JP7328155B2 - Steam turbine controller and steam turbine generator - Google Patents

Description

The present invention relates to a steam turbine control device and steam turbine power generation equipment.

A steam turbine is generally driven by steam supplied through a steam control valve. In steam turbine power generation equipment in which a generator is driven by a steam turbine, the rotation speed deviation between the measured rotation speed (actual rotation speed) and the target rotation speed (for example, rated rotation speed) of the steam turbine is a function of the speed regulation rate (hereinafter referred to as speed adjustment rate function) may be set (see Patent Document 1, etc.).

In such steam turbine power generation equipment, while the generator is connected in parallel (combined) with the power system (for example, commercial power system), the opening of the steam control valve is controlled according to the rotation speed deviation under the speed regulation function. be done. For example, if the measured rotation speed of the steam turbine is lower than the target rotation speed, the steam control valve is opened by a ratio corresponding to the rotation speed deviation from the current opening, and the working fluid supply flow rate is increased to increase the steam turbine. increase the number of revolutions of Conversely, if the measured rotation speed of the steam turbine is higher than the target rotation speed, the steam control valve is closed by a rate corresponding to the rotation speed deviation from the current opening, and the working fluid supply flow rate is reduced to reduce the steam Decrease the turbine speed. Such feedback control allows the rotation speed of the steam turbine to converge to the target rotation speed, thereby stabilizing the system frequency.

JP-A-3-92505

In recent years, the number of cases where power generation equipment using natural energy such as wind power and sunlight is connected to the power system has increased, and the proportion of such power generation equipment in the power system has also increased. However, the output of power generation equipment that uses such natural energy is likely to fluctuate depending on the season, time, weather conditions, etc., and this is one of the causes of system frequency instability. In a steam turbine power generation facility in which a power generator is connected in parallel with the electric power system, such fluctuations in the system frequency may cause the rotational speed of the steam turbine to fluctuate, thereby destabilizing the power output.

At this time, when the opening degree of the steam control valve and the rotation speed deviation are set to be in a simple proportional relationship, when the rotation speed of the steam turbine abruptly changes, the opening degree of the steam control valve also changes abruptly. For example, if the system frequency suddenly changes while the steam turbine speed is statically stable near the target speed, the steam turbine speed may drop sharply under the influence of the system frequency. In this case, the flow rate of steam supplied to the steam turbine increases more than necessary, and hunting or the like may occur, and the rotation speed of the steam turbine may become unstable.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a steam turbine control device and a steam turbine power generation facility that can suppress sensitive changes in the degree of opening of a steam control valve and smoothly converge the rotation speed of a steam turbine to a target rotation speed or its vicinity. to do.

In order to achieve the above object, the present invention provides a boiler for generating steam, a steam turbine driven by the steam supplied from the boiler, a generator driven by the steam turbine, and a steam generator from the boiler. A steam turbine power generation facility equipped with a steam control valve for adjusting a flow rate of steam supplied to a turbine, and a rotational speed deviation, which is a difference between a measured rotational speed of the steam turbine and a preset target rotational speed, is reduced. The steam turbine control device for controlling the steam control valve includes a storage device and an arithmetic device, and the storage device stores a target rotation speed of the steam turbine and an operation amount of the steam control valve. A plurality of options preset for each value of the rotation speed deviation and a limit change rate preset for a change in the speed regulation rate are stored, and the arithmetic unit stores, for each value of the rotation speed deviation A speed regulation rate function is defined by the manipulated variable arbitrarily selected from the options , the opening of the steam control valve is controlled according to the rotational speed deviation under the defined speed regulation rate function, and the rotation When the selection of the manipulated variable is changed for at least one of the individual values of the numerical deviation, the current speed regulation rate function is transitioned to the changed speed regulation rate function at the limited rate of change. It is characterized by

According to the present invention, it is possible to suppress sensitive changes in the degree of opening of the steam control valve and to smoothly converge the rotational speed of the steam turbine to or near the target rotational speed.

Schematic diagram showing the configuration of a turbine control device according to an embodiment of the present invention. Graph showing the speed regulation function (basic function) of the steam turbine defined by the relationship between the rotation speed deviation and the operation amount of the steam control valve Graph showing the steam turbine speed regulation function (function with adjustment) defined by the relationship between the rotational speed deviation and the operation amount of the steam control valve 1 is a flow chart showing a switching operation of a speed regulation rate by a steam turbine control device according to an embodiment of the present invention; Waveform diagram showing an example of how the speed regulation rate and the like transition along with the switching operation in FIG.

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

-composition-
FIG. 1 is a schematic diagram showing the configuration of a steam turbine power generation facility according to one embodiment of the present invention. The steam turbine power generation facility shown in FIG.

The boiler 1 heats water supplied by a feedwater pump (not shown) to generate steam, which is supplied to the steam turbine 2 . Although the heat source of the boiler 1 is not shown, representative examples of the heat source of the boiler 1 are, for example, gas turbine exhaust gas, combustion heat of fuel, nuclear reactor, and the like.

Steam turbine 2 is driven by steam supplied from boiler 1 . The steam that has driven the steam turbine 2 is led to a condenser (not shown), returned to water, and supplied to the boiler 1 again by a feed water pump (not shown).

The rotor of the generator 3 is coaxially connected to the rotor of the steam turbine 2 . The generator 3 is driven by the rotational power of the steam turbine 2 to generate electricity. The generator 3 is connected to a power system (for example, a commercial power system). In addition to the steam turbine power generation facility shown in FIG. 1, at least one other power generation facility (not shown) is connected to the power system. Other power generation facilities connected to the power system may include power generation facilities that generate power using natural energy (renewable energy) such as wind power and sunlight.

The steam control valve 4 is an electromagnetically driven valve and adjusts the flow rate of steam supplied from the boiler 1 to the steam turbine 2 . The basic degree of opening of the steam control valve 4 is an intermediate degree of opening (for example, 50% degree of opening). As the opening degree of the steam control valve 4 increases, the flow rate of steam supplied to the steam turbine 2 increases, and the output of the steam turbine 2 and thus the power generation amount of the generator 3 increase. Conversely, when the degree of opening of the steam control valve 4 decreases, the flow rate of steam supplied to the steam turbine 2 decreases, and the output of the steam turbine 2 and thus the amount of power generated by the generator 3 decreases.

The steam turbine power generation facility is equipped with a rotation speed sensor 5 that measures the rotation speed of the steam turbine 2 . The measured rotation speed Xm of the steam turbine 2 measured by the rotation speed sensor 5 is inputted to the rotation speed deviation calculation circuit 13 of the steam turbine control device 10 .

The steam turbine control device 10 is a computer, and includes a memory (storage device) 11, a CPU (arithmetic device) 12, a timer (not shown), and the like. The steam turbine control device 10 adjusts the steam control valve 4 so that the rotation speed deviation X (=Xm-Xt), which is the difference between the measured rotation speed Xm of the steam turbine 2 and the preset target rotation speed Xt, becomes small. It has the ability to control In particular, the steam turbine control device 10 of the present embodiment defines a speed regulation rate function with the operation amount (correction amount) of the steam control valve 4 selected for each value of the rotational speed deviation X as described later, and the defined speed It is configured to control the opening degree of the steam control valve 4 according to the rotational speed deviation X under the regulation rate function. The steam control valve 4 is controlled by the steam turbine control device 10 according to the rotational speed deviation X, so that the rotational speed of the steam turbine 2 converges to or near the target rotational speed Xt. Whether the rotation speed of the steam turbine 2 converges to the target rotation speed Xt or converges to the target rotation speed Xt or its vicinity depends on how the speed regulation rate function is designed as will be described later with reference to FIGS. depending on whether it is done.

An example of the target rotation speed Xt is the rated rotation speed. The rated rotation speed is the rotation speed of the steam turbine 2 under the operating conditions of the steam turbine 2 specified by the manufacturer.

The memory 11 of the steam turbine control device 10 stores programs related to control of the steam control valve 4 and data necessary for executing the programs. The programs and data stored in the memory 11 are read into the CPU 12, and the CPU 12 controls the steam control valve 4 according to the value of the rotation speed deviation X. The data stored in the memory 11 includes a plurality of preset options (described later) for each value of the rotation speed deviation X for the operation amount Y of the steam control valve 4 . Here, in this embodiment, each value of the rotational speed deviation X is appropriately represented as Xn (n=natural number). The difference between Xn and Xn-1 can be the minimum difference between the two values of the rotational speed that can be identified according to the resolution of the rotational speed sensor 5. do. In other words, each value Xn of the rotation speed deviation X is an arbitrarily set constant. A plurality of options Yn1 and Yn2 of two operation amounts Y are associated with each value Xn of the rotational speed deviation X and set. The memory 11 stores individual values Xn of the rotational speed deviation X and a plurality of options Yn1 and Yn2 of the manipulated variable Y set for each value Xn. The operator can arbitrarily select the value of the manipulated variable Y for each value Xn of the rotational speed deviation X from options Yn1 and Yn2 using the input device 20 . The input device 20 is a user interface for inputting a speed regulation rate switching signal Ss (described later) and the like to the steam turbine control device 10 .

In addition to the manipulated variable Y, the memory 11 also stores data such as a target rotational speed Xt of the steam turbine 2 and a preset limit change rate R for changes in the speed regulation rate of the steam turbine 2 . The limited rate of change R is the amount of change in the manipulated variable Y per unit time when the value of the manipulated variable Y defining the speed adjustment rate is changed from one value to another value for a certain value Xn of the rotational speed deviation X. It is the specified value for That is, in the present embodiment, when the selection of the operation amount Y is changed from the first option Yn1 to the second option Yn2 for a certain rotation speed deviation Xn, the first option Yn1 is changed to the second option Yn2 at a constant rate in terms of time. The value of the manipulated variable Y changes. Simultaneously with the switching operation, the value of the manipulated variable Y is not temporally discretely switched to the second option Yn2, but the manipulated variable Y starts to change due to the switching operation, and gradually changes from the first option Yn1 to the second option Yn2. Transition and switch over time.

The CPU 12 includes a rotation speed deviation calculation circuit 13 , a speed regulation rate switching circuit 14 , a manipulated variable calculation circuit 15 and an opening command value calculation circuit 16 . The speed adjustment rate switching circuit 14 further includes a selection circuit 17 and a change rate limiting circuit 18 . In other words, the CPU 12 configures the rotation speed deviation calculation circuit 13, the speed regulation rate switching circuit 14, the manipulated variable calculation circuit 15, and the opening command value calculation circuit 16, and executes the function of each circuit according to the program.

A rotational speed deviation calculation circuit 13 calculates a rotational speed deviation X (=Xm-Xt), which is the difference between the measured rotational speed Xm measured by the rotational speed sensor 5 and the target rotational speed Xt stored in the memory 11, Output to the manipulated variable calculation circuit 15 .

The speed regulation rate switching circuit 14 selects the operation amount Y for each value Xn of the rotation speed deviation X by the selection circuit 17 based on the speed regulation rate switching signal Ss input from the input device 20 in response to the operator's switching operation. A value is selected from options Yn1 and Yn2 and output to the change rate limiting circuit 18 . The speed regulation rate switching signal Ss is a signal containing ON/OFF data for each value Xn of the rotational speed deviation X, for example. For example, the rotation speed deviation X1 will be described. For example, when the rotational speed deviation X1 setting in the speed regulation rate switching signal Ss is ON, the selection circuit 17 selects the first option Y11 as the manipulated variable Y corresponding to the rotational speed deviation X1. Then, data (X1, Y11) defining a speed adjustment rate function for the rotational speed deviation X1 is output from the selection circuit 17 to the change rate limiting circuit 18. FIG. Conversely, when the rotation speed deviation X1 is set to OFF in the speed regulation rate switching signal Ss, the second option Y12 is selected as the manipulated variable Y corresponding to the rotation speed deviation X1. Then, data (X1, Y12) defining a speed regulation rate function for the rotational speed deviation X1 is output from the selection circuit 17 to the change rate limiting circuit 18. FIG.

The speed adjustment rate switching circuit 14 also adds the data of the limit change rate R stored in the memory 11 to the data output from the selection circuit 17 by the change rate limiting circuit 18 and outputs the data to the manipulated variable calculation circuit 15 .

The manipulated variable calculation circuit 15 generates a speed regulation rate function based on the data input from the speed regulation rate switching circuit 14, and adjusts the steam according to the current rotation speed deviation X calculated by the rotation speed deviation calculation circuit 13. The operation amount Y of the valve 4 is calculated and output to the opening command value calculation circuit 16 . At this time, when the selection of the manipulated variable Y is changed for at least one of the individual values Xn of the rotational speed deviation X, the speed regulation rate function is changed from the current speed regulation rate function to the changed speed regulation rate function. Transition at rate R. For example, assuming that the limited rate of change R defines the amount of change in the manipulated variable Y per unit time t as k (%), the value of the manipulated variable Y is changed from Yn1 to Yn2 for the rotational speed deviation X1. . In this case, the value output after time t is (Yn1+k) and the value output after time 2t is (Yn1+2k) for the manipulated variable Y corresponding to the rotation speed deviation X1, and the value of the manipulated variable Y gradually changes. To go. If there is a difference of 10k (%) between the manipulated variables Yn1 and Yn2, it takes 10t from the start to the completion of switching the value of the manipulated variable Y for the rotational speed deviation X1.

The opening command value calculation circuit 16 adds the manipulated variable Y input from the manipulated variable calculation circuit 15 to the basic value Sv0 of the opening command for the steam control valve 4, and uses this as the opening command value Sv for the steam control valve 4. output to As a result, the opening degree of the steam control valve 4 is controlled to the opening degree command value Sv. Note that the basic value Sv0 of the opening command is calculated according to the load command S1 input to the steam turbine control device 10 from the host controller (not shown) according to the required power generation amount from the central load dispatching center, for example. It is the degree of opening of the steam control valve 4 . This basic value Sv0 is a value calculated based on the specifications of the steam turbine power generation equipment without considering the measured rotation speed Xm, and is a constant value if the required power generation amount is constant.

2 and 3 are graphs showing the steam turbine speed regulation rate function (steam control valve control characteristic) defined by the relationship between the rotation speed deviation and the operation amount of the steam control valve. FIG. 3 illustrates the adjusted function. In the graphs of FIGS. 2 and 3 , the horizontal axis represents the rotation speed deviation X (rpm), and the vertical axis represents the operation amount Y (%) of the steam control valve 4 . The graphs shown in FIGS. 2 and 3 correspond to graphical representations of examples of the speed adjustment rate function generated by the manipulated variable calculation circuit 15. FIG.

In this embodiment, the positive and negative values of the rotation speed deviation X (=Xm-Xt) are distinguished. X>0 when Xm>Xt, X=0 when Xm=Xt, and X<0 when Xm<Xt take. X1 and X2 illustrated in FIGS. 2 and 3 are negative values, and X3 and Xa are positive values. a is one of the values of n.

In this embodiment, the first option Yn1 for the operation amount Y is set to a different value for each value Xn of the rotational speed deviation X. Selecting the first option Yn1 for all the values Xn of the rotation speed deviation X defines the basic function of the speed regulation rate shown in FIG. Under this basic function, the manipulated variable Y decreases in proportion to the rotational speed deviation X through the origin (0, 0). That is, if the rotational speed deviation X>0, the operation amount Y increases in the valve closing direction in proportion to the magnitude (absolute value) of the rotational speed deviation X, and the opening degree of the steam control valve 4 reaches its current value. On the other hand, it decreases by the magnitude (absolute value) of the manipulated variable Y. On the contrary, if the rotation speed deviation X<0, the operation amount Y increases in the valve opening direction in proportion to the magnitude (absolute value) of the rotation speed deviation X, and the opening degree of the steam control valve 4 reaches the current value. On the other hand, it increases by the magnitude (absolute value) of the manipulated variable Y. When the rotation speed deviation X=0, the operation amount Y is 0 (zero), so the opening degree of the steam control valve 4 is maintained at the current value. Therefore, the rotation speed of the steam turbine 2 is feedback-controlled so as to converge to the target rotation speed Xt.

On the other hand, the second option Yn2 is set to 0 (zero). The graph of FIG. 3 shows an example in which the selection of the manipulated variable Y of the rotational speed deviations X2 and X3 is changed from the basic function of FIG. 2 to the second options Y22 and Y32 (=0). According to the speed regulation rate function after adjustment illustrated in FIG. Openness is maintained. In the example of FIG. 3, the rotation speed of the steam turbine 2 is set so that the rotation speed deviation X falls within the range X2-X3 in which the second option Yn2 is selected, that is, at or near the target rotation speed Xt. It is feedback controlled to converge.

-motion-
FIG. 4 is a flow chart showing the switching operation of the speed regulation rate by the steam turbine control device. FIG. 5 is a waveform diagram showing an example of how the speed regulation rate and the like change along with the switching operation of FIG. The vertical axis of each waveform diagram shown in FIG. 5 indicates the magnitude of each parameter, and the horizontal axis is a common time axis. Here, the case of switching the speed adjustment rate function from the function shown in FIG. 2 to the function shown in FIG. 3 will be described as an example. In order to facilitate understanding, a state in which the rotation speed deviation X is constant at X2 will be described as an example. The number Xm is controlled and converges to the target rotation speed Xt or its vicinity.

・START
First, with the speed regulation rate function defined as shown in FIG. 2, a speed regulation rate switching signal Ss for switching to the speed regulation rate function shown in FIG. 3 is input to the steam turbine controller 10 at time T0 shown in FIG. Suppose it was As a result, the steam turbine control device 10 starts executing the procedure of FIG. 4 at time T0. The speed regulation rate switching signal Ss defining the speed regulation rate in FIG. 3 includes information such as {(X1, X2, X3, . . . Xa)=(ON, OFF, OFF, .

・Step S101
When the procedure of FIG. 4 is started, the steam turbine control device 10 selects one of the manipulated variables Yn1 and Yn2 for each rotation speed deviation Xn in the selection circuit 17 based on the speed regulation rate switching signal Ss in step S101, These data are output to the change rate limiting circuit 18 . Here, the data input to the change rate limiting circuit 18 are {(X1, Y11), (X2, Y22), (X3, Y32), . . . (Xa, Ya1)}.

・Step S102
When the procedure moves to step S102 , the steam turbine control device 10 outputs the data generated by the selection circuit 17 and the limit change rate R (=k/t) to the manipulated variable calculation circuit 15 .

・Step S103-END
In subsequent steps S103 and S104, the steam turbine control device 10 limits the speed regulation rate function from the function shown in FIG. 2 to the function shown in FIG. A transition is made at a rate of change R. For example, after time t from time T0, a speed regulation rate function is generated based on data {(X1, Y11), (X2, Y22-k), (X3, Y32+k), . . . (Xa, Ya1)} (step S103 ). Then, it is determined whether the speed adjustment rate function after time t matches the function in FIG. 3 (step S104). In this determination, consistency with the data {(X1, Y11), (X2, Y22), (X3, Y32), . . . (Xa, Ya1)} of the speed regulation rate function in FIG. If the determination in step S104 is not satisfied, the steam turbine control device 10 returns the procedure to step S103. Then, the steam turbine control device 10 outputs the data {(X1, Y11), (X2, Y22-2k), (X3, Y32+2k), . is generated, and the determination in step S104 is performed again.

As a result, the manipulated variable Y of the rotational speed deviation X2 is reduced from Y21 by k per time t, that is, at the limit rate of change R to Y22. Similarly, the manipulated variable Y of the rotational speed deviation X3 increases from Y31 to Y32 by k per time t. If there is a difference of 10k between Y21 and Y22, the procedure of steps S103 and S104 is repeated 10 times, and after 10t (=time T1), the transition of the manipulated variable Y for the rotational speed deviation X2 is completed (FIG. 5). . At this time, for example, if the difference between Y31 and Y32 is greater than 10k and the transition of the manipulated variable Y for the rotational speed deviation X3 has not been completed, the procedure of step S103 is repeated until the determination of step S104 is satisfied. Conversely, if the difference between Y31 and Y32 is 10 k or less, and the transition of the manipulated variable Y for the rotational speed deviation X3 has already been completed when the transition of the manipulated variable Y for the rotational speed deviation X2 is completed, the switching of the speed regulation rate is completed. Then, the steam turbine control device 10 ends the flow of FIG.

In this example, the rotational speed deviation X=X2. In switching the speed regulation rate function to the function of FIG. 3, the manipulated variable Y of the rotational speed deviation X2 transitions from Y21 to Y22 from time T0 to T1 as shown in FIG. Therefore, from time T0 to T1, the opening degree command value Sv of the steam control valve 4 is calculated based on the speed regulation rate during transition. As a result, from time T0 to T1, even if the rotational speed deviation X is constant at X2, the opening command value Sv linearly decreases by the difference between the manipulated variables Y21 and Y22 over time 10t (FIG. 5). .

-effect-
In general, in steam turbine power generation equipment, a speed regulation rate function is defined in which the rotation speed deviation and the opening degree of the steam control valve are defined in a simple proportional relationship, as shown in FIG. Depending on the steam turbine power plant and at times, a speed regulation rate function such as that of FIG. 2 may be appropriate. However, there are tendencies in how the rotation speed deviation occurs for each steam turbine power generation facility, or depending on the time and season. In some cases, it immediately turns to the suppression direction without correcting the degree. As for the rotational speed deviation, which can be naturally settled immediately without correcting the opening of the steam control valve, if the opening of the steam control valve changes excessively, for example, hunting will occur and the target speed of the steam turbine will not be reached. It may take time to converge at or near the number of revolutions.

In contrast, in the present embodiment, the value of the manipulated variable Y can be selected from a plurality of options Yn1 and Yn2 prepared for each value Xn of the rotational speed deviation X to design the speed regulation rate. For example, if a specific range of rotation speed deviation X is found from the past operational performance data of the steam turbine power generation equipment, which is not preferable when the opening of the steam control valve changes excessively, options Yn1, Yn1, Yn2 with a smaller absolute value is selected. As a result, it is possible to prevent the valve opening from changing more than necessary while the rotation speed deviation X is changing within the specific range. In particular, in the present embodiment, the second option Yn2 of the manipulated variable Y is set to 0 for each rotation speed deviation Xn, so a kind of dead zone can be ensured in a specific range by selecting the second option Yn2. In this case, the opening degree of the steam control valve 4 can be maintained as long as the rotational speed deviation X remains within the specific range.

Further, for example, when changing the selection of the operation amount Y for the rotational speed deviation Xn in a specific range, it is assumed that the rotational speed deviation Xn may coincide with the current rotational speed deviation. In such a case, if the speed regulation rate switching signal Ss is input and the speed regulation rate function is discretely switched from the function shown in FIG. 2 to the function shown in FIG. , and the opening of the steam control valve 4 changes suddenly.

With respect to this point, in the present embodiment, the speed adjustment rate function is changed at the limit change rate R so as to be switched over time. As described above with reference to FIG. 5, even if the selection of the manipulated variable Y is changed with respect to the rotational speed deviation currently occurring in the steam turbine 2, a sudden change in the opening degree of the steam control valve 4 can be suppressed. .

As described above, according to the present embodiment, the speed of the steam turbine 2 can be smoothly converged to or near the target speed Xt by suppressing sensitive changes in the degree of opening of the steam control valve 4 .

-Modification-
Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and can be appropriately modified in design as long as it does not depart from the gist of the present invention described in the scope of claims. .

For example, it is not always necessary to include 0 in the options for the manipulated variable Y for each value Xn of the rotational speed deviation X. Further, the number of options prepared as the value of the manipulated variable Y for each value Xn of the rotational speed deviation X does not need to be two, and may be three or more. By increasing the options for the manipulated variable Y, the speed regulation rate of the steam control valve 4 can be adjusted more flexibly.

Further, in terms of expression, the speed regulation rate is defined by the relationship between the rotation speed deviation X and the operation amount Y of the steam control valve 4, but the rotation speed deviation X is the target rotation speed Xt (constant) and the measured rotation speed Xm. and corresponds to the change in the measured rotational speed Xm. Therefore, the speed adjustment rate can be expressed by the relationship between the measured rotational speed Xm and the manipulated variable Y. This is also defined by the relationship between the rotational speed deviation X and the manipulated variable Y of the steam control valve 4, although there is a difference in expression. It is synonymous with the speed regulation rate.

Further, in the above embodiment, the limit rate of change R for the manipulated variable Y of each value Xn of the rotation speed deviation X is not distinguished. A different limit change rate R value may be arbitrarily set. The limit change rate R of the manipulated variable Y can be arbitrarily set for each rotation speed deviation Xn, and of course the same value can be set for the limit change rate R for all rotation speed deviations Xn.

DESCRIPTION OF SYMBOLS 1... Boiler 2... Steam turbine 3... Generator 4... Steam control valve 10... Steam turbine controller 11... Memory (storage device) 12... CPU (arithmetic unit) R... Limit change rate, X Rotation speed deviation X1, X2, Xa, Xn Individual values of rotation speed deviation Xm Measured rotation speed Xt Target rotation speed Y Operation amount of steam control valve Yn1, Yn2 Selection of operation amount

Claims (3)

A boiler for generating steam, a steam turbine driven by the steam supplied from the boiler, a generator driven by the steam turbine, and a steam control valve for adjusting the flow rate of the steam supplied from the boiler to the steam turbine. Steam turbine control for controlling the steam control valve so as to reduce the rotational speed deviation, which is the difference between the measured rotational speed of the steam turbine and a preset target rotational speed in the device,
comprising a storage device and an arithmetic device,
In the storage device, a target rotational speed of the steam turbine, a plurality of preset options for the operation amount of the steam control valve for each value of the rotational speed deviation, and preset changes in the speed regulation rate. a limit rate of change is stored,
The computing device is
A speed regulation rate function is defined by the manipulated variable arbitrarily selected from the options for each value of the rotational speed deviation, and the steam control valve is opened according to the rotational speed deviation under the defined speed regulation rate function. and when the selection of the manipulated variable is changed for at least one of the individual values of the speed deviation, from the current speed regulation rate function to the changed speed regulation rate function at the limited rate of change. A steam turbine controller configured to transition. 2. A steam turbine control system according to claim 1, wherein one of the plurality of options for said manipulated variable set for each value of said rotational speed deviation is zero. A steam turbine power generation facility comprising the steam turbine control device according to claim 1, the boiler, the steam turbine, the generator, and the steam control valve.

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