Control device, control method, and program

A control device for adjusting an amount of fuel to be supplied to a gas turbine based on a rotational speed of the gas turbine, such that a frequency of electric power output by a power generator that generates electric power using the gas turbine is within a given range, includes a load value acquisition unit configured to acquire a load value that is a value of a load applied to the power generator after cutoff of a part of the load applied to the power generator when the part of the load applied to the power generator is cut off, an arithmetic unit configured to calculate an adjusted value that is a value of the load different from the load value by carrying out an arithmetic operation on the load value and a bias, and a command unit configured to adjust the amount of fuel by outputting a first signal for causing the power generator to output electric power corresponding to the adjusted value.

TECHNICAL FIELD

The present disclosure relates to a control device, a control method, and a program.

BACKGROUND ART

Patent Document 1 discloses technology for maintaining a load amount within an operation limit of a turbine in a power plant by performing a power generation process according to an internal load amount when an independent operation within the power plant is performed due to a power system failure.

RELATED ART DOCUMENTS

Patent Document

Patent Document 1

SUMMARY OF INVENTION

Problem to be Solved by the Invention

In an internal power generation facility that supplies electric power to an internal factory or the like and receives/transmits electric power from/to an external power system, a load applied to an internal power generator changes due to cutoff of the external power system and a frequency of electric power output by the power generator can change temporarily. Technology for adjusting electric power to be output by the power generator based on an internal load applied to the power generator after the above-described cutoff such that the frequency is stabilized is known. However, even if the adjustment is made, the frequency may change greatly due to inertia when the load of the external power system to be cut off is greater than the internal load.

An objective of the present disclosure is to provide a control device, a control method, and a program for solving the above-described problems.

Means for Solving the Problem

According to the present disclosure, there is provided a control device for adjusting an amount of fuel to be supplied to a gas turbine based on a rotational speed of the gas turbine such that a frequency of electric power output by a power generator that generates electric power using the gas turbine is within a given range, the control device including: a load value acquisition unit configured to acquire a load value that is a value of a load applied to the power generator after cutoff of a part of the load applied to the power generator when the part of the load applied to the power generator is cut off; an arithmetic unit configured to calculate an adjusted value that is a value of the load different from the load value by carrying out an arithmetic operation on the load value and a bias; and a command unit configured to adjust the amount of fuel by outputting a first signal for causing the power generator to output electric power corresponding to the adjusted value.

According to the present disclosure, there is provided a control method for use in a control device for adjusting an amount of fuel to be supplied to a gas turbine based on a rotational speed of the gas turbine such that a frequency of electric power output by a power generator that generates electric power using the gas turbine is within a given range, the control method including: a step of acquiring a load value that is a value of a load applied to the power generator after cutoff of a part of the load applied to the power generator when the part of the load applied to the power generator is cut off; a step of calculating an adjusted value that is a value different from the load value by carrying out an arithmetic operation on the load value and a bias; and a step of adjusting the amount of fuel by outputting a first signal for causing the power generator to output electric power corresponding to the adjusted value.

According to the present disclosure, there is provided a program for causing a computer of a control device for adjusting an amount of fuel to be supplied to a gas turbine based on a rotational speed of the gas turbine such that a frequency of electric power output by a power generator that generates electric power using the gas turbine is within a given range to execute: a step of acquiring a load value that is a value of a load applied to the power generator after cutoff of a part of the load applied to the power generator when the part of the load applied to the power generator is cut off; a step of calculating an adjusted value that is a value different from the load value by carrying out an arithmetic operation on the load value and a bias; and a step of adjusting the amount of fuel by outputting a first signal for causing the power generator to output electric power corresponding to the adjusted value.

Effect of the Invention

According to at least one of the above-described aspects, when a part of a load applied to a power generator is cut off, it is possible to stabilize a frequency of electric power by limiting a change in a frequency of electric power output by the power generator.

EMBODIMENTS FOR CARRYING OUT THE INVENTION

First Embodiment

(Configuration of Control System)

Hereinafter, an embodiment is described in detail with reference to the drawings.

FIG.1is a diagram showing a configuration of a control system1according to a first embodiment.

The control system1includes an internal power system10, an external power system20, and a control device100.

The power system is a system in which a power generation process and a power transmission and reception process for supplying electric power output by a power generator to a power reception facility are integrated.

The control system1is a system that supplies fuel related to a value obtained by carrying out an arithmetic operation on a load applied to the internal power system10and a bias when the load applied to the external power system20is cut off. Thereby, the control system1can stabilize a frequency of the electric power by limiting a change in the frequency of the electric power output by the internal power system10.

The load represents electric power that is consumed by a facility or the like.

When the load applied to the external power system20is cut off, an amount by which the load is changed due to the cutoff is also referred to as a lost load.

The internal power system10generates electric power at a factory facility equipped with a power generator500, supplies electric power to an internal facility600, and receives electric power from the external power system20.

The external power system20receives electric power from the internal power system10and supplies electric power to the internal power system10. The external power system20is connected to the internal power system10through an electric wire or the like.

The control device100is a device that adjusts an amount of fuel supplied to the power generator500based on a value obtained by carrying out an arithmetic operation on the load applied to the power generator500and the bias when a part of the load applied to the power generator500is cut off. Thereby, the control device IOM can stabilize the frequency of the electric power by limiting the change in the frequency of the electric power output by the power generator500.

(Configuration of Internal Power System)

Hereinafter, a configuration of the internal power system10is described.

The internal power system10includes a gas turbine30, the power generator500, and the internal facility600.

The gas turbine30includes an inlet guide vane (IGV)31, a compressor32, a combustor33, a turbine34, a rotor35, and a fuel valve36.

The IGV31is provided on an inlet side of the compressor32and adjusts a flow rate of air flowing into the compressor32.

The compressor32generates compressed air by compressing the inflowing air.

The combustor33mixes the air compressed by the compressor32with the fuel to generate high-temperature combustion gas. Examples of the above-described fuel include light oil, kerosene, natural gas, hydrogen, by-product gas of a blast furnace, and coal gasification gas.

The turbine34rotates the rotor35with the combustion gas and drives the power generator500.

The rotor35connects the turbine34and the power generator500and is rotated by the turbine34, such that the electric power generated by the turbine34is transmitted to the power generator500and the power generator500is driven.

The fuel valve36adjusts a flow rate of the fuel gas supplied to the combustor33.

The combustor33is a device that generates a high-temperature and high-pressure combustion gas by mixing the fuel supplied via the fuel valve36with air and burning it. The fuel valve36is a valve that adjusts the flow rate of fuel supplied to the combustor33in response to a signal transmitted from the control device100.

The power generator500is a device that outputs electric power using motive power generated by the gas turbine30. The power generator500connects an internal facility600A, an internal facility600B, the gas turbine30, and the external power system20.

The internal facility600is a mechanical facility that operates by supplying the electric power output by the power generator50in the factory facility where the internal power system10is present.

The facility that outputs electric power in the internal power system10is the power generator500. In the internal power system10, facilities that consume electric power are the internal facility600A and the internal facility600B. The load of the internal facility600A is referred to as a load L1. The load of the internal facility600B is referred to as a load L2.

The external power system20is a system including a facility configured to receive the supplied electric power output from the power generator500of the internal power system10and consumes electric power of a load L3and a power generator (not shown) configured to supply electric power to the internal power system10and the like.

(Configuration of Control Device)

Hereinafter, a configuration of the control device100will be described.

FIG.2is a schematic block diagram showing the configuration of the control device100.

The control device100includes a rotational speed acquisition unit110, a determination unit120, a load value acquisition unit130, an arithmetic unit140, and a command unit150.

The rotational speed acquisition unit110acquires a rotational speed of the turbine34provided in the gas turbine30.

The determination unit120determines whether or not the load of the external power system20is cut off. For example, the determination unit120is connected to a breaker (not shown) provided between the internal power system10and the external power system20and determines that cutoff of the load of the external power system20occurs when receiving a signal indicating cutoff from the breaker. When not receiving a signal indicating cutoff from the breaker, the determination unit120determines that the load of the external power system20is not cut off.

The load value acquisition unit130acquires a load value when the determination unit120determines that the load of the external power system20is cut off. The load value is a value of the load applied to the power generator500when the load of the external power system20is cut off.

When the load of the external power system20is not cut off, the value of the load applied to the power generator500becomes a value obtained by carrying out an addition operation on the value of the load of the external power system20and the value of the load of the internal power system10. That is, when the load of the external power system20is not cut off, the value of the load applied to the power generator500becomes a value obtained by carrying out an addition operation on the load U, the load L2, and the load L3.

On the other hand, when the load of the external power system20is cut off, the value of the load applied to the power generator500becomes the value of the load of the internal power system10. That is, when the load of the external power system20is cut off, the value of the load applied to the power generator500becomes a value obtained by carrying out an addition operation on the loads L1and L2. Hereinafter, the value obtained by carrying out the addition operation on the loads L1and L2is referred to as an internal load.

The load value acquisition unit130is connected to the internal facility600A and the internal facility600B and receives the value of the load L1and the value of the load L2. Subsequently, the load value acquisition unit130acquires a load value by carrying out the addition operation on the value of the load L1and the value of the load L2. That is, the load value becomes the same value as the internal load.

The arithmetic unit140calculates an adjusted value by carrying out an arithmetic operation on the load value acquired by the load value acquisition unit130and a preset bias. The adjusted value is a value of the load different from the load value. An example of the bias is a negative real number. That is, the arithmetic unit140calculates the adjusted value that is less than the value of the internal load. Electric power corresponding to the adjusted value is lower than electric power indicated by the value of the internal load. Examples of a value obtained by carrying out the arithmetic operation on the load value and the bias in the arithmetic unit140include a value obtained by carrying out an addition operation on the load value and the bias and a value obtained by carrying out a multiplication operation on the load value and the bias.

The command unit150outputs a signal to the fuel valve36and adjusts the amount of fuel to be supplied to the combustor33such that the frequency of the electric power output by the power generator500is within a given range. Examples of the above-described given range include a frequency greater than or equal to 49.5 Hz and less than or equal to 50.5 Hz.

Hereinafter, an operation of the command unit150is specifically described.

The command unit150adjusts the amount of fuel by outputting the signal to the fuel valve36based on the rotational speed of the turbine34acquired by the rotational speed acquisition unit110such that the frequency of the electric power output by the power generator500is within the given range. For example, when the rotational speed of the turbine34acquired by the rotational speed acquisition unit110exceeds the given range, the command unit150outputs a signal for decreasing the amount of fuel to the fuel valve36. Thereby, the amount of fuel supplied by the fuel valve36to the combustor33is decreased. Therefore, the rotational speed of the turbine34is decreased. That is, when the rotational speed of the turbine34exceeds the given range, the command unit150can make the rotational speed set within the given range. The frequency of the electric power output by the power generator500varies with the rotational speed of the turbine34. Thus, the control system1can set the frequency of the electric power output by the power generator500within the given range according to an operation of the command unit150.

The command unit150outputs a signal for increasing the amount of fuel to the fuel valve36when the rotational speed of the turbine34acquired by the rotational speed acquisition unit110is less than the given range that is preset. Thereby, the amount of fuel to be supplied by the fuel valve36to the combustor33is increased. Thus, the rotational speed of the turbine34is increased. That is, when the rotational speed of the turbine34is less than the given range, the command unit150can make the rotational speed set within the given range. Thus, the control system1can set the frequency of the electric power output by the power generator500within the given range according to the operation of the command unit150.

Also, when the load of the external power system20is cut off, the command unit150outputs a first signal for outputting the power corresponding to the adjusted value to the power generator500to the fuel valve36and adjusts the amount of fuel to be supplied to the combustor33.

Hereinafter, an operation of the control system1when the command unit150adjusts the amount of fuel by outputting the first signal is described.

When a part of the load of the external power system20is cut off, the determination unit120determines that the load of the external power system20is cut off. Subsequently, the load value acquisition unit130acquires a load value. The arithmetic unit140calculates an adjusted value based on the load value acquired by the load value acquisition unit130and the bias. The command unit150outputs the first signal to the fuel valve36to adjust the amount of fuel to be supplied to the combustor33such that the power generator500outputs the electric power corresponding to the adjusted value.

When the load of the external power system20is not cut off, the electric power output by the power generator500corresponds to a value obtained by carrying out an addition operation on values of the internal load and the load13. On the other hand, when the load of the external power system20is cut off, the fuel valve36receives the first signal as a fuel command value from the command unit150and adjusts the amount of fuel to be supplied to the combustor33. Thereby, the electric power output by the power generator500corresponds to the internal load.

FIG.3is a graph showing a change in the load applied to the power generator500when the load of the external power system20is cut off. The vertical axis of the graph inFIG.3represents a load applied to the power generator500. The horizontal axis of the graph inFIG.3represents time. Time C inFIG.3indicates a time when cut off of the load of the external power system20occurs.

As shown inFIG.3, the load applied to the power generator500becomes lower after time C than before. The load applied to the power generator500before time C is a value obtained by carrying out an addition operation on the values of the internal load and the load L3. On the other hand, when the load L3is cut off at time C, a lost load occurs and the load applied to the power generator500is decreased. That is, after time C, the load applied to the power generator500is the value of the internal load.

FIG.4is a graph showing an amount of fuel supplied to the combustor33by the fuel valve36according to the fuel command value when the load of the external power system20is cut off. The vertical axis in the graph ofFIG.4represents an amount of fuel supplied to the combustor33by the fuel valve36. The horizontal axis of the graph inFIG.4represents time. The solid line in the graph ofFIG.4indicates an amount of fuel supplied to the combustor33of the control system1. The dotted line in the graph ofFIG.4indicates an amount of fuel supplied to a combustor of a system other than the control system1(hereinafter referred to as another system) when the amount of fuel is adjusted by the other system. The other system adjusts the amount of fuel to be supplied to the combustor based on the load value, unlike the control system1which adjusts the amount of fuel based on the adjusted value. The other system and the control system1have similar configurations, except for the adjustment of the amount of fuel described above.

As shown inFIG.3, the load applied to the power generator500at time C is decreased by an amount for the lost load. Thus, the load value acquisition unit130acquires a value of the internal load as the load value. The arithmetic unit140calculates an adjusted value by carrying out an arithmetic operation on the acquired load value and the bias. The command unit150outputs the first signal indicating the amount of fuel to the fuel valve36based on the adjusted value. As shown inFIG.4, the fuel valve36receives the first signal as a fuel command value and decreases the amount of fuel to be supplied to the combustor33.

The fuel valve of the other system also decreases the amount of fuel to be supplied to the combustor at time C. However, the other system that adjusts the amount of fuel based on the load value instead of the adjusted value supplies a larger amount of fuel to the combustor after time C than the control system1. Because the control system1supplies the combustor33with the amount of fuel based on the adjusted value, the control system1supplies the combustor33with a smaller amount of fuel decreased by an amount corresponding to the bias compared with the other system that adjusts the amount of fuel based on the load value.

After time C, the command unit150of the control system1outputs a second signal, which is a signal for changing the electric power output by the power generator500from the adjusted value to the value corresponding to the load value over time and adjusts the amount of fuel. Thereby, the fuel valve36receives the signal as the fuel command value and adjusts the amount of fuel to be supplied to the combustor33. That is, an amount of fuel corresponding to the bias gradually becomes zero.

Likewise, after time C, the command unit of the other system also outputs a signal to the fuel valve such that the frequency of the electric power output by the power generator is within a given range. Thereby, the fuel valve receives the signal and adjusts the amount of fuel to be supplied to the combustor33.

At time C, the amount of fuel supplied by the fuel valve36of the control system1is different from the amount of fuel supplied by the fuel valve of the other system. However, because the internal load after time C is similar, the amount of fuel supplied by the fuel valve36of the control system1is similar to the amount of fuel supplied by the fuel valve of the other system.

FIG.5is a graph showing the electric power output by the power generator500when the load of the external power system20is cut off. The vertical axis in the graph ofFIG.5represents electric power output by the power generator500. The horizontal axis in the graph ofFIG.5represents time. The solid line in the graph ofFIG.5indicates the electric power output by the power generator500of the control system1. The dotted line in the graph ofFIG.5indicates electric power output by the power generator of the other system.

Before time C, the electric power output by the power generator500corresponds to a value obtained by adding the value of the load L3to the value of the internal load. On the other hand, when the load for the lost load is cut off at time C, the electric power output by the power generator500corresponds to the adjusted value. After a given period of time passes from time C, the electric power output by the power generator500corresponds to the internal load according to the signal output by the command unit150.

On the other hand, the electric power output by the power generator of the other system after time C corresponds to the internal load. That is, the electric power output by the power generator of the other system after time C is greater than the electric power output by the power generator500of the control system1after time C by an amount corresponding to the bias. After the given period of time passes from time C, the electric power output by the power generator500of the control system1is similar to the electric power output by the power generator of the other system.

FIG.6is a graph showing the frequency of the electric power output by the power generator500when the load of the external power system20is cut off. The vertical axis in the graph ofFIG.6represents a frequency of the electric power output by the power generator5). The horizontal axis of the graph inFIG.6represents time. The solid line in the graph ofFIG.6indicates a frequency of electric power output by the power generator500of the control system1. The dotted line in the graph ofFIG.6indicates a frequency of electric power output by the power generator of the other system.

Before time C, the frequency of the electric power output by the power generator500is kept within a given range according to the signal output by the command unit150. Immediately after time C, the frequency of the electric power output by the power generator500temporarily increases. Although the load applied to the power generator500is decreased by an amount for the lost load front time C as shown inFIG.3, the electric power output by the power generator500is gradually decreased during a given period of time from time C as shown inFIG.5. Thus, immediately after time C, a surplus is generated in the electric power output by the power generator500and the frequency of the electric power output by the power generator500is temporarily increased by inertia or the like due to the surplus.

As shown inFIG.5, until the given period of time elapses from time C, the electric power output by the power generator500of the control system1is less than the electric power output by the power generator of the other system. Thereby, until the given period of time elapses from time C, the surplus in the electric power output by the power generator500of the control system1is less than the surplus in the electric power output by the power generator of the other system. Thus, until the given period of time elapses from time C, a change in the frequency of the electric power output by the power generator500of the control system1is less than a change in the frequency of the electric power output by the power generator of the other system. That is, when the load of the external power system20is cut off, the control system1can stabilize the frequency of the electric power by limiting the change in the frequency of the electric power output by the power generator500as compared with the other system.

FIG.7is a circuit diagram showing a control process of the control system1.

When the control system1is in normal operation, the control system1issues a fuel command based on the rotational speed of the turbine34. Thereby, the control system1adjusts the frequency of the electric power output by the power generator500such that the frequency is within a given range.

On the other hand, when the load of the external power system20is cut off, the control system1issues a fuel command based on the internal load and the bias.

(Operation of Control System)

Hereinafter, the operation of the control system1when the load of the external power system20is cut off is described.

FIG.8is a flowchart showing the operation of the control system1when the load of the external power system20is cut off.

The load of the external power system20is cut off. Subsequently, the determination unit120receives a signal indicating the cutoff from the breaker and determines that the load of the external power system20is cut off (step S1).

The load value acquisition unit130acquires a load value from the internal facility600A and the internal facility600B (step S2). That is, the load value acquisition unit130acquires the load value by acquiring a value of the load applied to the power generator500.

The arithmetic unit140calculates an adjusted value by carrying out an arithmetic operation on the load value acquired by the load value acquisition unit130in step S2and a preset bias (step S3).

The command unit150outputs a first signal to the fuel valve36based on the adjusted value calculated in step S3(step S4).

The fuel valve36receives the signal of step S4and adjusts an amount of fuel to be supplied to the combustor33(step S5). That is, the fuel valve36receives the signal output in step S4as a fuel command value and decreases the amount of fuel to be supplied to the combustor33.

Because the amount of fuel to be supplied to the combustor33in step S5is small, the electric power output by the power generator500is low (step6). According to step S6, the electric power output by the power generator500corresponds to a value obtained by subtracting the bias from the internal load.

The command unit150outputs a signal such that the electric power output by the power generator500corresponds to the internal load (step S7). Thereby, when a given period of time elapses from step S6, the electric power output by the power generator500corresponds to the load value.

When the load of the external power system20is cut off, the control system1adjusts the electric power output by the power generator500such that the electric power corresponds to the adjusted value. Thereby, the surplus in the electric power output by the power generator500is decreased immediately after the load of the external power system20is cut off. Thus, the control system1can stabilize the frequency of the electric power by limiting a change in the frequency of the electric power output by the power generator500when a part of the load applied to the power generator500is cut off.

In the control system1, the control device100may be configured to be provided in the gas turbine30. Even in this case, the command unit150of the control device100adjusts an amount of fuel to be supplied to the combustor33by outputting the first signal for causing the power generator500to output the electric power corresponding to the adjusted value to the fuel valve36.

Modified Examples

After the first signal is output, the command unit150may adjust the amount of fuel by outputting a plurality of signals such that the power generator500outputs electric power corresponding to the load value,

FIG.9is a graph showing a frequency of an independent operation system for which the power generator500of the control system1is responsible according to a modified example.

For example, as shown inFIG.9, after the first signal is transmitted at time C, the command unit150may output three signals at time T1, time T2, and time T3and adjust a frequency of the independent operation system for which the power generator500is responsible step by step.

According to the present disclosure, the control device100for adjusting an amount of fuel to be supplied to the gas turbine30based on a rotational speed of the gas turbine30such that a frequency of electric power output by the power generator500that generates electric power using the gas turbine30is within a given range includes the load value acquisition unit130configured to acquire a load value that is a value of a load applied to the power generator500after cutoff when a part of the load applied to the power generator500is cut off; the arithmetic unit140configured to calculate an adjusted value that is a value of the load value different from the load value by carrying out an arithmetic operation on the load value and a bias; and the command unit150configured to adjust the amount of fuel by outputting a first signal for causing the power generator500to output electric power corresponding to the adjusted value.

When a pan of the load applied to the power generator500is cut off, the control device10adjusts the electric power output by the power generator500such that the electric power corresponds to the adjusted value. Thereby, the surplus in the amount of electric power output by the power generator500is decreased immediately after a part of the load applied to the power generator500is cut off. Thus, the control device10can stabilize the frequency of the electric power by limiting the change in the frequency of the electric power output by the power generator500when a part of the load applied to the power generator500is cut off.

After the first signal is output, the command unit150of the control device100according to the present disclosure adjusts the amount of fuel by outputting a second signal, which is a signal for changing the electric power output by the power generator500from an adjusted value to a value corresponding to a load value over time.

Thereby, when the load of the external power system20is cut off, the control device100can decrease the change in the frequency of the electric power output by the power generator500before and after the cutoff.

Also, when the load of the external power system20applied to the power generator500is cut off, the load value acquisition unit130of the control device100acquires the load value that is the value of the load applied to the power generator500after the cutoff.

When the load of the external power system20is cut off, the control device100adjusts the electric power output by the power generator500such that the electric power corresponds to the adjusted value. Thereby, the surplus in the electric power output by the power generator500is decreased immediately after the load of the external power system20is cut off. Thus, when the load of the external power system20is cut off, the control device100can stabilize the frequency of the electric power by limiting the change in the frequency of the electric power output by the power generator500.

Second Embodiment

(Configuration of Control System)

Hereinafter, a control system1according to a second embodiment is described. The control system1according to the second embodiment calculates a bias such that a value of a load of a power generator500decreased by cutting off a load of an external power system20is proportional to a bias. The control system1is a system that transmits a first signal to a fuel valve36such that the power generator500outputs electric power corresponding to an adjusted value by calculating the adjusted value based on the calculated bias.

A configuration of a control device100of the control system1according to the second embodiment is a configuration including a bias calculation unit160in addition to the configuration of the control device100of the control system1according to the first embodiment.

FIG.10is a schematic block diagram showing the configuration of the control device100according to the second embodiment.

The bias calculation unit160calculates the bias such that the value of the load of the power generator500(hereinafter referred to as the decreased value) decreased due to cutoff of the load of the external power system20is proportional to the bias. For example, the bias calculation unit160obtains the decreased value by subtracting the load value from a value obtained by carrying out an addition operation on a load L1, a load L2, and a load L3stored in a storage device (not shown) provided in the control device100. The decreased value due to the cutoff of the load of the external power system20is the same value as the load L3. Subsequently, the bias calculation unit160calculates the bias by multiplying the obtained decreased value by a preset coefficient. An example of the above-described coefficient is one or more real numbers. By calculating the bias in this way, the bias calculated by the bias calculation unit160is proportional to the decreased value.

The bias calculation unit160may calculate the bias according to an arithmetic operation other than a multiplication operation.

(Operation of Control System)

Hereinafter, an operation of the control system1when the load of the external power system20is cut off is described.

FIG.11is a flowchart showing the operation of the control system1when the load of the external power system20is cut off.

The operations front step S1to step S2and front step S3to step S9are similar to the operations from step S1to step S2and from step S3to step S9in the control system1according to the first embodiment.

The bias calculation unit160obtains the decreased value based on the load value identified in step S2and the value obtained by carrying out an addition operation on the load L1, the load L2, and the load L3stored in the storage device. Also, the bias calculation unit160calculates the bias by multiplying the obtained decreased value by the preset coefficient (step S21).

The bias used when the arithmetic unit140calculates the adjusted value in step S3is the bias calculated in step S21.

The control system1calculates the adjusted value based on the bias calculated based on the decreased value due to the cutoff of the load of the external power system20. Also, the control system1outputs a first signal to the fuel valve36such that the electric power calculated by the power generator500corresponds to the adjusted value. Thereby, the control system1can adjust the electric power output by the power generator500in accordance with the decreased value due to the cutoff of the load of the external power system20and can further stabilize the frequency of the electric power.

The control device100according to the present disclosure includes the bias calculation unit160configured to calculate a bias such that the value of the load of the power generator500decreased due to cutoff is proportional to the bias, and the arithmetic unit140calculates the adjusted value by carrying out the arithmetic operation on the load value and the calculated bias.

The control device100calculates the adjusted value based on the bias calculated based on the decreased value due to the cutoff of the load of the external power system20. Also, the control device10outputs the first signal to the fuel valve36such that the electric power calculated by the power generator500corresponds to the adjusted value. Thereby, the control device10can adjust the electric power output by the power generator500in accordance with the decreased value due to the cutoff of the load of the external power system20and can further stabilize the frequency of the electric power.

Other Embodiments

Although the above embodiments are described above in detail with reference to the drawings, the specific configuration is not limited to the above and various design changes can be made.

The control device100may calculate the bias based on operating conditions associated with at least one of the power generator500and the gas turbines30. Examples of the operating conditions include an atmospheric temperature, a temperature of the power generator500, a temperature of the gas turbine30, and an amount of heat of fuel. For example, the control device100may include a first correction unit configured to correct the bias based on a value of at least one of a temperature of the gas turbine, an atmospheric temperature around the gas turbine, and an amount of heat of the fuel. The control device100can adjust the power output by the power generator500based on the adjusted value suitable for an operating condition by calculating the bias as described above and can stabilize the frequency of the electric power.

Also, the control device100may calculate the bias based on constraint conditions of the gas turbine30such as the surge of the compressor32and the combustion stability of the combustor33. For example, the control device100may include a second correction unit configured to correct the bias based on a value of at least one of compressor surge occurring in the gas turbine and stability of the fuel.

The control device100can adjust the electric power output by the power generator500based on the adjusted value suitable for the constraint condition of the gas turbine30by calculating the bias as described above and can stabilize the frequency of the electric power.

FIG.12is a schematic block diagram showing a configuration of a computer according to at least one embodiment.

A computer1100includes a processor1110, a main memory1120, a storage1130, and an interface1140.

The above-described control system1is mounted in the computer1100. The operation of each of the above-described processing units is stored in the storage1130in the form of a program. The processor1110reads a program from the storage1130, loads the program into the main memory1120, and executes the above process in accordance with the program. Also, the processor1110secures a storage area corresponding to each of the above-described storage units in the main memory1120in accordance with the program.

The program may be a program for implementing some of the functions exerted on the computer1100. For example, the program may exert the function in combination with another program already stored in the storage1130or in combination with another program mounted in another device. In another embodiment, the computer1100may include a custom large scale integrated circuit (LSI) such as a programmable logic device (PLD) in addition to or in place of the above configuration. Examples of the PLD include a programmable array logic (PAIL), a generic army logic (GAL), a complex programmable logic device (CPLD), and a field programmable gate array (FPGA). In this case, some or all of the functions implemented by the processor1110may be implemented by the integrated circuit.

Examples of the storage1130include magnetic disks, magneto-optical disks, semiconductor memories, and the like. The storage1130may be internal media directly connected to a bus of the computer1100or external media connected to the computer via the interface1140or a communication circuit. Also, when the above program is distributed to the computer1100via a communication circuit, the computer1100receiving the distributed program may load the program into the main memory1120and execute the above process. In at least one embodiment, the storage1130is a non-transitory tangible storage medium.

Also, the program may be a program for implementing some of the above-mentioned functions. Furthermore, the program may be a so-called differential file (differential program) for implementing the above-described function in combination with another program already stored in the storage1130.

The control device100described in each embodiment is ascertained, for example, as follows.

(1) According to the present disclosure, the control device100for adjusting an amount of fuel to be supplied to the gas turbine30based on a rotational speed of the gas turbine30such that a frequency of electric power output by the power generator500that generates electric power using the gas turbine30is within a given range includes the load value acquisition unit130configured to acquire a load value that is a value of a load applied to the power generator500after cutoff of a part of the load applied to the power generator500when the part of the load applied to the power generator500is cut off; the arithmetic unit140configured to calculate an adjusted value that is a value of the load different from the load value by carrying out an arithmetic operation on the load value and a bias; and the command unit150configured to adjust the amount of fuel by outputting a first signal for causing the power generator500to output electric power corresponding to the adjusted value.

When the part of the load applied to the power generator500is cut off, the control device100adjusts the electric power output by the power generator500such that the electric power corresponds to the adjusted value. Thereby, the surplus amount of electric power output by the power generator500is decreased immediately after the part of the load applied to the power generator500is cut off. Thus, the control device100can stabilize the frequency of the electric power by limiting a change in the frequency of the electric power output by the power generator500when the part of the load applied to the power generator500is cut off.

(2) According to the present disclosure, after the first signal is output, the command unit150of the control device100may adjust the amount of fuel by outputting a second signal, which is a signal for changing the electric power output by the power generator500from the adjusted value to a value corresponding to the load value over time.

Thereby, when the load of the external power system20is cut off, the control device100can decrease a change in the frequency of the electric power output by the power generator500before and after the cutoff.

(3) Also, the load value acquisition unit130of the control device100may acquire the load value, which is the value of the load applied to the power generator500after cutoff of a load of an external power system20applied to the power system500, when the load of the external power system20applied to the power generator500is cut off.

When the load of the external power system20is cut off, the control device100adjusts the electric power output by the power generator500such that the electric power corresponds to the adjusted value. Thereby, the surplus amount of electric power output by the power generator500is decreased immediately after the load of the external power system20is cut off. Thus, the control device100can stabilize the frequency of the electric power by limiting a change in the frequency of the electric power output by the power generator500when the load of the external power system20is cut off.

(4) According to the present disclosure, the control device100may include the bias calculation unit160configured to calculate the bias such that a value of the load of the power generator500decreased due to the cutoff is proportional to the bias, wherein the arithmetic unit140may calculate the adjusted value by carrying out the arithmetic operation on the load value and the calculated bias.

The control device100calculates the adjusted value based on the bias calculated based on the decreased value due to the cutoff of the load of the external power system20. Also, the control device100outputs the first signal to the fuel valve36such that the electric power calculated by the power generator500corresponds to the adjusted value. Thereby, the control system1can adjust the electric power output by the power generator500in accordance with the decreased value due to the cutoff of the load of the external power system20and can further stabilize the frequency of the electric power.

(5) The control device100may include a first correction unit configured to correct the bias based on a value of at least one of a temperature of the gas turbine, an atmospheric temperature around the gas turbine, and an amount of heat of the fuel.

Thereby, the control device100can correct the bias based on the operating conditions such as the temperature of the gas turbine and the atmospheric temperature, and can further stabilize the frequency of the electric power output by the power generator500.

(6) The control device100may include a second correction unit configured to correct the bias based on a value of at least one of compressor surge occurring in the gas turbine and stability of the fuel.

Thereby, the control device100can correct the bias based on the constraint condition of the gas turbine such a, the compressor surge and can further stabilize the frequency of the electric power output by the power generator500.

(7) According to the present disclosure, a control method for use in the control device100for adjusting an amount of fuel to be supplied to the gas turbine30based on a rotational speed of the gas turbine30such that a frequency of electric power output by the power generator500that generates electric power using the gas turbine30is within a given range includes a step of acquiring a load value that is a value of a load applied to the power generator500after cutoff of a part of the load applied to the power generator500when the part of the load applied to the power generator500is cut oPt, a step of calculating an adjusted value that is a value different from the load value by carrying out an arithmetic operation on the load value and a bias; and a step of adjusting the amount of fuel by outputting a first signal for causing the power generator500to output electric power corresponding to the adjusted value.

When the part of the load applied to the power generator500is cut off, a user of the control method can adjust the electric power output by the power generator500such that the electric power corresponds to the adjusted value. Thereby, the surplus amount of electric power output by the power generator500is decreased immediately after the part of the load applied to the power generator500is cut off. Thus, the user of the control method can stabilize the frequency of the electric power by limiting a change in the frequency of the electric power output by the power generator500when the part of the load applied to the power generator500is cut off.

(8) According to the present disclosure, a program for causing a computer of the control device100for adjusting an amount of fuel to be supplied to the gas turbine30based on a rotational speed of the gas turbine30such that a frequency of electric power output by the power generator500that generates electric power using the gas turbine30is within a given range to execute: a step of acquiring a load value that is a value of a load applied to the power generator500after cutoff of a part of the load applied to the power generator500when the part of the load applied to the power generator500is cut off; a step of calculating an adjusted value that is a value different from the load value by carrying out an arithmetic operation on the load value and a bias; and a step of adjusting the amount of fuel by outputting a first signal for causing the power generator500to output electric power corresponding to the adjusted value.

When the pan of the load applied to the power generator500is cut off, a user of the program can adjust the electric power output by the power generator500such that the electric power corresponds to the adjusted value. Thereby, the surplus amount of electric power output by the power generator500is decreased immediately after the part of the load applied to the power generator500is cut off. Thus, the user of the program can stabilize the frequency of the electric power by limiting a change in the frequency of the electric power output by the power generator5M when the part of the load applied to the power generator500is cut off.

INDUSTRIAL APPLICABILITY

The present disclosure relates to a control device, a control method, and a program.

According to the present disclosure, when a part of a load applied to a power generator is cut off, it is possible to stabilize a frequency of electric power by limiting a change in a frequency of electric power output by the power generator.