A thermal power unit analog hysteresis control device and method

Abstract

The invention discloses an analog quantity hysteresis control device and method for a thermal power unit. The structure of the device is that a first analog quantity input terminal board is connected to a first analog quantity input module; a second analog quantity input terminal board is connected to a second analog quantity input module; a first analog quantity output terminal board is connected to the first analog quantity output module; a second analog quantity output terminal board 6 is connected to a second analog quantity output module 8; a first analog quantity input module 3, a second analog quantity input module 4, a first analog quantity output module 7 and a second analog quantity output module 8 are connected to a controller 9 through a CAN bus, and the controller 9 has the lowest physical address on the CAN bus and the highest priority of the controller 9; the device has a simple structure, can work in both synchronous and asynchronous modes, performs independent and associated hysteresis control on two analog quantities, and performs high and low limit and change rate control on the two analog quantities.

Description

Technical Field

[0001] The invention relates to the technical field of thermal power station automatic control, and in particular to a thermal power unit analog hysteresis control device and method. Background Art

[0002] In the control process of thermal power plants, analog control is complex and changeable. Due to the hysteresis of the power generation process, the control logic often uses various hysteresis control strategies. Due to the coupling between systems, the hysteresis control characteristics between analog quantities are correlated. Refined hysteresis control of two or more analog quantities can greatly improve the control quality of the unit. For example, in the boiler combustion process, due to the hysteresis of the combustion system, the current coal feed of the pulverizer can only be reflected in the main steam pressure, main steam temperature and flue gas emissions after a certain lag time. Therefore, hysteresis control is widely used in the process control of the unit and determines the control quality of the unit. Although common PID control can achieve hysteresis, when the measured value fluctuates greatly, it is difficult for the output to track the given value well. LEADLAG control has the functions of filtering and hysteresis control, but the delayed hysteresis control achieved through LEADLAG is not accurate enough. The main limitations of the existing technology are:

[0003] (1) Analog hysteresis control can complete the independent hysteresis operation of two analog quantities within a given hysteresis time.

[0004] (2) The analog hysteresis control has two opposing first-in-first-out queues. The hysteresis control operates according to the operation cycle and has a compensation option. It can compensate the output of the two analog quantities and output the actual delay time of the two analog quantities and the delay time that still needs to be compensated.

[0005] (3) The analog hysteresis control has high and low limit control to ensure that the hysteresis analog quantity participating in the operation does not exceed or fall below the given high and low limits, ensuring that the controlled object or system operates within the safe parameter range.

[0006] (4) Analog hysteresis control can satisfy the requirement that two analog quantities are associated with each other according to the same hysteresis rule. Summary of the invention

[0007] In order to overcome the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a device and method for analog hysteresis control of a thermal power unit. The device has a simple structure and can operate in both synchronous and asynchronous modes. It can perform independent and associated hysteresis control on two analog quantities, and perform high and low limit and change rate control on the two analog quantities.

[0008] In order to achieve the above purpose, the present invention adopts the following technical scheme:

[0009] A thermal power unit analog quantity hysteresis control device comprises a first analog quantity input terminal board 1, a second analog quantity input terminal board 2, a first analog quantity input module 3, a second analog quantity input module 4, a first analog quantity output terminal board 5, a second analog quantity output terminal board 6, a first analog quantity output module 7, a second analog quantity output module 8 and a controller 9; the first analog quantity input terminal board 1 and the first analog quantity input module 3 are connected through a standard DB37 line; the second analog quantity input terminal board 2 and the second analog quantity input module 4 are connected through a standard DB37 line; the first analog quantity output terminal board 5 and the first analog quantity output module 7 are connected through a standard DB37 line; the second analog quantity output terminal board 6 and the second analog quantity output module 8 are connected through a standard DB37 line; the first analog quantity input module 3, the second analog quantity input module 4, the first analog quantity output module 7 and the second analog quantity output module 8 are connected to the controller 9 through a CAN bus, the controller 9 has the lowest physical address on the CAN bus, and the controller 9 has the highest priority.

[0010] The analog input channels of the first analog input terminal board 1 and the second analog input terminal board 2 are respectively connected to the analog measurement values ​​Q1 and Q2 from the measurement object; the analog quantities P1 and T1 output after the analog hysteresis control device calculates are output through the first analog output terminal board 5 and the second analog output terminal board 6 respectively.

[0011] The first analog input terminal board 1 and the second analog input terminal board 2 each include a terminal board input channel; the first analog input module 3 and the second analog input module 4 each include an analog input channel.

[0012] The first analog output terminal board 5 and the second analog output terminal board 6 each include a terminal board output channel; the first analog output module 7 and the second analog output module 8 each include an analog output channel.

[0013] The working method of the analog hysteresis control device for thermal power generation units is specifically as follows:

[0014] The first analog input terminal board 1 collects the analog signal Q1 of the measured object, and the second analog input terminal board 2 collects the analog signal Q2 of the measured object. The first analog input module 3 converts the analog signal collected from the first analog input terminal board 1 into a digital signal and sends it to the controller 9. The second analog input module 4 converts the analog signal collected from the second analog input terminal board 2 into a digital signal and sends it to the controller 9; the controller 9 performs analog hysteresis control operation. After the operation is completed, the controller sends the two-way output analog quantity to the first analog output module 7 and the second analog output module 8 through the CAN bus respectively. The first analog output module 7 and the second analog output module 8 convert the digital signal into a 4-20mA analog signal and send it to the first analog output terminal board 5 and the second analog output terminal board 6 respectively. The first analog output terminal board 5 and the second analog output terminal board 6 send the output analog signal to the external system;

[0015] The above analog hysteresis control calculation method is as follows:

[0016] The inputs of analog hysteresis control include: input working mode ASI, first channel input analog AI1, second channel input analog AI2, first channel compensation option SE1, second channel compensation option SE2, first channel delay time DeT1 and second channel delay time DeT2; the outputs include: output working mode ASO, first channel output analog AO1, second channel output analog AO2, first channel actual delay time ADeT1, second channel actual delay time ADeT2, first channel compensation time DT1 and second channel compensation time DT2; first channel delay time DeT1, in milliseconds, represents the absolute time of delayed output of first channel input analog AI1, and second channel delay time DeT2, in milliseconds, represents the absolute time of delayed output of second channel input analog AI2;

[0017] The analog hysteresis control includes the following parameters: operation cycle T, calculation times N, first array A1, second array A2, output upper limit AOmax, output lower limit AOmin, output values ​​AO1Last and AO2Last of the previous operation cycle, first output change rate R1 and second output change rate R2, hysteresis target cycle number TN, and first output bias B1 and second output bias B2;

[0018] The operation cycle T represents the time interval from the start time of the current calculation to the start time of the next calculation of the analog hysteresis control; the number of calculations N represents the cumulative number of operation cycles of the analog hysteresis control; the first array A1 and the second array A2 have the same length, which is 1001, accommodating 1001 elements, denoted as A1

[1001] and A2

[1001] , and four global index variables r1, f1, r2, f2 are defined, and their value ranges are all 0, 1, ..., i, ..., 1000, representing the subscript index for accessing the first array A1 and the second array A2; the output high limit AOmax represents the output of the first output analog AO1 and the second output analog AO2 The maximum value of the output; the output lower limit AOmin, represents the minimum value of the first output analog quantity AO1 and the second output analog quantity AO2; AO1Last represents the output value of the first output analog quantity AO1 in the previous operation cycle, and AO2Last represents the output value of the second output analog quantity AO2 in the previous operation cycle; the first output change rate R1 represents the change rate of the first output analog quantity AO1 relative to the output value AO1Last of the previous operation cycle; the second output change rate R2 represents the change rate of the second output analog quantity AO2 relative to the output value AO2Last of the previous operation cycle. The calculation formula of the output change rate is as follows:

[0019] R1=∣AO1-AO1Last∣ / AO1Last;

[0020] R2=∣AO2-AO2Last∣ / AO2Last;

[0021] Among them, ||| represents absolute value operation, and / represents division operation;

[0022] AI1[1], AI1[2], …, AI1[i], …, AI1

[1000] represent the value of each data item of the first input analog quantity AI1, and AI2[1], AI2[2], …, AI2[i], …, AI2

[1000] represent the value of each data item of the second input analog quantity AI2, where the value range of i is 1 to 1000;

[0023] The analog hysteresis control is divided into two working modes according to the relationship between the first analog input AI1 and the second analog input AI2: synchronous mode and asynchronous mode. The synchronous mode is represented by 0, and the asynchronous mode is represented by 1. The working mode of the analog hysteresis control depends on the input working mode ASI. When ASI=0, it means that the analog hysteresis control works in synchronous mode. When ASI=1, it means that the analog hysteresis control works in asynchronous mode. The output working mode ASO of the analog hysteresis control tracks the input working mode ASI, that is, ASO=ASI.

[0024] The input working mode ASI and the output working mode ASO are used for the cascade of analog hysteresis control. When one or more analog hysteresis control cascades work, the working modes of all subsequent analog hysteresis control track the working mode of the previous analog hysteresis control; global index variable f1 = r1 = 1;

[0025] Each operation cycle is calculated according to the following method:

[0026] Determine the first compensation option SE1 and the second compensation option SE2. When SE1=1, it means that the compensation calculation is turned on. When the set delay time has not arrived, the first output analog quantity AO1 immediately outputs the value of the first input analog quantity AI1; when the first compensation option SE1 input is 0, it means that the compensation calculation is turned off. When the set delay time has not arrived, the first output analog quantity AO1 outputs 0, and the first compensation option SE1 defaults to 0; when SE2=1, it means that the compensation calculation is turned on. When the set delay time has not arrived, the second output analog quantity AO2 immediately outputs the value of the second input analog quantity AI2; when the second compensation option SE2 input is 0, it means that the compensation calculation is turned off. When the set delay time has not arrived, the second output analog quantity AO2 outputs 0, and the second compensation option SE2 defaults to 0;

[0027] Determine the working mode of analog hysteresis control and calculate the output according to the corresponding method based on the working mode:

[0028] 1. Synchronous mode

[0029] When ASI=0, analog hysteresis control works in synchronous mode; in synchronous mode, the second delay time DeT2 is invalid and does not participate in the calculation. The hysteresis time of the first input analog AI1 and the second input analog AI2 is the same;

[0030] First, calculate the target number of cycles TN required to delay the output of analog hysteresis control according to the following formula: TN = DeT1 / T;

[0031] When TN≤1000, and (r1+1)%TN≠f1, A1[r1]=AI1, A2[r1]=AI2, r1=(r1+1)%TN, AO1=AI1[f1], AO2=A2[f1], ADeT2=0, DT2=0, f1=(f1+1)%TN, ADeT1=T×|r1-f1|; DT1=T×(TN-|r1-f1|);

[0032] When TN≤1000, and (r1+1)%TN==f1, A1[r1]=AI1, A2[r1]=AI2, r1=(r1+1)%TN, AO1=A1[f1], AO2=A2[f1], f1=(f1+1)%TN, ADeT1=T×TN, DT1=0, ADeT2=0, DT2=0;

[0033] When TN>1000, and (r1+1)%1000≠f1, A1[r1]=AI1, A2[r1]=AI2, r1=(r1+1)%1000, AO1=AI1[f1], AO2=A2[f1], f1=(f1+1)%1000, ADeT1=T×|r1-f1|; DT1=T×(TN-|r1-f1|), ADeT2=0, DT2=0;

[0034] When TN>1000, and (r1+1)%1000==f1, A1[r1]=AI1, A2[r1]=AI2, r1=(r1+1)%1000, AO1=A1[f1], AO2=A2[f1], f1=(f1+1)%1000, ADeT1=T×1000, ADeT2=0; DT1=T×(TN-1000), DT2=0;

[0035] % indicates remainder operation;

[0036] 2. Asynchronous mode

[0037] When ASI=1, analog hysteresis control works in asynchronous mode, and the first analog input AI1 and the second analog input AI2 are independently calculated for hysteresis output. The calculation method is as follows:

[0038] When TN≤1000 and (r1+1)%TN≠f1, A1[r1]=AI1, r1=(r1+1)%TN, AO1=AI1[f1], f1=(f1+1)%TN, ADeT1=T×|r1-f1|; DT1=T×(TN-|r1-f1|);

[0039] When TN≤1000, and (r2+1)%TN≠f2, A2[r2]=AI2, r2=(r2+1)%TN, AO2=A2[f2], f2=(f2+1)%TN, ADeT2=T×|r2-f2|; DT2=T×(TN-|r2-f2|);

[0040] When TN≤1000, and (r1+1)%TN==f1, A1[r1]=AI1, r1=(r1+1)%TN, AO1=A1[f1], f1=(f1+1)%TN, ADeT1=T×TN, DT1=0;

[0041] When TN≤1000, and (r2+1)%TN==f2, A2[r2]=AI2, r2=(r2+1)%TN, AO2=A2[f2], f2=(f2+1)%TN, ADet2=T×TN; DT2=0;

[0042] When TN>1000, and (r1+1)%1000≠f1, A1[r1]=AI1, A2[r2]=AI2, r1=(r1+1)%1000, r2=(r2+1)%1000, AO1=AI1[f1], AO2=A2[f2], f2=(f2+1)%1000, ADeT1=T×|r1-f1|, DT1=T×(TN-|r1-f1|), ADeT2=T×|r2-f2|, DT2=T×(TN-|r2-f2|);

[0043] When TN>1000, and (r1+1)%1000==f1, A1[r1]=AI1, A2[r1]=AI2, r1=(r1+1)%1000, AO1=A1[f1], AO2=A2[f2], f1=(f1+1)%1000, ADeT1=T×1000, ADet2=T×1000; DT1=T×(TN-1000), DT2=T×(TN-1000);

[0044] After the calculation of the first output analog quantity AO1 and the second output analog quantity AO2 is completed, the output values ​​of the first output analog quantity AO1 and the second output analog quantity AO2 need to be judged and calculated according to the following constraints:

[0045] If |AO1-AO1Last| / AO1Last>R1, then AO1=AO1Last+AO1Last*R;

[0046] If |AO2-AO2Last| / AO2Last>R2, then AO2=AO2Last+AO2Last*R;

[0047] The first output analog quantity AO1 and the second output analog quantity AO2 are both subject to the constraints of the output high limit AOmax and the output low limit AOmin: if AO1>AOmax, AO1=AOmax, if AO1 <AOmin,AO1=AOmin;

[0048] If AO2>AOmax, AO2=AOmax, if AO2 <AOmin,AO2=AOmin。

[0049] Compared with the prior art, the present invention has the following advantages:

[0050] 1. Analog hysteresis control can complete the independent hysteresis operation of two analog quantities within a given hysteresis time.

[0051] 1. The analog hysteresis control has two opposing first-in-first-out queues set inside. The hysteresis control is calculated according to the operation cycle and is equipped with compensation options. It can compensate the output of the two analog quantities and output the actual delay time of the two analog quantities and the delay time that still needs to be compensated at the same time.

[0052] 3. The analog hysteresis control has high and low limit control to ensure that the hysteresis analog quantity participating in the operation does not exceed or fall below the given high and low limits, ensuring that the controlled object or system operates within the safe parameter range.

[0053] 4. Analog hysteresis control can satisfy the associated hysteresis control of two analog quantities according to the same hysteresis rule. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 The present invention is a schematic diagram of the composition and connection structure of an analog hysteresis control device.

[0055] Figure 2 It is a logic model diagram of analog hysteresis control method.

[0056] Figure 3 Schematic diagram of analog hysteresis control application. DETAILED DESCRIPTION

[0057] The present invention is further described in detail below in conjunction with the accompanying drawings and application examples in engineering.

[0058] like Figure 1 As shown, the present invention is an analog hysteresis control device for a thermal power unit, comprising a first analog input terminal board 1, a second analog input terminal board 2, a first analog input module 3, a second analog input module 4, a first analog output terminal board 5, a second analog output terminal board 6, a first analog output module 7, a second analog output module 8 and a controller 9;

[0059] The first analog input terminal board 1 and the second analog input terminal board 2 each include a terminal board input channel; the first analog input module 3 and the second analog input module 4 each include an analog input channel, the first analog input terminal board 1 and the first analog input module 3 are connected via a standard DB37 line; the second analog input terminal board 2 and the second analog input module 4 are connected via a standard DB37 line;

[0060] The first analog output terminal board 5 and the second analog output terminal board 6 each include a terminal board output channel; the first analog output module 7 and the second analog output module 8 each include an analog output channel, the first analog output terminal board 5 and the first analog output module 7 are connected via a standard DB37 line; the second analog output terminal board 6 and the second analog output module 8 are connected via a standard DB37 line;

[0061] The first analog input module 3, the second analog input module 4, the first analog output module 7 and the second analog output module 8 are connected to the controller 9 via the CAN bus. The controller 9 has the lowest physical address on the CAN bus and the highest priority.

[0062] The analog input channels of the first analog input terminal board 1 and the second analog input terminal board 2 are respectively connected to the analog measurement values ​​Q1 and Q2 from the measurement object; the analog quantities P1 and T1 output after the analog hysteresis control device calculates are output through the first analog output terminal board 5 and the second analog output terminal board 6 respectively.

[0063] The working method of the analog hysteresis control device for thermal power generation units described in the present invention is as follows:

[0064] The first analog input terminal board 1 collects the 4-20mA analog signal Q1 of the measured object through hard wiring, the second analog input terminal board 2 collects the 4-20mA analog signal Q2 of the measured object through hard wiring, the first analog input module 3 converts the analog signal collected from the first analog input terminal board 1 into a digital signal and sends it to the controller 9, the second analog input module 4 converts the analog signal collected from the second analog input terminal board 2 into a digital signal and sends it to the controller 9; the controller 9 performs analog hysteresis control operation, after the operation, the controller sends the two-way output analog quantity to the first analog output module 7 and the second analog output module 8 through the CAN bus respectively, the first analog output module 7 and the second analog output module 8 convert the digital signal into a 4-20mA analog signal and send it to the first analog output terminal board 5 and the second analog output terminal board 6 respectively, the first analog output terminal board 5 and the second analog output terminal board 6 send the output analog signal to the external system through hard wiring.

[0065] The above analog hysteresis control calculation method is as follows:

[0066] Analog hysteresis control is represented by the symbol SLAGS, and its logic model is as follows: Figure 2 As shown, the input includes: input working mode ASI, first input analog quantity AI1, second input analog quantity AI2, first compensation option SE1, second compensation option SE2, first delay time DeT1 and second delay time DeT2; the output includes: output working mode ASO, first output analog quantity AO1, second output analog quantity AO2, first actual delay time ADeT1, second actual delay time ADeT2, first compensation time DT1 and second compensation time DT2.

[0067] The first delay time DeT1, in milliseconds, represents the absolute time of the first analog input AI1 delay output. The second delay time DeT2, in milliseconds, represents the absolute time of the second analog input AI2 delay output.

[0068] The analog hysteresis control includes the following parameters: operation cycle T, calculation times N, first array A1, second array A2, output upper limit AOmax, output lower limit AOmin, output values ​​AO1Last and AO2Last of the previous operation cycle, first output change rate R1 and second output change rate R2, hysteresis target cycle number TN, and first output bias B1 and second output bias B2.

[0069] The operation cycle T represents the time interval from the start time of the current calculation to the start time of the next calculation of the analog hysteresis control; the number of calculations N represents the cumulative number of operation cycles of the analog hysteresis control; the first array A1 and the second array A2 have the same length, which is 1001, and can accommodate 1001 elements, denoted as A1

[1001] and A2

[1001] . Four global index variables r1, f1, r2, and f2 are defined, and their value ranges are 0, 1, ..., i, ..., 1000, indicating the subscript index for accessing the first array A1 and the second array A2; the output high limit AOmax represents the first output analog AO1 and the second output analog AO2 The maximum value of the output; the output lower limit AOmin, represents the minimum value of the first output analog quantity AO1 and the second output analog quantity AO2; AO1Last represents the output value of the first output analog quantity AO1 in the previous operation cycle, and AO2Last represents the output value of the second output analog quantity AO2 in the previous operation cycle; the first output change rate R1 represents the change rate of the first output analog quantity AO1 relative to the output value AO1Last of the previous operation cycle; the second output change rate R2 represents the change rate of the second output analog quantity AO2 relative to the output value AO2Last of the previous operation cycle. The calculation formula of the output change rate is as follows:

[0070] R1=∣AO1-AO1Last∣ / AO1Last;

[0071] R2=∣AO2-AO2Last∣ / AO2Last;

[0072] Among them, ||| represents absolute value operation, and / represents division operation.

[0073] AI1[1], AI1[2], …, AI1[i], …, AI1

[1000] represent the value of each data item of the first input analog quantity AI1, and AI2[1], AI2[2], …, AI2[i], …, AI2

[1000] represent the value of each data item of the second input analog quantity AI2, where the value range of i is 1 to 1000.

[0074] Analog hysteresis control can be divided into two working modes according to the relationship between the first analog input AI1 and the second analog input AI2: synchronous mode (indicated by 0) and asynchronous mode (indicated by 1). The working mode of analog hysteresis control depends on the input working mode ASI. When ASI=0, it means that the analog hysteresis control works in synchronous mode. When ASI=1, it means that the analog hysteresis control works in asynchronous mode. The output working mode ASO of analog hysteresis control tracks the input working mode ASI, that is, ASO=ASI.

[0075] The input working mode ASI and the output working mode ASO are used for the cascade of analog hysteresis control. When one or more analog hysteresis controls are cascaded, the working modes of all subsequent analog hysteresis controls track the working mode of the previous analog hysteresis control; the global index variable f1=r1=1.

[0076] Each operation cycle is calculated according to the following method:

[0077] Determine the first compensation option SE1 and the second compensation option SE2. When SE1=1, it means that the compensation calculation is turned on. When the set delay time has not arrived, the first output analog quantity AO1 immediately outputs the value of the first input analog quantity AI1. When the first compensation option SE1 input is 0, it means that the compensation calculation is turned off. When the set delay time has not arrived, the first output analog quantity AO1 outputs 0. The first compensation option SE1 defaults to 0. When SE2=1, it means that the compensation calculation is turned on. When the set delay time has not arrived, the second output analog quantity AO2 immediately outputs the value of the second input analog quantity AI2. When the second compensation option SE2 input is 0, it means that the compensation calculation is turned off. When the set delay time has not arrived, the second output analog quantity AO2 outputs 0. The second compensation option SE2 defaults to 0.

[0078] Determine the working mode of analog hysteresis control and calculate the output according to the corresponding method based on the working mode:

[0079] 1. Synchronous mode

[0080] When ASI = 0, analog hysteresis control works in synchronous mode. In synchronous mode, the second delay time DeT2 is invalid and does not participate in the calculation. The hysteresis time of the first input analog AI1 and the second input analog AI2 is the same.

[0081] First, calculate the target number of cycles TN required to delay the output of analog hysteresis control according to the following formula: TN = DeT1 / T;

[0082] When TN≤1000, and (r1+1)%TN≠f1, A1[r1]=AI1, A2[r1]=AI2, r1=(r1+1)%TN, AO1=AI1[f1], AO2=A2[f1], ADeT2=0, DT2=0, f1=(f1+1)%TN, ADeT1=T×|r1-f1|; DT1=T×(TN-|r1-f1|);

[0083] When TN≤1000, and (r1+1)%TN==f1, A1[r1]=AI1, A2[r1]=AI2, r1=(r1+1)%TN, AO1=A1[f1], AO2=A2[f1], f1=(f1+1)%TN, ADeT1=T×TN, DT1=0, ADeT2=0, DT2=0;

[0084] When TN>1000, and (r1+1)%1000≠f1, A1[r1]=AI1, A2[r1]=AI2, r1=(r1+1)%1000, AO1=AI1[f1], AO2=A2[f1], f1=(f1+1)%1000, ADeT1=T×|r1-f1|; DT1=T×(TN-|r1-f1|), ADeT2=0, DT2=0;

[0085] When TN>1000, and (r1+1)%1000==f1, A1[r1]=AI1, A2[r1]=AI2, r1=(r1+1)%1000, AO1=A1[f1], AO2=A2[f1], f1=(f1+1)%1000, ADeT1=T×1000, ADeT2=0; DT1=T×(TN-1000), DT2=0;

[0086] % indicates the remainder operation.

[0087] 2. Asynchronous mode

[0088] When ASI=1, analog hysteresis control works in asynchronous mode, and the first analog input AI1 and the second analog input AI2 are independently calculated for hysteresis output. The calculation method is as follows:

[0089] When TN≤1000 and (r1+1)%TN≠f1, A1[r1]=AI1, r1=(r1+1)%TN, AO1=AI1[f1], f1=(f1+1)%TN, ADeT1=T×|r1-f1|; DT1=T×(TN-|r1-f1|);

[0090] When TN≤1000, and (r2+1)%TN≠f2, A2[r2]=AI2, r2=(r2+1)%TN, AO2=A2[f2], f2=(f2+1)%TN, ADeT2=T×|r2-f2|; DT2=T×(TN-|r2-f2|);

[0091] When TN≤1000, and (r1+1)%TN==f1, A1[r1]=AI1, r1=(r1+1)%TN, AO1=A1[f1], f1=(f1+1)%TN, ADeT1=T×TN, DT1=0;

[0092] When TN≤1000, and (r2+1)%TN==f2, A2[r2]=AI2, r2=(r2+1)%TN, AO2=A2[f2], f2=(f2+1)%TN, ADet2=T×TN; DT2=0;

[0093] When TN>1000, and (r1+1)%1000≠f1, A1[r1]=AI1, A2[r2]=AI2, r1=(r1+1)%1000, r2=(r2+1)%1000, AO1=AI1[f1], AO2=A2[f2], f2=(f2+1)%1000, ADeT1=T×|r1-f1|, DT1=T×(TN-|r1-f1|), ADeT2=T×|r2-f2|, DT2=T×(TN-|r2-f2|);

[0094] When TN>1000, and (r1+1)%1000==f1, A1[r1]=AI1, A2[r1]=AI2, r1=(r1+1)%1000, AO1=A1[f1], AO2=A2[f2], f1=(f1+1)%1000, ADeT1=T×1000, ADet2=T×1000; DT1=T×(TN-1000), DT2=T×(TN-1000);

[0095] After the calculation of the first output analog quantity AO1 and the second output analog quantity AO2 is completed, the output values ​​of the first output analog quantity AO1 and the second output analog quantity AO2 need to be judged and calculated according to the following constraints:

[0096] If |AO1-AO1Last| / AO1Last>R1, then AO1=AO1Last+AO1Last*R;

[0097] If |AO2-AO2Last| / AO2Last>R2, then AO2=AO2Last+AO2Last*R;

[0098] The first output analog quantity AO1 and the second output analog quantity AO2 are both subject to the constraints of the output high limit AOmax and the output low limit AOmin: if AO1>AOmax, AO1=AOmax, if AO1 <AOmin,AO1=AOmin;

[0099] If AO2>AOmax, AO2=AOmax, if AO2 <AOmin,AO2=AOmin。

[0100] Example:

[0101] As attached Figure 3 As shown, the structural diagram of the on-site engineering implementation and deployment, in which Sig-1 and Sig-2 represent the NOx content A and NOx content B measured at different positions of the flue. According to the path of flue gas emission, measuring point A is in front of measuring point B; Sig-5 and Sig-6 represent the two-way lag time T1 and time T2 respectively. Through analog lag control, the flue gas NOx content A and NOx content B are delayed to T1 and T2 respectively to participate in the calculation, and the ammonia injection amount A and ammonia injection amount B required for flue gas treatment are calculated; the ammonia injection amount calculation in the figure means that the required ammonia injection amount A and ammonia injection amount B are calculated using the flue gas NOx content. The ammonia injection amount A and ammonia injection amount B are controlled by the ammonia injection grid. There are two ammonia injection grids corresponding to the ammonia injection amount A and ammonia injection amount B respectively. The two ammonia injection grids are installed at the outlet positions of the flue on both sides. When controlling the amount of ammonia injection A and ammonia injection B, the working mode of the analog lag control method is controlled by changing the value of ASI. Figure 3 The analog hysteresis control shown works in asynchronous mode. According to the NOx content A and NOx content B currently measured, the analog hysteresis control is used to delay the A and B routes by T1 and T2 times respectively. After the ammonia injection amount is calculated, the ammonia injection amount of the A route ammonia injection grid after T1 time and the ammonia injection grid of the B route after T2 time are calculated.

Claims

1. A thermal power unit analog hysteresis control device, characterized in that: The device comprises a first analog quantity input terminal board (1), a second analog quantity input terminal board (2), a first analog quantity input module (3), a second analog quantity input module (4), a first analog quantity output terminal board (5), a second analog quantity output terminal board (6), a first analog quantity output module (7), a second analog quantity output module (8) and a controller (9); the first analog quantity input terminal board (1) and the first analog quantity input module (3) are connected via a standard DB37 line; the second analog quantity input terminal board (2) and the second analog quantity input module (4) are connected via a standard D The first analog output terminal board (5) and the first analog output module (7) are connected via a standard DB37 line; the second analog output terminal board (6) and the second analog output module (8) are connected via a standard DB37 line; the first analog input module (3), the second analog input module (4), the first analog output module (7) and the second analog output module (8) are connected to the controller (9) via a CAN bus, the controller (9) has the lowest physical address on the CAN bus, and the controller (9) has the highest priority; The first analog input terminal board (1) collects the analog signal Q1 of the measurement object, and the second analog input terminal board (2) collects the analog signal Q2 of the measurement object. The first analog input module (3) converts the analog signal collected from the first analog input terminal board (1) into a digital signal and sends it to the controller (9). The second analog input module (4) converts the analog signal collected from the second analog input terminal board (2) into a digital signal and sends it to the controller (9). The controller (9) performs analog hysteresis control operation. After the operation is completed, the controller sends two output analog quantities to the first analog output module (7) and the second analog output module (8) through the CAN bus. The first analog output module (7) and the second analog output module (8) convert the digital signal into a 4-20mA analog signal and send it to the first analog output terminal board (5) and the second analog output terminal board (6). The first analog output terminal board (5) and the second analog output terminal board (6) send the output analog signal to the external system. The analog hysteresis control calculation method is as follows: The inputs of analog hysteresis control include: input working mode ASI, first channel input analog AI1, second channel input analog AI2, first channel compensation option SE1, second channel compensation option SE2, first channel delay time DeT1 and second channel delay time DeT2; the outputs include: output working mode ASO, first channel output analog AO1, second channel output analog AO2, first channel actual delay time ADeT1, second channel actual delay time ADeT2, first channel compensation time DT1 and second channel compensation time DT2; first channel delay time DeT1, in milliseconds, represents the absolute time of delayed output of first channel input analog AI1, and second channel delay time DeT2, in milliseconds, represents the absolute time of delayed output of second channel input analog AI2; The analog hysteresis control includes the following parameters: operation cycle T, calculation times N, first array A1, second array A2, output upper limit AOmax, output lower limit AOmin, output values ​​AO1Last and AO2Last of the previous operation cycle, first output change rate R1 and second output change rate R2, hysteresis target cycle number TN, and first output bias B1 and second output bias B2; The operation cycle T represents the time interval from the start time of the current calculation to the start time of the next calculation of the analog hysteresis control; the number of calculations N represents the cumulative number of operation cycles of the analog hysteresis control; the first array A1 and the second array A2 have the same length, which is 1001, accommodating 1001 elements, denoted as A1[1001] and A2[1001], and four global index variables r1, f1, r2, f2 are defined, and their value ranges are all 0, 1, ..., i, ..., 1000, representing the subscript index for accessing the first array A1 and the second array A2; the output high limit AOmax represents the maximum value of the output of the first output analog quantity AO1 and the second output analog quantity AO2; the output low limit AOmin represents the maximum value of the output of the first output analog quantity AO1 and the second output analog quantity AO2 The minimum output value; AO1Last indicates the output value of the first output analog quantity AO1 in the previous operation cycle, and AO2Last indicates the output value of the second output analog quantity AO2 in the previous operation cycle; the first output change rate R1 indicates the change rate of the first output analog quantity AO1 relative to the output value AO1Last of the previous operation cycle; the second output change rate R2 indicates the change rate of the second output analog quantity AO2 relative to the output value AO2Last of the previous operation cycle. The calculation formula of the output change rate is as follows: R1=∣AO1-AO1Last∣ / AO1Last; R2=∣AO2-AO2Last∣ / AO2Last; Among them, ||| represents absolute value operation, and / represents division operation; AI1[1], AI1[2], …, AI1[i], …, AI1[1000] represent the value of each data item of the first input analog quantity AI1, and AI2[1], AI2[2], …, AI2[i], …, AI2[1000] represent the value of each data item of the second input analog quantity AI2, where the value range of i is 1 to 1000; The analog hysteresis control is divided into two working modes according to the relationship between the first analog input AI1 and the second analog input AI2: synchronous mode and asynchronous mode. The synchronous mode is represented by 0, and the asynchronous mode is represented by 1. The working mode of the analog hysteresis control depends on the input working mode ASI. When ASI=0, it means that the analog hysteresis control works in synchronous mode. When ASI=1, it means that the analog hysteresis control works in asynchronous mode. The output working mode ASO of the analog hysteresis control tracks the input working mode ASI, that is, ASO=ASI. The input working mode ASI and the output working mode ASO are used for the cascade of analog hysteresis control. When one or more analog hysteresis control cascades work, the working modes of all subsequent analog hysteresis control track the working mode of the previous analog hysteresis control; global index variable f1=r1=1; Each operation cycle is calculated according to the following method: Determine the first compensation option SE1 and the second compensation option SE2. When SE1=1, it means that the compensation calculation is turned on. When the set delay time has not arrived, the first output analog quantity AO1 immediately outputs the value of the first input analog quantity AI1; when the first compensation option SE1 input is 0, it means that the compensation calculation is turned off. When the set delay time has not arrived, the first output analog quantity AO1 outputs 0, and the first compensation option SE1 defaults to 0; when SE2=1, it means that the compensation calculation is turned on. When the set delay time has not arrived, the second output analog quantity AO2 immediately outputs the value of the second input analog quantity AI2; when the second compensation option SE2 input is 0, it means that the compensation calculation is turned off. When the set delay time has not arrived, the second output analog quantity AO2 outputs 0, and the second compensation option SE2 defaults to 0; Determine the working mode of analog hysteresis control and calculate the output according to the corresponding method based on the working mode:

1. Synchronous mode When ASI=0, analog hysteresis control works in synchronous mode; in synchronous mode, the second delay time DeT2 is invalid and does not participate in the calculation. The hysteresis time of the first input analog AI1 and the second input analog AI2 is the same; First, calculate the target number of cycles TN required to delay the output of analog hysteresis control according to the following formula: TN=DeT1 / T; When TN≤1000 and (r1+1)%TN≠f1, A1[r1]=AI1, A2[r1]=AI2, r1=(r1+1)%TN, AO1=AI1[f1], AO2=A2[f1], ADeT2=0, DT2=0, f1=(f1+1)%TN, ADeT1=T×|r1-f1|; DT1=T×(TN-|r1-f1|); When TN≤1000, and (r1+1)%TN==f1, A1[r1]=AI1, A2[r1]=AI2, r1=(r1+1)%TN, AO1=A1[f1], AO2=A2[f1], f1=(f1+1)%TN, ADeT1=T×TN, DT1=0, ADeT2=0, DT2=0; When TN>1000, and (r1+1)%1000≠f1, A1[r1]=AI1, A2[r1]=AI2, r1=(r1+1)%1000, AO1=AI1[f1], AO2=A2[f1], f1=(f1+1)%1000, ADeT1=T×|r1-f1|; DT1=T×(TN-|r1-f1|), ADeT2=0, DT2=0; When TN>1000, and (r1+1)% 1000==f1, A1[r1]=AI1, A2[r1]=AI2, r1=(r1+1)% 1000, AO1=A1[f1], AO2=A2[f1], f1=(f1+1)% 1000, ADeT1=T×1000, ADeT2=0; DT1=T×(TN-1000), DT2=0; % indicates the remainder operation; 2. Asynchronous mode When ASI=1, analog hysteresis control works in asynchronous mode, and the first input analog AI1 and the second input analog AI2 are independently calculated for hysteresis output. The calculation method is as follows: When TN≤1000 and (r1+1)%TN≠f1, A1[r1]=AI1, r1=(r1+1)%TN, AO1=AI1[f1], f1=(f1+1)%TN, ADeT1=T×|r1-f1|; DT1=T×(TN-|r1-f1|); When TN≤1000 and (r2+1)%TN≠f2, A2[r2]=AI2,r2=(r2+1)%TN, AO2=A2[f2], f2=(f2+1)%TN, ADeT2=T×|r2-f2|; DT2=T×(TN-|r2-f2|); When TN≤1000 and (r1+1)%TN==f1, A1[r1]=AI1, r1=(r1+1)%TN, AO1=A1[f1], f1=(f1+1)%TN, ADeT1=T×TN, DT1=0; When TN≤1000, and (r2+1)%TN==f2, A2[r2]=AI2, r2=(r2+1)%TN, AO2=A2[f2], f2=(f2+1)%TN, ADet2=T×TN; DT2=0; When TN>1000, and (r1+1)%1000≠f1, A1[r1]=AI1, A2[r2]=AI2, r1=(r1+1)%1000, r2=(r2+1)%1000, AO1=AI1[f1], AO2=A2[f2], f2=(f2+1)%1000, ADeT1=T×|r1-f1|, DT1=T×(TN-|r1-f1|), ADeT2=T×|r2-f2|, DT2=T×(TN-|r2-f2|); When TN>1000, and (r1+1)% 1000==f1, A1[r1]=AI1, A2[r1]=AI2, r1=(r1+1)% 1000, AO1=A1[f1], AO2=A2[f2], f1=(f1+1)% 1000, ADeT1=T×1000, ADet2=T×1000; DT1=T×(TN-1000), DT2=T×(TN-1000); After the calculation of the first output analog quantity AO1 and the second output analog quantity AO2 is completed, the output values ​​of the first output analog quantity AO1 and the second output analog quantity AO2 need to be judged and calculated according to the following constraints: If |AO1-AO1Last| / AO1Last >R1, then AO1=AO1Last+AO1Last*R; If |AO2-AO2Last| / AO2Last >R2, then AO2=AO2Last+AO2Last*R; The first output analog quantity AO1 and the second output analog quantity AO2 are both subject to the constraints of the output high limit AOmax and the output low limit AOmin: if AO1>AOmax, AO1=AOmax, if AO1 <AOmin,AO1=AOmin; If AO2>AOmax, AO2=AOmax, if AO2 <AOmin,AO2=AOmin。 2. The analog hysteresis control device for a thermal power unit according to claim 1, characterized in that: The analog input channels of the first analog input terminal board (1) and the second analog input terminal board (2) are respectively connected to analog measurement values ​​Q1 and Q2 from the measurement object; the analog quantities P1 and T1 output after operation by the analog hysteresis control device are respectively output through the first analog output terminal board (5) and the second analog output terminal board (6).

3. The analog hysteresis control device for a thermal power unit according to claim 1, characterized in that: The first analog input terminal board (1) and the second analog input terminal board (2) each include a terminal board input channel; the first analog input module (3) and the second analog input module (4) each include an analog input channel.

4. The analog hysteresis control device for a thermal power unit according to claim 1, characterized in that: The first analog output terminal board (5) and the second analog output terminal board (6) each include a terminal board output channel; the first analog output module (7) and the second analog output module (8) each include an analog output channel.

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