A differential control method and system for main steam pressure process signals

Abstract

This invention discloses a differential control method and system for the main steam pressure process signal. The method involves acquiring the main steam pressure process signal of a thermal power unit, subtracting the main steam pressure process signal from a second integral signal output by a second integrator using a first subtractor to generate a feedback output signal, integrating the feedback output signal using the first integrator to obtain a first integral signal, integrating the first integral signal using a second integrator to obtain a second integral signal, processing the second integral signal using an adjustable proportional control module to obtain an adjustable proportional control signal, and processing the main steam pressure process signal and the adjustable proportional control signal using a second subtractor to obtain a cosine-type tracking differential signal. This invention improves the differential tracking efficiency of the main steam pressure process signal by subtracting the main steam pressure process signal from the corresponding adjustable proportional control signal.

Description

Technical Field

[0001] This invention relates to the field of industrial process control, and in particular to a differential control method and system for main steam pressure process signals. Background Technology

[0002] During the operation of thermal power units, it is necessary to perform advanced observation of the main steam pressure process signal. Current methods for advanced observation of the main steam pressure process signal typically employ common differentiators. These common differentiators are tracking differentiators constructed based on a first-order inertial filter (FOIF). However, FOIF is a typical exponential tracking filter, which suffers from low output-to-input tracking efficiency. Therefore, common differentiators also suffer from low output-to-input differentiation efficiency.

[0003] Therefore, there is an urgent need for a differential control strategy for the main steam pressure process signal to solve the problem of low differential tracking efficiency of the main steam pressure process signal. Summary of the Invention

[0004] This invention provides a differential control method and system for the main steam pressure process signal to improve the differential tracking efficiency of the main steam pressure process signal.

[0005] To address the aforementioned problems, one embodiment of the present invention provides a differential control method for the main steam pressure process signal, applied to a cosine-type tracking differentiator. The cosine-type tracking differentiator includes: a first subtractor, a second subtractor, a first integrator, a second integrator, and an adjustable proportional control module. The method includes:

[0006] Acquire the main steam pressure process signal of the thermal power unit;

[0007] Using the first subtractor, a subtraction operation is performed on the main steam pressure process signal and the second integral signal output by the second integrator to obtain the feedback output signal corresponding to the main steam pressure process signal;

[0008] Using the first integrator, the feedback output signal is integrated to obtain the first integrated signal corresponding to the feedback output signal;

[0009] Using the second integrator, the first integral signal is integrated to obtain the second integral signal corresponding to the first integral signal;

[0010] Using the adjustable proportional control module, the second integral signal is received, and an adjustable proportional control signal corresponding to the second integral signal is generated;

[0011] Using the second subtractor, the main steam pressure process signal is received at the minuend of the second subtractor, and the adjustable proportional control signal is received at the subtrahend end of the second subtractor. Through subtraction, the cosine-type tracking differential signal corresponding to the main steam pressure process signal is obtained.

[0012] As an improvement to the above solution, the adjustable proportional control module includes: a delay unit, an adder, and an adjustable proportional controller; the step of using the adjustable proportional control module to receive the second integral signal and generate an adjustable proportional control signal corresponding to the second integral signal includes:

[0013] Using the delay unit, the second integral signal is received, and the second integral signal is delayed to obtain the first delayed signal;

[0014] Using the adder, the first delayed signal and the second integral signal are received, and the first addition signal is obtained through addition operation;

[0015] Using the adjustable proportional controller, the first addition signal is received, and an adjustable proportional control signal corresponding to the second integral signal is obtained through a preset proportional controller gain.

[0016] As an improvement to the above scheme, the first integrator includes:

[0017]

[0018] In the formula, f FI (s) is the Laplace transfer function of the first integrator; T T The time constant is used for tracking, and the unit is seconds (s).

[0019] As an improvement to the above scheme, the second integrator includes:

[0020]

[0021] In the formula, f FI (s) is the Laplace transfer function of the second integrator; T T The time constant is used for tracking, and the unit is seconds (s).

[0022] As an improvement to the above solution, the delay device includes:

[0023]

[0024] T L =T T

[0025] In the formula, f L (s) is the Laplace transfer function of the delay; T LThe tracking time constant is expressed in seconds (s); Note: T L By T T get.

[0026] As an improvement to the above solution, the adjustable proportional controller includes:

[0027] f k (s)=K P

[0028] In the formula, f k (s) is the Laplace transfer function of the proportional controller; Kp is the proportional controller gain, in dimensionless form.

[0029] Accordingly, one embodiment of the present invention also provides a differential control system for the main steam pressure process signal, including: thermal power unit equipment, data acquisition device and cosine tracking differentiator; wherein, the cosine tracking differentiator is applied to the differential control method for the main steam pressure process signal as described in the present invention;

[0030] The thermal power unit equipment is used to generate the main steam pressure process signal;

[0031] The data acquisition device is used to acquire the main steam pressure process signal and transmit it to the cosine-type tracking differentiator.

[0032] The cosine-type tracking differentiator is used to receive the main steam pressure process signal and generate a cosine-type tracking differential signal corresponding to the main steam pressure process signal.

[0033] As an improvement to the above scheme, the cosine-type tracking differentiator includes:

[0034]

[0035] T L =T T

[0036] In the formula, fQCTD(s) is the Laplace transfer function of the cosine-type tracking differentiator; TT is the tracking time constant in seconds; T L K is the delay time constant, in seconds; P This represents the proportional gain, and the unit is dimensionless.

[0037] As can be seen from the above, the present invention has the following beneficial effects:

[0038] This invention provides a differential control method for the main steam pressure process signal. The method involves acquiring the main steam pressure process signal of a thermal power unit, subtracting the main steam pressure process signal from a second integral signal output by a second integrator using a first subtractor to generate a feedback output signal, integrating the feedback output signal using the first integrator to obtain a first integral signal, integrating the first integral signal using a second integrator to obtain a second integral signal, processing the second integral signal using an adjustable proportional control module to obtain an adjustable proportional control signal, and processing the main steam pressure process signal and the adjustable proportional control signal using a second subtractor to obtain a cosine-type tracking differential signal. Compared to existing differentiators using FOIF for differential tracking, this invention significantly accelerates the cutoff rate of the main steam pressure process signal output by subtracting the main steam pressure process signal from the corresponding adjustable proportional control signal, thereby improving the differential tracking efficiency of the main steam pressure process signal.

[0039] Furthermore, the present invention adds the second integral signal corresponding to the main steam pressure process signal to the first time signal corresponding to the main steam pressure process signal, and outputs the signal after addition according to the preset proportional controller gain as an adjustable proportional control signal, which can further improve the differential rate of the main steam pressure process signal, thereby improving the differential tracking efficiency of the main steam pressure process signal. Attached Figure Description

[0040] Figure 1 This is a flowchart illustrating a differential control method for the main steam pressure process signal provided in an embodiment of the present invention.

[0041] Figure 2 This is a schematic diagram of the structure of a cosine-type tracking differentiator provided in an embodiment of the present invention;

[0042] Figure 3 This is a schematic diagram of the differential control system for the main steam pressure process signal provided in an embodiment of the present invention;

[0043] Figure 4 This is a schematic diagram of the output result of the second integrator process provided in an embodiment of the present invention;

[0044] Figure 5 This is a schematic diagram of the delay output of the second integrator output result provided in an embodiment of the present invention.

[0045] Figure 6 This is a comparison chart of the process output results of a cosine-type tracking differentiator provided in an embodiment of the present invention and a commonly used differentiator;

[0046] Figure 7 This is a schematic diagram of a terminal device structure provided in an embodiment of the present invention. Detailed Implementation

[0047] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] Example 1

[0049] See Figure 1 , Figure 1 This is a flowchart illustrating a differential control method for main steam pressure process signals according to an embodiment of the present invention. The method is as follows: Figure 1 As shown, this embodiment includes steps 101 to 106, and the specific steps are as follows:

[0050] The method is applied to a cosine-type tracking differentiator, such as... Figure 2 As shown, the cosine-type tracking differentiator includes: a first subtractor 201, a second subtractor 202, a first integrator 203, a second integrator 204, and an adjustable proportional control module 205;

[0051] Step 101: Obtain the main steam pressure process signal of the thermal power unit.

[0052] In this embodiment, the main steam pressure data of the thermal power unit is collected by a pressure sensor, and the main steam pressure process signal is generated based on the main steam pressure data.

[0053] Step 102: Using the first subtractor 201, perform a subtraction operation on the main steam pressure process signal and the second integral signal output by the second integrator to obtain the feedback output signal corresponding to the main steam pressure process signal.

[0054] In this embodiment, the main steam pressure process signal is input to the minuend of the first subtractor, and the second integral signal output by the second integrator is input to the subtrahend of the first subtractor, thereby performing a subtraction operation.

[0055] Step 103: Using the first integrator 203, perform integration on the feedback output signal to obtain the first integrated signal corresponding to the feedback output signal.

[0056] In this embodiment, the first integrator 203 includes:

[0057]

[0058] In the formula, f FI (s) is the Laplace transfer function of the first integrator 203; T TThe time constant is used for tracking, and the unit is seconds (s).

[0059] Step 104: Using the second integrator 204, perform integration on the first integral signal to obtain the second integral signal corresponding to the first integral signal.

[0060] In this embodiment, the second integrator 204 includes:

[0061]

[0062] In the formula, f FI (s) is the Laplace transfer function of the second integrator 204; T T The time constant is used for tracking, and the unit is seconds (s).

[0063] In one specific embodiment, in T T =100s, to obtain the process output PV of the second integrator. SOOL (t), such as Figure 4 As shown.

[0064] Step 105: Using the adjustable proportional control module 205, receive the second integral signal and generate an adjustable proportional control signal corresponding to the second integral signal.

[0065] In this embodiment, the adjustable proportional control module 205 includes: a delay unit 206, an adder 207, and an adjustable proportional controller 208; the step of using the adjustable proportional control module 205 to receive the second integral signal and generate an adjustable proportional control signal corresponding to the second integral signal includes:

[0066] Using the delay unit 206, the second integral signal is received, and the second integral signal is delayed to obtain the first delayed signal;

[0067] Using the adder 207, the first delayed signal and the second integral signal are received, and the first addition signal is obtained through addition operation;

[0068] Using the adjustable proportional controller 208, the first addition signal is received, and an adjustable proportional control signal corresponding to the second integral signal is obtained through a preset proportional controller gain.

[0069] In this embodiment, the delay unit 206 includes:

[0070]

[0071] T L =T T

[0072] In the formula, fL (s) is the Laplace transfer function of the delay; T L The tracking time constant is expressed in seconds (s); Note: T L By T T get.

[0073] In one specific embodiment, in T T =100s, T L =T T =100s, and the delayed output PV of the second integrator is obtained. L (t), such as Figure 5 As shown.

[0074] In this embodiment, the adjustable proportional controller 208 includes:

[0075] f k (s)=K P

[0076] In the formula, f k (s) is the Laplace transfer function of the proportional controller; Kp is the proportional controller gain, in dimensionless form.

[0077] Step 106: Using the second subtractor 202, the main steam pressure process signal is received at the minuend of the second subtractor, and the adjustable proportional control signal is received at the subtrahend end of the second subtractor. Through subtraction, the cosine-type tracking differential signal corresponding to the main steam pressure process signal is obtained.

[0078] In one specific embodiment, the differential characteristics of the cosine-type tracking differentiator are compared with those of a commonly used differentiator:

[0079] With a gain of 1, the commonly used differentiator expression is:

[0080] f CD (s)=1-f FOIF (s)

[0081]

[0082] In the formula, f CD (s) is the Laplace transfer function of the commonly used differentiator; f FOIF (s) is the Laplace transfer function of the first-order inertial filter; T FOIF Let be the filtering time constant of the first-order inertial filter, in seconds;

[0083] Set T T =100s, T L =T T =100s, T FOIF =100s, KP =0.5, the input signal is a unit step, and the process output PV of the cosine tracking differentiator is obtained. QCTD (t), the commonly used differentiator process outputs PV CD (t), such as Figure 6 As shown.

[0084] Depend on Figure 6 It can be seen that, compared with the commonly used differentiator, the cosine tracking differentiator has a higher cutoff speed in the process output. When t>100s, the cosine tracking differentiator output has already tracked the input, while the commonly used differentiator output tracks 61% of the input. This shows that the differentiating performance of the cosine tracking differentiator is significantly better than that of the commonly used differentiator.

[0085] See Figure 3 , Figure 3 This is a schematic diagram of the structure of a differential control system for the main steam pressure process signal according to an embodiment of the present invention, including: thermal power unit equipment 301, data acquisition device 302, and cosine tracking differentiator 303; wherein, the cosine tracking differentiator 303 is applied to the differential control method for the main steam pressure process signal as described in the present invention;

[0086] The thermal power unit equipment 301 is used to generate the main steam pressure process signal;

[0087] The data acquisition device 302 is used to acquire the main steam pressure process signal and transmit it to the cosine-type tracking differentiator.

[0088] The cosine-type tracking differentiator 303 is used to receive the main steam pressure process signal and generate a cosine-type tracking differential signal corresponding to the main steam pressure process signal.

[0089] As an improvement to the above scheme, the cosine-type tracking differentiator 303 includes:

[0090]

[0091] T L =T T

[0092] In the formula, f QCTD (s) is the Laplace transfer function of the cosine-type tracking differentiator 303; T T To track the time constant, the unit is seconds; T L K is the delay time constant, in seconds; P This represents the proportional gain, and the unit is dimensionless.

[0093] This embodiment acquires the main steam pressure process signal of a thermal power unit. A first subtractor subtracts the main steam pressure process signal from a second integrator to generate a feedback output signal. The first integrator then integrates the feedback output signal to obtain a first integral signal. A second integrator integrates the first integral signal to obtain a second integral signal. An adjustable proportional control module processes the second integral signal to obtain an adjustable proportional control signal. Finally, a second subtractor processes the main steam pressure process signal and the adjustable proportional control signal to obtain a cosine-type tracking differential signal. This cosine-type tracking differential control method achieves high signal differential tracking efficiency, thereby improving the forward observation performance of the main steam pressure control and ultimately enhancing the efficiency of the main steam pressure process control.

[0094] Example 2

[0095] See Figure 7 , Figure 7 This is a schematic diagram of the terminal device structure provided in an embodiment of the present invention.

[0096] One terminal device in this embodiment includes: a processor 701, a memory 702, and a computer program stored in the memory 702 and executable on the processor 701. When the processor 701 executes the computer program, it implements the steps of the differential control method for the various main steam pressure process signals described above in this embodiment, for example... Figure 1 All steps of the differential control method for the main steam pressure process signal shown. Alternatively, when the processor executes the computer program, it implements the functions of each module in the above-described device embodiments, for example: Figure 3 The diagram shows all modules of the differential control system for the main steam pressure process signal.

[0097] In addition, embodiments of the present invention also provide a computer-readable storage medium, the computer-readable storage medium including a stored computer program, wherein, when the computer program is executed, it controls the device where the computer-readable storage medium is located to perform the differential control method of the main steam pressure process signal as described in any of the above embodiments.

[0098] Those skilled in the art will understand that the schematic diagram is merely an example of a terminal device and does not constitute a limitation on the terminal device. It may include more or fewer components than shown in the diagram, or combine certain components, or different components. For example, the terminal device may also include input / output devices, network access devices, buses, etc.

[0099] The processor 701 may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor. The processor 701 is the control center of the terminal device, connecting various parts of the terminal device through various interfaces and lines.

[0100] The memory 702 can be used to store the computer programs and / or modules. The processor 701 implements various functions of the terminal device by running or executing the computer programs and / or modules stored in the memory and calling the data stored in the memory 702. The memory 702 may mainly include a program storage area and a data storage area. The program storage area may store the operating system, at least one application program required for a function (such as sound playback function, image playback function, etc.), etc.; the data storage area may store data created according to the use of the mobile phone (such as audio data, phonebook, etc.). In addition, the memory may include high-speed random access memory, and may also include non-volatile memory, such as hard disk, memory, plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0101] Wherein, if the modules / units integrated in the terminal device are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments of the present invention can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when the computer program is executed by a processor, it can implement the steps of the various method embodiments described above. Wherein, the computer program includes computer program code, which can be in the form of source code, object code, executable file, or some intermediate form, etc. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, portable hard drive, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium, etc.

[0102] It should be noted that the device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Furthermore, in the accompanying drawings of the device embodiments provided by this invention, the connection relationships between modules indicate that they have communication connections, which can be specifically implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement this without any creative effort.

[0103] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method of differential control of a main steam pressure process signal, characterized by The application is applied to a cosine tracking differentiator, and the cosine tracking differentiator comprises a first subtracter, a second subtracter, a first integrator, a second integrator and an adjustable proportional control module; the method comprises: Obtain the main steam pressure process signal of the thermal power generating unit; Using the first subtracter, the main steam pressure process signal and the second integral signal output by the second integrator are subjected to subtraction operation to obtain the feedback output signal corresponding to the main steam pressure process signal; Using the first integrator, the feedback output signal is subjected to integral operation to obtain the first integral signal corresponding to the feedback output signal; Using the second integrator, the first integral signal is subjected to integral operation to obtain the second integral signal corresponding to the first integral signal; Using the adjustable proportional control module, the second integral signal is received to generate the adjustable proportional control signal corresponding to the second integral signal; wherein the adjustable proportional control module comprises a delay device, an adder and an adjustable proportional controller; using the adjustable proportional control module to receive the second integral signal and generate the adjustable proportional control signal corresponding to the second integral signal comprises: using the delay device to receive the second integral signal, performing delay operation on the second integral signal to obtain the first delay signal; using the adder to receive the first delay signal and the second integral signal, and obtaining the first addition signal through addition operation; using the adjustable proportional controller to receive the first addition signal and obtaining the adjustable proportional control signal corresponding to the second integral signal through the preset proportional controller gain; Using the second subtracter, the main steam pressure process signal is received at the minuend end of the second subtracter, and the adjustable proportional control signal is received at the subtrahend end of the second subtracter, and the cosine tracking differential signal corresponding to the main steam pressure process signal is obtained through subtraction operation The cosine tracking differentiator comprises: where f QCTD (s) is the Laplace transfer function of the cosine-type tracking differentiator; T T is the tracking time constant, in s; T L is the time delay constant, in s; K P is the proportional gain, dimensionless.

2. The method of derivative control of a main steam pressure process signal according to claim 1, characterized in that, The first integrator comprises: wherein f FI s is the Laplace transfer function of the first integrator; T T is the tracking time constant in s.​ 3. The method of derivative control of a main steam pressure process signal according to claim 1, wherein, The second integrator comprises: wherein f FI s is the Laplace transfer function of the second integrator; T T is the tracking time constant in s.​ 4. The method of derivative control of a main steam pressure process signal according to claim 1, wherein, The delay device comprises: wherein f L s is the Laplace transfer function of the delay; T L is the tracking time constant in s; it is explained that: T L is obtained from T T is obtained from​ 5. The method of derivative control of a main steam pressure process signal according to claim 1, wherein, The adjustable proportional controller comprises: wherein f k ( s ) is the Laplace transfer function of the proportional controller; Kp is the proportional controller gain, dimensionless.

6. A derivative control system for a main steam pressure process signal, characterized by It comprises: Thermal power generating unit equipment, data acquisition device and cosine tracking differentiator; wherein the cosine tracking differentiator is applied to the differential control method of the main steam pressure process signal in any one of claims 1 to 5; The thermal power generating unit equipment is used for generating the main steam pressure process signal; The data acquisition device is used for acquiring the main steam pressure process signal and transmitting the main steam pressure process signal to the cosine tracking differentiator; The cosine tracking differentiator is used for receiving the main steam pressure process signal and generating the cosine tracking differential signal corresponding to the main steam pressure process signal.

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