A control method and device for a gas turbine combined cycle unit

Abstract

An embodiment of the present invention discloses a control method and device for a gas turbine combined cycle unit. The control method includes: detecting whether the load reference value of the gas turbine combined cycle unit has decreased to the stage of the current actual load when the gas turbine combined cycle unit performs AGC control to adjust the load and enters the temperature control mode; when the detection result is yes, controlling the fuel stroke reference by the temperature when the load reference value is equal to the current actual unit load; calculating, according to the fuel stroke reference, the speed reference corresponding to the fuel stroke reference for speed control of the gas turbine combined cycle unit in the speed control mode, so that the gas turbine combined cycle unit can promptly exit the temperature control mode and enter the speed control mode, realizing seamless switching control. The solution provided by the present invention can achieve the technical effect that the unit can automatically and quickly respond to the AGC load command.

Description

Technical Field

[0001] The present invention relates to the field of application of automatic control technologies, and particularly to a control method and device for a gas turbine combined cycle unit. Background Art

[0002] Automatic Generation Control (AGC for short) is a basic and important function in the operation control of modern power grids. It is an advanced technical means of closed-loop control established between a highly automated energy management system of the power grid and a coordinated control system of generator sets. Implementing AGC can achieve real-time power supply-demand balance on the premise of high-quality electric energy, improve the economic operation of the power grid, and reduce the labor intensity of power grid and power plant dispatching and operation personnel. With the rapid development of the automation level of the power system and the improvement of the social requirements for power supply quality, AGC has become an important step in realizing the economic and optimal operation of the power grid and an inevitable trend in the high-level development of power technologies.

[0003] Currently, domestic power grids generally require that the load regulation of thermal power plant units participate in AGC control. Due to its advantages such as high efficiency, low emissions, flexible start-stop, and good peak shaving performance (the load change range and change rate are generally better than those of coal-fired units), the gas turbine combined cycle unit increasingly undertakes the task of peak shaving in the current power grid structure. Therefore, the gas turbine combined cycle unit has a very close relationship with AGC. According to the characteristics of the gas turbine, each gas turbine has a basic load (i.e., the maximum load) during operation, and the maximum load is directly affected by factors such as the ambient air temperature. Usually, when the gas turbine loads up to the basic load, the unit will enter the temperature control mode, and the fuel quantity output by the exhaust gas temperature control loop is less than the output of the speed control loop. Since the speed control loop initially maintains a positive deviation, in the first few minutes before the gas turbine load command starts to decrease, the fuel quantity output by the speed control loop is still greater than the output value of the temperature control loop, and the unit is still in the temperature control mode. That is, within the first few minutes after the unit enters the temperature control mode and the load decreases, the load change rate of the unit cannot reach the default value and cannot respond to the AGC control command in a timely manner until the unit exits the temperature control mode and enters the speed control mode, seriously affecting the AGC regulation performance.

[0004] Aiming at the problem in the above-mentioned prior art that the AGC control command cannot be responded to in a timely manner in the temperature control mode, resulting in seriously affecting the AGC regulation performance, no effective solution has been proposed yet. Summary of the Invention

[0005] To solve the above technical problems, embodiments of the present invention are expected to provide a control method and device for a gas turbine combined cycle unit, so as to at least solve the problem in the prior art that the AGC control command cannot be responded to in a timely manner in the temperature control mode, resulting in seriously affecting the AGC regulation performance.

[0006] The technical solution of the present invention is realized as follows:

[0007] In a first aspect, an embodiment of the present invention provides a control method for a gas turbine combined cycle unit, including: detecting whether the load reference value of the gas turbine combined cycle unit decreases to the current actual load when the gas turbine combined cycle unit executes AGC control to adjust the load and enters the temperature control mode; in the case where the detection result is yes, controlling the fuel stroke reference by the temperature when the load reference value is equal to the current actual unit load; calculating the speed reference corresponding to the fuel stroke reference for speed control of the gas turbine combined cycle unit in the speed control mode based on the fuel stroke reference, so that the gas turbine combined cycle unit can timely exit the temperature control mode and enter the speed control mode to achieve seamless switching control.

[0008] Optionally, the method further includes: the change of the fuel stroke reference is proportional to the difference between the given control reference and the actual speed.

[0009] Further optionally, the method further includes: after the gas turbine combined cycle unit is connected to the grid, performing deviation dead zone optimization control on the fuel stroke reference by differential speed control, where performing deviation dead zone optimization control on the fuel stroke reference by differential speed control includes: when the speed deviation is within a preset interval, no deviation adjustment is performed, and until the speed deviation is greater than the preset interval, the deviation after being greater than the preset interval is adjusted.

[0010] Optionally, the speed reference is the output after being selected by an intermediate value selection gate, where the intermediate value selection gate is set with a high limit value, a low limit value during the operation stage, a low limit value during the start-up or shutdown stage, and a preset value.

[0011] Further optionally, calculating the speed reference corresponding to the fuel stroke reference for speed control of the gas turbine combined cycle unit in the speed control mode based on the fuel stroke reference includes: during the AGC load reduction process of the gas turbine combined cycle unit, when the load reference value decreases to the current actual load, at the critical position, making the fuel stroke reference for speed control of the gas turbine combined cycle unit track the current fuel stroke reference for temperature control; when the load reference value decreases to be less than the actual load, the gas turbine combined cycle unit timely exits the temperature control mode and seamlessly enters the speed control mode.

[0012] Second aspect, an embodiment of the present invention provides a control device for a gas turbine combined cycle unit, including: a detection module, configured to detect whether the load reference value of the gas turbine combined cycle unit decreases to the current actual load when the gas turbine combined cycle unit performs AGC control to adjust the load and enters the temperature control mode; a control module, configured to, when the detection result is yes, control the fuel stroke reference by the temperature when the load reference value is equal to the current actual unit load; a calculation module, configured to calculate the speed reference corresponding to the fuel stroke reference for speed control of the gas turbine combined cycle unit in the speed control mode based on the fuel stroke reference, so that the gas turbine combined cycle unit can promptly exit the temperature control mode and enter the speed control mode to achieve seamless switching control.

[0013] Optionally, the change of the fuel stroke reference is proportional to the difference between the given control reference and the actual speed.

[0014] Further optionally, the device further includes: an optimization control module, configured to perform deviation dead zone optimization control on the fuel stroke reference of the differential speed control after the gas turbine combined cycle unit is connected to the grid. Among them, performing deviation dead zone optimization control on the fuel stroke reference of the differential speed control includes: when the speed deviation is within a preset interval, no deviation adjustment is performed, and until the speed deviation is greater than the preset interval, the deviation after being greater than the preset interval is adjusted.

[0015] Optionally, the speed reference is the output selected by the intermediate value selection gate. Among them, the intermediate value selection gate is provided with a high limit value, a low limit value in the operation stage, a low limit value in the start or stop stage, and a preset value.

[0016] Further optionally, the calculation module includes: a tracking unit, configured to, during the AGC load reduction process of the gas turbine combined cycle unit, when the load reference value decreases to the current actual load, make the fuel stroke reference for speed control of the gas turbine combined cycle unit track the current fuel stroke reference for temperature control at the critical position; a calculation unit, configured to, when the load reference value decreases to be less than the actual load, the gas turbine combined cycle unit promptly exits the temperature control mode and seamlessly enters the speed control mode.

[0017] An embodiment of the present invention provides a control method and device for a gas turbine combined cycle unit. When the gas turbine combined cycle unit performs AGC control to adjust the load and enters the temperature control mode, it is detected whether the load reference value of the gas turbine combined cycle unit is reduced to the stage of the current actual load; when the detection result is yes, the fuel stroke reference is controlled by the temperature when the load reference value is equal to the current actual unit load; the rotational speed reference corresponding to the rotational speed control fuel stroke reference of the gas turbine combined cycle unit in the rotational speed control mode is calculated based on the fuel stroke reference, so that the gas turbine combined cycle unit can timely exit the temperature control mode and enter the rotational speed control mode, realizing seamless switching control, thereby achieving the technical effect that the unit can automatically and quickly respond to the AGC load instruction. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings described herein are used to provide a further understanding of the present invention, and constitute a part of this application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention, and do not constitute an improper limitation to the present invention. In the drawings:

[0019] Figure 1 It is a schematic flowchart of a control method for a gas turbine combined cycle unit provided in Embodiment 1 of the present invention;

[0020] Figure 2 It is a schematic structural diagram of a control method for a gas turbine combined cycle unit provided in Embodiment 1 of the present invention;

[0021] Figure 3 It is a schematic diagram of a control device for a gas turbine combined cycle unit provided in Embodiment 2 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0023] It should be noted that the terms "first", "second", etc. in the specification, claims and drawings of the present invention are used to distinguish different objects, rather than to limit a specific order.

[0024] It should also be noted that the following various embodiments of the present invention can be executed independently, and the various embodiments can also be combined with each other. The embodiments of the present invention do not make specific limitations on this.

[0025] Embodiment 1

[0026] In a first aspect, an embodiment of the present invention provides a control method for a gas turbine combined cycle unit. Figure 1 It is a schematic flow chart of a control method for a gas turbine combined cycle unit provided by Embodiment 1 of the present invention; as Figure 1 shown, the control method for a gas turbine combined cycle unit provided by an embodiment of the present application includes:

[0027] Step S102, when the gas turbine combined cycle unit executes AGC control to adjust the load and the gas turbine combined cycle unit enters the temperature control mode, detect whether the load reference value of the gas turbine combined cycle unit decreases to the stage of the current actual load;

[0028] Step S104, when the detection result is yes, control the fuel stroke reference through the temperature when the load reference value is equal to the current actual unit load;

[0029] Step S106, calculate the speed reference corresponding to the fuel stroke reference for speed control of the gas turbine combined cycle unit in the speed control mode according to the fuel stroke reference, so that the gas turbine combined cycle unit can timely exit the temperature control mode and enter the speed control mode to achieve seamless switching control.

[0030] Optionally, the control method for a gas turbine combined cycle unit provided by an embodiment of the present application further includes: the change of the fuel stroke reference is proportional to the difference between the given control reference and the actual speed.

[0031] Furthermore, optionally, the control method for a gas turbine combined cycle unit provided by an embodiment of the present application further includes: after the gas turbine combined cycle unit is connected to the grid, perform deviation dead zone optimization control through the fuel stroke reference of differential speed control, wherein performing deviation dead zone optimization control through the fuel stroke reference of differential speed control includes: when the speed deviation is within a preset interval, no deviation adjustment is performed, and until the speed deviation is greater than the preset interval, the deviation after being greater than the preset interval is adjusted.

[0032] Optionally, the speed reference is the output selected through an intermediate value selection gate, wherein the intermediate value selection gate is provided with a high limit value, a low limit value in the operation stage, a low limit value in the start or stop stage, and a preset value.

[0033] Further, optionally, in step S106, calculating the speed reference corresponding to the fuel stroke reference for speed control of the gas turbine combined cycle unit in the speed control mode based on the fuel stroke reference includes: during the AGC load reduction process of the gas turbine combined cycle unit, when the load reference value decreases to the current actual load, at the critical position, making the fuel stroke reference for speed control of the gas turbine combined cycle unit track the current fuel stroke reference for temperature control; when the load reference value decreases to less than the actual load, the gas turbine combined cycle unit promptly exits the temperature control mode and smoothly enters the speed control mode.

[0034] In summary, Figure 2 FIG. is a schematic structural diagram of a control method for a gas turbine combined cycle unit provided in Embodiment 1 of the present invention. As Figure 2 shown,

[0035] In the control method for the gas turbine combined cycle unit provided in the embodiment of the present application, when the gas turbine combined cycle unit (hereinafter referred to as the unit) is under AGC control to adjust the load and the unit has entered the temperature control mode, during the stage when the unit load reference value (change amount, not a fixed value) decreases to the current actual load, through the fuel stroke reference for temperature control (FSRT) when the load reference value is equal to the current actual unit load, the speed reference (TNR) corresponding to the fuel stroke reference for speed control (FSRN) of the unit in the speed control mode under this condition is inversely calculated, so as to complete the unit's prompt exit from the temperature control mode and entry into the speed control mode, and achieve seamless switching control; at the same time, the speed control of the unit is optimized to improve the regulation performance of the unit under AGC control.

[0036] In the embodiment of the present application, the speed control of the gas turbine combined cycle unit follows the proportional control law, that is, the change in the fuel stroke reference (FSR) is proportional to the difference between the given control reference (speed given value or speed reference) TNR and the actual speed, i.e.:

[0037] ΔFSR ∝ (TNR - TNHSYS)

[0038] FSRN = (TNR - TNHSYS) * K DROOP + FSRN0

[0039] In the formula, FSRN - fuel stroke reference for droop speed control;

[0040] TNHSYS - speed with filter rate limit

[0041] TNR - speed reference;

[0042] K DROOP - control constant determining the droop rate δ of droop speed control;

[0043] FSRN0——The FSR value at full speed (rated speed) and no load of the gas turbine, a fixed constant;

[0044] After the gas turbine combined cycle unit is connected to the grid, deviation dead zone optimization control is carried out through the above-mentioned differential speed control (FSRN). That is, when the speed deviation is within 2 revolutions, no deviation adjustment is performed. It is not until the speed deviation exceeds 2 revolutions that the deviation beyond 2 revolutions is adjusted. That is,

[0045] FSRN = (TNR - F1(x)) * K DROOP + FSRN0

[0046] Among them,

[0047] In the speed control logic, TNR is the output selected through the intermediate value selection gate (i.e., high and low limits), and the intermediate value selection gate is set with 4 constant inputs. That is, the high limit value TNRK1, the low limit value TNRK2 during the operation stage, the low limit value TNRK3 during the start-up or shutdown stage, and the preset value TNRK4;

[0048] Among them, during operation, TNRK1 = 107%, so as to ensure that when the differential speed control droop rate δ = 4%, even if the grid has surplus power (frequency up to 103%), this gas turbine can still generate full power; during the overspeed test of the unit, TNRK1 = 111.5%, so that the turbine can raise the speed to this value when it is no load.

[0049] The low limit value TNRK2 during the operation stage = 95%, ensuring that even when the grid has insufficient power (frequency as low as 95%), the turbine load can still be reduced to zero through TNR;

[0050] The low limit value TNRK3 during the start-up or shutdown stage = 0%, that is, when the unit starts from zero speed, the speed control can intervene in the FSR control;

[0051] The preset value TNRK4 = 100.3%, which is used for the speed to prepare for grid connection. Usually, the rated value of the grid frequency is 100%, and the extra 0.3% is to avoid reverse power generation of the generator caused by grid frequency fluctuations after grid connection.

[0052] Z -1 Composes a digital integrator with the adder. L83JDn determines a certain value of the lifting rate constant TNKR1_n, that is, different integration rate constants are selected through different logics. The automatic load lifting / lowering command L70R / L70L determines the integration direction. That is, when L70R = 1 and L70L = 0, the integral value rises, gradually increasing TNR. Reverse integration is used to reduce TNR. When L70R = 0 and L70L = 0, the integration stops and TNR remains unchanged.

[0053] During the AGC load reduction process of the unit, when the load reference value decreases to the current actual load, at this critical position, the fuel stroke reference of speed control (FSRN) of the unit is made to track the fuel stroke reference of temperature control (FSRT) at this time. As the load reference value decreases to be less than the actual load, the unit promptly exits the temperature control mode and seamlessly enters the speed control mode.

[0054] FSRT = FSRN = (TNR - F1(x)) * K DROOP + FSRN0

[0055] That is, TNR = (FSRT - FSRN0) / K DROOP + F1(x)

[0056] Denote the speed reference (TNR) corresponding to the fuel stroke reference of speed control under the fuel stroke reference of temperature control when the unit is in the temperature control mode as F2(x), that is, F2(x) = (FSRT - FSRN0) / K DROOP + F1(x)

[0057] Among them, the calculation logic of the speed reference is as follows:

[0058] TNR(i) = IF(A, IF(B, F2(x), TNR(i - 1)), TNR(i - 1))

[0059] Among them:

[0060] TNR(i): The speed reference at the current moment;

[0061] TNR(i - 1): The speed reference at the previous moment;

[0062] Selection logic A: After the unit is connected to the grid, AGC control is enabled and the unit is in the temperature control mode;

[0063] Selection logic B: Under condition A, when the unit load reference value decreases to the actual load, a short pulse signal or rising edge signal is triggered;

[0064] Through the control method of the gas turbine combined cycle unit provided by the embodiments of the present application, for the gas turbine combined cycle unit when AGC controls the regulated load and the unit has entered the temperature control mode, it can promptly exit the temperature control mode and seamlessly enter the speed control mode, quickly respond to the AGC control command, respond to the grid control, and improve the automation level of the unit and the competitiveness of the power plant.

[0065] An embodiment of the present invention provides a control method for a gas turbine combined cycle unit. When the gas turbine combined cycle unit performs AGC control to adjust the load and enters the temperature control mode, it is detected whether the load reference value of the gas turbine combined cycle unit has decreased to the stage of the current actual load; when the detection result is yes, the fuel stroke reference is controlled by the temperature when the load reference value is equal to the current actual unit load; the speed reference corresponding to the fuel stroke reference for speed control of the gas turbine combined cycle unit in the speed control mode is calculated based on the fuel stroke reference, so that the gas turbine combined cycle unit can timely exit the temperature control mode and enter the speed control mode to achieve seamless switching control, thereby achieving the technical effect that the unit can automatically and quickly respond to the AGC load command.

[0066] Embodiment 2

[0067] Secondly, an embodiment of the present invention provides a control device for a gas turbine combined cycle unit. Figure 3 As shown in the schematic diagram of the control device for a gas turbine combined cycle unit provided in Embodiment 2 of the present invention, Figure 3 The control device for the gas turbine combined cycle unit provided in the embodiment of the present application includes: a detection module 32, configured to detect whether the load reference value of the gas turbine combined cycle unit has decreased to the stage of the current actual load when the gas turbine combined cycle unit performs AGC control to adjust the load and enters the temperature control mode; a control module 34, configured to control the fuel stroke reference by the temperature when the load reference value is equal to the current actual unit load when the detection result is yes; a calculation module 36, configured to calculate the speed reference corresponding to the fuel stroke reference for speed control of the gas turbine combined cycle unit in the speed control mode based on the fuel stroke reference, so that the gas turbine combined cycle unit can timely exit the temperature control mode and enter the speed control mode to achieve seamless switching control.

[0068] Optionally, the change in the fuel stroke reference is proportional to the difference between the given control reference and the actual speed.

[0069] Furthermore, optionally, the control device for the gas turbine combined cycle unit provided in the embodiment of the present application further includes: an optimization control module, configured to perform deviation dead zone optimization control on the fuel stroke reference of the differential speed control after the gas turbine combined cycle unit is connected to the grid, where performing deviation dead zone optimization control on the fuel stroke reference of the differential speed control includes: when the speed deviation is within a preset interval, no deviation adjustment is performed, and until the speed deviation is greater than the preset interval, the deviation after being greater than the preset interval is adjusted.

[0070] Optionally, the rotational speed reference is the output selected by an intermediate value selection gate, where the intermediate value selection gate is set with a high limit value, a low limit value during the operation stage, a low limit value during the startup or shutdown stage, and a preset value.

[0071] Further optionally, the calculation module includes: a tracking unit, configured to, during the AGC load reduction process of the gas turbine combined cycle unit, when the load reference value decreases to the current actual load, make the rotational speed control fuel stroke reference of the gas turbine combined cycle unit track the current temperature control fuel stroke reference at the critical position; a calculation unit, configured to, when the load reference value decreases to be less than the actual load, the gas turbine combined cycle unit promptly exits the temperature control mode and seamlessly enters the rotational speed control mode.

[0072] An embodiment of the present invention provides a control device for a gas turbine combined cycle unit. When the gas turbine combined cycle unit performs AGC control to adjust the load and enters the temperature control mode, it detects the stage where the load reference value of the gas turbine combined cycle unit decreases to the current actual load; in the case where the detection result is yes, it controls the fuel stroke reference through the temperature when the load reference value is equal to the current actual unit load; calculates the rotational speed reference corresponding to the rotational speed control fuel stroke reference of the gas turbine combined cycle unit in the rotational speed control mode based on the fuel stroke reference, so that the gas turbine combined cycle unit promptly exits the temperature control mode and enters the rotational speed control mode, realizing seamless switching control, thereby achieving the technical effect that the unit can automatically and quickly respond to the AGC load instruction.

[0073] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present invention. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, as well as the combination of flows and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for realizing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0074] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing devices to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device, and the instruction device realizes the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0075] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus, so that a series of operation steps are executed on the computer or other programmable apparatus to produce a computer-implemented process, thereby the instructions executed on the computer or other programmable apparatus provide steps for implementing the functions specified in one process or a plurality of processes and / or blocks Figure 1 one process or a plurality of processes and / or blocks Figure 1 in one block or a plurality of blocks.

[0076] As mentioned above, it is only a preferred embodiment of the present invention, and is not used to limit the protection scope of the present invention.

Claims

1. A control method for a gas turbine combined cycle unit, characterized in that Including: When the gas turbine combined cycle unit executes AGC control to adjust the load and the gas turbine combined cycle unit enters the temperature control mode, detecting the stage at which the load reference value of the gas turbine combined cycle unit is reduced to the current actual load; When the detection result is yes, controlling the fuel stroke reference by the temperature when the load reference value is equal to the current actual unit load; Calculating the speed reference corresponding to the fuel stroke reference controlled by speed in the speed control mode of the gas turbine combined cycle unit according to the fuel stroke reference, so that the gas turbine combined cycle unit can timely exit the temperature control mode and enter the speed control mode to realize seamless switching control.

2. The control method according to claim 1, wherein The method further includes: the change of the fuel stroke reference is proportional to the difference between the given control reference and the actual speed.

3. The control method according to claim 2, characterized in that, The method further includes: After the gas turbine combined cycle unit is connected to the grid, performing deviation dead zone optimization control through the fuel stroke reference controlled by droop speed control, wherein, the performing deviation dead zone optimization control through the fuel stroke reference controlled by droop speed control includes: when the speed deviation is within a preset range, no deviation adjustment is performed until the speed deviation is greater than the preset range, and then the deviation after being greater than the preset range is adjusted.

4. The control method according to any one of claims 1 to 3, characterized in that, The speed reference is the output selected by the intermediate value selection gate, wherein the intermediate value selection gate is provided with a high limit value, a low limit value in the operation stage, a low limit value in the start or stop stage, and a preset value.

5. The control method according to claim 4, characterized in that, The calculating the speed reference corresponding to the fuel stroke reference controlled by speed in the speed control mode of the gas turbine combined cycle unit according to the fuel stroke reference includes: During the AGC load reduction process of the gas turbine combined cycle unit, when the load reference value is reduced to the current actual load, at the critical position, making the fuel stroke reference controlled by the speed of the gas turbine combined cycle unit track the current fuel stroke reference controlled by temperature; When the load reference value is reduced to less than the actual load, the gas turbine combined cycle unit timely exits the temperature control mode and seamlessly enters the speed control mode.

6. A control device for a gas turbine combined cycle unit, characterized in that, Including: A detection module, configured to detect the stage at which the load reference value of the gas turbine combined cycle unit is reduced to the current actual load when the gas turbine combined cycle unit executes AGC control to adjust the load and the gas turbine combined cycle unit enters the temperature control mode; A control module, configured to control the fuel stroke reference by the temperature when the load reference value is equal to the current actual unit load when the detection result is yes; A calculation module, configured to calculate the speed reference corresponding to the fuel stroke reference controlled by speed in the speed control mode of the gas turbine combined cycle unit according to the fuel stroke reference, so that the gas turbine combined cycle unit can timely exit the temperature control mode and enter the speed control mode to realize seamless switching control.

7. The control device according to claim 6, characterized in that The change of the fuel stroke reference is proportional to the difference between the given control reference and the actual speed.

8. The control device according to claim 7, wherein The device further includes: An optimization control module is used to perform deviation dead zone optimization control through a fuel stroke reference with differential speed control after the gas turbine combined cycle unit is connected to the grid. Among them, the deviation dead zone optimization control through the fuel stroke reference with differential speed control includes: when the speed deviation is within a preset range, no deviation adjustment is performed until the speed deviation is greater than the preset range, and then the deviation after being greater than the preset range is adjusted.

9. The control device according to any one of claims 6 to 8, characterized in that, The speed reference is the output after being selected by an intermediate value selection gate, where the intermediate value selection gate is provided with a high limit value, a low limit value in the operation stage, a low limit value in the startup or shutdown stage, and a preset value.

10. The control device according to claim 9, characterized in that, The calculation module includes: A tracking unit is used to make the speed control fuel stroke reference of the gas turbine combined cycle unit track the current temperature control fuel stroke reference at the critical position when the load reference value decreases to the current actual load during the AGC load reduction process of the gas turbine combined cycle unit. A calculation unit is used to make the gas turbine combined cycle unit promptly exit the temperature control mode and smoothly enter the speed control mode when the load reference value decreases to be less than the actual load.

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