Gas turbine control device, gas turbine control method, and program

Abstract

To provide a gas turbine control device that can respond quickly to load fluctuations. [Solution] The gas turbine control device includes a mode switching unit that switches on or off a frequency response mode that prioritizes following the grid frequency; a measurement value acquisition unit that acquires a rotational speed measurement value obtained by measuring the rotational speed of the gas turbine; a rotational speed output unit that outputs the rotational speed measurement value as the rotational speed of the gas turbine when the frequency response mode is on, and outputs a virtual rotational speed value as the rotational speed of the gas turbine in place of the rotational speed measurement value when the frequency response mode is off; and a command value calculation unit that calculates a control command value based on the difference between the rotational speed of the gas turbine output by the rotational speed output unit and the target rotational speed.

Description

Technical Field

[0001] The present disclosure relates to a gas turbine control device, a gas turbine control method, and a program.

Background Art

[0002] There are a governor mode (GV mode) and a load limit mode (LD mode) as methods for controlling the load of a gas turbine by the flow rate of fuel supplied to the gas turbine. In the GV mode, the fuel flow rate is proportionally controlled (P control) so that the difference between the system frequency and the speed setting of the gas turbine becomes small. In the LD mode, the fuel flow rate is proportionally integrated controlled (PI control) so that the output setting and the generator output match (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Since the GV mode is P control, it can respond quickly to fluctuations in the system frequency. On the other hand, since the LD mode performs PI control on the difference between the output setting and the generator output, the response is slower than that of the GV mode in terms of the control method. For this reason, for example, in a power generation plant or the like, when there is a desire to accelerate the response to a change in the output setting (load fluctuation), it is difficult to further accelerate the response in the LD mode. On the other hand, even if the output is specified in the GV mode, it is affected by fluctuations in the system frequency and it is difficult to maintain the required output.

[0005] An object of the present disclosure is to provide a gas turbine control device, a gas turbine control method, and a program that can respond quickly to load fluctuations.

Means for Solving the Problems

[0006] According to a first aspect of this disclosure, the gas turbine control device includes: a mode switching unit that switches on or off a frequency response mode that changes the fuel flow rate supplied to the gas turbine in response to the system frequency; a measurement value acquisition unit that acquires a rotational speed measurement value obtained by measuring the rotational speed of the gas turbine; a rotational speed output unit that outputs the rotational speed measurement value as the rotational speed of the gas turbine when the frequency response mode is on, and outputs a virtual rotational speed value as the rotational speed of the gas turbine in place of the rotational speed measurement value when the frequency response mode is off; and a command value calculation unit that calculates a control command value for the fuel flow rate supplied to the gas turbine based on the difference between the rotational speed of the gas turbine output by the rotational speed output unit and a target rotational speed.

[0007] According to a first aspect of the present disclosure, a gas turbine control method includes the steps of: switching on or off a frequency response mode that changes the fuel flow rate supplied to a gas turbine in response to a system frequency; acquiring a rotational speed measurement value obtained by measuring the rotational speed of the gas turbine; outputting the rotational speed measurement value as the rotational speed of the gas turbine when the frequency response mode is on, and outputting a virtual rotational speed value as the rotational speed of the gas turbine in place of the rotational speed measurement value when the frequency response mode is off; and calculating a control command value for the fuel flow rate supplied to the gas turbine based on the difference between the output rotational speed of the gas turbine and a target rotational speed.

[0008] According to a first aspect of this disclosure, the program causes the gas turbine control device to perform the following steps: switching on or off a frequency response mode that changes the fuel flow rate supplied to the gas turbine in response to the system frequency; acquiring a rotational speed measurement value obtained by measuring the rotational speed of the gas turbine; outputting the rotational speed measurement value as the rotational speed of the gas turbine when the frequency response mode is on, and outputting a virtual rotational speed value as the rotational speed of the gas turbine in place of the rotational speed measurement value when the frequency response mode is off; and calculating a control command value for the fuel flow rate supplied to the gas turbine based on the difference between the output rotational speed of the gas turbine and the target rotational speed. [Effects of the Invention]

[0009] According to the above embodiment, it is possible to respond quickly to load fluctuations. [Brief explanation of the drawing]

[0010] [Figure 1] This diagram shows the overall configuration of the gas turbine system according to the first embodiment. [Figure 2] This is a block diagram showing the functional configuration of a gas turbine control device according to the first embodiment. [Figure 3] This is a block diagram showing the calculation logic of a gas turbine control device according to the first embodiment. [Figure 4] This is a schematic block diagram showing the configuration of a computer according to one embodiment. [Modes for carrying out the invention]

[0011] <First Embodiment> The embodiments will be described in detail below with reference to the drawings.

[0012] (Overall configuration of the gas turbine system) Figure 1 is a diagram showing the overall configuration of a gas turbine system according to the first embodiment. The gas turbine system 100 is used in power plants and the like. As shown in Figure 1, the gas turbine system 100 comprises a gas turbine 1, a generator 6, and a gas turbine control device 10 that controls the gas turbine 1.

[0013] The gas turbine 1 comprises a compressor 2, a combustor 3, and a turbine 4. The compressor 2 and the turbine 4 are connected by a rotor 5. The compressor 2 compresses air taken in from the outside to produce compressed air. The combustor 3 mixes the compressed air supplied from the compressor 2 with fuel and burns it to produce high-temperature combustion gas. The turbine 4 is rotated by the combustion gas generated in the combustor 3. The rotor 5 is provided with a rotational speed measuring unit S1 capable of measuring the rotational speed of the gas turbine 1 (rotor 5). In the following description, the rotational speed of the gas turbine 1 will also be referred to as the GT rotational speed.

[0014] The generator 6 is connected to the turbine 4 and is driven by the turbine 4 to generate electricity. The generator 6 is also connected in parallel and disconnectibly to a power system (not shown). The generator 6 is equipped with an output sensor S2 capable of measuring the output of the generator 6 [MW]. In the following description, the output of the generator 6 will also be referred to as the GT output.

[0015] (Functional configuration of gas turbine control system) Figure 2 is a block diagram showing the functional configuration of a gas turbine control device according to the first embodiment. As shown in Figure 2, the gas turbine control device 10 includes a measurement value acquisition unit 11, a fuel command value calculation unit 12, a command value acquisition unit 13, and a mode switching unit 14.

[0016] The measurement value acquisition unit 11 acquires measurement values ​​from sensors provided on various parts of the gas turbine 1 and the generator 6. In this embodiment, the measurement value acquisition unit 11 acquires the GT rotational speed from at least the rotational speed measurement unit S1 and the GT output from the output sensor S2.

[0017] The fuel command value calculation unit 12 calculates the fuel command value CSO (Control Signal Output) and outputs it to the gas turbine 1. The gas turbine 1 adjusts the opening of the flow control valve 7 so that the amount of fuel supplied to the combustor 3 matches the fuel command value CSO. The fuel command value calculation unit 12 includes a governor control unit 23, a load limiter control unit 24, a temperature control unit 25, and a selection unit 27.

[0018] In GV mode, after the gas turbine 1 has reached a predetermined rotational speed (e.g., rated rotational speed), the governor control unit 23 performs rotational speed control as governor operation and calculates and outputs a control command value GVCSO (GoVernor Control Signal Output) for controlling the fuel flow rate to bring the GT rotational speed closer to the target rotational speed. In this embodiment, the governor control unit 23 has a frequency response mode. When the frequency priority mode is on, the governor control unit 23 monitors the fluctuation of the GT rotational speed due to fluctuations in the power grid frequency, as in the conventional technology, and controls the fuel flow rate to bring the GT rotational speed closer to the target rotational speed. On the other hand, when the frequency response mode is off, the governor control unit 23 does not monitor the fluctuation of the GT rotational speed due to fluctuations in the grid frequency, and controls the fuel flow rate based on the requested load command value from a higher-level system (not shown). The control command value GVCSO output by the governor control unit 23 is also referred to as the first control command value.

[0019] In the LD mode, the load limiter control unit 24 calculates and outputs a control command value LDCSO (Load limit Control Signal Output) for controlling the fuel flow rate so as to execute load control as load limiter operation and bring the actual load closer to the target load. The target load is a required load command value input from the upper system. The load limiter control unit 24 calculates a control command value LDCSO that approaches this deviation to zero by proportional-integral control (PI control) based on the deviation between the target load and the actual load (GT output measured by the output sensor S2). The control command value LDCSO output by the load limiter control unit 24 is also referred to as the second control command value. The temperature control unit 25 calculates and outputs a control command value EXCSO (Exhaust temperature Control Signal Output) for controlling the fuel flow rate so as to execute exhaust gas temperature control of the turbine 4 and keep the exhaust gas temperature within the allowable range. In addition, the temperature control unit 25 calculates and outputs a control command value BPCSO (Blade Path temperature Control Signal Output) for executing blade path temperature control so that the blade path temperature (temperature of combustion gas) is within the allowable range. Note that the load limiter control unit 24 and the temperature control unit 25 may use those of the prior art.

[0020] Note that the operator of the gas turbine 1 can arbitrarily switch between the GV mode and the LD mode of the gas turbine control device 10. In this embodiment, an example in which the gas turbine control device 10 operates in the GV mode will be described.

[0021] The selection unit 27 is a minimum selector that selects and outputs the minimum value among the control command values GVCSO, LDCSO, EXCSO, and BPCSO calculated by each control unit. The minimum value selected by the selection unit 27 is output to the gas turbine 1 as the fuel command value CSO.

[0022] The command value acquisition unit 13 acquires command values ​​from a higher-level system (not shown). The higher-level system is, for example, a central power dispatch center. In this embodiment, the command value acquisition unit 13 acquires at least a requested load command value from the higher-level system.

[0023] The mode switching unit 14 accepts operator input and switches the frequency response mode on or off. The operator performs mode switching, for example, by operating an input device (not shown) of the gas turbine control device 10. Alternatively, the operator may perform mode switching remotely through a terminal device (not shown) that is communicatively connected to the gas turbine control device 10.

[0024] (Governance control unit's calculation logic) Figure 3 is a block diagram showing the calculation logic of a gas turbine control device according to the first embodiment. Figure 3 illustrates the calculation logic of the governor control unit 23, which is part of the fuel command value calculation unit 12 of the gas turbine control device 10. As shown in Figure 3, the governor control unit 23 includes a target rotational speed calculation unit 31, a rotational speed output unit 32, and a command value calculation unit 33.

[0025] The target rotational speed calculation unit 31 calculates the target rotational speed SPSET of the gas turbine 1 based on the requested load command value ALRSET input from the higher-level system. The target rotational speed calculation unit 31 includes a subtractor 311, a proportional calculator 312, a function generator 313, and an analog memory 314. The subtractor 311 calculates the output deviation by subtracting the GT output [MW] (measured value of the output sensor S2) from the requested load command value ALRSET [MW]. The proportional calculator 312 outputs a value obtained by multiplying the output deviation by a predetermined coefficient. The function generator 313 calculates the target rotational speed SPSET of the gas turbine 1 based on the value input from the proportional calculator 312 and records it in the analog memory 314. The analog memory 314 inputs the recorded target rotational speed SPSET to the command value calculation unit 33.

[0026] The rotational speed output unit 32 outputs a measured rotational speed or a virtual rotational speed of the gas turbine 1 according to a value (mode SW) indicating whether the frequency response mode is on or off. The rotational speed output unit 32 includes a switch 321 and a signal generator 322. When the frequency response mode is on, the switch 321 inputs the measured rotational speed to the command value calculation unit 33. On the other hand, when the frequency response mode is off, the switch 321 inputs the virtual rotational speed to the command value calculation unit 33. The measured rotational speed may be the actual rotational speed using the measured value from the rotational speed measurement unit S1 as is, or it may be a modified actual rotational speed modified, for example, based on the requirements of the power system operator. The modified actual rotational speed is modified, for example, to have a dead zone in part of the value range. The virtual rotational speed is, for example, a fixed value (for example, 3000 rpm) generated by the signal generator 322. In other embodiments, the virtual rotational speed may be calculated by multiplying the fixed value generated by the signal generator 322 by a predetermined coefficient.

[0027] The command value calculation unit 33 calculates the control command value GVCSO of the gas turbine 1 based on the target rotational speed SPSET and the GT rotational speed. The command value calculation unit 33 includes a subtractor 331 and a proportional calculator 332. The subtractor 331 calculates the rotational speed deviation by subtracting the GT rotational speed from the target rotational speed SPSET. This GT rotational speed is a measured rotational speed value when the frequency response mode is on, and a virtual rotational speed value when it is off. The proportional calculator 332 calculates a value obtained by multiplying the rotational speed deviation by a predetermined gain. The value calculated by the proportional calculator 332 using proportional control (P control) based on the deviation between the target rotational speed SPSET and the GT rotational speed becomes the control command value GVCSO of the governor control unit 23.

[0028] As described above, when the frequency response mode is on, the governor control unit 23 calculates the control command value GVCSO based on the deviation between the measured rotational speed of the gas turbine 1, which is linked to the grid frequency, and the target rotational speed. In other words, the governor control unit 23 can output a control command value GVCSO that allows the GT rotational speed to be adjusted in response to fluctuations in the grid frequency, similar to conventional governor control. On the other hand, when the frequency response mode is off, the governor control unit 23 calculates the control command value GVCSO based on the deviation between a virtual rotational speed value that is not linked to the grid frequency and the target rotational speed. As a result, unlike conventional governor control, the governor control unit 23 is not affected by fluctuations in the grid frequency and can output a control command value GVCSO that allows the GT output to be adjusted to satisfy the requested load command value given by the higher-level system. Furthermore, when the frequency response mode is off, the governor control unit 23 calculates the control command value GVCSO according to the requested load command value by P control, so it can respond to load fluctuations faster than the load limiter control unit 24, which calculates the control command value LDCSO by PI control. Therefore, the gas turbine control device 10 can meet the need for a quick response to load fluctuations by turning off the frequency response mode. On the other hand, the load limiter control unit 24 can reduce steady-state deviations by PI control, so it can calculate a control command value LDCSO that allows the GT output to accurately follow the requested load command value.

[0029] (Effects and Benefits) As described above, the gas turbine control device 10 according to this embodiment includes a mode switching unit 14 that switches on or off a frequency response mode that changes the fuel flow rate supplied to the gas turbine 1 in response to the system frequency; a measurement value acquisition unit 11 that acquires a rotational speed measurement value that measures the rotational speed of the gas turbine 1; a rotational speed output unit 32 that outputs the rotational speed measurement value as the GT rotational speed when the frequency response mode is on, and outputs a virtual rotational speed value as the GT rotational speed instead of the rotational speed measurement value when the frequency response mode is off; and a command value calculation unit 33 that calculates a control command value GVCSO for the fuel flow rate supplied to the gas turbine 1 based on the difference between the GT rotational speed output by the rotational speed output unit 32 and the target rotational speed.

[0030] In conventional technology, the control command value LDCSO corresponding to load fluctuations was calculated in LD mode, but it was difficult to respond quickly to load fluctuations in LD mode, which performs PI control. Furthermore, although the GV mode, which performs P control, can respond more quickly than LD mode in conventional technology, even if the target rotational speed is set according to the load fluctuation, the GT rotational speed (measured value) changes due to fluctuations in the grid frequency. In that case, in the conventional GV mode, for example, if the target rotational speed corresponding to the required load is 3150 rpm, a fuel command value CSO equivalent to 100% is output if the GT rotational speed (measured value) is 3000 rpm, but if the GT rotational speed (measured value) is affected by fluctuations in the grid frequency and becomes 3050 rpm, a fuel command value CSO equivalent to 66% is output. Thus, in conventional GV mode, it was difficult to maintain a GT output corresponding to the required load due to fluctuations in the grid frequency. In contrast, the gas turbine control device 10 according to this embodiment calculates a control command value based on the rotational speed measurement value when the frequency response mode is on in GV mode, and based on a virtual rotational speed value without using the rotational speed measurement value when the frequency response mode is off. In this way, the gas turbine control device 10 can output a control command value GVCSO in GV mode that can adjust the GT rotational speed and GT output in response to load fluctuations without being affected by fluctuations in the grid frequency. Furthermore, the GV mode, which performs P control, can respond to load fluctuations faster than the LD mode, which performs PI control. Therefore, the gas turbine control device 10 can respond to load fluctuations more quickly than the conventional LD ​​mode.

[0031] Furthermore, the mode switching unit 14 accepts operator input and switches the frequency response mode on or off.

[0032] In this way, the gas turbine control device 10 can be switched between conventional governor control and governor control that responds to load fluctuations by the operator. This allows for flexible switching of whether to prioritize the response to frequency fluctuations or load fluctuations, in response to different requests, such as requests from higher-level systems like the central power dispatch center (to maintain the grid frequency) or requests from operators of the gas turbine 1, such as power generators (for example, to respond to load fluctuations).

[0033] Furthermore, the gas turbine control device 10 includes a target rotational speed calculation unit 31 that calculates a target rotational speed based on a requested load command value instructed from a higher-level system.

[0034] In this way, the gas turbine control device 10 can quickly adjust the GT output of the gas turbine 1 in accordance with requests from a higher-level system.

[0035] Furthermore, the gas turbine control device 10 includes a rotational speed output unit 32 and a command value calculation unit 33, and a governor control unit 23 that outputs a first control command value GVCSO, which is a control command value for fuel flow calculated by proportional control (P control) based on the difference between the rotational speed of the gas turbine 1 and the target rotational speed, based on the command value calculation unit 33; a load limiter control unit 24 that calculates and outputs a second control command value LDCSO, which is a control command value for fuel flow calculated by proportional-integral control (PI control) based on the difference between the required load command value and the output of the gas turbine 1, so as to bring the output of the gas turbine 1 closer to the required load command value instructed by the higher-level system; and a selection unit 27 that selects the lower of the first control command value GVCSO and the second control command value LDCSO and outputs it to the gas turbine 1 as a fuel command value CSO.

[0036] In this way, when the frequency response mode is off, the governor control unit 23 calculates the control command value GVCSO according to the requested load command value by P control, so it can respond to load fluctuations faster than the load limiter control unit 24 which calculates the control command value LDCSO by PI control. Therefore, the gas turbine control device 10 can meet the need for a quick response to load fluctuations by turning off the frequency response mode. On the other hand, the load limiter control unit 24 can reduce steady-state errors by PI control, so it can calculate a control command value LDCSO that allows the GT output to accurately follow the requested load command value. In other words, the gas turbine control device 10 can achieve both speed and accuracy in following load fluctuations.

[0037] (Computer configuration) Figure 4 is a schematic block diagram showing the configuration of a computer according to one embodiment. The computer 900 comprises a processor 901, main memory 902, auxiliary memory 903, and interface 904. The gas turbine control device 10 described above is implemented in the computer 900. The operation of each processing unit described above is stored in the auxiliary memory 903 in the form of a program. The processor 901 reads the program from the auxiliary memory 903, expands it into the main memory 902, and executes the above processing according to the program. The processor 901 also allocates memory area in the main memory 902 to be used for the above processing according to the program.

[0038] The program may be for implementing a part of the functions to be performed by the computer 900. For example, the program may perform functions in combination with other programs already stored in the auxiliary storage device 903, or in combination with other programs implemented in other devices. In other embodiments, the computer may be equipped with a custom LSI (Large Scale Integrated Circuit) such as a PLD (Programmable Logic Device) in addition to, or in place of, the above configuration. Examples of PLDs include PAL (Programmable Array Logic), GAL (Generic Array Logic), CPLD (Complex Programmable Logic Device), FPGA (Field Programmable Gate Array), etc. In this case, some or all of the functions implemented by the processor may be implemented by the integrated circuit.

[0039] Examples of auxiliary storage devices 903 include HDDs (Hard Disk Drives), SSDs (Solid State Drives), magnetic disks, magneto-optical disks, CD-ROMs (Compact Disc Read Only Memory), DVD-ROMs (Digital Versatile Disc Read Only Memory), and semiconductor memory. The auxiliary storage device 903 may be an internal medium directly connected to the bus of the computer 900, or it may be an external medium (external storage device 910) connected to the computer 900 via an interface 904 or a communication line. Furthermore, if this program is distributed to the computer 900 via a communication line, the computer 900 that receives the distribution may expand the program into the main memory 902 and execute the above processing. In at least one embodiment, the auxiliary storage device 903 is a tangible storage medium that is not temporary.

[0040] <Other Embodiments> Although one embodiment has been described in detail above with reference to the drawings, the specific configuration is not limited to that described above, and various design changes are possible. In other embodiments, the order of the above-described processes may be changed as appropriate. Also, some processes may be executed in parallel.

[0041] <Note> The above-described embodiment can be understood, for example, as follows:

[0042] (1) According to the first embodiment, the gas turbine control device 10 includes a mode switching unit 14 that switches on or off a frequency response mode that changes the fuel flow rate supplied to the gas turbine in response to the system frequency, a measurement value acquisition unit 11 that acquires a rotational speed measurement value that measures the rotational speed of the gas turbine 1, a rotational speed output unit 32 that outputs the rotational speed measurement value as the rotational speed of the gas turbine 1 when the frequency response mode is on, and outputs a virtual rotational speed value as the rotational speed of the gas turbine 1 instead of the rotational speed measurement value when the frequency response mode is off, and a command value calculation unit 33 that calculates a control command value GVCSO for the fuel flow rate supplied to the gas turbine based on the difference between the rotational speed of the gas turbine 1 output by the rotational speed output unit 32 and the target rotational speed.

[0043] In this way, the gas turbine control device 10 calculates a control command value in GV mode based on the rotational speed measurement when the frequency response mode is on, and based on a virtual rotational speed value without using the rotational speed measurement when the frequency response mode is off. In this way, the gas turbine control device 10 can output a control command value GVCSO in GV mode that can adjust the GT rotational speed and GT output in response to load fluctuations without being affected by fluctuations in the grid frequency. Furthermore, since the GV mode can respond to load fluctuations faster than the LD mode, the gas turbine control device 10 can respond to load fluctuations more quickly than conventional control using the LD mode.

[0044] (2) According to the second embodiment, in the gas turbine control device 10 according to the first embodiment, the mode switching unit 14 receives an operation from the operator and switches the frequency response mode on or off.

[0045] In this way, the gas turbine control device 10 can be switched between conventional governor control and governor control that responds to load fluctuations by the operator. This allows for flexible switching of whether to prioritize the response to frequency fluctuations or load fluctuations, in response to different requests, such as requests from higher-level systems like the central power dispatch center (to maintain the grid frequency) or requests from operators of the gas turbine 1, such as power generators (for example, to respond to load fluctuations).

[0046] (3) According to the third embodiment, the gas turbine control device 10 according to the first or second embodiment further comprises a target rotational speed calculation unit 31 that calculates a target rotational speed based on a requested load command value instructed from a higher-level system.

[0047] In this way, the gas turbine control device 10 can quickly adjust the GT output of the gas turbine 1 in accordance with requests from a higher-level system.

[0048] (4) According to the fourth embodiment, the gas turbine control device 10 according to any one of the first to third embodiments includes a governor control unit 23 which has a rotational speed output unit 32 and a command value calculation unit 33 and outputs a first control command value GVCSO, which is a control command value of fuel flow calculated by proportional control based on the difference between the rotational speed of the gas turbine 1 and the target rotational speed, and a load limiter control unit 24 which calculates and outputs a second control command value LDCSO, which is a control command value of fuel flow calculated by proportional-integral control based on the difference between the required load command value and the output of the gas turbine 1, so as to bring the output of the gas turbine 1 closer to the required load command value instructed by the higher-level system, and a selection unit 27 which selects the lower of the first control command value GVCSO and the second control command value LDCSO and outputs it to the gas turbine 1 as a fuel command value CSO.

[0049] In this way, when the frequency response mode is off, the governor control unit 23 calculates the control command value GVCSO according to the requested load command value by P control, so it can respond to load fluctuations faster than the load limiter control unit 24 which calculates the control command value LDCSO by PI control. Therefore, the gas turbine control device 10 can meet the need for a quick response to load fluctuations by turning off the frequency response mode. On the other hand, the load limiter control unit 24 can reduce steady-state errors by PI control, so it can calculate a control command value LDCSO that allows the GT output to accurately follow the requested load command value. In other words, the gas turbine control device 10 can achieve both speed and accuracy in following load fluctuations.

[0050] (5) According to the fifth aspect, the gas turbine control method includes the steps of: switching on or off a frequency response mode that changes the fuel flow rate supplied to the gas turbine in response to the system frequency; acquiring a rotational speed measurement value obtained by measuring the rotational speed of the gas turbine 1; outputting the rotational speed measurement value as the rotational speed of the gas turbine 1 when the frequency response mode is on, and outputting a virtual rotational speed value as the rotational speed of the gas turbine 1 instead of the rotational speed measurement value when the frequency response mode is off; and calculating a control command value GVCSO for the fuel flow rate supplied to the gas turbine based on the difference between the output rotational speed of the gas turbine 1 and the target rotational speed.

[0051] (6) According to the sixth aspect, the program causes the gas turbine control device 10 to perform the following steps: switching on or off a frequency response mode that changes the fuel flow rate supplied to the gas turbine in response to the system frequency; acquiring a rotational speed measurement value obtained by measuring the rotational speed of the gas turbine 1; outputting the rotational speed measurement value as the rotational speed of the gas turbine 1 when the frequency response mode is on, and outputting a virtual rotational speed value as the rotational speed of the gas turbine 1 instead of the rotational speed measurement value when the frequency response mode is off; and calculating a control command value GVCSO for the fuel flow rate supplied to the gas turbine based on the difference between the output rotational speed of the gas turbine 1 and the target rotational speed. [Explanation of Symbols]

[0052] 100 Gas Turbine Systems 1 Gas Turbine 2 Compressor 3 Combustor 4 Turbines 5 rotors 6 Generators 7 Flow control valve 10 Gas turbine control system 11 Measurement Value Acquisition Unit 12 Fuel command value calculation unit 13 Command value acquisition unit 14 Mode switching section 23 Governor Control Unit 24 Load limiter control unit 25 Temperature control unit 27 Selection Section 31 Target rotation speed calculation unit 32. Rotational Speed ​​Output Section 33 Command Value Calculation Unit

Claims

1. A mode switching unit that switches on or off a frequency response mode that changes the fuel flow rate supplied to the gas turbine in response to the system frequency, A measurement value acquisition unit that acquires a rotational speed measurement value obtained by measuring the rotational speed of the gas turbine, A rotational speed output unit that outputs the rotational speed measurement value as the rotational speed of the gas turbine when the frequency response mode is on, and outputs a virtual rotational speed value as the rotational speed of the gas turbine when the frequency response mode is off, A command value calculation unit calculates a control command value for the fuel flow rate supplied to the gas turbine based on the difference between the rotational speed output by the rotational speed output unit and the target rotational speed, A gas turbine control device equipped with the following features.

2. The mode switching unit receives an operator's input and switches the frequency response mode on or off. The gas turbine control device according to claim 1.

3. The system further includes a target rotational speed calculation unit that calculates the target rotational speed based on the requested load command value instructed from a higher-level system. The gas turbine control device according to claim 1 or 2.

4. A governor control unit having the rotational speed output unit and the command value calculation unit, wherein the command value calculation unit outputs a first control command value which is the control command value of the fuel flow rate calculated by proportional control based on the difference between the rotational speed of the gas turbine and the target rotational speed, A load limiter control unit calculates and outputs a second control command value, which is a fuel flow control command value calculated by proportional-integral control based on the difference between the requested load command value and the output of the gas turbine, so that the output of the gas turbine approaches the requested load command value instructed by the higher-level system. A selection unit that selects the lower of the first control command value and the second control command value and outputs it to the gas turbine as a fuel command value, The gas turbine control device according to claim 1, further comprising:

5. A step of switching on or off a frequency response mode that changes the fuel flow rate supplied to the gas turbine in response to the system frequency, The steps include: obtaining a rotational speed measurement value obtained by measuring the rotational speed of the gas turbine; The steps include: outputting the rotational speed measurement value as the rotational speed of the gas turbine when the frequency response mode is on, and outputting a virtual rotational speed value as the rotational speed of the gas turbine when the frequency response mode is off; A step of calculating a control command value for the fuel flow rate supplied to the gas turbine based on the difference between the output rotational speed of the gas turbine and the target rotational speed, A gas turbine control method having the following features.

6. A step of switching on or off a frequency response mode that changes the fuel flow rate supplied to the gas turbine in response to the system frequency, The steps include: obtaining a rotational speed measurement value obtained by measuring the rotational speed of the gas turbine; The steps include: outputting the rotational speed measurement value as the rotational speed of the gas turbine when the frequency response mode is on, and outputting a virtual rotational speed value as the rotational speed of the gas turbine when the frequency response mode is off; A step of calculating a control command value for the fuel flow rate supplied to the gas turbine based on the difference between the output rotational speed of the gas turbine and the target rotational speed, A program that instructs the gas turbine control system to execute a command.

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