12... Voltage detection device, 13... Emergency stop protection device, 14... Output detection device, 15... Input detection device, 81... Water pressure rising wave, 82... Water pressure decreasing wave, 8
3...Synthetic wave. Applicant's agent Sato - Summary Figures 2 and 5

Claims (1)

[Scope of Claims] 1. A branch waterway in which the waterway consists of a single hydraulic pipe connected to the upper pond and a plurality of branch pipes branching from the penstock, and each branch pipe is connected to a pump water wheel or a water wheel and a pump. In a pumped-storage power plant, during steady operation in which pumping operation by some pump-turbines or pumps and water-turbine power generation operation by all or part of the remaining pump-turbines or water turbines are performed in parallel, the pump pumping operation is performed. If an accident occurs on either side of the engine or the turbine generator, the rotational speed and voltage of the accident engine will be detected, and if one or both of these are within allowable values, a control signal will be transmitted to the accident engine, In addition to controlling the closing of the guide vane or inlet valve, the control signal is also transmitted to the healthy machine, and the power that the pump pump operation machine receives from the power system and the power that the water turbine generator operation machine supplies to the power system are controlled. The guide vanes or inlet valves of the healthy aircraft are controlled to close in parallel to prevent sudden changes in the relative input/output difference, and the guide vanes or inlet valves of the accident aircraft and the healthy aircraft reach a predetermined small opening or fully closed position. After that, the accidental machine and the healthy machine are disconnected from the power system and stopped. 2. When one or both of the rotational speed and voltage of the accident aircraft exceed the allowable values, a control signal is transmitted to the accident aircraft and the healthy aircraft to disconnect them from the power system, and the guide vanes of the accident aircraft and the healthy aircraft are 2. A method for controlling the transient operation of a branch waterway pumped storage power plant according to claim 1, characterized in that the inlet valve and the inlet valve are closed and stopped in parallel. 3. When one or both of the rotational speed and voltage of the accident aircraft exceed the allowable values, a control signal is transmitted to the healthy aircraft to disconnect it from the power system, and the guide vanes and inlets of the accident aircraft and the healthy aircraft are A method for controlling the transient operation of a branch waterway pumped storage power plant according to claim 1, characterized in that the operation of a branch waterway pumped storage power plant is stopped by controlling a valve to close.