Thermal power generating unit primary frequency modulation parameter optimization method and system considering industrial air exhaust heat supply influence

Abstract

The invention relates to the technical field of power system frequency modulation control, in particular to a thermal power generating unit primary frequency modulation parameter optimization method and system considering industrial air exhaust heat supply influence. A thermal power generating unit high-precision dynamic model capable of simulating wide load regulation is formed by establishing a dynamic simulation model of a medium-low pressure communicating pipeline steam extraction module and connecting a series single reheating type steam turbine and a speed regulation system simulation model of the series single reheating type steam turbine, and the coupling effect relation and the influence degree of heat supply steam extraction amount change and frequency disturbance change are obtained through simulation evaluation. The optimization intervals of the frequency modulation dead zone, the frequency modulation amplitude limiting and the difference adjustment coefficient are quantified, a parameter optimization design scheme considering the adjustment speed and the system stability is given, the problems of power overshoot and adjustment delay under the deep peak regulation working condition are solved, and the unit frequency stability can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power system frequency modulation control, in particular to a method and system for optimizing primary frequency modulation parameters of thermal power generating units considering the influence of industrial steam extraction and heat supply. BACKGROUND

[0002] With large-scale grid connection of new energy and continuous expansion of load peak-valley difference of power systems, deep peak regulation of thermal power generating units has become an important technical means to ensure the flexibility and frequency stability of power grids. Industrial steam extraction and heat supply thermal power generating units play a key role in regional integrated energy systems. However, under deep peak regulation conditions, the units need to respond to frequency disturbances of power grids frequently, and the primary frequency modulation dynamic characteristics are affected by multiple factors such as coupling effect of heat supply module, nonlinear effect of low load, and frequency modulation parameter setting, which can easily cause power overshoot, regulation delay, and even instability, seriously threatening the safe operation of power grids. Therefore, it is of important theoretical value and engineering significance to reveal the frequency modulation dynamic response mechanism of industrial steam extraction and heat supply thermal power generating units under deep peak regulation conditions and optimize the configuration of key frequency modulation parameters to improve the frequency stability of power systems.

[0003] Traditional research on frequency modulation of thermal power generating units focuses on dynamic models and parameter optimization under pure condensing conditions, and pays insufficient attention to the dynamic coupling effect of steam extraction and heat supply module and main steam system. Changes in steam extraction flow will significantly change the power distribution of the steam turbine, and then affect the frequency modulation output characteristics. However, existing models mostly use linearization assumptions, which cannot accurately depict nonlinear characteristics such as boiler combustion stability threshold and steam pressure fluctuation under low load. In addition, for deep peak regulation scenarios (such as 30% to 50% rated load), existing research lacks quantitative analysis of the synergistic effect of frequency modulation dead zone, frequency modulation limit, and frequency modulation coefficient, resulting in dependence on experience for parameter setting, which makes it difficult to balance the regulation sensitivity and system stability. SUMMARY

[0004] In view of the problems in the prior art, the present application provides a method and system for optimizing primary frequency modulation parameters of thermal power generating units considering the influence of industrial steam extraction and heat supply. The specific technical solutions are as follows:

[0005] A method for optimizing primary frequency modulation parameters of thermal power generating units considering the influence of industrial steam extraction and heat supply, comprising the following steps:

[0006] Step S1: According to the input, output and working process of industrial steam extraction and heat supply, a dynamic simulation model of the middle-low pressure connection pipeline steam extraction module is established, and a series of single reheat steam turbine and its speed regulation system simulation model is connected, to obtain a simulation model system capable of simulating and calculating the influence of industrial steam extraction and heat supply on the output power of the steam turbine generator;

[0007] Step S2: Based on the unit step disturbance test data, the simulation calculation results of the established simulation model system are compared to evaluate the simulation error and verify the simulation accuracy of the established simulation model system in the wide load range of the thermal power unit from deep peak shaving to rated power operation;

[0008] Step S3: Simulate and analyze the influence of nonlinear fluctuation in the frequency modulation process under different peak shaving depths, set simulation conditions including frequency step-up with increased steam extraction, frequency step-up with decreased steam extraction, frequency step-down with increased steam extraction, and frequency step-down with decreased steam extraction, and evaluate the coupling relationship and influence degree of heat supply steam extraction variation and frequency disturbance variation through simulation;

[0009] Step S4: According to the influence path of frequency modulation dead zone, frequency modulation limit and modulation coefficient on power regulation dynamic response characteristics, determine the parameter optimization interval considering regulation speed and system stability;

[0010] Step S5: For the source-load bilateral random-intermittent coupled disturbance scenario, simulate and evaluate the improvement effect of different frequency modulation parameter configurations on the anti-interference ability of the steam turbine generator system.

[0011] Preferably, the simulation model system capable of simulating the influence of industrial extraction heat supply on the output power of the steam turbine generator includes a speed regulation system dynamic model constructed based on the PID control principle, a series combination single-reheat steam turbine model considering the heat supply module, a butterfly valve installed in the low-pressure connecting pipeline heat supply extraction module model, a heat and electricity decoupling module composed of a heat storage tank and an electric boiler, and a two-stage bypass system of the heat supply unit steam turbine composed of a high-pressure bypass and a low-pressure bypass;

[0012] The speed regulation system, the two-stage bypass system of the heat supply unit steam turbine, and the heat supply extraction module are respectively connected with the steam turbine; the heat supply extraction module is respectively connected with the speed regulation system and the heat and electricity decoupling module; the speed regulation system, the heat and electricity decoupling module, and the steam turbine are respectively connected with the single-machine infinite system.

[0013] Preferably, the speed regulation system includes a speed regulator and an actuator; the actuator includes a high-pressure control valve actuator and a medium-pressure control valve actuator; the actuator includes a slide valve oil motor; wherein the speed regulator inputs the speed deviation Δω and the electromagnetic power p E and outputs the control valve opening degree command signal Pcv; the actuator receives the signal of the control valve opening degree command P cv and outputs the signal of the control valve opening degree signal P GV .

[0014] Preferably, the speed regulation system dynamic model and the butterfly valve installed in the low-pressure connecting pipeline extraction heat supply module model are represented as:

[0015]

[0016] Where: L D To control the displacement of the slide valve; L Z is the displacement of the oil motor; L h is the displacement of the slide valve; T D is the inertia time constant of the spool valve; T h k is the inertia time constant of the oil motor; GV P is the static magnification of the valve. GV is the valve opening; k p is the static magnification of the system internal pressure, p m is the internal pressure of the system V m is the internal volume of the system; ρ g is the gas density; T e is the time constant of the heating steam extraction volume; B is the heating steam extraction volume output, M IP is the steam flow rate at the outlet of the intermediate pressure cylinder; M e is the extraction steam heating flow rate; M LP is the intake flow rate of the low-pressure cylinder; K es is the pressure inequality coefficient; Q is the fuel combustion power; T FL and T FUEL are the combustion response time constant and the combustion lag time constant respectively; m W is the water-cooled wall absorption power; T WF is the heat absorption time constant.

[0017] Preferably, the specific method of evaluating the simulation error in step S2 is:

[0018] Based on the actual unit's frequency regulation benchmark step change, a per-unit upward / downward step disturbance is set at the speed deviation input of the speed regulation system module model. The frequency regulation deadband, regulation coefficient, and frequency regulation limit parameters are also set. The simulation results of the unit's primary frequency regulation dynamics are compared with the measured data. The simulated primary frequency regulation dynamics, overshoot, and regulation time should conform to actual performance, and the error compared with the measured primary frequency regulation data should be within the allowable range.

[0019] Preferably, in step S4, the parameter optimization range of the frequency modulation dead zone is 0.033Hz to 0.10Hz; the parameter optimization range of the frequency modulation limiter is 2.22% to 4.44%; and the parameter optimization range of the modulation difference coefficient is 4.5% to 10%.

[0020] Preferably, the effect of different frequency modulation parameter configurations on improving the anti-interference ability of the steam turbine generator system specifically includes anti-interference performance indicators and output indicators, wherein the anti-interference performance indicators include: high-voltage valve overshoot ≤8%, adjustment time ≤60s, steady-state error ≤0.5% rated power; output indicators include: frequency deviation recovery time ≤30s, frequency modulation contribution ≥80%.

[0021] A primary frequency modulation parameter optimization system of a thermal power generating unit considering the influence of industrial extraction heat supply, the method comprises:

[0022] A modeling module is configured to establish a dynamic simulation model of the medium and low pressure connection pipeline extraction module according to the input, output and working process of the industrial extraction heat supply, access the simulation model of the series single reheat steam turbine and its speed regulation system, and obtain a simulation model system capable of simulating and calculating the output power of the steam turbine generator affected by the industrial extraction heat supply.

[0023] An evaluation and verification module is configured to compare the simulation calculation results of the established simulation model system with the step disturbance test data of the unit, evaluate the simulation error, and verify the simulation accuracy of the established simulation model system in the wide load range from deep peak shaving to rated power operation of the thermal power generating unit.

[0024] A simulation analysis module is configured to simulate and analyze the influence of nonlinear fluctuation in the frequency modulation process under different peak shaving depths, set the simulation conditions including the increase of extraction amount when the frequency increases, the decrease of extraction amount when the frequency increases, the increase of extraction amount when the frequency decreases, and the decrease of extraction amount when the frequency decreases, and obtain the coupling relationship and influence degree of the heat extraction amount change and the frequency disturbance change through simulation evaluation.

[0025] A parameter optimization module is configured to determine the parameter optimization interval considering the regulation speed and system stability according to the influence path of the frequency modulation dead zone, frequency modulation amplitude limiting and frequency modulation coefficient on the power regulation dynamic response characteristics.

[0026] A simulation evaluation module is configured to simulate and evaluate the improvement effect of different frequency modulation parameter configurations on the anti-interference ability of the steam turbine generator system for the random-intermittent coupling disturbance scene of the source and load.

[0027] A computer readable storage medium comprises a stored program, wherein the computer readable storage medium controls the device where the computer readable storage medium is located to execute the primary frequency modulation parameter optimization method of the thermal power generating unit considering the influence of industrial extraction heat supply when the program is running.

[0028] A processor is configured to run a program, wherein the processor executes the primary frequency modulation parameter optimization method of the thermal power generating unit considering the influence of industrial extraction heat supply when the program is running.

[0029] Compared with the prior art, the beneficial effects of the present application are:

[0030] The present application considers that the primary frequency modulation dynamic characteristics of a thermal power generating unit under deep peak regulation working condition are influenced by multiple factors such as coupling effect of steam extraction and heat supply module, low load nonlinear effect and frequency modulation parameter setting, quantitative analysis of the synergistic effect of frequency modulation dead zone, frequency modulation limiting amplitude and frequency modulation coefficient, balance of regulation sensitivity and system stability, optimization of key frequency modulation parameter configuration, avoidance of power overshoot, regulation delay and even instability problem, and the present application has important theoretical value and engineering significance for improving the frequency stability of a power system. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the specific embodiments or the prior art, the drawings needed to be used in the specific embodiments or the prior art description will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, each element or part is not necessarily drawn according to the actual proportion.

[0032] Figure 1 The method flowchart of the present application.

[0033] Figure 2 The model structure diagram of an industrial steam extraction thermal power generating unit in the present application.

[0034] Figure 3 The speed governor model diagram of an industrial steam extraction thermal power generating unit in the present application.

[0035] Figure 4 The actuator model diagram of an industrial steam extraction thermal power generating unit in the present application.

[0036] Figure 5 The simulation result and measured data comparison analysis diagram of a heat supply unit primary frequency modulation in the present application, wherein Figure 5 (a) is a comparison analysis diagram of upward step of disturbance frequency, Figure 5 (b) is a comparison analysis diagram of downward step of disturbance frequency.

[0037] Figure 6 The primary frequency modulation dynamic process schematic diagram of a heat supply unit under different peak regulation depths in the present application, Figure 6 (a) is a schematic diagram of upward step of frequency disturbance under different peak regulation depths, Figure 6 (b) is a schematic diagram of downward step of frequency disturbance under different peak regulation depths.

[0038] Figure 7 The variable frequency primary frequency modulation dynamic process schematic diagram of a deep peak regulation heat supply unit in the present application, Figure 7 (a) is a schematic diagram of upward step of variable frequency disturbance, Figure 7 (b) is a schematic diagram of downward step of variable frequency disturbance.

[0039] Figure 8Fig. 1 is a schematic diagram of simulation results of the influence of steam extraction power mutation of a deep peak-shaving heat supply unit in the application on frequency modulation, Figure 8 Fig. 2 is a schematic diagram of simulation results of the influence of frequency disturbance upward step, Figure 8 Fig. 3 is a schematic diagram of simulation results of the influence of frequency disturbance downward step.

[0040] Figure 9 Fig. 4 is a schematic diagram of simulation results of the influence of frequency modulation dead zone parameters on primary frequency modulation action of a unit in the application, Figure 9 Fig. 5 is a schematic diagram of the influence on turbine output power, Figure 9 Fig. 6 is a schematic diagram of the influence on high-pressure control valve opening signal.

[0041] Figure 10 Fig. 7 is a schematic diagram of simulation results of the influence of frequency modulation limiting parameter on primary frequency modulation action of a unit in the application, Figure 10 Fig. 8 is a schematic diagram of the influence on turbine output power, Figure 10 Fig. 9 is a schematic diagram of the influence on high-pressure control valve opening signal.

[0042] Figure 11 Fig. 10 is a schematic diagram of simulation results of the influence of frequency modulation difference coefficient on primary frequency modulation action of a unit in the application, Figure 11 Fig. 11 is a schematic diagram of the influence on turbine output power, Figure 11 Fig. 12 is a schematic diagram of the influence on high-pressure control valve opening signal.

[0043] Figure 12 Fig. 13 is a schematic diagram of simulation results of the influence of frequency modulation dead zone parameter setting on stability of a unit in the application, Figure 12 Fig. 14 is a schematic diagram of the influence on turbine output power, Figure 12 Fig. 15 is a schematic diagram of the influence on high-pressure control valve opening signal.

[0044] Figure 13 Fig. 16 is a schematic diagram of simulation results of the influence of frequency modulation limiting parameter setting on stability of a unit in the application, Figure 13 Fig. 17 is a schematic diagram of the influence on turbine output power, Figure 13 Fig. 18 is a schematic diagram of the influence on high-pressure control valve opening signal.

[0045] Figure 14 Fig. 19 is a schematic diagram of simulation results of the influence of frequency modulation difference coefficient setting on stability of a unit in the application, Figure 14 Fig. 20 is a schematic diagram of the influence on turbine output power, Figure 14 Fig. 21 is a schematic diagram of the influence on high-pressure control valve opening signal.

[0046] Figure 15 Fig. 22 is a schematic diagram of an optimization system of the application. DETAILED DESCRIPTION

[0047] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0048] It will be understood that when used in this specification and the appended claims, the terms “comprises” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0049] It should also be understood that the terms used in the present specification are only for the purpose of describing particular embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0050] It should be further understood that the term "and / or" used in the present description and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0051] Example 1:

[0052] like Figure 1 As shown, this embodiment provides a method for optimizing the primary frequency regulation parameters of a thermal power unit considering the influence of industrial exhaust gas heating, comprising the following steps:

[0053] Step S1: Based on the input, output and workflow of industrial exhaust heat supply, a dynamic simulation model of the medium and low pressure interconnecting pipeline extraction module is established, and a simulation model of a series single reheat steam turbine and its speed control system is connected to obtain a simulation model system that can simulate and calculate the impact of industrial exhaust heat supply on the output power of the steam turbine generator.

[0054] like Figure 2 As shown in the figure, the simulation model system that can simulate and calculate the impact of industrial extraction heating on the output power of steam turbine generator includes a speed control system dynamic model based on PID control principle, a series combination single reheat steam turbine model considering the heating module, a medium and low pressure connecting pipeline heating extraction module model equipped with a butterfly valve, a thermoelectric decoupling module composed of a heat storage tank and an electric boiler, and a two-stage bypass system of the steam turbine of the heating unit composed of a high-pressure bypass and a low-pressure bypass.

[0055] The speed regulating system, the two-stage bypass system of the steam turbine of the heat supply unit, and the heat supply extraction module are connected with the steam turbine respectively; the heat supply extraction module is connected with the speed regulating system and the thermal power decoupling module respectively; the speed regulating system, the thermal power decoupling module, and the steam turbine are connected with the single-machine infinite system respectively.

[0056] The speed regulating system comprises a speed regulator and an actuator; the actuator comprises a high-pressure regulating valve actuator and a medium-pressure regulating valve actuator; the actuator comprises a slide valve oil motor.

[0057] Reference Figure 3 And Figure 4 Considering the characteristics of frequency regulation and power regulation, a speed regulating system model is established as shown in the figure, which has the functions of multi-mode switching of pressure control, DEH open-loop control and load control, but in the present application, the load control mode is selected for the special working condition that the heat supply unit needs to respond to the heat user demand and the power grid load fluctuation in real time, dynamically adjust the output parameters and participate in the deep peak shaving operation. The main decision basis is that the huge heat storage characteristics of the heat supply pipe network can realize the rapid adjustment of the power generation load through the fast closing valve opening adjustment, and this characteristic forms a synergistic effect with the rapid response mechanism of the load control mode. When the load control mode is selected, the speed regulator inputs the speed deviation Δω and the electromagnetic power Ep and then outputs the regulating valve opening degree command signal Pcv.

[0058] The signal accepted by the actuator is the regulating valve opening degree command P cv , and the output signal is the regulating valve opening degree signal P GV .

[0059] The actuator usually adopts a slide valve oil motor in actual production, so the regulating valve opening degree command is represented as the displacement L D of the control slide valve, and the regulating valve opening degree signal is represented as the displacement L Z of the oil motor. In actual industrial production, the dynamic characteristics of the actuator satisfy the following formula:

[0060]

[0061] Figure 3 In the formula, Δω is the deviation of the speed reference value and the speed (ω ref -ω); T1 is the inertia time constant of the frequency measurement link; K is the speed deviation amplification multiple (the difference coefficient); K2 is the load control feedforward coefficient; K P , K I , and K D are the PID proportion, differentiation, and integration link multiples; P CV is the regulating valve opening degree command signal; T R is the inertia time constant of the power measurement link; the upper and lower limits of the frequency regulation dead zone are ε u and -ε dThe upper and lower limits of the primary frequency modulation are σ u and -σ d .

[0062] In actual industrial production, the inertia time constant D T of the slide valve and the inertia time constant h T of the oil motor differ by more than 102s, so the influence of the slide valve time constant on the actuator can be ignored when building the transfer function model. The transfer function obtained after Laplace transformation of the above two formulas is

[0063]

[0064] Figure 4 K P , K I , K D are the PID proportion, differentiation and integration link multiples; S PIDmax , S PIDmin are the upper and lower limits of the comprehensive amplification link output; VE open , VE close are the overspeed opening and closing coefficients; T o , T c are the oil motor opening and closing time constants; P max and P min are the maximum and minimum valve opening degrees.

[0065] The dynamic model of the speed regulating system and the model of the middle-low pressure connecting pipeline steam extraction and heating module with the butterfly valve are represented as:

[0066]

[0067] In the formula, L D is the displacement of the control slide valve; L Z is the displacement of the oil motor; L h is the displacement of the slide valve; T D is the inertia time constant of the slide valve; T h is the inertia time constant of the oil motor; k GV is the static amplification multiple of the regulating valve, P GV is the regulating valve opening degree; k p is the static amplification multiple of the system internal pressure, p m is the system internal pressure; V m is the system internal volume; ρ g is the gas density; T e is the heating steam extraction volume time constant; B is the heating steam extraction volume output, M IP is the steam flow at the outlet of the medium pressure cylinder; M e is the steam extraction and heating flow; M LP is the low pressure cylinder inlet flow; K es is the pressure differential ratio coefficient; Q is the fuel combustion power; TFL and T FUEL are the combustion response time constant and the combustion lag time constant respectively; m W is the water-cooled wall absorption power; T WF is the heat absorption time constant.

[0068] Step S2: Based on the unit step disturbance test data, the simulation calculation results of the established simulation model system are compared to evaluate the simulation error and verify the simulation accuracy of the established simulation model system in a wide load range from deep peak regulation to rated power operation of the thermal power unit.

[0069] The specific approach to evaluating simulation errors is:

[0070] Based on the actual unit's frequency regulation benchmark step change, a per-unit upward / downward step disturbance is set at the speed deviation input of the speed regulation system module model. The frequency regulation deadband, regulation coefficient, and frequency regulation limit parameters are also set. The simulation results of the unit's primary frequency regulation dynamics are compared with the measured data. The simulated primary frequency regulation dynamics, overshoot, and regulation time should conform to actual performance, and the error compared with the measured primary frequency regulation data should be within the allowable range.

[0071] Compare the actual data of the unit frequency step disturbance test with the dynamic error of the simulation results to verify the accuracy of the model;

[0072] The simulation error judgment criteria are: overshoot deviation ≤ 5%, adjustment time deviation ≤ 10%;

[0073] The least squares method is used to fit the model parameters to ensure the dynamic consistency of main steam pressure, extraction steam flow and power response.

[0074] The technical solution of the present invention is described below in conjunction with a specific embodiment. First, based on the actual unit frequency regulation benchmark at t = 100s from 3000r / min to 3011r / min, at the speed deviation Δω of the speed regulation system module model input end, set an upward / downward step disturbance with a per-unit value of Δω = 0.0036, and at the same time set the frequency regulation dead zone parameter to 0.033Hz, the adjustment coefficient to 4.5%, and the frequency regulation limit parameter to 4.44%. Comparing the simulation results of the unit model's full frequency regulation dynamic process with the measured data, the results are as follows Figure 5 As shown in the figure, the simulation results of the primary frequency regulation dynamic process, overshoot, and adjustment time are consistent with the actual situation, and the error compared with the measured data of the primary frequency regulation of the unit is within the allowable range.

[0075] Step S3: Simulate the influence of nonlinear fluctuation in frequency modulation process under different peak regulation depths, set simulation conditions including frequency step-up with increasing extraction steam, frequency step-up with decreasing extraction steam, frequency step-down with increasing extraction steam, and frequency step-down with decreasing extraction steam, and evaluate the coupling relationship and influence degree of heating extraction steam variation and frequency disturbance variation through simulation.

[0076] The frequency modulation control strategy in heating mode uses power compensation coordination algorithm when extraction steam suddenly changes, dynamically adjusts the opening degree of the regulating valve and the extraction valve command; when the extraction steam decreases, the fast power tracking mode is enabled to suppress the overshoot.

[0077] The frequency modulation coordination strategy is to establish a dynamic mapping table of frequency modulation parameters and extraction heating demand; according to different peak regulation depths at 20% to 50% power level, the PID parameters are adjusted in real time to ensure the regulation speed and system stability.

[0078] Specifically, the frequency modulation dead zone parameter is set to 0.033 Hz, the regulation difference coefficient is set to 4.5%, and the frequency modulation limiting parameter is set to 4.44%, a step-up / down speed disturbance is applied to the speed regulation system, the unit peak regulation depth reaches 0.40(p.u.), 0.35(p.u.), 0.30(p.u.), 0.25(p.u.), and 0.20(p.u.), and the turbine output power is read, and the output result is as shown in Figure 6

[0079] According to the information in Figure 6 , it can be known that under the conditions of given dead zone parameter, regulation difference coefficient, and frequency modulation limiting parameter, when the peak regulation depth reaches the maximum, i.e. 0.20(p.u.), the primary frequency modulation curve appears fluctuation compared to the curve with smaller peak regulation depth, the main reason is that when the heating unit peak regulation depth is large, there are nonlinear links of the unit, and the boiler touches the stable combustion criticality at low load. According to the primary frequency modulation dynamic process results of the heating unit model with different peak regulation depths, it can be concluded that the simulation model can meet the demand of primary frequency modulation dynamic whole process simulation analysis under deep peak regulation conditions (30% to 50% rated conditions), the simulation results are consistent with the actual situation, and are within the allowable error range.

[0080] In the influence of frequency disturbance amplitude and direction on frequency modulation, the frequency modulation dead zone parameter is set to 0.033 Hz, the regulation difference coefficient is set to 4.5%, and the frequency modulation limiting parameter is set to 4.44%, the depth peak regulation heating unit is set to 0.3(p.u.) rated condition, a step-up / down speed disturbance is applied to the speed regulation system, further, the frequency disturbance is set to 0.0013(p.u.), 0.0026(p.u.), 0.0033(p.u.), and 0.0040(p.u.), and the result is as shown in​Figure 7 shown.

[0081] Figure 7 In the figure, when the frequency disturbance increases, the frequency regulation pressure of the system shows a trend of gradually increasing. When the frequency disturbance is 0.0040 (pu), the frequency regulation pressure of the unit is the largest. It can be clearly seen that during the frequency regulation process, the overshoot of the turbine output power increases significantly, the regulation time is prolonged, and the stability of the frequency regulation process is reduced.

[0082] Regarding the impact of the heating mode on the frequency modulation process, if frequency fluctuation occurs during the normal steam extraction heating process of the unit, a frequency modulation action is performed, and the result is shown in the figure.

[0083] Figure 8 There are four situations: (1) Increase in step extraction volume on frequency: the power generated will be further reduced, but the peak-shaving depth is too large, which may lead to low-load instability; (2) Decrease in step extraction volume on frequency: the frequency regulation power deviation is compensated, but the overshoot is too large and the stability is reduced. (3) Increase in step extraction volume on frequency: the frequency regulation power deviation is compensated, but the overshoot is large and low-load instability may occur; (4) Decrease in step extraction volume on frequency: the output power also increases and the operation process is smooth, without overshoot, and is not affected by the peak-shaving depth.

[0084] The effect of FM dead zone parameter setting on FM process. Setting the adjustment coefficient to 4.5%, setting the FM limit parameter to 4.44%, changing the FM dead zone size, the simulation result of a FM action is as follows: Figure 8 As shown. Figure 9 The information in this article indicates that as the frequency regulation deadband expands, the heating unit's response to grid frequency disturbances gradually weakens. However, when the frequency regulation deadband exceeds a certain threshold, if the grid frequency disturbance amplitude is less than the preset deadband range, the heating unit's speed regulation system will remain inactive. While this setting effectively reduces the frequent frequency adjustments caused by grid frequency disturbances, it also causes the system to lose its primary frequency regulation function, thereby affecting the grid's frequency stability.

[0085] The effect of frequency modulation limit parameter setting on the frequency modulation process, setting the frequency modulation dead zone to 0.033Hz, the modulation coefficient to 4.5%, changing the frequency modulation limit value, the simulation results of a frequency modulation action process are as follows Figure 10 As shown in the figure, we can see that as the frequency regulation limit parameter increases, the sensitivity of the heating unit to grid frequency disturbances increases significantly, and its power regulation amplitude shows a clear increasing trend.

[0086] The effect of the adjustment coefficient setting on the frequency modulation process, setting the frequency modulation dead zone to 0.033Hz, the frequency modulation limit value to 4.44%, changing the adjustment coefficient, the simulation results of a frequency modulation action are as follows Figure 11The information in the figure shows that the frequency response characteristics of the heat supply unit and the regulation difference coefficient present a significant negative correlation, that is, as the regulation difference coefficient increases, the dynamic response amplitude of the unit to the power grid frequency disturbance presents a significant attenuation trend. When the regulation difference coefficient is too small, the primary frequency modulation has a greater impact on the unit, and the system is prone to have a large overshoot and a prolonged regulation time, which will directly affect the transient stability of the power grid frequency and may even lead to system frequency instability.

[0087] Step S4: According to the influence path of the frequency modulation dead zone, the frequency modulation limit and the regulation difference coefficient on the power regulation dynamic response characteristics, the parameter optimization interval considering the regulation speed and system stability is determined. The parameter optimization interval of the frequency modulation dead zone is 0.033Hz-0.10Hz; the parameter optimization interval of the frequency modulation limit is 2.22%-4.44%; and the parameter optimization interval of the regulation difference coefficient is 4.5%-10%. Specifically:

[0088] The influence of the frequency modulation dead zone parameter setting of the industrial extraction steam turbine unit on the disturbance is shown in the figure. Figure 12 According to the information in the figure, it can be seen that when the frequency modulation dead zone is too small, the system will have a significant dynamic response overshoot during the recovery process after the disturbance, specifically, the maximum overshoot of the high-pressure governor opening degree signal is significantly increased, the regulation time is prolonged, and the operation stability of the unit is directly affected. On the other hand, when the frequency modulation dead zone is set too large, although it can effectively reduce the response frequency of the unit to the small fluctuation of the power grid frequency, it will significantly weaken the regulation ability of the system to the set frequency disturbance, resulting in a decrease in the stability margin of the power grid frequency and an increase in the risk of system instability. Therefore, the optimization setting of the frequency modulation dead zone needs to balance the regulation sensitivity of the unit and the system stability, that is, it is appropriate to set 0.033Hz-0.10Hz.

[0089] The influence of the frequency modulation limit parameter setting of the industrial extraction steam turbine unit on the disturbance is shown in the figure. Figure 13

[0090] According to the information in the figure, it can be seen that the larger the frequency modulation limit parameter setting is, the greater the impact of the power grid frequency disturbance on the unit will be. When the frequency modulation limit parameter setting is the maximum, the system will have a significant dynamic response overshoot during the recovery process after the disturbance, the maximum overshoot of the high-pressure governor opening degree signal is significantly increased, the regulation time is prolonged, and the operation stability of the unit is directly affected. However, when the frequency modulation limit parameter setting is reduced, the frequency modulation performance of the unit presents a gradually decreasing trend. Therefore, it is appropriate to set the frequency modulation limit parameter of the heat supply unit to 2.22%-4.44%.

[0091] ​The influence of the setting of the adjustment coefficient of the industrial extraction steam unit on the disturbance, the setting of the frequency modulation limit parameter is 4.44%, the frequency modulation dead zone is 0.033Hz, the adjustment coefficient is changed, and the simulation result is as shown in Figure 14

[0092] According to the information in the figure, it can be known that the setting of the adjustment coefficient and the dynamic response characteristics of the heat supply unit present a nonlinear relationship. When the adjustment coefficient is small, the impact of the grid frequency disturbance on the unit is significantly increased. When the adjustment coefficient is set to the maximum value, the system will have a significant dynamic response overshoot phenomenon during the recovery process after the disturbance, the maximum overshoot of the high-pressure governing valve opening signal is significantly increased, the regulation time is prolonged, and the operation stability of the unit is affected. In addition, although the small adjustment coefficient is beneficial to improve the dynamic response speed of the unit, the system can recover to the state before the disturbance more quickly, but the anti-interference ability of the system to small disturbances of the grid is significantly reduced, and the operation condition of the unit is frequently fluctuated. Therefore, the optimization setting of the adjustment coefficient needs to seek the best balance point between the dynamic response speed and the operation stability, that is, the setting is between 4.5% and 10%, which is more appropriate.

[0093] Step S5: For the source-load bilateral random-intermittent coupling disturbance scene, the improvement effect of different frequency modulation parameter configurations on the anti-interference ability of the steam turbine generator system is simulated and evaluated, so as to support the design of the frequency modulation control strategy of the industrial extraction steam thermal power unit.

[0094] When evaluating the frequency modulation support ability of the thermal power unit under the random fluctuation of wind power / photovoltaic, for the anti-interference parameter configuration method under the source-load bilateral disturbance, firstly, the joint configuration method of the frequency modulation dead zone, the frequency modulation limit and the adjustment coefficient is adopted, and the new energy output fluctuation is simulated based on the random-intermittent coupling disturbance method, and the parameter robustness is verified.

[0095] The improvement effect of different frequency modulation parameter configurations on the anti-interference ability of the steam turbine generator system specifically includes anti-interference performance indexes and output indexes, wherein the anti-interference performance indexes include: the high-pressure governing valve overshoot is less than or equal to 8%, the regulation time is less than or equal to 60s, and the steady-state error is less than or equal to 0.5% of the rated power; the output indexes include: the frequency deviation recovery time is less than or equal to 30s, and the frequency modulation contribution degree is greater than or equal to 80%. The grid dispatching system generates frequency modulation parameter optimization instructions, and realizes the source-grid coordinated control.

[0096] The present application establishes a dynamic simulation model of the low-pressure connecting pipeline extraction steam module, accesses the simulation model of the series single-reheat steam turbine and its speed regulation system, and constitutes a high-precision dynamic model of the thermal power unit capable of simulating wide load regulation. The coupling relationship and influence degree of the heat extraction steam volume change and the frequency disturbance change are obtained through simulation evaluation, the optimization interval of the frequency modulation dead zone, the frequency modulation limit and the adjustment coefficient is quantified, the parameter optimization design scheme considering the regulation speed and system stability is given, the power overshoot and regulation delay problem under the deep peak regulation condition is solved, and the frequency stability of the unit can be improved.​

[0097] Embodiment 2

[0098] As Figure 15 shown, based on the same inventive concept as embodiment 1, the embodiment provides a thermal power generating unit primary frequency modulation parameter optimization system considering the influence of industrial extraction heating, and the method comprises:

[0099] a modeling module, configured to establish a dynamic simulation model of the medium and low pressure connection pipeline extraction module according to the input, output and working process of the industrial extraction heating, access the simulation model of the series single reheat steam turbine and its speed regulation system, and obtain a simulation model system capable of simulating and calculating the output power of the steam turbine generator affected by the industrial extraction heating;

[0100] an evaluation and verification module, configured to compare the simulation calculation results of the established simulation model system with the step disturbance test data of the unit, evaluate the simulation error, and verify the simulation accuracy of the established simulation model system in the wide load range from deep peak shaving to rated power operation of the thermal power generating unit;

[0101] a simulation analysis module, configured to simulate and analyze the influence of nonlinear fluctuations in the frequency modulation process under different peak shaving depths, set simulation conditions including frequency step-up and extraction quantity increase, frequency step-up and extraction quantity decrease, frequency step-down and extraction quantity increase, and frequency step-down and extraction quantity decrease, and obtain the coupling relationship and influence degree of the heating extraction quantity change and the frequency disturbance change through simulation evaluation;

[0102] a parameter optimization module, configured to determine a parameter optimization interval considering the adjustment speed and system stability according to the influence path of the frequency modulation dead zone, frequency modulation amplitude limiting and frequency modulation coefficient on the power regulation dynamic response characteristics;

[0103] a simulation evaluation module, configured to simulate and evaluate the improvement effect of different frequency modulation parameter configurations on the anti-interference ability of the steam turbine generator system for the source-load bilateral random-intermittent coupling disturbance scene.

[0104] Embodiment 3

[0105] Based on the same inventive concept as embodiment 1, the embodiment provides a computer readable storage medium, which comprises a stored program, wherein the program controls the device where the computer readable storage medium is located to execute the primary frequency modulation parameter optimization method for thermal power generating units considering the influence of industrial extraction heating when the program is running.

[0106] Embodiment 4

[0107] Based on the same inventive concept as Example 1, this embodiment provides a processor, which is used to run a program, wherein when the program is running, the method for optimizing the primary frequency regulation parameters of a thermal power unit considering the influence of industrial exhaust gas heating is executed.

[0108] Those skilled in the art will appreciate that the units of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition of each example has been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0109] In the embodiments provided by the present invention, it should be understood that the division of units is merely a logical function division, and there may be other division methods in actual implementation, for example, multiple units can be combined into one unit, one unit can be split into multiple units, or some features can be ignored, etc.

[0110] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0111] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server or network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-0nly Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk, etc., various media that can store program code.

[0112] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention.

Claims

1. A method for optimizing the primary frequency modulation parameters of a thermal power unit considering the influence of industrial exhaust heating, characterized in that: The following steps are involved: Step S1: Based on the input, output, and workflow of industrial exhaust heat supply, a dynamic simulation model of the medium- and low-pressure interconnected pipeline steam extraction module is established, and a simulation model of a series-connected single-reheat steam turbine and its speed control system is connected to obtain a simulation model system that can simulate and calculate the impact of industrial exhaust heat supply on the output power of the steam turbine generator; Step S2: Based on the unit step disturbance test data, the simulation calculation results of the established simulation model system are compared to evaluate the simulation error and verify the simulation accuracy of the established simulation model system in a wide load range from deep peak regulation to rated power operation of the thermal power unit; Step S3: Simulating and analyzing the impact of nonlinear fluctuations in the frequency modulation process at different peak regulation depths. Simulation conditions include increasing the extraction steam volume with a frequency step increase, decreasing the extraction steam volume with a frequency step increase, and decreasing the extraction steam volume with a frequency step decrease. The coupling relationship between the change in the heating extraction steam volume and the change in the frequency disturbance and the degree of influence are obtained through simulation evaluation. Step S4: Determine the parameter optimization range that takes into account both regulation speed and system stability based on the impact path of the frequency modulation dead zone, frequency modulation limiter and modulation difference coefficient on the dynamic response characteristics of power regulation; Step S5: For the random-intermittent coupled disturbance scenario on both the source and load sides, simulate and evaluate the effect of different frequency modulation parameter configurations on improving the anti-interference capability of the steam turbine generator system.

2. The method for optimizing primary frequency regulation parameters of a thermal power unit considering the influence of industrial exhaust gas heating according to claim 1, characterized in that: The simulation model system capable of simulating and calculating the impact of industrial extraction heating on the output power of the steam turbine generator includes a speed control system dynamic model constructed based on the PID control principle, a series-combined single-reheat steam turbine model considering the heating module, a medium- and low-pressure interconnecting pipeline heating extraction module model equipped with a butterfly valve, a thermoelectric decoupling module consisting of a heat storage tank and an electric boiler, and a two-stage bypass system of the steam turbine of the heating unit consisting of a high-pressure bypass and a low-pressure bypass; The speed control system, the two-stage bypass system of the steam turbine of the heating unit, and the heating steam extraction module are respectively connected to the steam turbine; the heating steam extraction module is respectively connected to the speed control system and the thermoelectric decoupling module; the speed control system, the thermoelectric decoupling module, and the steam turbine are respectively connected to the single-machine infinite system.

3. The method for optimizing primary frequency regulation parameters of a thermal power unit considering the influence of industrial exhaust heat supply according to claim 2, characterized in that: The speed control system includes a speed regulator and an actuator; the actuator includes a high-pressure regulating valve actuator and a medium-pressure regulating valve actuator; the actuator includes a slide valve oil motor; wherein the speed regulator inputs a speed deviation Δω and an electromagnetic power p E The output valve opening command signal Pcv; the signal received by the actuator is the valve opening command P cv The output signal is the valve opening signal P GV .

4. The method for optimizing primary frequency regulation parameters of a thermal power unit considering the influence of industrial exhaust gas heating according to claim 3 is characterized in that: The dynamic model of the speed control system and the model of the medium and low pressure interconnecting pipeline steam extraction heating module equipped with butterfly valves are expressed as follows: Where: L D To control the displacement of the slide valve; L Z is the displacement of the oil motor; L h is the displacement of the slide valve; T D is the inertia time constant of the spool valve; T h k is the inertia time constant of the oil motor; GV P is the static magnification of the valve. GV is the valve opening; k p is the static magnification of the system internal pressure, p m is the internal pressure of the system V m is the internal volume of the system; ρ g is the gas density; T e is the time constant of the heating steam extraction volume; B is the heating steam extraction volume output, M IP is the steam flow rate at the outlet of the intermediate pressure cylinder; M e is the extraction steam heating flow rate; M LP is the intake flow rate of the low-pressure cylinder; K es is the pressure inequality coefficient; Q is the fuel combustion power; T FL and T FUEL are the combustion response time constant and the combustion lag time constant respectively; m W is the water-cooled wall absorption power; T WF is the heat absorption time constant.

5. The method for optimizing primary frequency regulation parameters of thermal power units considering the influence of industrial exhaust heat supply according to claim 1 is characterized in that: The specific method of evaluating the simulation error in step S2 is: Based on the actual unit's frequency regulation benchmark step change, a per-unit upward / downward step disturbance is set at the speed deviation input of the speed regulation system module model. The frequency regulation deadband, regulation coefficient, and frequency regulation limit parameters are also set. The simulation results of the unit's primary frequency regulation dynamics are compared with the measured data. The simulated primary frequency regulation dynamics, overshoot, and regulation time should conform to actual performance, and the error compared with the measured primary frequency regulation data should be within the allowable range.

6. The method for optimizing primary frequency regulation parameters of thermal power units considering the influence of industrial exhaust heat supply according to claim 1, characterized in that: In step S4, the parameter optimization range of the frequency modulation dead zone is 0.033Hz to 0.10Hz; the parameter optimization range of the frequency modulation limiter is 2.22% to 4.44%; and the parameter optimization range of the modulation difference coefficient is 4.5% to 10%.

7. The method for optimizing primary frequency regulation parameters of thermal power units considering the influence of industrial exhaust heat supply according to claim 1, characterized in that: The effects of different frequency modulation parameter configurations on improving the anti-interference ability of the steam turbine generator system specifically include anti-interference performance indicators and output indicators. The anti-interference performance indicators include: high-voltage valve overshoot ≤8%, adjustment time ≤60s, steady-state error ≤0.5% rated power; the output indicators include: frequency deviation recovery time ≤30s, frequency modulation contribution ≥80%.

8. A thermal power unit primary frequency modulation parameter optimization system considering the influence of industrial exhaust heating, characterized in that: Applying the method according to any one of claims 1 to 7, comprising: The modeling module is used to establish a dynamic simulation model of the medium and low pressure pipeline extraction module based on the input, output and workflow of industrial exhaust heat supply. This is connected to the simulation model of the series single reheat steam turbine and its speed control system to obtain a simulation model system that can simulate and calculate the impact of industrial exhaust heat supply on the output power of the steam turbine generator; An evaluation and verification module is used to compare the unit step disturbance test data with the simulation calculation results of the established simulation model system, evaluate the simulation error, and verify the simulation accuracy of the established simulation model system over a wide load range from deep peak regulation to rated power operation of the thermal power unit; The simulation analysis module is used to simulate and analyze the impact of nonlinear fluctuations during the frequency regulation process at different peak regulation depths. The simulation conditions include frequency step increase with steam extraction capacity, frequency step increase with steam extraction capacity decrease, frequency step decrease with steam extraction capacity increase, and frequency step decrease with steam extraction capacity decrease. Through simulation evaluation, the coupling relationship between the change in heating steam extraction capacity and the change in frequency disturbance and the degree of influence are obtained. The parameter optimization module is used to determine the parameter optimization range that takes into account both regulation speed and system stability based on the impact path of frequency modulation dead zone, frequency modulation limit and modulation difference coefficient on the dynamic response characteristics of power regulation; The simulation evaluation module is used to simulate and evaluate the effect of different frequency modulation parameter configurations on the anti-interference capability of the steam turbine generator system in the random-intermittent coupling disturbance scenario on both the source and load sides.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium includes a stored program, wherein when the program is running, the device where the computer-readable storage medium is located is controlled to execute the method for optimizing the primary frequency regulation parameters of a thermal power unit considering the influence of industrial exhaust gas heating as described in any one of claims 1 to 7.

10. A processor, characterized in that: The processor is used to run a program, wherein when the program is run, the method for optimizing primary frequency regulation parameters of a thermal power unit considering the influence of industrial exhaust gas heating as described in any one of claims 1 to 7 is executed.

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