JP2002250270A - Device and method for automatic load adjustment in hydraulic power plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and a method for automatic load adjustment in a hydraulic power plant for controlling a load adjuster and a load limiter stably without causing variation of the load when the control is switched. SOLUTION: Variation of the output electric power of a hydraulic power generator 2 is detected by a load detector 3. The output of the load detector 3 is supplied to a comparator 4, which outputs the electric power deviation between the detected electric power and the commanded value for the load. When the electric power deviation is a prescribed value or larger, a speed governor control part 7 executes the control by changing the set value of the opening of guide vanes, and the load limiter 8 executes the control within the set value of the opening of the guide vanes. When the load detector 3 detects a large variation of the load, an operator gives a command for switching either to the load limiter 8 or the speed governor control part 7 for controlling the opening of the guide vanes 16. The timing of the switching is when the output voltage of the speed governor control part 7 becomes slightly higher than zero voltage, and the opening of the guide vanes is controlled at this timing by the speed governor control part or the load limiter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic load adjusting device and an automatic load adjusting method for a hydroelectric power plant.

[0002]

2. Description of the Related Art Conventionally, electric power supplied from a hydroelectric power plant is:
When a large load, for example, a factory starts operating, the load decreases or the frequency decreases. The change in the load power and the change in the frequency are automatically detected, and the guide vane opening is automatically adjusted to cope with the change. The device that automatically adjusts the opening of the guide vane includes an automatic load controller that selectively operates a load adjuster and a load limiter whose opening value is controlled by an electric motor to respond to load fluctuations. There is an adjustment device. The automatic load adjustment device of this hydropower plant is shown in FIG.
It is configured as follows. FIG. 4 is a circuit configuration diagram for explaining the configuration of a conventional automatic load adjusting device for a hydroelectric power plant.

[0003] A rotating shaft of a water turbine 61 is connected to a rotating shaft of a generator 62. The output circuit of the generator 62 has a load detector 6 for detecting the output power value of the generator 62.
3 are connected. The load detector 63 is connected to a comparator 64 which compares a power generation output detection signal detected by the load detector 63 with a preset load command value signal and outputs a deviation signal. The load control calculation unit 65 is connected to the comparator 64. An automatic load control unit 66 is configured by the circuit of the load control calculation unit 65, the comparator 64, and the load detector 63.

[0004] The automatic load controller 66 is connected to a governor controller 67 and a load limiter 68. The former governor controller 67 has a configuration in which a speed load adjustment calculator 70 is connected to an output terminal of a load adjuster 69. The load adjuster 69 has a configuration in which a setter 72 is connected so as to be controlled by an electric motor 71. The latter load limiter 68 is a motor 73
In this configuration, the limiting mechanism 74 is connected so as to be controlled as follows.

[0005] A guide vane operating mechanism 75 is connected to the load limiter 68 and the speed load adjustment calculating section 70. The guide vane operating mechanism 75 is a guide vane 7
6 is a configuration for adjusting the opening degree. Thus, the automatic load adjusting device 77 of the hydroelectric power plant is configured.

[0006] The automatic load adjusting device 77 constantly monitors the power usage status and adjusts the load whenever power fluctuation occurs. That is, during the parallel operation in which the turbine generator 62 is connected to the system, the load adjustment by the automatic load adjusting device 77 is performed by controlling the opening degree of the guide vane as follows. The power value supplied from the generator 62 to the grid is always detected by the load detector 63. The detected power value of the output of the generator 62 and a preset external load command power value are supplied to a comparator 64.

The comparator 64 compares the power value detected by the load detector 63 with the load command power value and outputs a deviation signal. This deviation signal is supplied to a load control calculation unit 65, which calculates the deviation signal so as to be zero and guide vanes 7
6 is calculated.

In order to control the guide vanes 76,
A signal for the operator to select the governor control unit 67 or the load limiter 68 is input to the load control calculation unit 65 from various circumstances. The selected governor control unit 67 or load limiter 6
8 controls the opening degree of the guide vane 76. Generator 62
In a stable state where there is no large change in the load power value supplied by the comparator 64, the deviation output of the comparator 64 is a zero value. At this time, the operator selects the governor control section 67.

The governor controller 67 includes a guide vane 76.
The guide vane 76 is controlled to the opening set value of, for example, 60% to perform the load adjustment operation. At this time, the opening of the guide vane 76 of the load limiter 68 is set to, for example, 100%.
The output voltage of the speed load adjustment calculation unit 70 is zero volt. The output zero V of the speed load adjustment calculation unit 70 is equal to the guide vane 7
The current state where the opening degree of No. 6 is not changed is continued. As described above, in the load adjustment operation, the opening of the guide vane 76 is adjusted until the output voltage of the speed load adjustment calculation unit 70 reaches a preset ± voltage, for example, 1 V, and stable power supply is performed.

[0010] During such automatic load control operation,
When a large load occurs, for example, when one of the factories starts operating, the load detector 63 detects a decrease in power.
At this time, the frequency has also changed to a low frequency. The load detector 63 outputs the detected value to the comparator 64. The comparator 64 performs a comparison operation with the load command value and outputs, for example, −9 W to the load control operation unit 65.

The load control calculator 65 switches to a load limiter 68 as a guide vane controller for reducing the -9 W to zero W. The selected load limiter 68 is the comparator 6
The limiting mechanism 74, for example, a gear, is rotationally driven by the electric motor 73 so that the output value of 4 becomes zero W. The guide vane operation mechanism 75 is configured to control the opening degree of the guide vane 76 by a hydraulic piston. The selected load limiter 68 rotates the gear by rotating the motor 73 for a predetermined period, and sequentially closes the guide vane opening set value from, for example, 100%, and sets it to, for example, 60%.

The set value is an opening of the guide vane 76 for compensating for a decrease in power and a decrease in frequency. That is,
This is the load limiting operation mode. The control of the guide vanes 76 is a control for operating the guide vane operating mechanism 75 by the mechanical operation of the limiting mechanism 74 and controlling the opening and closing of the guide vanes 76 to adjust the load. At this time, the load adjuster 69
Is set to 100% of the upper limit by rotating the electric motor 71.

In this way, when the measures to reduce the power and reduce the frequency are completed in the load limiting operation mode and the load is adjusted to a stable operation state, the output value of the comparator 64 becomes zero W.
become. At this time, the load control calculation unit 65 switches to the load adjustment operation mode again and performs the steady operation. That is, load adjustment by the load adjuster 69 is performed.

The load adjustment by the load adjuster 69 outputs the set value of the setter 72 to the speed load adjustment calculator 70.
The speed load adjustment operation unit 70 outputs a comparison operation value between the set value of the setting unit 72 and the guide vane control operation value output from the load control operation unit 65.

Therefore, the speed load calculator 70 outputs a control signal calculated so that the output voltage becomes zero voltage to the guide vane operating mechanism 75. This guide vane operating mechanism 75
Controls the opening and closing of the guide vanes 76 by the control signal. The setting device 72 of the load adjuster 69 is a variable resistor that is driven to rotate by the electric motor 71 to select a resistance value. The resistance value of this variable resistor is set according to the rotation angle of the electric motor 71.

This resistance value is a set value of the guide vane 76 opening. The speed load adjustment calculation unit 70 calculates the opening of the guide vanes 76 for setting the water turbine 61 to a predetermined rotation speed. In other words, the speed load adjustment calculator 70 calculates the control amount of the guide vane 76. This opening is, for example, 60%. At this time, the opening set value of the load limiter 68 is set to 100% of the upper limit.

Conversely, when the operation of a large factory stops, the load is reduced, the power is increased, and the frequency is changed to a higher frequency. This change in the power value is detected by the load detector 6.
3 detects. The detected power value is supplied to the comparator 64. The comparator 64 outputs a deviation power from the load command value, for example, +9 W. This deviation power value is calculated by the load control
5 is supplied. The load control calculating unit 65 switches the control of the guide vane opening to the load limiting operation. Load limiter 6
Numeral 8 controls the opening of the guide vanes 76 to adjust the rotation speed of the water turbine 61 and the generator 62 according to the lightened load.

In the control of the guide vanes, the guide vane operating mechanism 75 is operated by the mechanical operation of the limiting mechanism 74 to control the opening and closing of the guide vanes 76 to adjust the load.
That is, the load limiter 68 controls the power and frequency according to the load. When the load is adjusted in this way, the comparator 64
Output power value becomes zero W. At this time, the load control calculation unit 6
Reference numeral 5 switches to the load adjustment operation mode and performs a steady operation.

When switching from the automatic load control operation mode (load adjustment operation mode) by the load adjuster 69 to the automatic load control operation mode (load limit operation mode) by the load limiter 68, the operation is switched so that load fluctuation does not occur. , The opening set value of the load limiter 68 is sequentially moved in the closing direction from 100% to set it near the opening of the load regulator 69. The conventional control method sets the opening of the load limiter 68 from 100% of the upper limit to the target opening position for the time (period) that can be reached based on the load before switching.
3 is rotated. Thereafter, the load adjuster 69
Is adjusted (avoided) by raising the opening to 100% of the upper limit. The same control method is used when switching from the load limiting operation mode to the load adjustment operation mode.

[0020]

However, in the automatic load adjusting device 77 of the water turbine 1, when the mode is switched from the load adjusting operation mode to the load limiting operation mode, a load change may occur. The present inventor has stated that
As a result of the study, the following reasons were found. That is, at the time of the load adjustment operation, the set value of the limit mechanism 74 of the load limiter 68 is set to the opening degree of 100%. In this state, the detector 64
Detects a power fluctuation larger than the load command value, the load control calculation unit 65 switches to the load limiter 68 and adjusts the opening of the guide vane 76 suitable for the load. At this time, the load limiter 68 moves the opening in the closing direction sequentially from the opening of 100% to an appropriate opening. The amount of movement in the closing direction has been determined by setting the rotation period of the electric motor 73 as time. That is, by rotating the electric motor 73 for a rotation time of, for example, 4 seconds, the gear is rotated and the opening of the guide vane 76 is set. However, it has been found that the adjustment of the opening degree of the guide vanes 76 by this time may cause a slight positional shift in the rotational position of the gear. This displacement occurs even if a pulsating flow occurs in the water flow, and when the mode is switched from the load adjustment operation mode to the load limiting operation mode, a load fluctuation may occur. Further, it has been found that if the water level drop changes, the load does not reach the target position, or even if it reaches the target position, the load is different from the load before switching, causing load fluctuation.

The present invention has been made in view of the above points. When the load is adjusted by operating a load adjuster and a load limiter with an electric motor, a load fluctuation is caused when the control of the load adjuster and the load limiter is switched. It is an object of the present invention to provide an automatic load adjusting device and an automatic load adjusting method for a hydroelectric power plant that can stably control the guide vane opening without occurrence.

An object of the present invention is to monitor the outputs of the hydraulic power generator and the governor control unit, and when the output becomes zero, determine the timing of switching between the load adjustment operation mode and the load limit operation mode. By controlling the guide vanes as
It is an object of the present invention to provide an automatic load adjustment device and an automatic load adjustment method for a hydroelectric power plant that perform stable switching control without load fluctuation.

[0023]

In order to achieve the above-mentioned object, an automatic load adjusting device for a hydroelectric power plant according to the present invention is provided. In the automatic load adjustment device of the hydroelectric power plant that compensates for the increase or decrease of the load power of the hydraulic power generator, the output of the hydraulic power generator in one of the load adjustment operation mode or the load limit operation mode during operation. And after substantially matching the output of the hydraulic power generator by the other operation during the switching preparation.

An automatic load adjusting device for a hydroelectric power plant according to the present invention comprises: a load detector for detecting an output power value of a hydroelectric generator;
A deviation value output circuit connected to the load detector for outputting a deviation power value between a detected power value and a preset load command value, and a guide vane opening set value connected to the deviation value output circuit is changed. A governor control unit that controls the guide vanes, and a load limiter that controls the guide vanes by changing the set value of the guide vane opening within the limit value of the guide vane opening connected to the deviation value output circuit. Switching means for controlling the degree of opening of the guide vanes by switching to either the load limiter or the governor control section; and setting the degree of opening of the load limiter or the governor control section switched by the switching means. A set value adjusting means for sequentially changing the value, and a time when the output of the governor control unit becomes close to zero value is set as a switching timing by the governor control unit or the load limiter so that the guide vane is controlled by the set value adjusting means. Opening And characterized by being provided with a guide vane control means Gosuru.

An automatic load adjusting device for a hydroelectric power plant according to the present invention includes a load detector for detecting the output power of a hydroelectric generator, and an output value of a load detector connected to the load detector. A deviation value output circuit for outputting a deviation value in comparison with a load command value, and a guide vane opening control signal for outputting a comparator output value connected to the comparator to a zero value. A load control calculation unit, a governor control unit connected to the load control calculation unit for controlling the guide vane opening by sequentially changing the guide vane opening set value, and a guide connected to the load control calculation unit. A load limiter for sequentially controlling the guide vane opening within the limit value by sequentially changing the vane opening set value, and a load control calculation unit when the load detector detects a power fluctuation, wherein the governor control is performed. Section or load limiter And switching means for controlling the emission opening,
A set value adjusting means for sequentially changing the opening set value of the load limiter or the governor control unit switched by the switching means; and a governor control unit connected to an output terminal of the governor control unit. A detector for monitoring the output value, and selecting means for controlling the opening degree of the guide vane as the opening degree control operation mode by the governor control unit or the load limiter when the detection value of the detector becomes near zero. It is characterized by comprising.

[0026] The governor control section is characterized in that it has a load adjuster for controlling the rotation by an electric motor and setting the opening of the guide vane in advance.

The load limiter is characterized in that it has a limit mechanism for controlling the rotation by an electric motor to set a limit value of the guide vane opening in advance.

The automatic load adjustment method for a hydroelectric power plant according to the present invention includes a load detection step of detecting an output power value of a generator, and a deviation power value obtained by comparing the detected load power value with a preset load command value. And a load adjuster that controls the guide vane opening by changing the set value so that the deviation power value becomes zero, or guides the guide vane within a preset limit value of the guide vane opening. A selection step of controlling the guide vane opening degree by switching to one of the load limiters that controls by changing the set value of the vane opening degree, and setting the load adjuster or the load limiter set value selected by this selection step. And a guide vane control means for controlling the guide vanes when the output of the speed load adjustment calculating section is sequentially changed to a value close to zero as a switching timing.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of an automatic load adjusting device and method for a hydroelectric power plant according to the present invention will be described with reference to FIG. FIG. 1 is a circuit configuration diagram of an automatic load adjusting device of a hydroelectric power plant for explaining an embodiment of the present invention. This embodiment is a case where the control of the opening degree of the guide vanes when the load power of the hydroelectric generator fluctuates is performed by switching to a load adjuster or a load limiter. The timing of this switching is
This is an embodiment in which the switching timing is set to the time when the output power value of the generator controlling the current opening degree of the guide vane is adjusted to a value close to the value or the vicinity thereof.

The details will be described below. The rotating shaft of the turbine 1 is connected to the rotating shaft of the generator 2. A load detector 3 is connected to an output circuit of the generator 2 so as to detect a power value of the generator 2. The load detector 3 is connected to a deviation output circuit, for example, a comparator 4, which compares the generated output detection signal detected by the load detector 3 with a preset load command value signal and outputs a deviation signal. Have been. The comparator 4 is connected to a load control calculator 5. The load control calculator 5, the comparator 4, and the load detector 3
The automatic load control section 6 is constituted by the above circuit.

The load control calculator 5 calculates the guide vane opening so that the deviation signal of the comparator 4 becomes zero. The load control calculation unit 5 includes a governor control unit 7 and a load limiter 8
Is connected. The former governor controller 7 has a configuration in which the output terminal of the load adjuster 9 is connected to the input terminal of the speed load adjustment calculator 10. The load adjuster 9 has a configuration in which a setter 12 is connected to an electric motor 11.

The governor control unit 7 configured as described above controls the time setting unit 1 selected by rotating the motor 11.
The opening of the guide vanes 16 is controlled by gradually changing the opening of the set value of 2 from 100% to the opening downward.
The latter load limiter 8 has a configuration in which a limiting mechanism 14 is connected to an electric motor 13. The load limiter 8 controls the opening of the guide vanes 16 by rotating the motor 13 so that the set value is sequentially changed downward from the opening of 100%. The load limiter 8 and the speed load adjustment calculator 1
The guide vane operating mechanism 15 is connected to the output end of the zero. The guide vane operating mechanism 15 is configured to adjust the opening of the guide vane 16. An opening controller selection signal for selecting the load adjuster 9 and the load limiter 8 is input to the load control calculator 5.

The input of the opening controller selection signal is selected and determined by the operator of the power plant in consideration of the surrounding circumstances, the operating conditions of other power plants, and the like. Further, a feature of this embodiment is that a governor control output detector 17 is connected to an output terminal of the speed load adjustment calculation unit 10. The output terminal of the governor control output detector 17 is connected to the load control
And the feedback of the output of the speed load adjustment calculation unit 10. This feedback circuit is a circuit for removing the occurrence of load fluctuation with higher accuracy when switching to the load adjustment operation mode or the load limit operation mode.

The time when the output voltage of the speed load adjustment calculation unit 10 becomes zero V or a slightly higher voltage, for example, 0.5 V, is determined as the timing of switching between the load adjustment operation mode and the load limit operation mode. , Stable switching with little load fluctuation is enabled. This switching timing is controlled by the governor control output detector 1
7 is performed. The governor control output detector 17 detects the output voltage of the speed load adjustment operation unit 10, and detects the timing of switching to the load adjustment operation mode or the load limit operation mode specified by the operator. is there. The timing at which the output voltage of the governor control output detector 17 detects zero V or slightly higher voltage is determined as the switching timing. The output voltage for determining the timing of this switching is preferably within 1V. The optimal example is within 0.5V.

The load adjustment operation mode is an operation mode in which the set value of the setting device 12 is selected according to the magnitude of the change in the output power of the generator 2 to adjust and control the opening of the guide vanes 16. Therefore, the load adjustment operation mode is effective for compensating for a small ± voltage change in a relatively stable operation state. During this load adjustment operation, the opening set value of the load limiter 8 is set to 100% of the upper limit. The load limiting operation mode is a limited operation in which the guide vane opening cannot be equal to or greater than the set value. Therefore, the load limiting operation mode is effective for adapting the rotation speed of the hydraulic power generator 2 at a high speed when a large power change occurs, that is, when the load changes to a high power load or a low power load.

During the load limiting operation, the opening set value of the load regulator 9 is set to 100% of the upper limit. The electric motors 11 and 13 are motors, and are preferably synchronous motors. The setting device 12
Denotes a variable resistor, which has a configuration in which a rotation axis of the motor and an intermediate tap of the variable resistor are fixed, and a desired resistance value is selected by rotation of the motor. By coupling the gear to the coupling mechanism between the rotary shaft of the motor and the intermediate tap of the variable resistor, the accuracy of selecting the resistance value can be improved. The selection of the resistance value is the opening set value of the load adjuster 9.

The speed load adjustment operation section 10 compares the set value of the load adjuster 9 with the operation output value of the load control operation section 5 and outputs a control signal for controlling the opening of the guide vane 16. The zero value of this control signal means that the water turbine 1 and the generator 2 are rotated at the current opening degree without opening / closing control of the opening degree of the guide vane 16.

The guide vane operating mechanism 15 is configured to be mechanically directly coupled to the guide vane 16, and is typically constituted by a hydraulic piston. By moving this piston, the opening degree of the guide vane 16 provided at the water inlet of the water turbine 1 is hydraulically controlled. The limiting mechanism 14 is constituted by a gear. The rotation of the gear is such that the rotation shaft of the motor is coupled to the rotation shaft and the gear is rotated by the motor. The rotation of the gear controls the opening and closing of the guide vanes 16. Therefore, in the load adjustment operation, the opening degree of the guide vane is controlled by electrically controlling the hydraulic pressure. In the load control operation, the hydraulic piston is driven by the rotation of the gear, and the opening of the guide vane is controlled. Thus, the automatic load adjusting device 18 of the hydroelectric power plant is configured.

Next, an automatic load adjusting method by the automatic load adjusting device 18 will be described. This automatic load adjusting device 18
Constantly monitors the power usage status, adjusts the load whenever the power fluctuates in the load, and constantly supports stable power supply. That is, during the parallel operation in which the hydraulic power generator 2 is connected to the system, the load adjustment by the automatic load adjusting device 18 is performed by controlling the opening degree of the guide vane 16 as follows. Power value supplied from the generator 2 to the system, for example, 500
The load detector 3 always detects (monitors) the MW and the frequency, for example, 50 Hz. The detected power value of the output of the generator 2 and a load command power value preset from the outside are supplied to the comparator 4.

The comparator 4 compares the power value detected by the load detector 3 with a load command power value and outputs a deviation power. This deviation power is supplied to the load control calculation unit 5.
The load control calculator 5 calculates the deviation power to be zero W to calculate an opening control signal for the guide vanes 16. When a controller selection signal is input from the operator, the load control calculation unit 5 selects the specified governor control unit 7 (load adjuster 9) or load limiter 8. The selected governor control unit 7 or load limiter 8 controls the opening of the guide vane 16.

In a stable state where there is no large change in the load power value supplied by the generator 2, the deviation output power of the comparator 4 fluctuates around zero W. (The load command value is set in advance so that the output value of the comparator 4 becomes zero W in a stable state.) At this time, the operator sends the load control calculation unit 5 to, for example, the governor control unit 7 ( The signal for selecting (load adjustment operation) is input. The governor control unit 7 rotates the electric motor 11 in preparation for switching to gradually move the opening set value of the guide vanes 16 downward from 100%, and controls the opening and closing of the guide vanes 16 to, for example, 60%.

That is, the automatic load control operation mode (load adjustment operation mode) by the load adjuster 9 is performed. At this time,
The guide vane opening set value of the load limiter 8 is
3 is set to, for example, 100%. Further, the output voltage of the speed load adjustment calculation unit 10 is zero volt.
The output voltage of zero V of the speed load adjustment calculation unit 10 means control for continuing the current state in which the opening degree of the guide vane 16 is not moved.

The automatic load control operation mode by the governor controller 7 is executed until the output voltage of the speed load adjustment calculator 10 reaches a preset voltage, for example, ± 1 V. By adjusting the opening of the guide vanes 16 within the above range, stable power supply is realized. That is, if the output voltage of the speed load adjustment calculation unit 10 fluctuates within ± 1 V, the governor control unit 7 can control the opening degree of the guide vanes 16 in the load adjustment operation mode to compensate for the load fluctuation. is there.

Next, an embodiment of a method for compensating for the load fluctuation will be described more specifically. During the automatic load control operation by the load regulator 9, for example, at 8:00 in the morning, when a large number of factories start operating at the same time and a large load occurs, the generator 2 has a shortage of supply capacity and responds. No, the rotation speed drops. The load detector 3 detects a decrease in output power of the generator 2. At this time, the output of the generator 2 also has a low frequency, for example, 49.5 Hz. The load detector 3 outputs the detected value to the comparator 4. The comparator 4 performs a comparison operation with the load command value and outputs, for example, -9 W to the load control operation unit 5. The operator performs a control calculation to reduce the -9 W to zero W in the load control calculation unit 5. further,
The operator inputs a signal for switching to the load limiter 8 as a guide vane opening controller to the load control calculation unit 5.

In preparation for switching, the selected load limiter 8 rotates the electric motor 13 from the opening degree of 100% so that the output value of the speed load adjustment calculation unit 10 becomes close to zero V, and rotates the limiting mechanism 14 such as a gear. Drive to move the opening in the closing direction. The guide vane operation mechanism 15 is configured to control the opening degree of the guide vane 16 by a hydraulic piston. This control widens the opening of the guide vanes 16 so as to increase the rotation speed of the water turbine 1.

Controlling the degree of opening of the guide vanes 16 broadly increases the amount of water flowing into the turbine 1 and increases the rotation speed of the turbine 1. The selected load limiter 8 is a motor 13
To rotate the gears. This rotation controls the movement of the guide vane opening set value in the closing direction sequentially from, for example, 100%. In this control process, when the output voltage of the speed load adjustment operation unit 10 becomes higher than the balance voltage (zero V), for example, ± 1 V or more, the operator operates the load control operation unit 5.
To switch to the load limiting operation mode.

The load control calculation section 5 switches the drive of the guide vanes 16 from the load adjustment operation mode to the load limit operation mode and drives the guide vanes 16. After this switching operation, control for compensating for a decrease in power and a decrease in frequency in the load limiting operation mode is executed. That is, the load limiting operation mode is set. In the control of the guide vanes 16, the guide vane operating mechanism 15 is operated by the mechanical operation of the limiting mechanism 14, and the load is adjusted by controlling the opening and closing of the guide vanes 16. After the switching, the set value of the load regulator 9 is set to 100% of the upper limit by rotating the electric motor 11. In this way, the power reduction and the lowering of the frequency are compensated for by the load limiting operation, and the power 5
When the load is adjusted to a stable operation state of 00 MW and a frequency of 50 Hz, the output value of the comparator 4 becomes zero W.

At this time, the operator instructs the load control operation unit 5 to switch to the load adjustment operation mode again to switch to the load adjustment operation mode. In this load adjustment operation mode, the degree of opening of the guide vanes 16 is controlled following a slight change in the load, and power is supplied stably. Thereafter, the opening set value of the load limiter 8 is set to 100% of the upper limit. That is, the automatic load control operation mode by the load adjuster 9 is set. In the automatic load control operation mode by the load adjuster 9, the set value of the setter 12 is output to the speed load adjustment calculator 10.

The speed load adjustment calculation unit 10 includes a setting unit 12
Is compared with the set value of the opening control value of the load control calculation unit 5. The speed load adjustment calculator 10 outputs a control signal calculated so that the calculated output voltage becomes zero voltage to the guide vane operating mechanism 15. The guide vane operating mechanism 15 controls the opening and closing of the guide vanes 16 by the control signal. The setter 12 of the load adjuster 9 is a variable resistor that is driven to rotate by the motor 11 to select a resistance value. The resistance value of this variable resistor is set according to the rotation angle of the electric motor 11.
This resistance value is a set value of the guide vane 16 opening. The speed load adjustment calculation unit 10 calculates and outputs the opening degree of the guide vanes 16 for setting the water turbine 1 at a predetermined rotation speed. In other words, the speed load adjustment calculator 10 calculates the control amount of the guide vane 16. The guide vane opening is, for example, 60
%.

On the other hand, if many factories stop operating at the same time, for example, at 5:00 in the evening, the load becomes lighter.
The rotation speed of the generator 2 increases, the generated power increases, and the rotation frequency changes to a higher frequency. This change in the power value is detected by the load detector 3. The detected power value is supplied to the comparator 4. The comparator 4 outputs a deviation power from the load command value, for example, +9 W. This deviation value is supplied to the load control calculation unit 5. The load control calculation unit 5 switches to the load limiting operation mode.

In this load limiting operation mode, the load limiter 8 controls the opening degree of the guide vanes 16 to control the rotation speed of the water turbine 1 and the generator 2 according to the lightened load.
The control of the guide vanes 16 is performed by operating the guide vane operating mechanism 15 by the mechanical operation of the limiting mechanism 14 and controlling the guide vanes 16 in the closing direction to adjust the load. That is, the load limiter 8 suppresses the amount of water to the turbine 1 so as to reduce the rotation speed of the generator 2 according to the load, and controls the power to a predetermined power and a predetermined frequency. When the load is adjusted in this manner, the output of the comparator 4 becomes zero W. At this time, the load control calculation unit 5 switches to the load adjustment operation mode and performs a steady operation.

Next, a method of switching from the load adjustment operation mode to the load limitation operation mode and a method of switching from the load limitation operation mode to the load adjustment operation mode will be described more specifically. First, a method of switching from the load adjustment operation mode to the load limit operation mode will be described with reference to FIGS. FIG. 2 is a flowchart for specifically explaining the switching procedure of FIG. Load adjuster 9
, The opening of the load limiter 8 is set to 100% of the upper limit. For this reason, the output voltage of the speed load adjustment calculation unit 10 is almost 0 V of the balance voltage (Step 21). This state is a stable state.

In this state, the load detector 3 always detects a change in load power (step 22). The comparator 4 detects the magnitude of the detected power change (step 23). It is determined whether the magnitude of the power change is greater than or equal to a predetermined value (Step 25) or not (Step 26) (Step 24).

If not, the current automatic load control operation mode by the load adjuster 9 is continued (step 27). When the above-described large load increase is detected, the operator inputs a switch from the automatic load control operation mode using the load adjuster 9 to the automatic load control operation mode using the load limiter 8 to the load control calculation unit 5 (step). 28). At this time, in preparation for switching, the load limiter 8 rotates the electric motor 13 to sequentially move the opening set value by the limiting mechanism 14 from 100% in the closing direction (step 29).

In response to this movement, the opening of the guide vane 16 by the load limiter 8 is moved in the closing direction. In this process, when the opening degree of the load limiter 8 becomes close to the opening degree of the load adjuster 9, at this time, the governor control device 7 acts to increase the opening degree, and the speed load adjustment calculating unit 10 The output voltage rises above the balance voltage. At the same time, the governor control output detector 1
7 is slightly higher than the balance voltage (step 3).
0).

At this point, the control for lowering the opening set value of the load limiter 8 is stopped. This time is the timing of switching from the load adjustment operation mode to the load limit operation mode (step 31). (Substantially coincides with the output of the hydraulic power generator) After that, the opening set value of the load regulator 9 is increased to 100% of the upper limit (step 32). This state means that the switching to the load limiting operation mode has been completed. Thus, the speed load adjustment calculation unit 10
When the opening of the guide vanes 16 by the two controls coincides with each other by monitoring the output, the switching is performed, so that no load fluctuation occurs.

Next, the latter method for switching from the load limiting operation to the load adjustment operation mode will be specifically described with reference to FIGS. FIG. 3 is a flowchart for specifically explaining a method of switching from the load limiting operation mode to the load adjustment operation mode. In step 41, during the automatic load control operation by the load limiter 8, the set value of the opening degree of the load adjuster 9 is at 100% of the upper limit as described above. Therefore, the output voltage of the speed load adjustment calculation unit 10 is almost full level of 10V. This state is a stable state. In this state, the load detector 3 always detects a change in load power (step 42). The magnitude of the detected power change is detected by the comparator 4 (step 43).

Whether the magnitude of the power change is within a predetermined value (Step 4)
5) It is determined whether it is the above (step 46) (step 44). In the above case, the current automatic load control operation by the load limiter 8 is continued (step 47). Further, when a small change within ± is detected, the operator inputs a switch from the automatic load control operation by the load limiter 8 to the automatic load control operation by the load adjuster 9 to the load control calculation unit 5 (step 48). . The instructed load adjuster 9 rotates the electric motor 11 to sequentially move the opening set value from 100% in the closing direction in preparation for switching (step 49).

In accordance with this movement, the speed load adjustment calculation unit 10
Output voltage drops to almost 0 V of the balance voltage.
At this time, when the voltage detected by the governor control output detector 11 becomes slightly higher than the balance voltage (the timing of switching from the load limiting operation mode to the load adjustment operation mode) (step 50), the load adjuster 9 is stopped in the closing direction, and the mode is switched to the load adjustment operation mode (step 5).
1). (Substantially coincide with the output of the hydraulic power generator) After that, the opening set value of the load limiter 8 is set to 100% of the upper limit (step 52).

As described above, even if the operating speeds of the electric motors 11 and 13 or the upper limit positions of the load adjuster 9 and the load limiter 8 change, or the head drop changes, no load fluctuation occurs at the time of switching. In the above-described embodiment, the case where the steady operation after switching to the load limiting operation from the load adjustment operation and compensating for the power fluctuation is switched to the load adjustment operation mode is described.
It is needless to say that the opening degree of No. 6 may be controlled.

[0061]

According to the present invention, when the control when the load of the hydroelectric generator becomes large or light is compensated by switching between the load regulator and the load limiter,
Regardless of the water level head, the operating speed of the motor and the load adjuster, regardless of the upper limit position of the load limiter, without causing load fluctuation,
Can be limited to stable. Also, during the automatic load control operation with the load limiter, the output of the governor control unit is monitored without setting the opening value of the load regulator to the upper limit so that the voltage is always slightly higher than the balance voltage. By adjusting the position of the opening set value of the load adjuster, the dead time of the governor can be reduced when the load limiter interrupts the load during the load operation.

[Brief description of the drawings]

FIG. 1 is a circuit diagram for explaining an embodiment of an automatic load adjusting device for a hydroelectric power plant according to the present invention.

FIG. 2 is a flowchart for explaining an automatic load adjustment method for switching from the load adjustment operation mode to the load limit operation mode in FIG.

FIG. 3 is a flowchart for explaining an automatic load adjustment method for switching from the load limit operation mode to the load adjustment operation mode in FIG. 1;

FIG. 4 is a circuit configuration diagram of a conventional automatic load adjusting device for a hydroelectric power plant.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Water turbine, 2 ... Hydroelectric generator, 3 ... Load detector, 4 ... Comparator, 5 ... Load control calculation part, 6 ... Automatic load limiter, 7 ... Governor control part, 8 ... Load limiter, 9 ... load regulator, 10 ...
Speed load adjusting unit, 11, 13: electric motor, 12: setting device,
14 ... restriction mechanism, 15 ... guide vane operation mechanism, 16 ...
Guide vanes, 17: Governor control output detector, 18: Automatic load adjustment device of hydroelectric power plant, 28: Instruction to switch to load limit by operator, 29: Load limiter 8 sets opening degree to 1
Move in the closing direction sequentially from 00%, 30 ... Governor control output detector 17 Detects a voltage whose output voltage is slightly higher than zero voltage, 3
1 ... Switch to automatic load control operation by load limiter 8, 4
8: An instruction by the operator to switch to load adjustment; 49: The load adjuster 9 sequentially moves the opening set value from 100% in the closing direction;
0: governor control output detector 17 The output voltage is detected to be slightly higher than zero voltage.

Claims (6)

[Claims] 1. An automatic load control device for a hydroelectric power plant that adjusts the rotation speed of a hydroelectric generator while switching between a load adjustment operation mode and a load limit operation mode to compensate for an increase or decrease in the load power of the hydroelectric generator. Switching after making the output of the hydraulic power generator in one of the load adjustment operation modes or the load limiting operation mode during operation substantially equal to the output of the hydraulic power generator in the other operation mode in preparation for switching. An automatic load adjustment device for a hydroelectric power plant. 2. A load detector for detecting an output power value of a hydraulic power generator, and a deviation value output circuit connected to the load detector for outputting a deviation power value between the detected power value and a preset load command value. A speed controller controlling the guide vanes by changing the set value of the guide vane opening connected to the deviation value output circuit; and a limiter for the guide vane opening connected to the deviation value output circuit. A load limiter that controls the guide vane by changing the set value of the guide vane opening degree, and a switching means that controls the opening degree of the guide vane by switching to either the load limiter or the governor controller. Setting value adjusting means for sequentially changing the opening set value of the load limiter or the governor control unit switched by the switching means, and the output of the governor control unit becomes close to zero value by the set value adjusting means. Timing of switching time And a guide vane control means for controlling the degree of opening of the guide vanes by a governor control unit or a load limiter. 3. A load detector for detecting an output power of a hydroelectric generator, and a deviation value is output by comparing an output value of the load detector connected to the load detector with a preset load command value. And a load control calculator for outputting a control signal of the guide vane opening for setting the output value of the comparator connected to the comparator to zero, and a load control calculator connected to the load control calculator. A governor control unit for controlling the guide vane opening by sequentially changing the guide vane opening set value;
A load limiter connected to the load control calculating unit for sequentially changing the guide vane opening set value and controlling the guide vane opening within the limit value; and a load control when the load detector detects power fluctuation. The arithmetic unit includes a switching unit that controls the guide vane opening by switching to the governor control unit or the load limiter, and an opening set value of the load limiter or the governor control unit that is switched by the switching unit. And a detector that monitors the output value of the governor control unit connected to the output terminal of the governor control unit, and that the detected value of the detector is close to zero. Selecting means for controlling the degree of opening of the guide vanes as the degree of opening control operation mode by the governor controller or the load limiter. 4. The hydroelectric power plant according to claim 2, wherein the governor control unit has a load adjuster for controlling the rotation of the guide vane by an electric motor and setting the opening degree of the guide vane in advance. Automatic load adjuster. 5. The hydroelectric power plant according to claim 2, wherein the load limiter has a limit mechanism for setting a guide vane opening limit value in advance by controlling the rotation of the load limiter by an electric motor. Automatic load adjuster. 6. A load detection step of detecting an output power value of a generator, a deviation value output step of outputting a deviation power value by comparing the load detection power value with a preset load command value,
By changing the set value of the guide vane opening within the limit value of the guide vane opening or changing the set value of the guide vane opening so that the deviation power value becomes zero. A selection step of controlling the guide vane opening by switching to one of the load limiters to be controlled, and sequentially changing the set value of the load adjuster or the load limiter selected by the selection step, and outputting the speed load adjustment calculation unit output. And a guide vane control means for controlling the guide vanes at the time when the pressure becomes close to a zero value as a switching timing.