Source-grid coordination control method and system for waste heat boiler system

Abstract

The application discloses a source-grid coordination control method for a waste heat boiler system, comprising the following steps: acquiring grid-connection data information and data information of the waste heat boiler system; constructing a control object model of a target waste heat boiler system; calculating control signals of a generator set and a supplementary energy boiler in the waste heat boiler system based on a PID control scheme and a fuzzy control scheme; and completing source-grid coordination control of the target waste heat boiler system according to the obtained data information. The application further discloses a system for implementing the source-grid coordination control method for the waste heat boiler system. The application not only realizes source-grid coordination control of the waste heat boiler system, guarantees high quality of electric energy output by the waste heat boiler system, but also has higher reliability and better accuracy.

Description

Technical Field

[0001] This invention belongs to the field of automatic control, specifically relating to a source-grid coordinated control method and system for waste heat boiler systems. Background Technology

[0002] In the pyrometallurgical process of non-ferrous metals, a large amount of flue gas carrying high heat energy is generated. To improve energy utilization efficiency, many smelters have designed flue gas waste heat boilers to convert this heat energy into electrical energy. This has greatly improved the overall economy and efficiency of the smelting system.

[0003] However, this energy recovery method faces significant technical challenges: the pyrometallurgical process for non-ferrous metals is cyclical, with huge fluctuations in flue gas volume and temperature at different smelting stages. This leads to highly unstable steam output from the waste heat boiler, and in some stages (such as the start-up and shutdown of the smelting furnace), the output is insufficient to maintain the idling of the turbine in the generator unit. Therefore, to ensure the continuous and stable operation of the power generation system, researchers have introduced additional steam sources as supplementary energy boilers; for example, coal-fired boilers are often used as supplementary energy boilers.

[0004] Currently, the generator units in non-ferrous smelters typically have small installed capacities and mostly operate in micro-island grid configurations. Furthermore, existing control schemes are extremely simplistic, resulting in poor-quality power that fails to meet grid connection requirements. Moreover, the limited application of this low-quality power further reduces the overall system efficiency. Summary of the Invention

[0005] One of the objectives of this invention is to provide a highly reliable and accurate source-grid coordinated control method for waste heat boiler systems.

[0006] The second objective of this invention is to provide a system for implementing the source-grid coordinated control method for waste heat boiler systems.

[0007] The source-grid coordinated control method for waste heat boiler systems provided by this invention includes the following steps:

[0008] S1. Obtain grid connection data and waste heat boiler system data;

[0009] S2. Based on the data obtained in step S1, construct a control object model for the target waste heat boiler system;

[0010] S3. Based on the data obtained in step S1, and using the PID control scheme and fuzzy control scheme, calculate the control signals of the generator set and the supplementary energy boiler in the waste heat boiler system.

[0011] S4. Based on the data obtained in steps S2 and S3, complete the source-grid coordinated control of the target waste heat boiler system.

[0012] Step S1 specifically includes the following steps:

[0013] Acquire grid connection data and waste heat boiler system data;

[0014] The grid connection data information includes grid dispatch power command values ​​and grid frequency error values;

[0015] The data information of the waste heat boiler system includes the real-time output power of the generator set, the outlet pressure of the waste heat boiler, the main steam pressure of the supplementary energy boiler, the parameter data of the generator set, and the parameter data of the supplementary energy boiler.

[0016] Step S2 specifically includes the following steps:

[0017] The target waste heat boiler system includes a waste heat boiler, a supplementary energy boiler, and a generator set;

[0018] Waste heat boilers utilize the high-temperature flue gas generated during the smelting process to recover heat and produce steam; no regulating valve is installed at the outlet of the waste heat boiler to achieve full utilization of the waste heat steam.

[0019] The supplementary energy boiler is used to provide a stable steam source and to provide supplementary steam when the output of the waste heat boiler is insufficient; the supplementary energy boiler adopts a constant pressure operation mode to maintain the stability of the main steam pressure;

[0020] The generator set receives steam from the waste heat boiler and the supplementary energy boiler, converts thermal energy into mechanical energy and electrical energy in sequence, and outputs electrical energy.

[0021] The controlled objects of the target waste heat boiler system include supplementary energy boilers and generator sets;

[0022] The following formula is used as the control object model for the target waste heat boiler system:

[0023] In the formula This refers to the real-time output power of the generator set. To supplement the main steam pressure of the energy boiler; This is the transfer function between the real-time output power of the generator set and the opening degree of the regulating valve of the turbine in the generator set; To supplement the transfer function between the main steam pressure of the energy boiler and the opening of the regulating valve of the steam turbine in the generator set; This is the equivalent transfer function of the generator set's real-time output power and fuel input. The transfer function of main steam pressure and fuel feed rate for supplementary energy boilers; This refers to the opening degree of the regulating valve in the steam turbine of the generator set; This refers to the amount of fuel supplied.

[0024] and The output quantity of the control object model of the target waste heat boiler system;

[0025] and As the input quantity of the control object model of the target waste heat boiler system;

[0026] , , and The parameters of the control object model of the target waste heat boiler system.

[0027] When the generator set is a 300MW generator set and the supplementary energy boiler is a 1025t / h pulverized coal boiler, the parameter quantities of the control object model of the target waste heat boiler system are expressed as follows: .

[0028] Step S3 specifically includes the following steps:

[0029] Based on the data obtained in step S1, the power error is calculated; based on the power error, the control signal of the turbine in the generator set is calculated using a parallel PID control scheme and a fuzzy control scheme, so as to control the opening of the regulating valve of the turbine in the generator set.

[0030] Based on the data obtained in step S1, the pressure error is calculated. Based on the pressure error, the control signal for the supplementary energy boiler is calculated using a parallel PID control scheme and a fuzzy control scheme to control the fuel feed of the supplementary energy boiler.

[0031] The calculation to obtain the control signal of the steam turbine in the generator set specifically includes the following steps:

[0032] After the power grid dispatch power command value is processed by limiting the amplitude and the rate of change, the processed power grid dispatch power command value is obtained. ;

[0033] The power setting value is calculated using the following formula. :

[0034] In the formula The set frequency feedforward correction factor; This represents the power grid frequency error value.

[0035] The power error value is calculated using the following formula. :

[0036] In the formula This refers to the real-time output power of the generator set. The outlet pressure of the waste heat boiler The correction value, , This is the pressure correction factor. This is the actual measured value of the outlet pressure of the waste heat boiler. This refers to the rated outlet pressure of the waste heat boiler.

[0037] Power error value The PID control parameters of the steam turbine are calculated using a PID control scheme. :

[0038] In the formula This refers to the proportional coefficient in the PID control scheme for the steam turbine. The integral coefficient in the PID control scheme for the steam turbine; These are the differential coefficients in the PID control scheme for the steam turbine.

[0039] Power error value The fuzzy control parameters of the steam turbine are calculated using a fuzzy control scheme. :

[0040] The fuzzy language set is: {negative N, zero Z, positive P}, with both input and output using a three-element set;

[0041] Domain of discourse and quantization factor:

[0042] Power error The theoretical domain of physics is ,in This represents the maximum permissible power error under rated operating conditions; Mapping to the fuzzy domain for Quantification factor for The fuzzy input quantity is: ;

[0043] Softening control amount The fuzzy domain is: ; Scale factor for ,in This represents the maximum output amplitude of the softening control variable; the actual output after defuzzification is: ,in The value of the fuzzy universe of discourse obtained after defuzzification;

[0044] Input variables Membership function:

[0045] Output variables Membership function:

[0046] Fuzzy rule: When the power error is negative, the PID output is negative, then... The value is negative; when the power error is positive, the PID output is positive, then... It is positive;

[0047] Fuzzy reasoning:

[0048] Activation intensity Output fuzzy set ;

[0049] Activation intensity Output fuzzy set ;

[0050] Activation intensity Output fuzzy set ;

[0051] Total output fuzzy set: The rule outputs are merged using the maximum aggregation operator. ;

[0052] Defuzzification: Using the weighted average method ,in To output fuzzy universe of discourse discrete points in , This represents the membership value after aggregation at that point;

[0053] Actual softening control amount: ;

[0054] Finally, the control signals of the steam turbine in the generator set are obtained. for .

[0055] The calculation to obtain the control signal for the supplementary energy boiler specifically includes the following steps:

[0056] Based on the obtained main steam pressure of the supplementary energy boiler The pressure error value is calculated using the following formula. :

[0057] In the formula Main steam pressure setpoint;

[0058] Based on the feedforward mechanism, the feedforward control signal of the supplementary energy boiler is calculated using the following formula. :

[0059] In the formula This is the first decoupling coefficient set; This is the corrected speed regulating valve opening value; This is the corrected outlet pressure value of the waste heat boiler; This is the second decoupling coefficient that is set; This is the corrected main pressure value;

[0060] Pressure error value The PID control signal for the supplementary energy boiler is calculated using a PID control scheme. :

[0061] In the formula To supplement the proportional coefficient in the PID control scheme for energy boilers; To supplement the integral coefficient in the PID control scheme for energy boilers; To supplement the differential coefficients in the PID control scheme for energy boilers;

[0062] Pressure error value The fuzzy control signal for the supplementary energy boiler is calculated using a fuzzy control scheme. :

[0063] The fuzzy language set is: {negative N, zero Z, positive P}, with both input and output using a three-element set;

[0064] Domain of discourse and quantization factor:

[0065] Pressure error The theoretical domain of physics is ,in This is the maximum permissible value of pressure error under rated operating conditions; Mapping to the fuzzy domain for Quantification factor for The fuzzy input quantity is: ;

[0066] Softening control amount The fuzzy domain is: ; Scale factor for ,in This represents the maximum output amplitude of the softening control variable; the actual output after defuzzification is: ,in The value of the fuzzy universe of discourse obtained after defuzzification;

[0067] Input variables Membership function:

[0068] Output variables Membership function:

[0069] Fuzzy rule: When the power error is negative, the PID output is negative, then... The value is negative; when the power error is positive, the PID output is positive, then... It is positive;

[0070] Fuzzy reasoning:

[0071] Activation intensity Output fuzzy set ;

[0072] Activation intensity Output fuzzy set ;

[0073] Activation intensity Output fuzzy set ;

[0074] Total output fuzzy set: The rule outputs are merged using the maximum aggregation operator. ;

[0075] Defuzzification: Using the weighted average method ,in To output fuzzy universe of discourse discrete points in , This represents the membership value after aggregation at that point;

[0076] Actual softening control amount: ;

[0077] Finally, the control signal for the supplementary energy boiler is obtained. for .

[0078] This invention also provides a system for implementing the source-grid coordinated control method for a waste heat boiler system, comprising a data acquisition module, a model building module, a signal generation module, and a coordinated control module; the data acquisition module, model building module, signal generation module, and coordinated control module are connected in series; the data acquisition module is used to acquire grid-connected data information and waste heat boiler system data information, and upload the data information to the model building module; the model building module is used to construct a control object model of the target waste heat boiler system based on the received data information and the acquired data information, and upload the data information to the signal generation module; the signal generation module is used to calculate the control signals of the generator set and the supplementary energy boiler in the waste heat boiler system based on the received data information and the acquired data information, using PID control scheme and fuzzy control scheme, and upload the data information to the coordinated control module; the coordinated control module is used to complete the source-grid coordinated control of the target waste heat boiler system based on the received data information and the acquired data information.

[0079] The source-grid coordinated control method and system for waste heat boiler systems provided by this invention acquires and analyzes data from the waste heat boiler system and the power grid, and combines PID and fuzzy control schemes. This not only achieves source-grid coordinated control for waste heat boiler systems, ensuring high-quality power output from the waste heat boiler system, but also offers higher reliability and better accuracy. Attached Figure Description

[0080] Figure 1 This is a schematic diagram of the method flow of the present invention.

[0081] Figure 2 This is a schematic diagram comparing the control effects of embodiments of the method of the present invention.

[0082] Figure 3 This is a schematic diagram of the functional modules of the system of the present invention. Detailed Implementation

[0083] like Figure 1 The diagram shown is a flowchart of the method of the present invention: The source-grid coordinated control method for waste heat boiler systems disclosed in this invention includes the following steps:

[0084] S1. Obtain grid connection data and waste heat boiler system data; specifically including the following steps:

[0085] Acquire grid connection data and waste heat boiler system data;

[0086] The grid connection data information includes grid dispatch power command values ​​and grid frequency error values;

[0087] The data information of the waste heat boiler system includes the real-time output power of the generator set, the outlet pressure of the waste heat boiler, the main steam pressure of the supplementary energy boiler, the parameter data of the generator set, and the parameter data of the supplementary energy boiler.

[0088] S2. Based on the data obtained in step S1, construct a control object model for the target waste heat boiler system; specifically, this includes the following steps:

[0089] The target waste heat boiler system includes a waste heat boiler, a supplementary energy boiler, and a generator set;

[0090] Waste heat boilers utilize the high-temperature flue gas generated during the smelting process to recover heat and produce steam; no regulating valve is installed at the outlet of the waste heat boiler to achieve full utilization of the waste heat steam.

[0091] The supplementary energy boiler is used to provide a stable steam source and to provide supplementary steam when the output of the waste heat boiler is insufficient; the supplementary energy boiler adopts a constant pressure operation mode to maintain the stability of the main steam pressure;

[0092] The generator set receives steam from the waste heat boiler and the supplementary energy boiler, converts thermal energy into mechanical energy and electrical energy in sequence, and outputs electrical energy.

[0093] The controlled objects of the target waste heat boiler system include supplementary energy boilers and generator sets;

[0094] The following formula is used as the control object model for the target waste heat boiler system:

[0095] In the formula This refers to the real-time output power of the generator set. To supplement the main steam pressure of the energy boiler; This is the transfer function between the real-time output power of the generator set and the opening degree of the regulating valve of the turbine in the generator set; To supplement the transfer function between the main steam pressure of the energy boiler and the opening of the regulating valve of the steam turbine in the generator set; This is the equivalent transfer function of the generator set's real-time output power and fuel input. The transfer function of main steam pressure and fuel feed rate for supplementary energy boilers; This refers to the opening degree of the regulating valve in the steam turbine of the generator set; This refers to the amount of fuel supplied.

[0096] and The output quantity of the control object model of the target waste heat boiler system;

[0097] and As the input quantity of the control object model of the target waste heat boiler system;

[0098] , , and The parameters of the control object model of the target waste heat boiler system;

[0099] In practical implementation, when the generator set is a 300MW generator set and the supplementary energy boiler is a 1025t / h pulverized coal boiler, the parameter quantities of the control object model of the target waste heat boiler system are expressed as follows: ;

[0100] S3. Based on the data obtained in step S1, and using the PID control scheme and fuzzy control scheme, calculate the control signals for the generator set and the supplementary energy boiler in the waste heat boiler system; specifically including the following steps:

[0101] The PID control scheme is responsible for the main regulation task, while the parallel fuzzy control scheme outputs a "softening" control action when the system state approaches the set value based on the magnitude of the error signal. This action is superimposed on the PID output, aiming to weaken the integral saturation and excessive control force of the PID control scheme, thereby effectively suppressing overshoot and shortening the system's settling time.

[0102] Based on the data obtained in step S1, the power error is calculated. Based on the power error, and using a parallel PID control scheme and a fuzzy control scheme, the control signal for the turbine in the generator set is calculated to control the opening of the turbine's regulating valve. Specifically, the steps include:

[0103] After the power grid dispatch power command value is processed by limiting the amplitude and the rate of change, the processed power grid dispatch power command value is obtained. ;

[0104] The power setting value is calculated using the following formula. :

[0105] In the formula The set frequency feedforward correction factor; This represents the power grid frequency error value.

[0106] The power error value is calculated using the following formula. :

[0107] In the formula This refers to the real-time output power of the generator set. The outlet pressure of the waste heat boiler The correction value, , This is a pressure correction factor (determined based on on-site working conditions, with a typical range of 0.5 to 2.0). This is the actual measured value of the outlet pressure of the waste heat boiler. This is the rated outlet pressure of the waste heat boiler (using the design value).

[0108] Power error value The PID control parameters of the steam turbine are calculated using a PID control scheme. :

[0109] In the formula This refers to the proportional coefficient in the PID control scheme for the steam turbine. The integral coefficient in the PID control scheme for the steam turbine; These are the differential coefficients in the PID control scheme for the steam turbine.

[0110] Power error value The fuzzy control parameters of the steam turbine are calculated using a fuzzy control scheme. :

[0111] The fuzzy language set is: {negative N, zero Z, positive P}, with both input and output using a three-element set;

[0112] Domain of discourse and quantization factor:

[0113] Power error The theoretical domain of physics is ,in The maximum permissible value for power error under rated operating conditions (taken as 10%~20% of rated power); Mapping to the fuzzy domain for Quantification factor for The fuzzy input quantity is: ;

[0114] Softening control amount The fuzzy domain is: ; Scale factor for ,in The maximum output amplitude of the softened control quantity is taken as 5%~15% of the maximum value of the PID output; the actual output after defuzzification is: ,in The value of the fuzzy universe of discourse obtained after defuzzification;

[0115] Input variables Membership function:

[0116] Output variables Membership function:

[0117] Fuzzy rule: When the power error is negative (actual power is higher than the set value), the PID output is negative (the steam valve is closed). Also negative, the superposition enhances the effect of closing the steam valve, allowing the system to return to the vicinity of the setpoint more quickly; when the system approaches steady state from the negative error side, the PID integral accumulation still maintains a negative output, while The negative effect of the PID is weakened as the error decreases; when the error is near zero, the fuzzy output is close to zero, and the PID dominates the regulation; when the power error is positive (actual power is lower than the set value), the PID output is positive (open the steam valve). Also positive, the superposition enhances the effect of opening the steam valve; when the system approaches steady state from the positive error side, Reduce, which is equivalent to weakening the excessive positive effect of PID;

[0118] Fuzzy reasoning:

[0119] Activation intensity Output fuzzy set ;

[0120] Activation intensity Output fuzzy set ;

[0121] Activation intensity Output fuzzy set ;

[0122] Total output fuzzy set: The rule outputs are merged using the maximum aggregation operator. .

[0123] Defuzzification: Using the weighted average method ,in To output fuzzy universe of discourse discrete points in , This represents the membership value after aggregation at that point;

[0124] Actual softening control amount: ;

[0125] Finally, the control signals of the steam turbine in the generator set are obtained. for ;

[0126] Based on the data obtained in step S1, the pressure error is calculated. Based on the pressure error, and using a parallel PID control scheme and a fuzzy control scheme, the control signal for the supplementary energy boiler is calculated to control the fuel feed rate of the supplementary energy boiler. Specifically, the steps include:

[0127] Based on the obtained main steam pressure of the supplementary energy boiler The pressure error value is calculated using the following formula. :

[0128] In the formula Main steam pressure setpoint;

[0129] Based on the feedforward mechanism, the feedforward control signal of the supplementary energy boiler is calculated using the following formula. :

[0130] In the formula This is the first decoupling coefficient set; This is the corrected speed regulating valve opening value; This is the corrected outlet pressure value of the waste heat boiler; This is the second decoupling coefficient that is set; This is the corrected main pressure value;

[0131] Pressure error value The PID control signal for the supplementary energy boiler is calculated using a PID control scheme. :

[0132] In the formula To supplement the proportional coefficient in the PID control scheme for energy boilers; To supplement the integral coefficient in the PID control scheme for energy boilers; To supplement the differential coefficients in the PID control scheme for energy boilers;

[0133] Pressure error value The fuzzy control signal for the supplementary energy boiler is calculated using a fuzzy control scheme. :

[0134] The fuzzy language set is: {negative N, zero Z, positive P}, with both input and output using a three-element set;

[0135] Domain of discourse and quantization factor:

[0136] Pressure error The theoretical domain of physics is ,in This is the maximum permissible value of pressure error under rated operating conditions; Mapping to the fuzzy domain for Quantification factor for The fuzzy input quantity is: ;

[0137] Softening control amount The fuzzy domain is: ; Scale factor for ,in This represents the maximum output amplitude of the softening control variable; the actual output after defuzzification is: ,in The value of the fuzzy universe of discourse obtained after defuzzification;

[0138] Input variables Membership function:

[0139] Output variables Membership function:

[0140] Fuzzy rule: When the power error is negative, the PID output is negative, then... The value is negative; when the power error is positive, the PID output is positive, then... It is positive;

[0141] Fuzzy reasoning:

[0142] Activation intensity Output fuzzy set ;

[0143] Activation intensity Output fuzzy set ;

[0144] Activation intensity Output fuzzy set ;

[0145] Total output fuzzy set: The rule outputs are merged using the maximum aggregation operator. .

[0146] Defuzzification: Using the weighted average method ,in To output fuzzy universe of discourse discrete points in , This represents the membership value after aggregation at that point;

[0147] Actual softening control amount: ;

[0148] Finally, the control signal for the supplementary energy boiler is obtained. for ;

[0149] S4. Based on the data obtained in steps S2 and S3, complete the source-grid coordinated control of the target waste heat boiler system.

[0150] This invention designs two independent fuzzy control modules, connected in parallel with the turbine PID controller and the supplementary energy boiler PID controller of the generator set, respectively. The input to the fuzzy controller is the feedback signal corresponding to the error, and its output is added to that of the traditional PID controller to improve the controller output strength, thereby reducing the overshoot and settling time of the response result and improving the overall control quality. In specific implementation, a parameter tuning method combining empirical data and trial and error can be adopted. That is, the approximate parameter range is determined based on experience, and the tuning is carried out according to the proportional, integral, and derivative order based on the real-time curve.

[0151] The present invention adopts a parallel structure of PID controller and fuzzy controller. When the system error is large (such as sudden changes in the output of waste heat boiler), the PID controller is mainly used to achieve rapid adjustment. When the error is close to the set value, the fuzzy controller outputs a softening signal to cancel part of the PID output, avoiding overshoot caused by integral saturation. Compared with traditional PID control, it significantly reduces voltage and frequency fluctuations, so that the power quality meets the standards for use under non-electric heating loads.

[0152] The present invention implements a "furnace-following-turbine" operation mode, in which the steam turbine prioritizes response to load changes to ensure full utilization of waste heat boiler steam; the supplementary energy boiler operates in a "constant pressure" mode, which reduces the fluctuation of active power output caused by pressure fluctuations by stabilizing the main steam pressure; it solves the problem of "insufficient output to maintain steam turbine idling" and improves the stability of generator set output power.

[0153] The present invention introduces grid frequency error feedforward correction to compensate for load command changes in advance; it achieves decoupling of boiler and turbine by multiplying the speed regulating valve opening with the waste heat boiler outlet pressure, eliminating the strong coupling interference between boiler and turbine in traditional control, and effectively suppressing voltage flicker caused by load fluctuations.

[0154] The method of the present invention will be described below with reference to an embodiment:

[0155] Simulation verification: The controlled object adopts a simplified dual-input dual-output model. The approximate linearization result of a 300MW generator set paired with a 1025t / h pulverized coal boiler under rated load conditions is selected for simulation. The parallel fuzzy optimization control scheme (the scheme of this invention) is compared with the traditional PID feedforward decoupling control scheme.

[0156] The simulation parameters are set as follows: The turbine PID controller parameters for the generator set are: , , The PID controller parameters for the supplementary energy boiler are as follows: , , For ease of comparison, traditional PID schemes use the same parameters.

[0157] The comparison curves after simulation are shown below. Figure 2 As shown: At time 600s, a step disturbance is introduced at the superheated steam pressure outlet to simulate a sudden change in the operating condition of the waste heat boiler. In the step response, for load control, the overshoot of the curve using the parallel fuzzy softening scheme of this invention is approximately 13%, significantly less than the 20% of the traditional PID scheme. For pressure control, the overshoot of the scheme of this invention is approximately 7%, while the overshoot of the traditional scheme exceeds 20%, reaching the process alarm threshold. Furthermore, after the disturbance occurs, the adjustment time of the scheme of this invention is shorter, recovering stability in approximately 300s, demonstrating superior dynamic performance.

[0158] As can be seen from the above embodiments, the present invention, especially the parallel fuzzy optimization control scheme, can effectively solve the control problem in power generation systems with fluctuating heat sources. It is superior to traditional schemes in terms of control accuracy, response speed and robustness, and is simple to implement, with significant practical application value.

[0159] like Figure 3 The diagram shows the functional modules of the system of the present invention: The system disclosed in this invention for implementing the source-grid coordinated control method for a waste heat boiler system includes a data acquisition module, a model building module, a signal generation module, and a coordinated control module; the data acquisition module, model building module, signal generation module, and coordinated control module are connected in series; the data acquisition module is used to acquire grid-connected data information and waste heat boiler system data information, and upload the data information to the model building module; the model building module is used to construct a control object model of the target waste heat boiler system based on the received data information and the acquired data information, and upload the data information to the signal generation module; the signal generation module is used to calculate the control signals of the generator set and the supplementary energy boiler in the waste heat boiler system based on the received data information and the acquired data information, using PID control scheme and fuzzy control scheme, and upload the data information to the coordinated control module; the coordinated control module is used to complete the source-grid coordinated control of the target waste heat boiler system based on the received data information and the acquired data information.

Claims

1. A source-grid coordinated control method for a waste heat boiler system, comprising the following steps: S1. Obtain grid connection data and waste heat boiler system data; S2. Based on the data obtained in step S1, construct a control object model for the target waste heat boiler system; S3. Based on the data obtained in step S1, and using the PID control scheme and fuzzy control scheme, calculate the control signals of the generator set and the supplementary energy boiler in the waste heat boiler system. S4. Based on the data obtained in steps S2 and S3, complete the source-grid coordinated control of the target waste heat boiler system.

2. The source-grid coordinated control method for waste heat boiler systems according to claim 1, characterized in that... Step S1 specifically includes the following steps: Acquire grid connection data and waste heat boiler system data; The grid connection data information includes grid dispatch power command values ​​and grid frequency error values; The data information of the waste heat boiler system includes the real-time output power of the generator set, the outlet pressure of the waste heat boiler, the main steam pressure of the supplementary energy boiler, the parameter data of the generator set, and the parameter data of the supplementary energy boiler.

3. The source-grid coordinated control method for waste heat boiler systems according to claim 2, characterized in that... Step S2 specifically includes the following steps: The target waste heat boiler system includes a waste heat boiler, a supplementary energy boiler, and a generator set; Waste heat boilers utilize the high-temperature flue gas generated during the smelting process to recover heat and produce steam; no regulating valve is installed at the outlet of the waste heat boiler to achieve full utilization of the waste heat steam. The supplementary energy boiler is used to provide a stable steam source and to provide supplementary steam when the output of the waste heat boiler is insufficient; the supplementary energy boiler adopts a constant pressure operation mode to maintain the stability of the main steam pressure; The generator set receives steam from the waste heat boiler and the supplementary energy boiler, converts thermal energy into mechanical energy and electrical energy in sequence, and outputs electrical energy. The controlled objects of the target waste heat boiler system include supplementary energy boilers and generator sets; The following formula is used as the control object model for the target waste heat boiler system: In the formula This refers to the real-time output power of the generator set. To supplement the main steam pressure of the energy boiler; This is the transfer function between the real-time output power of the generator set and the opening degree of the regulating valve of the turbine in the generator set; To supplement the transfer function between the main steam pressure of the energy boiler and the opening of the regulating valve of the steam turbine in the generator set; This is the equivalent transfer function of the generator set's real-time output power and fuel input. The transfer function of main steam pressure and fuel feed rate for supplementary energy boilers; This refers to the opening degree of the regulating valve in the steam turbine of the generator set; This refers to the amount of fuel supplied. and The output quantity of the control object model of the target waste heat boiler system; and As the input quantity of the control object model of the target waste heat boiler system; , , and The parameters of the control object model of the target waste heat boiler system.

4. The source-grid coordinated control method for waste heat boiler systems according to claim 3, characterized in that... When the generator set is a 300MW generator set and the supplementary energy boiler is a 1025t / h pulverized coal boiler, the parameter quantities of the control object model of the target waste heat boiler system are expressed as follows: .

5. The source-grid coordinated control method for a waste heat boiler system according to claim 3, characterized in that... Step S3 specifically includes the following steps: Based on the data obtained in step S1, the power error is calculated; based on the power error, the control signal of the turbine in the generator set is calculated using a parallel PID control scheme and a fuzzy control scheme, so as to control the opening of the regulating valve of the turbine in the generator set. Based on the data obtained in step S1, the pressure error is calculated. Based on the pressure error, the control signal for the supplementary energy boiler is calculated using a parallel PID control scheme and a fuzzy control scheme to control the fuel feed of the supplementary energy boiler.

6. The source-grid coordinated control method for a waste heat boiler system according to claim 5, characterized in that... The calculation to obtain the control signal of the steam turbine in the generator set specifically includes the following steps: After the power grid dispatch power command value is processed by limiting the amplitude and the rate of change, the processed power grid dispatch power command value is obtained. ; The power setting value is calculated using the following formula. : In the formula The set frequency feedforward correction factor; This represents the power grid frequency error value. The power error value is calculated using the following formula. : In the formula This refers to the real-time output power of the generator set. The outlet pressure of the waste heat boiler The correction value, , This is the pressure correction factor. This is the actual measured value of the outlet pressure of the waste heat boiler. This refers to the rated outlet pressure of the waste heat boiler. Power error value The PID control parameters of the steam turbine are calculated using a PID control scheme. : In the formula This refers to the proportional coefficient in the PID control scheme for the steam turbine. The integral coefficient in the PID control scheme for the steam turbine; These are the differential coefficients in the PID control scheme for the steam turbine. Power error value The fuzzy control parameters of the steam turbine are calculated using a fuzzy control scheme. : The fuzzy language set is: {negative N, zero Z, positive P}, with both input and output using a three-element set; Domain of discourse and quantization factor: Power error The theoretical domain of physics is ,in This represents the maximum permissible power error under rated operating conditions; Mapping to the fuzzy domain for Quantification factor for The fuzzy input quantity is: ; Softening control amount The fuzzy domain is: ; Scale factor for ,in This represents the maximum output amplitude of the softening control variable; the actual output after defuzzification is: ,in The value of the fuzzy universe of discourse obtained after defuzzification; Input variables Membership function: Output variables Membership function: Fuzzy rule: When the power error is negative, the PID output is negative, then... The value is negative; when the power error is positive, the PID output is positive, then... It is positive; Fuzzy reasoning: Activation intensity Output fuzzy set ; Activation intensity Output fuzzy set ; Activation intensity Output fuzzy set ; Total output fuzzy set: The rule outputs are merged using the maximum aggregation operator. ; Defuzzification: Using the weighted average method ,in To output fuzzy universe of discourse discrete points in , This represents the membership value after aggregation at that point; Actual softening control amount: ; Finally, the control signals of the steam turbine in the generator set are obtained. for .

7. The source-grid coordinated control method for a waste heat boiler system according to claim 6, characterized in that... The calculation to obtain the control signal for the supplementary energy boiler specifically includes the following steps: Based on the obtained main steam pressure of the supplementary energy boiler The pressure error value is calculated using the following formula. : In the formula Main steam pressure setpoint; Based on the feedforward mechanism, the feedforward control signal of the supplementary energy boiler is calculated using the following formula. : In the formula This is the first decoupling coefficient set; This is the corrected speed regulating valve opening value; This is the corrected outlet pressure value of the waste heat boiler; This is the second decoupling coefficient that is set; This is the corrected main pressure value; Pressure error value The PID control signal for the supplementary energy boiler is calculated using a PID control scheme. : In the formula To supplement the proportional coefficient in the PID control scheme for energy boilers; To supplement the integral coefficient in the PID control scheme for energy boilers; To supplement the differential coefficients in the PID control scheme for energy boilers; Pressure error value The fuzzy control signal for the supplementary energy boiler is calculated using a fuzzy control scheme. : The fuzzy language set is: {negative N, zero Z, positive P}, with both input and output using a three-element set; Domain of discourse and quantization factor: Pressure error The theoretical domain of physics is ,in This is the maximum permissible value of pressure error under rated operating conditions; Mapping to the fuzzy domain for Quantification factor for The fuzzy input quantity is: ; Softening control amount The fuzzy domain is: ; Scale factor for ,in This represents the maximum output amplitude of the softening control variable; the actual output after defuzzification is: ,in The value of the fuzzy universe of discourse obtained after defuzzification; Input variables Membership function: Output variables Membership function: Fuzzy rule: When the power error is negative, the PID output is negative, then... The value is negative; when the power error is positive, the PID output is positive, then... It is positive; Fuzzy reasoning: Activation intensity Output fuzzy set ; Activation intensity Output fuzzy set ; Activation intensity Output fuzzy set ; Total output fuzzy set: The rule outputs are merged using the maximum aggregation operator. ; Defuzzification: Using the weighted average method ,in To output fuzzy universe of discourse discrete points in , This represents the membership value after aggregation at that point; Actual softening control amount: ; Finally, the control signal for the supplementary energy boiler is obtained. for .

8. A system for implementing the source-grid coordinated control method for a waste heat boiler system as described in any one of claims 1 to 7, characterized in that... It includes a data acquisition module, a model building module, a signal generation module, and a coordination control module; the data acquisition module, model building module, signal generation module, and coordination control module are connected in series; the data acquisition module is used to acquire grid-connected data information and waste heat boiler system data information, and upload the data information to the model building module; the model building module is used to construct the control object model of the target waste heat boiler system based on the received data information and the acquired data information, and upload the data information to the signal generation module; The signal generation module is used to calculate the control signals of the generator set and the supplementary energy boiler in the waste heat boiler system based on the received data and the acquired data, using PID control and fuzzy control schemes, and upload the data to the coordination control module. The coordination control module is used to complete the source-grid coordination control of the target waste heat boiler system based on the received data and the acquired data.

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