JPH1181920A - Combined cycle controller and gas turbine controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize a system operation by preventing a shaft governor setting signal from operating in the reverse direction of a governor operation. SOLUTION: A shaft load controller of a single-shaft combined cycle power generation plant is constituted to arrange a gas turbine, a steam turbine and a generator on a single shaft, to convert exhaust heat of a gas turbine into steam energy by an exhaust heat recovery boiler and to generate torque of the steam turbine. In this case, the controller is provided with a means 5b calculating output fluctuation amount of the gas turbine due to fluctuation of a system frequency, means 5c, 5d calculating output fluctuation amount of the steam turbine 2 due to fluctuation of the system frequency and a means obtaining total fluctuation amount by adding gas turbine output fluctuation amount and steam turbine output fluctuation amount and correcting a shaft load setting signal by the total fluctuation amount.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combined cycle control device and a gas turbine control device for a single-shaft combined cycle power plant in which a gas turbine, a steam turbine, and a generator are arranged on one shaft.

[0002]

2. Description of the Related Art FIG. 17 is a block diagram showing a configuration example of a general single-shaft combined cycle power plant of this type.

In FIG. 17, in a single-shaft combined cycle power plant, a gas turbine 1, a steam turbine 2, and a generator 3 are arranged and connected on the same shaft, and the exhaust gas (exhaust heat) of the gas turbine 1 is recovered as exhaust heat. After supplying the steam to the boiler 4 and converting the exhaust gas into steam energy by the exhaust heat recovery boiler 4, the steam is supplied to the steam turbine 2 via the steam turbine control valve 2a, that is, the torque of the steam turbine 2 is generated. Is configured.

FIG. 18 is a block diagram showing a configuration example of a conventional shaft load control device and a conventional shaft governor control device in the single-shaft combined cycle power plant.

In FIG. 18, a shaft load setting signal is input to a shaft load controller 5.

A shaft load control command output from the shaft load controller 5 is input to a shaft governor controller 6.

Further, a shaft speed / load control command output from the shaft governor controller 6 is output from an exhaust gas temperature controller 7 for protecting the gas turbine 1 from over-temperature, and a shaft start-up control for increasing the speed of the shaft. The low value selector 9 is input to the low value selector 9 together with the output command of the unit 8, and the signal selected by the low value selector 9 is used as a gas turbine fuel command.

That is, the shaft load controller 5 inputs an external shaft load setting signal (not shown) and a system frequency,
The deviation between the system frequency and the output from the setter 5a that sets the rated frequency is input to the proportional calculator 5b.

Further, a frequency variation compensation signal output from the proportional calculator 5b and a shaft load setting signal are added to obtain a shaft load correction setting signal.

Further, a shaft load control command which is a deviation signal between the shaft load correction setting signal and the shaft load measurement signal is output to the shaft governor controller 6.

The proportional calculator 5b is set so as to calculate the output fluctuation amount of the gas turbine 1 due to the governor operation when the system frequency fluctuates.

On the other hand, the shaft governor controller 6 inputs a shaft load control command to the governor setting device 6a.

Further, a deviation between the shaft governor setting signal output from the governor setting device 6a and the shaft speed measurement signal is obtained, and this deviation signal is input to the proportional calculator 6b.

Further, a fuel set value for maintaining the no-load rated speed set in the setting device 6c is added to the shaft output command output from the proportional calculator 6b, and the shaft speed / load control command is added. It is configured to be.

The governor setting unit 6a increases or decreases the output according to the input signal, and performs the same operation as the integrator.

In the proportional calculator 6b, a gain of the governor setting rate is set. If the setting rate is 5%, the deviation between the shaft governor setting signal and the speed moves by 5%, so that the shaft load becomes 100%. % Is set to move.

That is, when the speed is stable at 100%, the governor setting device 6a sets the shaft speed / load control command to the fuel command of the rated no-load speed at the 100% setting.
It is configured so that the rated load fuel command is obtained when the percentage is set.

FIG. 19 is a block diagram showing a configuration example of a conventional steam turbine speed control device in the single-shaft combined cycle power plant.

In FIG. 19, the output signal of the governor setting device 6a is input to the steam turbine speed controller 10.

The steam turbine speed control signal output from the steam turbine speed controller 10 and the output signal from the schedule controller 11 are input to a low value selector 12,
The signal selected by the low value selector 12 is configured to be a steam turbine control valve flow rate command.

That is, the steam turbine speed controller 10 calculates the deviation between the signal obtained by adding the shaft governor setting signal and the value from the setting device 10a and the shaft speed measurement signal to the proportional calculator 10
Input to b.

The signal output from the proportional calculator 10b is configured as a steam turbine speed control signal.

The value of the setter 10a is set to about 2%, and the value of the proportional calculator 10b is set to about 50 times.

Thus, when the shaft speed exceeds the setting of the shaft governor, the steam turbine control valve 2a starts to be closed, and when the shaft speed becomes a value 2% higher than the setting of the shaft governor, the steam turbine control valve 2a is fully closed. Operate.

At a rated load, when the shaft speed becomes 105% or more, the steam turbine control valve 2a starts to close,
Fully closed at 107%.

In the conventional shaft load control device and shaft governor control device configured as described above, when the system frequency is stable, an external shaft load setting signal (not shown) is increased or decreased. Thus, the fuel of the gas turbine 1 is increased or decreased by increasing or decreasing the shaft governor setting.

The load of the gas turbine 1 is increased or decreased, and at the same time, the exhaust gas temperature and the exhaust gas flow rate of the gas turbine 1 are increased or decreased, so that the heat input to the exhaust heat recovery boiler 4 is increased or decreased.

Thus, the load on the steam turbine 2 is increased or decreased by increasing or decreasing the steam energy.

That is, the load on the gas turbine 1 and the load on the steam turbine 2 are simultaneously controlled.

The operation of the steam turbine control valve 2a is as follows.
At start-up, the steam condition is satisfied, and the operation is performed from fully closed to fully open by schedule control, and when stopped, the load is lowered to a predetermined load, and it is operated from fully open to fully closed by schedule control. .

That is, during normal load operation, the steam turbine control valve 2a is fully opened. In the steam turbine speed control, the steam turbine control valve 2a is used to limit the shaft speed from becoming excessive when the load is cut off. Close.

As described above, the governor setting of the gas turbine 1 is used as the shaft governor setting signal of the shaft.
The steam turbine control valve 2a is operated by schedule control regardless of the setting of the shaft governor.

On the other hand, when the system frequency fluctuates, in the conventional shaft load control device, a deviation occurs between the system frequency and the output from the setter 5a which sets the rated frequency, and the governor operation is performed by the proportional calculator 5b. Is added to the shaft load setting signal, the deviation between the shaft load correction setting signal and the shaft load measurement signal does not occur. Therefore, the shaft governor controller 6 is stable without increasing or decreasing the shaft load control command. I do.

In this case, the calculation of the shaft load correction setting signal is as follows.
When the system frequency rises, in order to reduce the load by governor operation, the calculation is performed by reducing the gas turbine output fluctuation with respect to the shaft load setting signal.

On the other hand, when the system frequency is lowered, the calculation is performed by increasing the output fluctuation of the gas turbine in the reverse manner.

This frequency fluctuation compensation function is used when a load fluctuation occurs due to a governor operation during a system frequency fluctuation.
This is a function for preventing a deviation from the load setting from occurring and increasing / decreasing the shaft governor setting signal as if the load setting from the outside increased / decreased.

That is, if the frequency fluctuation compensation function is not provided, the system operates in a direction to cancel the governor operation, which is not preferable in system operation. Therefore, such a function is provided.

For example, if the frequency fluctuation compensation function is not provided and the supply of power to the power demand increases for some reason during the rated load operation, the balance between the demand and the supply is lost and the system frequency rises, the governor operation is performed. , The load, that is, the power supply is reduced, and the system frequency is stabilized.

However, since the load setting from the outside does not fluctuate, the load measurement signal is reduced with respect to the load setting for the load control, and the shaft governor setting signal is operated to be increased.

Therefore, in order to prevent the reverse operation of the governor operation, the fluctuation amount of the gas turbine output due to the governor operation is added to the shaft load setting signal.

FIG. 2 shows a problem occurring in the frequency fluctuation compensation function included in the conventional shaft load control device.
This will be described in detail using 0.

FIG. 20 is a diagram showing an operation example of a conventional combined cycle shaft load control device.

That is, in the conventional frequency fluctuation compensation function, only the output of the gas turbine 1 is compensated. Therefore, when the system frequency fluctuation continues and the output of the steam turbine 2 fluctuates with a delay, the shaft load is reduced. The correction amount of the shaft load correction setting signal is smaller than the fluctuation amount of the measurement signal.

For this reason, there is a problem that the shaft load control command fluctuates and the shaft governor setting signal is erroneously changed in the reverse of the governor operation.

Further, recent gas turbines perform premixed combustion in order to reduce NOx. However, in this premixed combustion, the operating load band for stable combustion is narrow, and the system frequency increases. When it is large, there is a problem that the governor operation deviates from a stable combustion load zone.

That is, in this case, the load zone for stable combustion is, for example, in the range of 60% to 100% load. If the governor has a 5% regulation rate, the load changes 40% with a frequency change of 2%. Therefore, when the frequency is 2% during 100% load operation,
If it increases by more than%, it will deviate from the stable combustion load zone.

[0047]

As described above, in the conventional combined cycle control device, when the system frequency fluctuates and the steam turbine output fluctuates,
There is a problem that the axis governor setting signal is operated in the reverse of the governor operation.

When the rise of the system frequency is large,
There has been a problem that the load deviates from the stable combustion load zone of the gas turbine.

A first object of the present invention is to prevent the shaft governor setting signal from being operated in the reverse of the governor operation even when the system frequency fluctuates and the steam turbine output fluctuates. Is to provide a combined cycle control device capable of stabilizing the pressure.

A second object of the present invention is to maintain a load zone for stable combustion of a gas turbine and to maintain a governor operation amount at a predetermined amount even when the rise in system frequency is large. An object of the present invention is to provide a combined cycle control device.

Further, a third object of the present invention is to maintain a load zone for stable combustion of a gas turbine and maintain a governor operation amount to a predetermined amount even when the rise in system frequency is large. An object of the present invention is to provide a gas turbine control device.

[0052]

In order to achieve the first object, a gas turbine, a steam turbine, and a generator are arranged on a single shaft, and the exhaust heat of the gas turbine is converted into steam energy by an exhaust heat recovery boiler. In the shaft load control device of the single-shaft combined cycle power plant configured to generate torque of the steam turbine, the invention according to claim 1 calculates the output fluctuation amount of the gas turbine due to the fluctuation of the system frequency. Means for calculating the output fluctuation amount of the steam turbine due to the fluctuation of the system frequency, and the gas turbine output fluctuation amount and the steam turbine output fluctuation amount are added to obtain the total fluctuation amount, and the shaft load setting signal is obtained by the total fluctuation amount. Means for correcting

Therefore, in the combined cycle control device according to the first aspect of the present invention, the steam turbine output fluctuating with a delay after the gas turbine fuel fluctuation is calculated, and the shaft load setting signal is calculated based on the total fluctuation with the gas turbine output fluctuation. Is corrected, the shaft load measurement signal matches the shaft load setting signal even when the system frequency fluctuation continues, so that the governor operation due to the system frequency fluctuation is not reversed.

Thus, the system operation can be stabilized.

According to the second aspect of the present invention, there is provided means for calculating a virtual shaft load when the system is stable, based on the shaft governor setting signal or a signal corresponding thereto, a shaft virtual load and a shaft load measurement signal. Means for obtaining a deviation from the above and correcting the shaft load setting signal with the deviation.

Therefore, in the combined cycle control device according to the second aspect of the present invention, the virtual shaft load when the system frequency is stable is calculated from the shaft governor setting signal or the equivalent signal. By calculating the amount of fluctuation of the shaft load due to the governor operation from the deviation from the measurement signal, and correcting the shaft load setting signal, even if the system frequency fluctuation continues, the shaft load measurement signal and the shaft load setting signal , The governor operation due to the system frequency fluctuation is not reversed.

Thus, system operation can be stabilized.

Further, according to the third aspect of the present invention, there is provided a means for calculating a virtual shaft load when the system is stable, based on the shaft governor setting signal or a signal corresponding thereto, a shaft virtual load and a shaft load measurement signal. When the system frequency is stable, the shaft load feedback control based on the deviation between the shaft load measurement signal and the shaft load setting signal is performed, and during the system frequency fluctuation, based on the deviation between the shaft virtual load and the shaft load setting signal. Switching means for switching to perform the axis virtual load feedback control.

Therefore, in the combined cycle control device according to the third aspect of the present invention, a virtual shaft load when the system frequency is stable is calculated from the shaft governor setting signal or the equivalent signal, and the system frequency fluctuates. At times, by performing axis virtual load feedback control, the axis governor setting signal can be controlled following the axis load setting signal, ignoring the axis load fluctuation caused by the system frequency fluctuation. It does not operate.

Thus, the system operation can be stabilized.

On the other hand, in order to achieve the second object,
A single-shaft combined cycle power generation system in which a gas turbine, a steam turbine, and a generator are arranged on one axis, and the exhaust heat of the gas turbine is converted to steam energy by an exhaust heat recovery boiler to generate steam turbine torque. In the shaft governor control device of the plant, in the invention of claim 4,
Means for limiting the lower limit of the gas turbine fuel command by the lower limit of the gas turbine fuel command; and means for reducing the steam turbine steam flow rate command based on the deviation between the limited gas turbine fuel command and the shaft governor command. Have.

Therefore, in the combined cycle control device according to the fourth aspect of the present invention, by limiting the lower limit of the gas turbine fuel command when the system frequency rises, it is possible to maintain the load zone of stable gas turbine combustion.

Further, when the gas turbine fuel reduction operation by the governor operation is limited by the lower limit, the output of the steam turbine is reduced to maintain the reduction of the shaft output by the governor operation at a predetermined amount. Can be.

As a result, both stable operation of the combined cycle power plant and stability of system operation can be satisfied at the same time.

According to the fifth aspect of the present invention, the fourth aspect is provided.
In the combined cycle control device according to the present invention, a means for correcting a delay in output fluctuation of the steam turbine due to a change in the gas turbine fuel command with a gas turbine fuel command is added.

Therefore, in the combined cycle control device according to the fifth aspect of the present invention, when the gas turbine fuel reduction operation due to the governor operation is limited to the lower limit, the limited output reduction amount is reduced by reducing the output on the steam turbine side. In such a case, when the system frequency continues to rise, a decrease in the steam turbine output accompanying a decrease in the gas turbine fuel occurs. Then, the reduction amount of the steam turbine output is corrected by increasing the gas turbine output, that is, by absorbing the steam turbine output fluctuation delay due to the fluctuation of the gas turbine fuel command on the gas turbine side, the shaft due to the governor operation. The output fluctuation amount can be maintained at a predetermined amount.

As a result, both the stable operation of the combined cycle power plant and the stability of the system operation can be satisfied at the same time.

According to a sixth aspect of the present invention, in the combined cycle control device according to the fourth aspect of the present invention, the delay of the output fluctuation of the steam turbine due to the fluctuation of the gas turbine fuel command is corrected by the steam turbine steam flow rate command. Is added.

Therefore, in the combined cycle control device according to the sixth aspect of the present invention, when the gas turbine fuel reduction operation due to the governor operation is limited to the lower limit, the limited output reduction amount is reduced by reducing the output on the steam turbine side. In such a case, when the system frequency continues to rise, a decrease in the steam turbine output accompanying a decrease in the gas turbine fuel occurs. Then, the steam turbine output is corrected by increasing the steam turbine flow rate command, that is, by absorbing the steam turbine output fluctuation delay due to the gas turbine fuel command fluctuation on the steam turbine side. And the amount of shaft output fluctuation due to the governor operation can be maintained at a predetermined amount.

Thus, both stable operation of the combined cycle power plant and stable system operation can be satisfied at the same time.

Further, according to the invention of claim 7, means for preferentially changing the steam turbine steam flow rate command by the shaft governor operation command, and the difference between the fluctuated steam turbine steam flow rate command and the shaft governor command. Means for reducing the gas turbine fuel command.

Therefore, in the combined cycle control device according to the present invention, when the system frequency rises, the steam turbine output is first reduced, and when the steam turbine control valve is fully closed, the output on the gas turbine side is reduced. By doing so, the reduction of the fuel command of the gas turbine can be limited to when the system frequency rise is large, the stable combustion of the gas turbine can be maintained, and the governor operation can be maintained at a predetermined amount. it can.

As a result, both stable operation of the combined cycle power plant and stability of system operation can be satisfied at the same time.

On the other hand, in order to achieve the third object,
In the invention according to claim 8, in the shaft governor control device of the affiliated plant configured by providing a plurality of gas turbines, means for limiting the lower limit of the gas turbine fuel command for each shaft by the lower limit of the gas turbine fuel command, Means for reducing a gas turbine fuel command for another shaft based on a deviation between the limited gas turbine fuel command and a governor command for a predetermined shaft.

Therefore, in the gas turbine control device according to the eighth aspect of the present invention, when the system frequency rises, the lower limit of the gas turbine fuel command for each shaft is limited, so that the load zone for stable combustion of the gas turbine for each shaft is reduced. Can be maintained.

Further, when the gas turbine fuel reduction operation by the governor operation on the predetermined shaft is limited by the lower limit, the gas turbine output of the other shaft is reduced, so that the reduction of the shaft output by the governor operation is determined by a predetermined amount. Can be maintained.

Thus, it is possible to simultaneously satisfy both the stable operation and the stable system operation of the affiliated plant constituted by providing a plurality of gas turbines.

[0078]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(First Embodiment: Claim 1) FIG. 1
FIG. 19 is a block diagram showing a configuration example of a combined cycle control device according to the present embodiment. The same or corresponding parts as those in FIG. 18 are denoted by the same reference numerals, and description thereof is omitted. State.

The difference between the combined cycle control device of the present embodiment and the conventional device of FIG. 18 is that the setting device 5a for setting the system frequency and the rated frequency.
Is input to the proportional calculator 5b, and is input to the proportional calculator 5c to calculate the ST output fluctuation target amount due to the governor operation, and to set the primary delay in which the delay time of the exhaust heat recovery boiler 4 is set. The total variation is obtained by adding the output variation of the steam turbine 2 output from the first-order lag calculator 5d and the output variation of the gas turbine 1 output from the proportional calculator 5b. Is obtained, and a shaft load setting signal is corrected by the frequency fluctuation compensation signal.

That is, the combined cycle control device of the present embodiment calculates the output fluctuation amount of the gas turbine 1 due to the system frequency fluctuation, and calculates the steam turbine output fluctuation amount due to the system frequency fluctuation. The turbine output fluctuation amount and the steam turbine output fluctuation amount are added to obtain a total fluctuation amount, and the shaft load setting signal is corrected based on the total fluctuation amount.

Next, in the combined cycle control device of the present embodiment configured as described above, when the system frequency fluctuates, the output fluctuation amount of the steam turbine 2 due to the governor operation can be calculated. Then, the deviation from the shaft load measurement signal is corrected by correcting the shaft load setting signal with a frequency fluctuation compensation signal obtained by adding the output fluctuation amount of the gas turbine 1 due to the governor operation and the output fluctuation amount of the steam turbine 2. Is eliminated, and the shaft governor setting signal is not operated in reverse.

FIG. 2 is a time characteristic diagram showing an operation example of frequency fluctuation compensation in this case.

As shown in FIG. 2, the output of the gas turbine 1 fluctuates instantaneously with respect to the system frequency fluctuation, and the output of the steam turbine 2 fluctuates with a delay. Therefore, by using the signal obtained by adding the two as a frequency fluctuation compensation signal, the shaft load setting signal can be corrected so as to match the fluctuation of the shaft load measurement signal due to the governor operation.

In this way, the reverse operation of the governor operation can be eliminated, and the system operation can be performed stably.

The time constant of the first-order lag calculator 5d may be corrected by the steam pressure or the like depending on the characteristics of the waste heat recovery boiler 4 (determined by the capacity and the like).

Further, instead of the first-order delay calculator 5d, a second-order delay calculator may be used, or the first-order delay calculator 5d may be used.
It is conceivable to further increase the calculation accuracy of the output fluctuation amount of the steam turbine 2 by adding a dead time calculator before d.

As described above, the combined cycle control device of the present embodiment calculates the output of the steam turbine 2 which fluctuates with a delay after the gas turbine fuel fluctuation, and calculates the total fluctuation with the fluctuation of the output of the gas turbine 1. Is used to correct the shaft load setting signal, so that the shaft load measurement signal matches the shaft load setting signal even when the system frequency fluctuates continuously during load operation and the output of the steam turbine 2 fluctuates. Therefore, it is possible to prevent the axis governor setting signal from being operated in the reverse of the governor operation, that is, to prevent the governor operation from being operated in reverse due to the system frequency fluctuation, thereby stabilizing the system operation.

Further, as compared with the conventional device, the proportional calculator 5
c, the first-order delay calculator 5d, and the addition means only need to be added, so that the configuration is not complicated,
It can be easily applied to existing devices.

(Second Embodiment: Claim 2) FIG.
FIG. 19 is a block diagram showing a configuration example of a combined cycle control device according to the present embodiment. The same or corresponding parts as those in FIG. 18 are denoted by the same reference numerals, and description thereof is omitted. State.

The combined cycle control device of the present embodiment is different from the above-described conventional device of FIG. 18 in that a system frequency input, a setting device 5a for setting a rated frequency, and a proportional calculator 5b are respectively provided. Omitted points,
And an axis governor setting signal output from the governor setting device 6a or a signal corresponding thereto is input to the function generator 5e to calculate an axis virtual load when the system is stable. The deviation from the load measurement signal is used as a frequency fluctuation compensation signal, and is added to the axis load setting signal to calculate an axis load correction setting signal. Is output to the axis governor setting device 6.

FIG. 4 is a characteristic diagram showing, as an example of the setting of the function generator 5e, the setting when the adjustment rate is 5%.

That is, the combined cycle control device according to the present embodiment calculates an axis virtual load when the system is stable, based on the axis governor setting signal or a signal corresponding thereto, and calculates the axis virtual load and the axis virtual load. A deviation from the load measurement signal is obtained, and the axis load setting signal is corrected based on the deviation.

Next, in the combined cycle control device of the present embodiment configured as described above, the virtual shaft load when the system is stable can be calculated from the shaft governor setting signal or the equivalent signal. . Then, when the system frequency fluctuates, the amount of fluctuation of the shaft load due to the shaft governor operation at the time of system frequency fluctuation is calculated from the deviation between the shaft virtual load and the shaft load measurement signal to correct the shaft load correction setting signal. Accordingly, even when the system frequency fluctuation continues, the deviation between the shaft load correction setting signal and the shaft load measurement signal is eliminated, and the shaft governor setting signal does not reversely operate.

FIG. 5 is a time characteristic diagram showing an operation example of frequency fluctuation compensation in this case.

As shown in FIG. 5, by correcting the shaft load correction setting signal by the fluctuation amount of the shaft load, the deviation from the shaft load measurement signal is eliminated, and the fluctuation of the shaft governor setting signal can be eliminated.

As described above, the combined cycle control device according to the present embodiment calculates an axis virtual load when the system frequency is stable from the axis governor setting signal or the equivalent signal, and calculates the axis virtual load and the axis virtual load. Since the amount of fluctuation of the shaft load due to the governor operation is calculated from the deviation from the load measurement signal and the shaft load setting signal is corrected, the system frequency fluctuation continues during the load operation and the output of the steam turbine 2 In the case of fluctuation of the shaft load, the shaft load measurement signal and the shaft load setting signal match, so that the shaft governor setting signal is prevented from being operated in the reverse of the governor operation, that is, the governor operation due to system frequency fluctuation is reversed. This makes it possible to stabilize system operation.

Further, as compared with the conventional device, the function generator 5
e and only some addition means, it is possible to make an extremely simple configuration.

(Third Embodiment: Claim 3) FIG. 6
FIG. 19 is a block diagram showing a configuration example of a combined cycle control device according to the present embodiment. The same or corresponding parts as those in FIG. 18 are denoted by the same reference numerals, and description thereof is omitted. State.

The combined cycle control device of the present embodiment differs from the conventional device of FIG. 18 in that the input of the system frequency and the setting device 5a and proportional operation device 5b for setting the rated frequency are respectively provided. Omitted points,
And an axis governor setting signal output from the governor setting device 6a or a signal corresponding thereto is input to the function generator 5e to calculate an axis virtual load when the system is stable. Signal switch 5 for switching the shaft load measurement signal
f, output the shaft load measurement signal during system frequency stabilization, and output the shaft virtual load during system frequency fluctuation, and use the feedback control command based on the deviation from the shaft load setting signal as the shaft load control command. This is the point of outputting to the governor setting device 6.

That is, the combined cycle control device according to the present embodiment calculates an axis virtual load when the system is stable based on the axis governor setting signal or a signal corresponding thereto, and calculates the axis virtual load and the axis virtual load. The load measurement signal is input, and the axis load feedback control is performed based on the deviation between the axis load measurement signal and the axis load setting signal while the system frequency is stable. The configuration is such that axis virtual load feedback control based on the deviation is performed.

Next, in the combined cycle control device of this embodiment configured as described above, when the system frequency fluctuates, the shaft load feedback control starts.
Since control can be switched to feedback using the virtual shaft load when the system frequency is not affected by the delay in steam turbine output fluctuation, the shaft governor setting signal does not reversely operate.

FIG. 7 is a time characteristic diagram showing an operation example of frequency fluctuation compensation in this case.

As shown in FIG. 7, when the system frequency fluctuates,
Since the shaft load setting signal does not deviate from the virtual shaft load, the fluctuation of the shaft governor setting signal can be eliminated.

As described above, in the combined cycle control device of the present embodiment, the shaft virtual load when the system frequency is stable is calculated from the shaft governor setting signal or the equivalent signal, and the system frequency fluctuates. When it is, the axis virtual load feedback control is performed,
Since the shaft governor setting signal can be controlled by following the shaft load setting signal, ignoring the shaft load fluctuation due to the system frequency fluctuation, it is possible to prevent the shaft governor setting signal from operating in the reverse of the governor operation. The governor operation due to the fluctuation is not reversed, thereby making it possible to stabilize the system operation.

The function generator 5 is different from the conventional device.
e, the signal switch 5f and the addition means only need to be configured, so that a very simple configuration can be achieved.

(Fourth Embodiment: Claim 4) FIG.
FIG. 18 is a block diagram showing a configuration example of a combined cycle control device according to the present embodiment. The same or corresponding parts as in FIGS. 18 and 19 are denoted by the same reference numerals, and description thereof is omitted. Only the part will be described.

In the combined cycle control device of the present embodiment, first, the difference from the conventional device of FIG. 18 is that the lower limit of the signal obtained by adding the output from the setter 6c and the output from the proportional calculator 6b. (For example, to limit the maximum output of the gas turbine 1 to 70% or less), and a lower limiter 6d is added.
The output signal from d is used as the shaft speed / load control command, and the gas turbine fuel limit signal obtained by subtracting the output signal from the input signal of the lower limiter 6d is output to the steam turbine speed controller 10. Is a point.

The difference from the conventional apparatus shown in FIG. 19 is that the gas turbine fuel limit signal is input to the steam turbine speed controller 10 and the gas turbine fuel command is equivalently converted into a steam turbine flow rate command at the output level. The difference is that the signal passed through the proportional calculator 10c is added to the output signal from the proportional calculator 10b, and the added signal is used as a steam turbine speed control signal.

That is, in the combined cycle control device of the present embodiment, the lower limit of the gas turbine fuel command is limited by the lower limit value of the gas turbine fuel command, and the deviation between the limited gas turbine fuel command and the shaft governor command is calculated. Based on this, the steam turbine steam flow command is reduced.

Next, in the combined cycle control device of the present embodiment configured as described above, even when the system frequency rise is large and the gas turbine fuel reduction command due to the governor operation is large, the lower limiter 6d controls the gas. The minimum fuel for stable combustion of the turbine 1 can be maintained.

When the fuel reduction operation of the gas turbine 1 due to the governor operation is limited by the lower limiter 6d, the limited output reduction amount, that is, the gas turbine fuel restriction signal is transmitted to the steam turbine speed controller 10. By inputting, the steam flow rate of the steam turbine 2 is reduced.

That is, by reducing the output reduction limit of the gas turbine 1 on the steam turbine 2 side,
The reduction of the shaft output due to the governor operation can be maintained at a predetermined amount.

The lower limiter 6d is activated when the shaft load measurement signal exceeds a predetermined value, and stops operating when the shaft load measurement signal falls below a predetermined value.

That is, during start-up / stop, the lower limit operation is stopped so that the input signal and the output signal of the lower limiter 6d match.

FIG. 9 is a time characteristic diagram showing an operation example of the governor command in this case.

As shown in FIG. 9, when the command to reduce the output of the gas turbine 1 due to the governor operation when the system frequency rises is limited, the output of the steam turbine 2 is reduced to reduce the governor operation amount as the shaft output. It can be quantitative.

In this way, the load zone for stable combustion of the gas turbine 1 can be maintained when the system frequency rises, and the reduction of the shaft output due to the governor operation can be maintained at a predetermined amount.

As described above, in the combined cycle control device of the present embodiment, the lower limit of the gas turbine fuel command is limited when the system frequency rises. It can be maintained.

When the fuel reducing operation of the gas turbine 1 by the governor operation is restricted by the lower limit, the steam turbine 2
Since the output on the side is reduced, it is possible to maintain the reduction of the shaft output due to the governor operation at a predetermined amount.

Thus, both stable operation of the combined cycle power plant and stability of system operation can be satisfied at the same time.

(Fifth Embodiment: Claim 5) FIG.
0 is a block diagram showing a configuration example of the combined cycle control device according to the present embodiment. The same or corresponding parts as in FIGS. 18 and 19 are denoted by the same reference numerals, and description thereof is omitted. Only the different parts will be described.

In the combined cycle control device of the present embodiment, first, the difference from the conventional device of FIG. 18 is that a signal obtained by adding the output from the setter 6c and the output from the proportional calculator 6b is The deviation between the output from the proportional calculator 6b and the output from the proportional calculator 6e for equivalently converting the shaft load measurement signal into a gas turbine fuel command at the output level is given by:
A lower limiter 6d for limiting the lower limit of the signal added as the gas turbine fuel command correction signal is added, and an output signal from the lower limiter 6d is used as a shaft speed / load control command.
The difference is that a gas turbine fuel limiting signal obtained by subtracting the output signal from the input signal of the lower limiter 6d is output to the steam turbine speed controller 10.

The difference from the conventional apparatus shown in FIG. 19 is that the gas turbine fuel limit signal is input to the steam turbine speed controller 10 and the gas turbine fuel command is equivalently converted into a steam turbine flow rate command at the output level. The difference is that the signal passed through the proportional calculator 10c is added to the output signal from the proportional calculator 10b, and the added signal is used as a steam turbine speed control signal.

That is, in the combined cycle control device of the present embodiment, the delay of the output fluctuation of the steam turbine 2 due to the fluctuation of the gas turbine fuel command in the aforementioned combined cycle control device of the fourth embodiment of FIG. , The gas turbine fuel command is used to make correction.

Next, in the combined cycle control device of the present embodiment configured as described above, even when the system frequency rise is large and the gas turbine fuel reduction command due to the governor operation is large, the lower limiter 6d controls the gas. The minimum fuel for stable combustion of the turbine 1 can be maintained.

When the fuel reduction operation of the gas turbine 1 by the governor operation is limited by the lower limiter 6d, the limited output reduction amount, that is, the gas turbine fuel restriction signal is sent to the steam turbine speed controller 10. By inputting, the steam flow rate of the steam turbine 2 is reduced.

That is, by reducing the output reduction limit of the gas turbine 1 on the steam turbine 2 side,
The reduction of the shaft output due to the governor operation can be maintained at a predetermined amount.

Further, in the combined cycle control device according to the fourth embodiment described above, it is not possible to compensate for the delay in the output fluctuation of the steam turbine 2 due to the fluctuation of the gas turbine fuel command when the increase of the system frequency continues. .

In this regard, in the present embodiment, a gas turbine fuel command corresponding to the shaft load measurement signal is calculated, and the deviation between the gas turbine fuel command and the shaft output command is determined by the lower limiter 6.
By adding to the input of d, the output fluctuation of the steam turbine 2 due to the gas turbine fuel command fluctuation is corrected by increasing the output of the gas turbine 1, that is, the steam turbine 2 due to the fluctuation of the gas turbine fuel command is corrected. By absorbing the output fluctuation delay on the gas turbine 1 side,
The shaft output fluctuation amount due to the governor operation can be maintained at a predetermined amount.

The lower limiter 6d is activated when the shaft load measurement signal is equal to or greater than a predetermined value, and is stopped when the signal is equal to or less than the predetermined value.

That is, during start-up / stop, the lower limit operation is stopped so that the input signal and the output signal of the lower limiter 6d match.

FIG. 11 is a time characteristic diagram showing an operation example of the governor command in this case.

As shown in FIG. 11, when the command to reduce the output of the gas turbine 1 due to the governor operation when the system frequency rises is limited, the output of the steam turbine 2 is reduced to reduce the governor operation amount as the shaft output. It can be quantitative.

When the system frequency continues to rise, the output of the steam turbine 2 decreases with the decrease in the output of the gas turbine 1. The amount of decrease in the output of the steam turbine 2 is determined by the gas turbine fuel command. Is increased so that the shaft output is maintained at a predetermined amount.

In this way, the load zone for stable combustion of the gas turbine 1 can be maintained when the system frequency rises, and the reduction in the shaft output due to the governor operation can be maintained at a predetermined amount.

As described above, in the combined cycle control device of the present embodiment, when the fuel reduction operation of the gas turbine 1 due to the governor operation is limited at the lower limit, the limited output reduction amount on the steam turbine 2 side is reduced. In the case where the output is reduced, if the increase of the system frequency continues, the output of the steam turbine 2 decreases due to the decrease in the fuel of the gas turbine 1. Since the correction is performed by increasing the output of the gas turbine 1, it is possible to maintain the shaft output fluctuation amount due to the governor operation at a predetermined amount.

As a result, both stable operation of the combined cycle power plant and stable system operation can be satisfied at the same time.

(Sixth Embodiment: Claim 6) FIG. 1
FIG. 2 is a block diagram showing a configuration example of a combined cycle control device according to the present embodiment. The same or corresponding parts as in FIGS. 18 and 19 are denoted by the same reference numerals, and description thereof is omitted. Only the different parts will be described.

In the combined cycle control device of this embodiment, first, the difference from the conventional device of FIG. 18 is that the lower limit of the signal obtained by adding the output from the setter 6c and the output from the proportional calculator 6b. Lower limiter 6 that limits
d, the output signal from the lower limiter 6d is used as the shaft speed / load control command, and the output from the proportional calculator 6e that converts the shaft load measurement signal into a gas turbine fuel command equivalently at the output level. The deviation from the output from the proportional calculator 6b is added as a steam turbine steam flow rate command correction signal to a signal obtained by subtracting the output signal from the input signal of the lower limiter 6d, and the gas turbine fuel limit signal, which is the added signal, is added. Is output to the steam turbine speed controller 10.

The difference from the conventional apparatus shown in FIG. 19 is that the gas turbine fuel limit signal is input to the steam turbine speed controller 10 and the gas turbine fuel command is equivalent to the steam turbine flow rate command at the output level. The difference is that the signal passed through the proportional calculator 10c to be converted is added from the output signal of the proportional calculator 10b, and this signal is used as a steam turbine speed control signal.

That is, in the combined cycle control device of the present embodiment, the delay of the output fluctuation of the steam turbine 2 due to the fluctuation of the gas turbine fuel command in the aforementioned combined cycle control device of the fourth embodiment of FIG. , And the correction is made by the steam turbine steam flow rate command.

Next, in the combined cycle control device of the present embodiment configured as described above, even when the system frequency rise is large and the gas turbine fuel reduction command due to the governor operation is large, the lower limiter 6d controls the gas. The minimum fuel for stable combustion of the turbine 1 can be maintained.

When the fuel reduction operation of the gas turbine 1 due to the governor operation is limited by the lower limiter 6d, the limited output reduction amount, that is, the gas turbine fuel restriction signal is sent to the steam turbine speed controller 10. By inputting, the steam flow rate of the steam turbine 2 is reduced.

That is, by reducing the output reduction limit of the gas turbine 1 on the steam turbine 2 side,
The reduction of the shaft output due to the governor operation can be maintained at a predetermined amount.

Further, in the combined cycle control device according to the fourth embodiment described above, it is not possible to compensate for the delay in the output fluctuation of the steam turbine 2 due to the fluctuation of the gas turbine fuel command when the increase of the system frequency continues. .

In this respect, in the present embodiment, a gas turbine fuel command corresponding to the shaft load measurement signal is calculated, and a deviation between the gas turbine fuel command and the shaft output command is added to the gas turbine fuel limit signal. As a result, the output fluctuation of the steam turbine 2 due to the gas turbine fuel command fluctuation is reduced by ST
The output is corrected by increasing the output, that is, the output of the steam turbine 2 is increased by absorbing the delay of the output variation of the steam turbine 2 due to the variation of the gas turbine fuel command on the steam turbine 2 side, and the shaft output by the governor operation is increased. The fluctuation amount can be maintained at a predetermined amount.

It should be noted that the lower limiter 6d is activated when the shaft load measurement signal becomes equal to or more than a predetermined value, and is stopped when it becomes equal to or less than the predetermined value.

That is, during start-up / stop, the lower limit limiting operation is stopped so that the input signal and the output signal of the lower limiter 6d match.

FIG. 11 is a time characteristic diagram showing an operation example of the governor command in this case.

As shown in FIG. 11, when the output reduction command of the gas turbine 1 due to the governor operation when the system frequency rises is limited, the output of the steam turbine 2 is reduced, so that the governor operation amount is determined as the shaft output. It can be quantitative.

When the system frequency continues to increase, the output of the steam turbine 2 decreases with the decrease in the output of the gas turbine 1. The amount of decrease in the output of the steam turbine 2 is determined by the gas turbine fuel command. Is increased so that the shaft output is maintained at a predetermined amount.

In this manner, the load zone for stable combustion of the gas turbine 1 can be maintained when the system frequency rises, and the reduction of the shaft output due to the governor operation can be maintained at a predetermined amount.

As described above, in the combined cycle control device of the present embodiment, when the fuel reduction operation of the gas turbine 1 due to the governor operation is limited at the lower limit, the limited output reduction amount is reduced by the steam turbine 2 side. In the case where the output is reduced, if the increase of the system frequency continues, the output of the steam turbine 2 decreases due to the decrease in the fuel of the gas turbine 1. Since the correction is made by increasing the steam flow rate command of the steam turbine 2, it is possible to maintain the shaft output fluctuation amount due to the governor operation at a predetermined amount.

As a result, both stable operation of the combined cycle power plant and stability of the system operation can be satisfied at the same time.

(Seventh Embodiment: Claim 7) FIG. 1
FIG. 3 is a block diagram showing a configuration example of a combined cycle control device according to the present embodiment. The same or corresponding parts as those in FIGS. 18 and 19 are denoted by the same reference numerals, and description thereof is omitted. Only the different parts will be described.

In the combined cycle control device of this embodiment, first, the difference from the conventional device of FIG. 18 is that the shaft governor setting signal output from the governor setting device 6a and the rated shaft speed are set. A deviation from the output from the setter 6f and an output from a function generator 6g for equivalently converting a steam turbine speed control restriction signal, which will be described later, into a gas turbine fuel command at an output level are added to generate a gas turbine fuel command correction signal. The gas turbine fuel command correction signal and the deviation between the shaft governor setting signal and the shaft speed measurement signal are input to the signal switch 6h, and the deviation between the shaft governor setting signal and the shaft speed measurement signal during system frequency stabilization. In addition, a gas turbine fuel command correction signal is input to the proportional calculator 6b during system frequency fluctuation.

Further, the difference from the conventional apparatus of FIG. 19 is that the setting device 10a is omitted and the lower limit of the output signal from the proportional calculator 10b is limited (corresponding to the fully closed position of the steam turbine control valve). The lower limiter 10d that sets the value is added, and the output signal from the lower limiter 10d is used as a steam turbine speed control signal, and the lower limiter 10d is set.
A difference is that a steam turbine speed control limit signal obtained by subtracting the output signal from the input signal is output to the shaft governor controller 6.

That is, in the combined cycle control device of this embodiment, the steam turbine steam flow command is preferentially changed by the shaft governor operation command, and the deviation between the changed steam turbine steam flow command and the shaft governor command is calculated. Based on this, the gas turbine fuel command is reduced.

Next, in the combined cycle control device according to the present embodiment configured as described above, when the system frequency fluctuates, the steam turbine steam flow rate command fluctuates preferentially, and the steam turbine control valve 2a is fully operated. After closing, the gas turbine fuel command will be changed.

Accordingly, when the frequency fluctuation is small,
System operation can be stabilized without changing the load of the gas turbine 1.

Further, even when the frequency fluctuation is large, the stable combustion of the gas turbine 1 can be maintained, and the governor operation can be maintained at a predetermined amount.

The setting of the proportional calculator 10b is changed to a value that gives a 5% adjustment rate.

FIG. 14 is a time characteristic diagram showing an operation example of the governor command in this case.

As shown in FIG. 14, when the system frequency fluctuates, the steam turbine steam flow command fluctuates preferentially, and the gas turbine fuel command fluctuates after the steam turbine control valve 2a is fully closed, thereby stabilizing the gas turbine 1. Combustion can be maintained, and governor operation can be maintained at a predetermined amount.

As described above, in the combined cycle control device of the present embodiment, when the system frequency rises, the output of the steam turbine 2 is first reduced, and when the steam turbine control valve 2a is fully closed, the gas turbine 1 Since the output of the gas turbine 1 is reduced, the reduction of the fuel command of the gas turbine 1 can be limited to when the system frequency rise is large, the stable combustion of the gas turbine 1 can be maintained, and The governor operation can be maintained at a predetermined amount.

Thus, both stable operation of the combined cycle power plant and stability of system operation can be satisfied at the same time.

(Eighth Embodiment: Claim 8) FIG.
FIG. 5 is a block diagram showing a configuration example of the combined cycle control device according to the present embodiment. The same or corresponding parts as those in FIG. 18 are denoted by the same reference numerals, and the description thereof will be omitted. Only mentioned.

Incidentally, reference numerals 6A to 6D in FIG. 15 denote shaft governor controllers provided corresponding to the combined cycles A to D axes, respectively.

Since the configuration of each of the shaft governor controllers 6A to 6D is the same, here, only the shaft governor controller 6A will be described as an example, and other shaft governor controllers 6B to 6D will be described.
The description of D is the same as that of the shaft governor controller 6A, and thus will not be repeated.

The combined cycle control device of the present embodiment differs from the above-described conventional device of FIG. 18 in that a series plant having a plurality of combined cycles (four in this example) is provided. Is 6A-6D
, Each axis governor controller 6A-6D
And a lower limiter 6dA for limiting the lower limit of the signal obtained by adding the output from the setter 6cA and the output from the proportional calculator 6bA and the signal obtained by adding the fuel limit signal from the other axis. The point that the output signal from the limiter 6dA is used as the shaft speed / load control command, and the gas turbine fuel limit signal obtained by subtracting the output signal from the input signal of the lower limiter 6dA are output to another shaft governor controller 6B. It is the point which did so.

That is, in the combined cycle control device of the present embodiment, the lower limit of the gas turbine fuel command for each of the axes A to D is limited by the lower limit of the fuel command of the gas turbine 1. And a gas turbine fuel command for another shaft is reduced based on a deviation between the governor command and a governor command for a predetermined shaft.

Next, in the combined cycle control device of the present embodiment configured as described above, the plurality of shaft governor controllers 6 are numbered so that the gas turbine fuel restriction signals are passed in numerical order. The last numbered gas turbine fuel restriction signal is passed to the first number.

For example, in a system plant in which four shaft governor controllers 6 of 6A to 6D are provided and the gas turbine 1 has a minimum stable load of 60%, the A-axis is operated at 100%, and the When the axis is operated at 70%, the C axis is 75%, and the D axis is 90%, the system frequency is increased by 1% and the load on each axis A to D is reduced by 20% by the axis governor operation. The situation at the time of operation is as follows.

FIG. 16 is a time characteristic diagram showing an operation example of a governor command for each of the axes A to D in this case.

As shown in FIG. 16, the load on the B-axis is reduced by 10% from 70% load to 60% of the minimum load, but the unacceptable remaining 10% of the load limiting signal LB is passed to the C-axis.

The C axis has a total of 30
% Load reduction is required, but since only 15% can reduce the load, the unacceptable remaining 15% load limit signal LC is passed to the D axis.

The D-axis is 35 in accordance with the governor operation of its own system.
% Load reduction is required, but since the load can only be reduced by 30%, the unacceptable remaining 5% load limit signal LD is passed to the A-axis.

The A-axis has a total of 25
% Load reduction.

In FIG. 16, for simplification of the expression, the operation is performed such that the operation by the load limiting signal from the other system occurs as an extension of the governor operation of the own system.
The governor operation of the own system and the operation by the load limiting signal from the other system operate simultaneously. Therefore, the governor of each system operates in synchronization with the system frequency fluctuation.

Further, in the above description, the gas turbine fuel limiting signal is passed continuously in an orderly manner as an example. However, the present invention is not limited to this, and the load limiting signal is passed in a series plant having a fixed operation pattern. The tip may be fixed.

In this way, when the system frequency increases, the load zones for stable combustion of the plurality of gas turbines 1 can be respectively maintained, and the decrease in shaft output due to the governor operation is maintained at a predetermined value as a series. can do.

Although the present embodiment has been described as a combined cycle power plant, a gas turbine power plant without a steam turbine is also described.
The same effect as described above can be obtained.

As described above, in the combined cycle control device of the present embodiment, when the system frequency rises, the lower limit of the gas turbine fuel command for each of the axes A to D is limited. It is possible to maintain the stable combustion load zone of the gas turbine 1.

Further, when the fuel reduction operation of the gas turbine 1 by the governor operation on the predetermined shaft is limited by the lower limit, the output of the gas turbine 1 on the other shaft is reduced, so that the shaft output by the governor operation is reduced. Can be maintained at a predetermined amount as a series.

Thus, both stable operation of the combined cycle power plant and stability of system operation can be satisfied at the same time.

In this embodiment, an example in which the present invention is applied to a combined cycle power plant is described. However, the present invention is not limited to this, and the present invention is similarly applied to a series plant including a plurality of gas turbines. Is what you can do.

[0188]

As described above, according to the first to third aspects of the present invention, the steam turbine output fluctuating with a delay after the gas turbine fuel fluctuation is calculated, and the total fluctuation with the gas turbine output fluctuation amount is calculated. The shaft load setting signal by the amount
Calculate the axis virtual load when the system frequency is stable from the axis governor setting signal or equivalent signal, and calculate the amount of fluctuation of the axis load due to governor operation from the deviation between this axis virtual load and the axis load measurement signal. Correct the load setting signal, or calculate the virtual axis load when the system frequency is stable from the axis governor setting signal or equivalent signal, and perform the virtual axis load feedback control when the system frequency fluctuates. Therefore, even when the system frequency fluctuates and the steam turbine output fluctuates, combined cycle control that can prevent the shaft governor setting signal from being operated in the reverse of the governor operation and stabilize system operation Equipment can be provided.

According to the invention of claims 4 to 7, the lower limit of the gas turbine fuel command is limited when the system frequency rises, and the gas turbine fuel reduction operation due to the governor operation is limited by the lower limit. Reduce the output on the turbine side, and if necessary, correct the delay in the output fluctuation of the steam turbine due to the fluctuation of the gas turbine fuel command with the gas turbine fuel command or the steam turbine steam flow rate command, or change the system frequency. Reduces steam turbine output when rising,
When the steam turbine control valve is fully closed, the output on the gas turbine side is reduced, so that even when the system frequency rises greatly, the load zone for stable combustion of the gas turbine is maintained and the governor operation amount is maintained. Can be provided at a predetermined amount.

As a result, both stable operation of the combined cycle power plant and stability of system operation can be satisfied at the same time.

Further, according to the invention of claim 8, when the system frequency rises, the lower limit of the gas turbine fuel command of each shaft is limited, and the gas turbine fuel reduction operation by the governor operation on the predetermined shaft is limited by the lower limit. Since the output of the gas turbine of other shafts is sometimes reduced, it is possible to maintain the load zone for stable combustion of the gas turbine and maintain the governor operation amount to a predetermined amount even when the system frequency rise is large. A possible gas turbine control device can be provided.

As a result, it is possible to simultaneously satisfy both the stable operation and the stable system operation of the affiliated plant constituted by providing a plurality of gas turbines.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a combined cycle control device according to a first embodiment of the present invention.

FIG. 2 is a time characteristic chart showing an operation example of frequency fluctuation compensation in the combined cycle control device according to the first embodiment.

FIG. 3 is a block diagram showing a combined cycle control device according to a second embodiment of the present invention.

FIG. 4 is a characteristic diagram showing an example of a function generator for calculating a virtual shaft load in the combined cycle control device according to the second embodiment.

FIG. 5 is a time characteristic diagram showing an operation example of frequency fluctuation compensation in the combined cycle control device according to the second embodiment.

FIG. 6 is a block diagram showing a combined cycle control device according to a third embodiment of the present invention.

FIG. 7 is a time characteristic chart showing an operation example of frequency fluctuation compensation in the combined cycle control device according to the third embodiment.

FIG. 8 is a block diagram showing a combined cycle control device according to a fourth embodiment of the present invention.

FIG. 9 is a time characteristic diagram showing an operation example of a governor command in the combined cycle control device according to the fourth embodiment.

FIG. 10 is a block diagram showing a combined cycle control device according to a fifth embodiment of the present invention.

FIG. 11 is a time characteristic diagram showing an operation example of a governor command in the combined cycle control device according to the fifth embodiment.

FIG. 12 is a block diagram showing a combined cycle control device according to a sixth embodiment of the present invention.

FIG. 13 is a block diagram showing a combined cycle control device according to a seventh embodiment of the present invention.

FIG. 14 is a time characteristic diagram showing an operation example of a governor command in the combined cycle control device according to the seventh embodiment.

FIG. 15 is a block diagram showing an eighth embodiment of the combined cycle control device according to the present invention.

FIG. 16 is a time characteristic diagram showing an operation example of a governor command in the combined cycle control device according to the eighth embodiment.

FIG. 17 is a block diagram showing a configuration example of a general single-shaft combined cycle power plant.

18 is a block diagram showing a configuration example of a conventional shaft load control device and a conventional shaft governor control device in the single-shaft combined cycle power plant shown in FIG.

19 is a block diagram showing a configuration example of a conventional steam turbine speed control device in the single-shaft combined cycle power plant of FIG.

FIG. 20 is a diagram showing an operation example of a conventional combined cycle shaft load control device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Gas turbine, 2 ... Steam turbine, 2a ... Steam turbine control valve, 3 ... Generator, 4 ... Waste heat recovery boiler, 5 ... Shaft load controller, 5a ... Setting device, 5b ... Proportional calculator, 5c ... Proportion 5d: first-order lag calculator, 5e: function generator, 5f: signal switcher, 6: axis governor controller, 6a: governor setting device, 6b: proportional calculator, 6c: setting device, 6d: lower limit 6e: proportional calculator, 6f: setting device, 6g: function generator, 6h: signal switcher, 7: exhaust gas temperature controller, 8: shaft start controller, 9: low value selector, 10: steam turbine Speed controller, 10a: setting device, 10b: proportional operation device, 10c: proportional operation device, 10d: lower limiter, 11: schedule controller, 12: low value selector.

Claims (8)

[Claims] A gas turbine, a steam turbine, and a generator are arranged on one axis, and the exhaust heat of the gas turbine is converted into steam energy by an exhaust heat recovery boiler to generate torque of the steam turbine. A shaft load control device for a single-shaft combined cycle power plant, comprising: means for calculating an output change amount of the gas turbine due to a change in system frequency; and means for calculating an output change amount of the steam turbine due to a change in the system frequency. And adding the gas turbine output fluctuation amount and the steam turbine output fluctuation amount calculated by the respective means to obtain a total fluctuation amount,
Means for correcting the shaft load setting signal based on the total fluctuation amount. 2. A configuration in which a gas turbine, a steam turbine, and a generator are arranged on one axis, and the exhaust heat of the gas turbine is converted into steam energy by an exhaust heat recovery boiler to generate torque of the steam turbine. A shaft load control device for a single-shaft combined cycle power plant, comprising: means for calculating a shaft virtual load when the system is stable, based on a shaft governor setting signal or a signal equivalent thereto, Means for obtaining a deviation between the shaft virtual load and the shaft load measurement signal, and correcting the shaft load setting signal based on the deviation. 3. A configuration in which a gas turbine, a steam turbine, and a generator are arranged on one axis, and exhaust heat of the gas turbine is converted into steam energy by an exhaust heat recovery boiler to generate torque of the steam turbine. A shaft load control device for a single-shaft combined cycle power plant, comprising: means for calculating a shaft virtual load when the system is stable, based on a shaft governor setting signal or a signal equivalent thereto, The axis virtual load and the axis load measurement signal are input, and the axis load feedback control is performed based on the deviation between the axis load measurement signal and the axis load setting signal while the system frequency is stable. Switching means for switching to perform axis virtual load feedback control based on the deviation between the load and the axis load setting signal. Unbound cycle control device. 4. A structure in which a gas turbine, a steam turbine, and a generator are arranged on one axis, and the exhaust heat of the gas turbine is converted into steam energy by an exhaust heat recovery boiler to generate torque of the steam turbine. A shaft governor control apparatus for a single-shaft combined cycle power plant, comprising: means for restricting a lower limit of a gas turbine fuel command by a lower limit of a fuel command of the gas turbine; Means for reducing the steam turbine steam flow rate command based on a deviation from the command. 5. The combined cycle control device according to claim 4, wherein a means for correcting a delay in output variation of the steam turbine due to a variation in the gas turbine fuel command with a gas turbine fuel command is added. A combined cycle control device characterized by the following. 6. The combined cycle control device according to claim 4, further comprising means for correcting a delay in output fluctuation of the steam turbine due to a change in the gas turbine fuel command with a steam turbine steam flow rate command. A combined cycle control device, characterized in that: 7. A configuration in which a gas turbine, a steam turbine, and a power generator are arranged on one axis, and exhaust heat of the gas turbine is converted into steam energy by an exhaust heat recovery boiler to generate torque of the steam turbine. In the shaft governor control device of the single-shaft combined cycle power plant, means for preferentially changing the steam turbine steam flow command by the shaft governor operation command, and the steam turbine steam flow command and the shaft governor command changed by the means. Means for reducing the gas turbine fuel command based on the deviation of the combined cycle control device. 8. A shaft governor control device of a series plant including a plurality of gas turbines, wherein: a means for limiting a lower limit of a gas turbine fuel command for each shaft by a lower limit value of a fuel command of the gas turbine; Means for reducing a gas turbine fuel command for another shaft based on a deviation between the gas turbine fuel command limited by the means and a governor command for a predetermined shaft.