A simulation method and system for thermal power units operating at wide load

Abstract

The present application provides a simulation method and system for a thermal power unit under wide load operation, the method comprising: constructing a single reheat steam turbine model according to the operation mechanism of the steam turbine of the thermal power unit using a power natural overregulation coefficient calculation method; analyzing the influence correlation of multiple preset influence data affecting the steam turbine of the thermal power unit on the single reheat steam turbine model through time domain and frequency domain, determining the influence conditions according to the influence correlation and adjusting the single reheat steam turbine model to obtain a single reheat steam turbine reconstruction model; obtaining the power valve position conversion coefficient and correction coefficient according to the configuration structure analysis of the regulating system of the thermal power unit, and constructing a regulating system model through the power valve position conversion coefficient and correction coefficient; and performing target simulation processing through the single reheat steam turbine reconstruction model and the regulating system model. In this way, the factors that have the greatest impact on the simulation accuracy of the model when the unit is under wide load operation are taken into account, and the simulation accuracy and applicable scope of the model are improved.

Description

Technical Field

[0001] The present application relates to the field of power system stability analysis, and in particular to a simulation method and system for a thermal power unit operating at a wide load. Background Art

[0002] With the large-scale access of new energy to the grid and the increasing proportion of power generation year by year, the "double high" characteristics of the new power system are becoming increasingly prominent. The improvement of the system's regulation and support capabilities faces many constraints, and safe and stable operation faces great risks and challenges. In order to solve the above problems, thermal power units are transformed into support and regulation power sources, and the load operation range is greatly expanded through flexibility transformation, and ultra-low load operation has become the norm. Usually, 50% or more of the rated load is called normal operating conditions, and 50% and below is called deep peak load operating conditions.

[0003] Through field measured data, the grid-related model of the steam turbine and its regulation system is established through simulation identification. It can be used to analyze the dynamic response characteristics of the power system when it is subjected to various interferences in a steady state. It is an important means of stability analysis of the power system. The accuracy and applicability of the model directly affect the results of the stability analysis of the power system. The commonly used models are mainly for units operating under conventional conditions. Under deep peak-shaving conditions, the simulation accuracy of the original model decreases. It is necessary to rebuild the grid-related model of the steam turbine to adapt to the characteristics of the wide load operation of the unit, and give the engineering application method of the model to improve the simulation accuracy and scope of application of the model.

[0004] At present, the commonly used steam turbine and governor model in power system stability analysis is the model provided in the "PSD-ST Transient Stability Program User Manual", referred to as the BPA model. Since the current domestic models in service are mainly single-reheat steam turbines, the commonly used steam turbine and its regulation system models are the single-reheat steam turbine model (referred to as TB card in the manual), the electro-hydraulic servo system model (referred to as GA / GA+ card), and the regulation system model (referred to as GJ / GJ+ card). Its transfer function is as follows Figures 1A to 1C shown.

[0005] Figure 1A In this case, S is the Laplace operator, P GV is the per unit opening value of the high-pressure valve, T CH is the volume time constant of the front steam chamber of the high pressure cylinder, T RH is the reheater volume time constant, T CO is the volume time constant of the low-pressure connecting pipe steam chamber, F HP 、F IP 、F LP It is the percentage of power of the high, medium and low cylinders in the whole machine. λ is the natural over-modulation coefficient of high-pressure cylinder power, P M It is the per unit value of turbine output power. Figure 1BIn this case, S is the Laplace operator, P is CV K is the integrated regulating valve position command per unit value, P , K D , K I is the proportional coefficient, differential coefficient and integral coefficient of the high pressure regulating valve servo card, T C is the oil motor closing time, T O is the oil motor start time, P MAX P is the maximum prime mover output power standard value (maximum stroke of the oil motor or maximum opening of the throttle valve), MIN is the minimum prime mover output power standard value (minimum stroke of the oil motor or minimum opening of the throttle valve), T2 is the oil motor stroke feedback link (LVDT) time, P GV is the per-unit value of the opening of the high-pressure regulating valve, VELopen is the per-unit value of the over-speed closing coefficient, and VELclose is the per-unit value of the over-speed opening coefficient. Figure 1C In the equation, S is the Laplace operator, Δω is the difference between the rated speed and the actual speed, and TW delay is the pure delay time of the frequency input signal, T1 is the time constant of the speed measurement link, T R is the time constant of an inertia link corresponding to the power feedback signal, TW2 delay is the pure delay time after the frequency signal is amplified, DP UP / DP DOWN It is the rising / falling rate limit per unit value of the input PID signal after the frequency signal is amplified. delay It is the pure delay time of the frequency signal after amplification and input into PID, TP delay is the pure delay time of the power feedback signal, P E is the per unit value of the turbine power feedback signal under load control conditions, P M1 is the per unit value of the turbine power feedback signal under the regulating stage pressure control condition, P REF is the power setting value per unit, K 0 is the control mode selection switch, K 1 is the speed deviation magnification factor, K 2 is the load control feedforward coefficient, T R is the time constant of the first-order inertia link in power feedback, K P is the multiple of the proportional link in the PID controller, K I is the integral factor multiple in the PID controller, K D is the multiple of the differential link in the PID controller, P CVIt is the unit value of the comprehensive regulating valve position command.

[0006] The BPA model greatly simplifies the real steam turbine system. The simulation effect of the unit operating under conventional pure condensing conditions is good. However, due to the influence of main steam pressure changes, valve nonlinearity, unit heating, low-pressure cylinder removal, etc., the simulation effect of the model for units operating under deep peak load regulation and heating conditions is poor. Therefore, the BPA model cannot meet the simulation needs of thermal power units operating under wide load conditions. Summary of the invention

[0007] The purpose of this application is to provide a simulation method and system for wide-load operation thermal power units to meet the simulation needs of wide-load operation thermal power units and the requirements of power system simulation, and to significantly improve the simulation accuracy and efficiency, greatly reducing the difficulty of engineering application.

[0008] To achieve the above-mentioned purpose, the simulation method of a wide-load operation thermal power unit provided in the present application specifically includes: constructing a single reheat steam turbine model according to the operating mechanism of the thermal power unit steam turbine using a power natural overregulation coefficient calculation method; analyzing the influence correlation of multiple preset influence data affecting the thermal power unit steam turbine on the single reheat steam turbine model through time domain and frequency domain analysis, determining the influence conditions according to the influence correlation and adjusting the single reheat steam turbine model to obtain a single reheat steam turbine reconstruction model; obtaining a power valve position conversion coefficient and a correction coefficient according to the configuration structure analysis of the thermal power unit's regulation system, and constructing a regulation system model through the power valve position conversion coefficient and the correction coefficient; and performing target simulation processing through the single reheat steam turbine reconstruction model and the regulation system model.

[0009] In the above-mentioned simulation method of a thermal power unit operating at a wide load, optionally, constructing a single reheat steam turbine model according to a method for calculating a natural power overmodulation coefficient comprises: respectively calculating the natural power overmodulation coefficient corresponding to two parts of the high-pressure cylinder divided by a draw as a dividing point; and constructing a single reheat steam turbine model according to the calculated natural power overmodulation coefficient.

[0010] In the above-mentioned simulation method for a thermal power unit operating at a wide load, optionally, the influencing conditions include the influence of main steam pressure changes, valve nonlinearity, and the influence of unit heating and flexibility transformation.

[0011] In the above-mentioned simulation method for a thermal power unit operating at a wide load, optionally, adjusting the single reheat steam turbine model through preset influencing conditions to obtain a single reheat steam turbine reconstruction model includes: when the influencing condition is affected by the change in main steam pressure, constructing a main steam adjustment function according to the influence of the main steam pressure on the steam flow rate; and adjusting the single reheat steam turbine model through the main steam adjustment function to obtain a single reheat steam turbine reconstruction model.

[0012] In the above-mentioned simulation method for a thermal power unit operating at a wide load, optionally, constructing a main steam adjustment function according to the influence of the steam flow on the main steam pressure comprises: constructing an integral function and an inertia function according to the state of the steam flow in the steam turbine, respectively, and constructing a main steam adjustment function according to the integral function and the inertia function; wherein the integral function is a corresponding integral function constructed when the steam flow entering the steam turbine changes, an imbalance occurs between the heat carried away by the steam flowing into the steam turbine per unit time and the heat generated by the combustion of the fuel, resulting in a change in the pressure of the drum boiler, and the heat of the fuel is greater than the heat carried away by the steam flow; and the inertia function is a corresponding inertia function with a proportional coefficient constructed when the main steam pressure changes due to a change in the steam flow entering the steam turbine when the drum pressure is constant.

[0013] In the above-mentioned simulation method of a thermal power unit operating at a wide load, optionally, adjusting the single reheat steam turbine model through preset influencing conditions to obtain a single reheat steam turbine reconstruction model includes: when the influencing condition is the nonlinear influence of the valve, constructing a valve management function according to the correlation between the measured regulating stage pressure, the measured main steam pressure and the total valve position instruction; and adjusting the single reheat steam turbine model according to the valve management function to obtain the single reheat steam turbine reconstruction model.

[0014] In the above-mentioned simulation method for a thermal power unit operating at a wide load, optionally, constructing a valve management function according to the correlation between the measured regulating stage pressure, the main steam pressure and the total valve position instruction includes: obtaining an actual equivalent valve position according to the ratio between the measured regulating stage pressure and the measured main steam pressure; constructing a valve linearity function curve according to the correlation between the actual equivalent valve position and the total valve position instruction; and constructing a valve management function according to the valve linearity function curve.

[0015] In the above-mentioned simulation method for a thermal power unit operating at a wide load, optionally, adjusting the single reheat steam turbine model through preset influencing conditions to obtain a single reheat steam turbine reconstruction model includes: when the influencing conditions are the influence of unit heating and flexibility transformation, constructing an extraction heating function according to the correlation between the main steam flow, the extraction flow and the turbine power; and adjusting the single reheat steam turbine model according to the extraction heating function to obtain a single reheat steam turbine reconstruction model.

[0016] In the above-mentioned simulation method for a thermal power unit operating at a wide load, optionally, the flexible transformation includes the impact of low-pressure cylinder removal and the impact of high and low bypass heating.

[0017] In the above-mentioned simulation method for a thermal power unit operating at a wide load, optionally, adjusting the single reheat steam turbine model through preset influencing conditions to obtain a single reheat steam turbine reconstruction model includes: when the influencing conditions are the influence of unit heating and flexibility transformation, calculating the operating data of the steam turbine when the low-pressure cylinder is cut off according to the thermal balance of the steam turbine to obtain a cut-off curve of the turbine power caused by the low-pressure cylinder cut-off; constructing a low-pressure cylinder cut-off function according to the cut-off curve, and adjusting the single reheat steam turbine model according to the low-pressure cylinder cut-off function to obtain a single reheat steam turbine reconstruction model.

[0018] In the above-mentioned simulation method for a thermal power unit operating at a wide load, optionally, adjusting the single reheat steam turbine model through preset influencing conditions to obtain a single reheat steam turbine reconstruction model includes: when the influencing conditions are the influence of unit heating and flexibility transformation, calculating the operating data of the steam turbine at high and low bypass heating according to the thermal balance of the steam turbine to obtain a bypass curve of high and low bypass heating for turbine power; constructing a bypass function according to the bypass curve, and adjusting the single reheat steam turbine model according to the bypass function to obtain a single reheat steam turbine reconstruction model.

[0019] In the above-mentioned simulation method for a thermal power unit operating at a wide load, optionally, the influence association of multiple preset influence data affecting the steam turbine of the thermal power unit on the single reheat steam turbine model is analyzed through time domain and frequency domain, including: analyzing the influence of the influencing conditions on the simulation accuracy of the reconstructed model of the single reheat steam turbine through time domain and frequency domain; determining the influence association based on the comparison result of the simulation accuracy influence and the preset threshold.

[0020] In the above-mentioned simulation method for a thermal power unit operating at a wide load, optionally, obtaining a power valve position conversion coefficient based on a configuration structure analysis of a regulation system of the thermal power unit includes: calling historical control system operation data of the thermal power unit based on the configuration structure of the regulation system of the thermal power unit; obtaining a proportional relationship between an input and an output of the thermal power unit based on the analysis of the historical control system operation data, and obtaining the power valve position conversion coefficient through the proportional relationship.

[0021] In the above-mentioned simulation method for a thermal power unit operating at a wide load, optionally, performing target simulation processing through the single reheat steam turbine reconstruction model and the regulation system model includes: performing static test simulation processing or load disturbance test simulation processing through the single reheat steam turbine reconstruction model and the regulation system model.

[0022] The present application also provides a simulation system for a wide-load operation thermal power unit, the system comprising: a turbine reconstruction module, a regulation module and a simulation module; the turbine reconstruction module is used to construct a single reheat steam turbine model according to the operating mechanism of the thermal power unit steam turbine using a power natural overregulation coefficient calculation method; the influence correlation of multiple preset influence data affecting the thermal power unit steam turbine on the single reheat steam turbine model is analyzed through time domain and frequency domain, the influence condition is determined according to the influence correlation, and the single reheat steam turbine model is adjusted to obtain a single reheat steam turbine reconstruction model; the regulation module is used to obtain a power valve position conversion coefficient and a correction coefficient according to the configuration structure analysis of the regulation system of the thermal power unit, and a regulation system model is constructed through the power valve position conversion coefficient and the correction coefficient; the simulation module is used to perform target simulation processing through the single reheat steam turbine reconstruction model and the regulation system model.

[0023] In the above-mentioned wide load operation thermal power unit simulation system, optionally, the steam turbine reconstruction module includes a construction unit, which is used to respectively calculate the power natural overmodulation coefficients corresponding to the two parts in which the high-pressure cylinder is divided with one extraction as the dividing point; and construct a single reheat steam turbine model according to the calculated power natural overmodulation coefficient.

[0024] In the above-mentioned wide load operation thermal power unit simulation system, optionally, the turbine reconstruction module also includes a regulating unit; the influencing conditions include the influence of main steam pressure change, valve nonlinearity, and the influence of unit heating and flexibility transformation; the regulating unit is used to construct an integral function and an inertia function respectively according to the state of the steam flow in the turbine when the influencing condition is the influence of the main steam pressure change, and construct a main steam adjustment function according to the integral function and the inertia function; wherein the integral function is when the steam flow entering the turbine changes, the heat carried away by the steam flowing into the turbine per unit time and the heat generated by the fuel combustion are unbalanced, resulting in a change in the pressure of the drum boiler, and the fuel heat is greater than the heat carried away by the steam flow; the inertia function is when the drum pressure is constant, the steam flow entering the turbine is changed, resulting in a change in the main steam pressure, resulting in a corresponding inertia function with a proportional coefficient; when the influencing condition is the nonlinearity of the valve, according to the measured regulating stage pressure and the actual The actual equivalent valve position is obtained by calculating the ratio of the measured main steam pressures, a valve linearity function curve is constructed according to the correlation between the actual equivalent valve position and the total valve position instruction, and a valve management function is constructed according to the valve linearity function curve; when the influencing condition is the influence of unit heating and flexibility transformation, an extraction heating function is constructed according to the correlation between the main steam flow, the extraction flow and the turbine power; when the influencing condition is the influence of unit heating and flexibility transformation, a cut-off curve of low-pressure cylinder cut-off for turbine power is obtained according to the operation data of the steam turbine when the low-pressure cylinder is cut off according to the thermal balance of the steam turbine, and a low-pressure cylinder cut-off function is constructed according to the cut-off curve; and a bypass curve of high and low bypass heating for turbine power is obtained according to the operation data of the steam turbine when the high and low bypass heating is calculated according to the thermal balance of the steam turbine, and a bypass function is constructed according to the bypass curve; the single reheat turbine model is adjusted according to the main steam adjustment function, the valve management function, the extraction heating function and the bypass function to obtain a single reheat turbine reconstruction model.

[0025] In the above-mentioned wide load operation thermal power unit simulation system, optionally, the turbine reconstruction module includes a verification module, and the verification module is used to analyze the influence of the influencing conditions on the simulation accuracy of the single reheat turbine reconstruction model through time domain and frequency domain; and determine the influence association based on the comparison result of the simulation accuracy influence and the preset threshold.

[0026] In the above-mentioned wide load operation simulation system of the thermal power unit, optionally, the regulation module includes a coefficient extraction unit, and the coefficient extraction unit is used to call the historical control system operation data of the thermal power unit according to the configuration structure of the regulation system of the thermal power unit; obtain the proportional relationship between the input and output of the thermal power unit according to the analysis of the historical control system operation data, and obtain the power valve position conversion coefficient through the proportional relationship.

[0027] In the above-mentioned wide load operation thermal power unit simulation system, optionally, the simulation module includes: performing static test simulation processing or load disturbance test simulation processing through the single reheat steam turbine reconstruction model and the regulation system model.

[0028] The present application also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above method when executing the computer program.

[0029] The present application also provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program for executing the above method.

[0030] The present application also provides a computer program product, comprising a computer program / instruction, which implements the steps of the above method when executed by a processor.

[0031] The beneficial technical effects of the present application are as follows: starting from the mechanism point of view, the factors that have the greatest impact on the model simulation accuracy when the unit is operating at wide load are taken into consideration, the single reheat turbine model and the regulation system model in the traditional BPA model are reconstructed and an application method is formed; the simulation accuracy and the applicable scope of the operating conditions of the model are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The drawings described herein are used to provide a further understanding of the present application, constitute a part of the present application, and do not constitute a limitation of the present application. In the drawings:

[0033] Figures 1A to 1C It is a transfer function diagram of a single reheat steam turbine model, an electro-hydraulic servo system model and a regulating system model in the prior art;

[0034] Figure 2 A schematic diagram of a flow chart of a method for simulating a thermal power unit in wide load operation provided in an embodiment of the present application;

[0035] Figure 3 A schematic diagram of the construction process of a single reheat steam turbine model provided in one embodiment of the present application;

[0036] FIG. 4A to FIG. 4C A schematic diagram of adjustment logic for the influence of main steam pressure change provided in one embodiment of the present application;

[0037] FIG. 5A to FIG. 5F A schematic diagram of the adjustment logic of the nonlinear effect of a valve provided in one embodiment of the present application;

[0038] FIG. 6A to FIG. 6B A schematic diagram of the adjustment logic of the heating supply of a unit and the impact of flexibility transformation provided in one embodiment of the present application;

[0039] FIG. 7A to FIG. 7B A schematic diagram of the adjustment logic of the low-pressure cylinder cut-off effect and the high and low bypass heating effect provided in one embodiment of the present application;

[0040] Figure 8 A schematic diagram of the heat supply influencing link of a unit provided in an embodiment of the present application;

[0041] Fig. 9 A schematic diagram of the low-side heating impact link provided in an embodiment of the present application;

[0042] Fig.10 A schematic diagram of a low-pressure cylinder removal influencing link provided in an embodiment of the present application;

[0043] Fig.11 A logical schematic diagram of a single reheat steam turbine reconstruction model provided in one embodiment of the present application;

[0044] FIG. 12A to FIG. 12B A schematic diagram of time domain analysis of the main steam pressure link provided by an embodiment of the present application;

[0045] FIG. 13A to FIG. 13B A schematic diagram of time domain analysis of a nonlinear link of a valve provided in an embodiment of the present application;

[0046] Fig.14 A schematic diagram showing the effect of valve nonlinearity on system frequency domain characteristics provided by an embodiment of the present application;

[0047] Fig.15 A schematic diagram showing the effect of a natural overmodulation coefficient on a system frequency domain characteristic provided by an embodiment of the present application;

[0048] Fig.16 A schematic diagram showing the effect of the work proportion correction coefficient provided in one embodiment of the present application on the frequency domain characteristics of the system;

[0049] Fig.17 A schematic diagram of a power valve position conversion coefficient acquisition process provided in an embodiment of the present application;

[0050] Fig.18 A schematic diagram of a control system reconstruction model structure provided in one embodiment of the present application;

[0051] Fig.19 A logic diagram of a measured solution provided in an embodiment of the present application;

[0052] Fig. 20 A schematic diagram showing a comparison of simulation results of a comprehensive valve position instruction provided in an embodiment of the present application;

[0053] Fig.21A schematic diagram showing a comparison of simulation results of the regulation stage pressure provided in an embodiment of the present application;

[0054] Fig. 22 A schematic diagram for comparing power simulation results provided in an embodiment of the present application;

[0055] Fig.23 A schematic diagram of the structure of an electronic device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0056] The following will describe the implementation methods of the present application in detail in conjunction with the accompanying drawings and embodiments, so that the implementation process of how the present application applies technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly. It should be noted that as long as there is no conflict, the various embodiments in the present application and the various features in the embodiments can be combined with each other, and the technical solutions formed are all within the protection scope of the present application.

[0057] In addition, the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be performed in an order different from that shown here.

[0058] Please refer to Figure 2 As shown, the simulation method for a thermal power unit with wide load operation provided in this application specifically includes:

[0059] S201 constructs a single reheat steam turbine model based on the operation mechanism of the steam turbine of the thermal power unit using the power natural overregulation coefficient calculation method;

[0060] S202 analyzes the influence correlation of multiple preset influence data affecting the steam turbine of the thermal power unit on the single reheat steam turbine model through time domain and frequency domain, determines the influence condition according to the influence correlation, and adjusts the single reheat steam turbine model to obtain a single reheat steam turbine reconstruction model;

[0061] S203 obtains a power valve position conversion coefficient and a correction coefficient according to a configuration structure analysis of the regulation system of the thermal power unit, and constructs a regulation system model through the power valve position conversion coefficient and the correction coefficient;

[0062] S204 performs target simulation processing through the single reheat steam turbine reconstruction model and the regulation system model.

[0063] In actual work, this application first starts from the perspective of mechanism, builds a single reheat steam turbine model that takes into account the influence of main steam pressure changes, valve nonlinearity, unit heating and flexibility transformation, and analyzes the impact of the added links on the model simulation results from the perspective of time domain and frequency domain. Then, by summarizing the configuration structure of the actual regulation system of the thermal power unit, the power-valve position conversion coefficient and PID correction coefficient are added, and a regulation system model that is closer to the actual unit is built. Finally, an engineering application method for the reconstructed model is given, including a big data acquisition method for the equivalent valve position curve corresponding to the valve flow characteristic and a measurement and calculation method for the heating coefficient. The specific implementation process of each step will be described in detail in the subsequent embodiments, and will not be described in detail here.

[0064] Please refer to Figure 3 As shown, in one embodiment of the present application, constructing a single reheat steam turbine model according to a power natural overregulation coefficient calculation method includes:

[0065] S301 calculates the power natural overmodulation coefficients corresponding to the two parts of the high-pressure cylinder divided by one pumping as the dividing point;

[0066] S302 constructs a single reheat steam turbine model according to the calculated power natural overregulation coefficient.

[0067] Specifically, the work done by the steam turbine is determined by the flow rate of steam flowing through the flow part and the enthalpy drop, but the previous model did not consider the influence of enthalpy drop, so this application uses the power natural overmodulation coefficient to correct this problem. In actual work, the power of a simple steam turbine unit can be expressed as:

[0068] (Formula 1)

[0069] Where: G is the steam flow rate at the inlet of the turbine stage group;

[0070] h is the isentropic enthalpy drop of steam inside the turbine stage group;

[0071] η is the thermal efficiency of the steam turbine stage group;

[0072] First, consider the change of flow rate G. Assuming that the steam turbine consists of a group of pressure stages, according to the variable operating principle of the steam turbine pressure stage group, we have:

[0073] (Formula 2)

[0074] Among them: G', p', T' are the variable operating parameters (steam flow, inlet steam pressure and inlet steam temperature). Ignoring the change of inlet steam temperature during the variable operating process, then:

[0075] (Formula 3)

[0076] make , define the inlet and exhaust steam pressure ratio ,have:

[0077] (Formula 4)

[0078] Now consider the change of isentropic enthalpy drop h. The enthalpy drop of the steam flowing through the turbine is the expansion work of the constant flow medium. Assuming that the flow of steam inside the turbine does not have flow changes such as extraction, for the isentropic process, we have:

[0079] pv k = constant (Equation 5)

[0080] Where: v is the specific volume of steam; k is the process adiabatic index, and for superheated steam, k=1.3. Therefore:

[0081] (Formula 6)

[0082] Therefore, the change in the isentropic enthalpy drop of the stage group is:

[0083] (Formula 7)

[0084] Similarly, , and ignoring the change of inlet steam temperature, we have:

[0085] (Formula 8)

[0086] When the operating conditions change, ignoring the change in stage group efficiency, then:

[0087] (Formula 9)

[0088] make , differentiating k and rearranging the above formula yields:

[0089] (Formula 10)

[0090] in , called the natural overregulation coefficient of power.

[0091] The existing calculation method regards the high-pressure cylinder as a group of pressure stages, and the pressure ratio is the high-pressure cylinder exhaust pressure / regulating stage pressure. The natural overshoot coefficient calculated by this method deviates too much from the simulation fitting value and is too small. To solve this problem, the present application improves the calculation method of the high-pressure cylinder power overshoot coefficient, in which the natural overshoot coefficient is represented by the symbol λ * The improvement plan is as follows:

[0092] The high-pressure cylinder is divided into two parts with the first extraction as the dividing point. The first part is from the steam inlet of the high-pressure cylinder to the first extraction, represented by subscript 1, and the second part is from the first extraction to the steam exhaust port of the high-pressure cylinder, represented by subscript 2. The natural overshoot coefficient of the high-pressure cylinder can be calculated using the following formula:

[0093] (Formula 11)

[0094] in, k 1 、k 2 is the work proportionality coefficient, λ 1 , 2 is the natural overmodulation coefficient of the first and second parts.

[0095] (Formula 12)

[0096] in, ε 1 is the pressure ratio of the first part, which is numerically equal to the ratio of the pressure at the first extraction point to the pressure at the steam inlet of the high-pressure cylinder.

[0097] (Formula 13)

[0098] in, ε 2 is the pressure ratio of the second part, which is numerically equal to the ratio of the pressure at the exhaust port of the high-pressure cylinder to the pressure at the first extraction point.

[0099] (Formula 14)

[0100] in, P 1. P 2 is the work done by the first and second parts:

[0101] (Formula 15)

[0102] in, G in is the steam inlet flow rate of the high pressure cylinder, G tjj To adjust the leakage flow rate, H in is the steam enthalpy at the steam inlet, H tjj is the steam enthalpy after the regulating stage, H 1 is the steam enthalpy at the extraction point.

[0103] (Formula 16)

[0104] in, G 1 is the extraction steam flow of the first stage heater, H out is the exhaust enthalpy of the high pressure cylinder.

[0105] In one embodiment of the present application, the influencing conditions include the influence of main steam pressure change, valve nonlinearity, and the influence of unit heating and flexibility transformation. Figure 4A As shown, in one embodiment of the present application, adjusting the single reheat steam turbine model by preset influencing conditions to obtain a single reheat steam turbine reconstruction model includes:

[0106] S401: when the influencing condition is affected by the change of main steam pressure, constructing a main steam adjustment function according to the influence of the main steam pressure on the steam flow rate;

[0107] S402 adjusts the single reheat steam turbine model through the main steam adjustment function to obtain a single reheat steam turbine reconstruction model.

[0108] Among them, constructing a main steam adjustment function according to the influence of steam flow on main steam pressure includes: constructing an integral function and an inertia function according to the state of the steam flow in the steam turbine, and constructing a main steam adjustment function according to the integral function and the inertia function; wherein the integral function is a corresponding integral function constructed when the steam flow entering the steam turbine changes, an imbalance occurs between the heat carried away by the steam flowing into the steam turbine per unit time and the heat generated by the combustion of the fuel, resulting in a change in the pressure of the drum boiler, and the heat of the fuel is greater than the heat carried away by the steam flow; the inertia function is a corresponding inertia function with a proportional coefficient constructed when the main steam pressure changes due to a change in the steam flow entering the steam turbine when the drum pressure is constant.

[0109] Specifically, in actual work, the mathematical model of the drum boiler body includes several modules such as the combustion system, water-cooled wall, evaporating heating surface, and superheater.

[0110] Combustion system:

[0111] The combustion and heat release process is a complex chemical and physical change. In the analysis and design of the boiler-machine coordinated control system, if the combustion system's regulating system is reasonably designed and the combustion is stable, the combustion and heat release process can be roughly approximated as a first-order inertia link with a delay:

[0112] (Formula 17)

[0113] in, μ B is the combustion rate instruction, Q r is the heat released by fuel combustion, τ is the pure delay time of combustion and heat release process, and T1 is the time constant, which may vary according to different system designs.

[0114] Water wall:

[0115] (Formula 18)

[0116] in, Q r is the heat released by the combustion of fuel, S G is the total effective heat absorption of the boiler heating surface (expressed in steam flow units), and T2 is the time constant of the boiler heat transfer process.

[0117] Evaporation heating surface:

[0118] The heat absorbed by the evaporating heating surface is used to heat the feed water to saturated steam. Considering the energy storage of the boiler drum, the drum pressure P d Reflects the amount of heat absorbed by the boiler (the amount of steam generated), S G Superheated steam at superheater inlet S F Balance:

[0119] (Formula 19)

[0120] in, C B is the drum heat storage coefficient.

[0121] Superheater Model:

[0122] Since the volume of the superheater is relatively small, this application takes into account the resistance characteristics of the superheater, and its volume characteristics are merged into the volume characteristics of the boiler drum. P d and main steam pressure P T The pressure is the same as the steam flow rate entering the turbine S F There is a square root relationship between them:

[0123] (Formula 20)

[0124] in, K sh is the resistance coefficient of the superheater pipe.

[0125] In summary, the schematic diagram of the drum boiler model is as follows: Figure 4BAs shown; Since the drum boiler model needs to add input and the model structure is complex, in order to reduce the complexity of the model, this application simplifies the boiler and its control system model into a main steam pressure model with main steam flow as input. The simplification steps are as follows: Under ideal conditions, the main steam pressure is mainly affected by the drum pressure and steam flow. The drum pressure is mainly affected by the heat released by fuel combustion and the steam flow entering the turbine. Near a given operating condition, it can be considered that the fuel heat is basically unchanged. The main steam pressure is mainly affected by the flow change, which can be divided into two parts: The first part is that when the steam flow entering the turbine changes, there is an imbalance between the heat carried away by the steam flowing into the turbine per unit time and the heat generated by the fuel combustion, resulting in a change in the pressure of the drum boiler. When the fuel heat is greater than the heat carried away by the steam flow, it is manifested as an increase in the drum pressure, otherwise it is manifested as a decrease in the drum pressure. This part of the impact can be described by an integral link, where T c represents the heat storage time constant; the second part is that when the drum pressure is constant, changing the steam flow entering the turbine will cause the pressure loss from the drum to the steam inlet of the turbine to change, thereby causing the main steam pressure to change. For example, when the steam flow increases, the pressure loss increases and the main steam pressure decreases. When the main steam flow decreases, the pressure loss decreases and the main steam pressure increases. This part of the impact can be described by a first-order inertia link with a proportional coefficient, where, T p is the inertia link time constant, K is the proportionality coefficient. The simplified model of the main steam pressure link is as follows Figure 4C shown.

[0126] Please refer to Figure 5A As shown, in one embodiment of the present application, adjusting the single reheat steam turbine model by preset influencing conditions to obtain a single reheat steam turbine reconstruction model includes:

[0127] S501: when the influencing condition is a nonlinear influence of the valve, constructing a valve management function according to the correlation between the measured regulating stage pressure, the measured main steam pressure and the total valve position instruction;

[0128] S502 adjusts the single reheat steam turbine model according to the valve management function to obtain a single reheat steam turbine reconstruction model.

[0129] Among them, constructing a valve management function according to the correlation between the measured regulating stage pressure, the main steam pressure and the total valve position instruction includes: obtaining the actual equivalent valve position according to the ratio between the measured regulating stage pressure and the measured main steam pressure; constructing a valve linearity function curve according to the correlation between the actual equivalent valve position and the total valve position instruction; and constructing a valve management function according to the valve linearity function curve.

[0130] Specifically, in actual work, most steam turbine units are controlled by 4 high-pressure regulating steam valves equipped with independent servo control mechanisms to control the steam inlet of the unit. The unit steam supply regulation methods include single valve regulation method and sequential valve regulation method. The number of equal-area nozzles arranged on each high-pressure regulating valve of the unit is 24. Under the sequential valve method, the opening order of each regulating valve is GV1 and GV4 are opened at the same time, followed by GV2, and finally GV3.

[0131] Taking the above type of unit as an example, the valve control function in the DEH control logic configuration is realized through a proportional bias factor and three flow functions. The specific logic flow is shown below. Figure 5B As shown, F b (x) is the back pressure correction function; k 1 、 k 2 、k 3 、k 4 、b 1 、b 2 、b 3 、b 4 It is the proportional bias factor for controlling the valve opening sequence in the sequential valve mode; F 1(x) is the flow distribution function under the sequential valve mode (also used to adjust the valve overlap, also called the overlap function); F 2(x) is the flow instruction correction function; F d (x) is the flow characteristic function of each valve in the single valve mode (the inherent flow characteristic of the regulating valve).

[0132] Usually, do not consider F b (x) and F d (x) The impact on the unit flow characteristics. The former is the correction of the unit back pressure on the turbine treatment and the latter is the inherent flow property of the turbine regulating valve. The flow distribution function is mainly considered. F 1(x) and flow instruction correction function F2 (x) influence. When the high-pressure regulating valve of the steam turbine unit is opened, the valve opening area changes. The theoretical steam flow through the valve is calculated using the valve nominal area (nominal diameter) and the parameters before and after the valve. Then, based on the flow characteristic curve obtained from the test, namely: the characteristic flow ratio (the ratio of actual flow to theoretical flow), the ratio of actual flow to theoretical flow, the relationship between pressure loss and valve relative lift, the third parameter can be calculated after two of the conditions are known. In the commonly used flow characteristic curve of the steam inlet valve of the steam turbine unit, one is the diameter of the throat of the diffuser as the nominal diameter; the other is the diameter of the sealing ring where the valve core contacts the valve seat. The former is more common. There are two definitions of theoretical flow: one is to calculate the critical flow using the parameters before the valve and the throat area. G * , the characteristic flow ratio calculated according to this definition is always less than 1. The calculation formula is as follows:

[0133] (Formula 21)

[0134] Where: G u is the theoretical flow rate through the valve, kg / s;

[0135] F V is the nominal area of ​​the valve throat, ;

[0136] p 0 is the steam pressure before the valve, Pa;

[0137] v 0 is the specific volume of steam before the valve, kg / m 3 ;

[0138] β is the Peng Taimen coefficient.

[0139] When the pressure ratio before and after the valve is constant, and the relative lift of the valve L (valve lift) / D (nominal diameter) is less than 0.2, the relationship between the opening and the flow rate is a straight line. When the relative lift is greater than 0.2, the flow rate increases very slowly. When L / D is greater than 0.3, the flow area of ​​the valve has been limited by the reserve area of ​​the diffuser. Continuing to increase the valve opening will not increase the flow area and flow rate. Therefore, the flow characteristic curve at this time is a horizontal line. See below for details. Figure 5C The actual flow characteristics of the regulating valve group and the actual flow characteristics of each valve obtained through the test according to the above method are shown in the figure. Figure 5D and Figure 5E shown.

[0140] The flow characteristic curve of the valve reflects the relationship between the turbine flow command and the actual flow. In theory, the flow command and the actual flow characteristics should be equal, but Figure 5D It can be found that in actual systems, the linearity of the curve of the valve flow characteristic is often poor, which causes a serious decline in the frequency regulation performance of the turbine and may even cause accidents. The model established in this application can take into account the nonlinear influence of the valve flow characteristic. In order to reduce the complexity of the model, the above-mentioned valve management module is simplified into a valve linearity correction function to implement relevant simulation analysis. The actual equivalent valve position is obtained by dividing the measured regulating stage pressure by the measured main steam pressure. The valve linearity function curve is plotted with the actual equivalent valve position as the ordinate and the measured total valve position instruction as the abscissa. The valve linearity function is used to replace the valve management module and is substituted into the model for simulation. The simplified model of the valve nonlinear link is as follows: Fig. 5F In the above embodiment, the engineering method of obtaining the equivalent valve position can be realized by existing technology, which will not be described in detail here.

[0141] Please refer to Fig. 6A As shown, in one embodiment of the present application, adjusting the single reheat steam turbine model by preset influencing conditions to obtain a single reheat steam turbine reconstruction model includes:

[0142] S601: when the influencing condition is the influence of unit heating and flexibility transformation, constructing an extraction heating function according to the correlation between the main steam flow, the extraction flow and the turbine power;

[0143] S602 adjusts the single reheat steam turbine model according to the extraction heat supply function to obtain a single reheat steam turbine reconstruction model.

[0144] Specifically, after the steam turbine is extracted for heating, the amount of steam doing work in the cylinder after the extraction point will change, and the same change in the regulating valve will cause a difference in the steam turbine power. Therefore, the impact of steam extraction for heating on the steam turbine power needs to be considered, as follows Figure 6B shown.

[0145] D e =x extraction steam flow constant value operating line

[0146] D e =0 condensing steam operating line

[0147] Minimum stable combustion evaporation of boiler

[0148] Maximum steam inlet flow

[0149] Condensate constant value operating line

[0150] Back pressure line

[0151] Minimum condensate flow rate line

[0152] P e1 Electric power axis

[0153] D I Steam volume axis

[0154] P e1max Maximum output of turbine generator

[0155] Through mechanism and data analysis, it can be found that under the same main steam flow rate, as the extraction steam flow rate increases, the turbine power decreases; under the same extraction steam flow rate, the main steam flow rate and the turbine power are still in a linear relationship. Therefore, a model considering the influence of extraction steam heating can be established as follows:

[0156] (Formula 22)

[0157] in, P e is the turbine power, k is a constant coefficient, P t is the main steam pressure, z is the turbine valve opening, k D is the influence coefficient of steam extraction on turbine power, and D is the steam extraction amount.

[0158] In one embodiment of the present application, the flexible transformation includes the impact of low pressure cylinder removal and high and low bypass heating. Fig. 7A , adjusting the single reheat steam turbine model through preset influencing conditions to obtain a single reheat steam turbine reconstruction model includes:

[0159] S701: when the influencing condition is the influence of the unit heating and flexibility transformation, the operation data of the steam turbine when the low-pressure cylinder is cut off is calculated according to the thermal balance of the steam turbine to obtain a cut-off curve of the low-pressure cylinder cut-off on the steam turbine power;

[0160] S702 constructs a low-pressure cylinder cut-off function according to the cut-off curve, and adjusts the single-reheat steam turbine model according to the low-pressure cylinder cut-off function to obtain a single-reheat steam turbine reconstruction model.

[0161] Please refer to Figure 7B As shown, adjusting the single reheat steam turbine model by preset influencing conditions to obtain a single reheat steam turbine reconstruction model includes:

[0162] S703: when the influencing condition is the influence of the unit heating and flexibility transformation, the operation data of the steam turbine under high and low bypass heating is calculated according to the thermal balance of the steam turbine to obtain the bypass curve of the high and low bypass heating on the steam turbine power;

[0163] S704: constructing a bypass function according to the bypass curve, and adjusting the single reheat steam turbine model according to the bypass function to obtain a single reheat steam turbine reconstruction model.

[0164] Specifically, when the low-pressure cylinder of the steam turbine is cut off, the low-pressure cylinder only retains the minimum cooling steam flow, and the low-pressure cylinder does not do work. It can be seen that the modeling principle and process of the low-pressure cylinder cut-off condition are similar to the extraction steam heating influence model, but it is necessary to combine the steam turbine thermal balance calculation and the low-pressure cylinder cut-off operation data to obtain the influence curve of the low-pressure cylinder cut-off on the steam turbine power. The form of the curve is similar to the curve of the extraction steam turbine power affected by the extraction steam volume. After obtaining the influence curve of the low-pressure cylinder cut-off on the steam turbine power, the low-pressure cylinder cut-off influence model can be established using a method similar to the extraction steam heating influence model.

[0165] When the turbine is in high and low bypass heating, the steam flow of the high-pressure cylinder, the medium-pressure cylinder and the low-pressure cylinder will decrease accordingly. As the high and low bypass heating steam extraction volume changes, the turbine power decreases accordingly. It can be seen that the modeling principle and process of high and low bypass heating conditions are similar to the extraction steam heating influence model, but it is necessary to combine the turbine thermal balance calculation and high and low bypass heating operation data to obtain the influence curve of high and low bypass heating on the turbine power. The form of the curve is similar to the influence curve of the extraction steam turbine power by the extraction steam volume. After obtaining the influence curve of high and low bypass heating on the turbine power, the high and low bypass heating influence model can be established by a method similar to the extraction steam heating influence model.

[0166] According to the principles of thermodynamics, the amount of work done by steam entering each cylinder is equal to the product of the steam flow rate and the enthalpy difference before and after the blade, as shown in the following formula:

[0167] (Formula 23)

[0168] In the formula, p is the work done by the blades forward and backward, q m is the mass flow rate of steam passing through the blade, H 1 is the enthalpy value of the unit mass of steam before flowing through the blade, H 2 is the enthalpy value corresponding to the unit mass of steam after flowing through the blade.

[0169] Among them, the enthalpy values ​​corresponding to the unit mass of steam flowing before and after the blades have the following relationship:

[0170] (Formula 24)

[0171] In the formula H * is the enthalpy value per unit mass after steam flows through the blade under ideal conditions (isentropic process), and η is the efficiency of the turbine blade.

[0172] For a given steam turbine, the steam state before and after each stage of the blades will not change significantly when the operating conditions change. Therefore, in order to simplify the calculation, when calculating the power of the steam turbine, it is usually assumed that the work done by a unit mass of steam flowing through each stage of the turbine blades is the same. Therefore, the amount of work done by the steam in each stage of the steam turbine cylinder is consistent with the change in the steam mass flow rate entering each stage of the cylinder, as shown in the following formula:

[0173] (Formula 25)

[0174] In the formula, P is the total work done, P HP ,q HP , ΔH HP is the work done by the high pressure cylinder, steam flow rate and enthalpy change, P IP ,q IP , ΔH IP is the work done by the intermediate pressure cylinder, steam flow and enthalpy change, P LP ,q LP , ΔH LP The work done, steam flow rate and enthalpy change of the low pressure cylinder.

[0175] For the unit operating under pure condensing conditions, the flow through the high-pressure cylinder, the intermediate-pressure cylinder, and the low-pressure cylinder is basically unchanged. Therefore, the total flow entering the turbine is q = q HP ≈q IP ≈q LP , and each enthalpy change is a constant. Normalizing both sides of the above equation, we can get the following equation:

[0176] (Formula 26)

[0177] and:

[0178] (Formula 27)

[0179] In the formula, F HP , F IP , F LP It is the work ratio of high, medium and low pressure cylinders.

[0180] From the above formula, we can see that for a specific steam turbine, the enthalpy drop of each stage of the blades is basically unchanged, and the flow rate is basically the same. Therefore, even if the unit is operating under variable conditions, there is a certain relationship between the work done by each stage of the cylinder, that is, the corresponding work ratio F HP , F IP , F LP It is certain.

[0181] However, for special working conditions such as low bypass heating, high bypass heating, low pressure cylinder removal, etc., the work ratio of each cylinder will no longer be equal to F HP , F IP , F LP The reason is that the steam flow through each cylinder is no longer basically the same due to steam extraction, and the work done by each cylinder needs to be calculated by the following formula:

[0182] (Formula 28)

[0183] Under the low-pressure bypass heating condition, the steam is divided into two parts after flowing out of the reheater. One part enters the intermediate pressure cylinder to do work, and the other part is pumped to the low-pressure cylinder bypass for heating. This part of steam no longer performs work and can be excluded when calculating power, that is, q HP= q,q IP =q LP ≠q HP , we can get the work done by each cylinder as shown in the following formula:

[0184] (Formula 29)

[0185] In the formula, k 1 is the correction coefficient of low bypass heating flow rate, .

[0186] Under heating conditions, the steam is divided into two parts after flowing out of the intermediate pressure cylinder. One part enters the low pressure cylinder to do work, and the other part is pumped to the heat exchanger for heating. This part of the steam is excluded when calculating the power, that is, q HP= q IP =q,q LP ≠q HP Therefore, the work done by each cylinder is as follows:

[0187] (Formula 30)

[0188] In the formula, k 2 is the correction coefficient of heating flow rate, .

[0189] Under the low-pressure cylinder cut-off condition, after the steam flows out of the intermediate-pressure cylinder, a small part enters the low-pressure cylinder to maintain operation, and the rest is pumped to the heat exchanger through the low-pressure cylinder bypass for heating. Similar to the heating condition, this part of the steam is excluded when calculating the power, that is, q HP= q IP =q,q LP ≠q HP Therefore, the work done by each cylinder is as follows:

[0190] (Formula 31)

[0191] In the formula, k 3 is the correction coefficient of the low-pressure cylinder cut-off flow rate, .

[0192] Since the enthalpy drop of steam before and after passing through the blade is assumed to be constant, the flow correction factor k 1 、k 2 、k 3 are numerically equal to the proportional coefficient of work done k LPH 、k GR 、k LPC , needs to be determined by fitting actual data.

[0193] Based on the above principle, the impact of unit heating and flexibility transformation is obtained as follows: Figures 8 to 10 As shown, among which, Figure 8 middle, k GR is the heating flow correction coefficient, P 1 is the heating off switch, P 2 is the heating switch; Fig. 9 middle, k LPH is the low bypass heating flow correction coefficient, N 1 is the low bypass heating closing switch, N 2 is the low bypass heating switch; Fig.10 middle, k LPC is the low pressure cylinder cut-off flow correction coefficient, O 1 is the low pressure cylinder cut-off switch, O 2 is the low pressure cylinder cut-off switch.

[0194] Therefore, the single reheat steam turbine model can be constructed and generated through the above embodiment, which can also be called a single reheat steam turbine reconstruction model. For details, please refer to Fig.11 As shown, P CV It is the comprehensive regulating valve position command per unit value. P GV is the per unit value of high-pressure valve opening,P zq is the per unit value of the main steam pressure, P tjj is the per unit pressure value of the regulating stage, T CH is the steam volume time constant, T RH is the reheat volume time constant, T CO is the crossover tube time constant, λ is the natural overshoot coefficient of the high pressure cylinder, F HP is the work proportional coefficient of the high pressure cylinder, F IP is the work proportional coefficient of the medium pressure cylinder, F LP is the work proportional coefficient of the low-pressure cylinder, k LPH is the low bypass heating flow correction coefficient, k GR is the heating flow correction coefficient, k LPC is the low pressure cylinder cut-off flow correction coefficient, P M is the per-unit value of steam turbine power, N 1 is the low bypass heating closing switch, N 2 is the low bypass heating switch, P 1 is the heating off switch, P 2 is the heating switch, O 1 is the low pressure cylinder cut-off switch, O 2 is the low pressure cylinder cut-off switch, the actuator can be Figure 1B shown.

[0195] In one embodiment of the present application, the influence association of multiple preset influence data affecting the steam turbine of a thermal power unit on a single reheat steam turbine model through time domain and frequency domain analysis includes: analyzing the influence of the influencing conditions on the simulation accuracy of the reconstructed model of the single reheat steam turbine through time domain and frequency domain analysis; determining the influence association based on the comparison result of the simulation accuracy influence and a preset threshold.

[0196] In the time domain: For details, please refer to FIG. 12A to FIG. 12B As shown, FIG. 12A to FIG. 12B Figure 2 shows the comparison between the simulation results of the regulating stage pressure and power of a 315MW subcritical unit at 20% rated load, before and after considering the main steam pressure, and the actual regulating stage pressure and power. FIG. 12A to FIG. 12BIt can be seen that considering the influence of the main steam pressure can make the model have higher simulation accuracy. In the actual process, the main steam pressure will change to a certain extent with the change of the valve opening, and weaken the influence of the valve opening on the regulating stage pressure. For example, when the valve opening increases, the steam inlet flow increases, the pressure loss increases, the drum pressure remains unchanged temporarily, and the main steam pressure decreases. Ultimately, in a short period of time after the valve is actuated, the change in the flow entering the turbine is smaller than the change in the flow when the main steam pressure is constant. Please refer to FIG. 13A to FIG. 13B As shown, FIG. 13A to FIG. 13B The figure shows the comparison between the simulation results of the regulating stage pressure and power of a 600MW subcritical unit at 80% rated load before and after considering valve nonlinearity and the actual regulating stage pressure and power. It can be seen from the figure that considering the influence of valve nonlinearity can make the model have higher simulation accuracy. FIG. 13A to FIG. 13B It can be seen that after considering the nonlinear influence of the valve, the model can more realistically reflect the corresponding relationship between the comprehensive valve position command and the flow rate. This ability is reflected in the model simulation results as it can more accurately reflect the gain effect of the steam flow entering the turbine when the comprehensive valve position command changes by unit amplitude, avoiding the problem of the model's simulation results being too large or insufficient for the change in flow rate (regulating stage pressure) when the command changes due to the ideal assumption that "the command and flow rate are linearly related".

[0197] In the frequency domain: Perform frequency domain analysis on the system, select to close / enable the valve nonlinear module, and the frequency domain characteristics of the system change as follows: Fig.14 As shown by Fig.14 It can be seen that when the system frequency disturbance is greater than 0.004rad / sec, the valve nonlinearity will have a certain impact on the amplitude-frequency characteristics of the system. When the system frequency disturbance is between 0.001rad / sec-0.02rad / sec, the valve nonlinearity will have a certain impact on the phase-frequency characteristics of the system. Therefore, after comprehensive consideration, it is recommended to consider the impact of valve nonlinearity when the frequency disturbance is greater than 0.004rad / sec, that is, when the grid disturbance frequency is greater than 0.0006Hz. Perform frequency domain analysis on the system, select the power natural overmodulation coefficient values ​​obtained by the new / old natural overmodulation coefficient calculation method, and the system frequency domain characteristics change as shown below: Fig.15 As shown by Fig.15It can be seen that when the system frequency disturbance is greater than 0.08rad / sec, the natural overmodulation coefficient will have a certain impact on the amplitude-frequency characteristics of the system. When the system frequency disturbance is between 0.02rad / sec-0.3rad / sec, the natural overmodulation coefficient will have a certain impact on the phase-frequency characteristics of the system. Therefore, after comprehensive consideration, it is recommended to consider the impact of the natural overmodulation coefficient when the frequency disturbance is greater than 0.08rad / sec, that is, when the grid disturbance frequency is greater than 0.0127Hz. Perform frequency domain analysis on the system. Take the correction coefficient of the work ratio of the low-pressure cylinder under heating conditions as an example. Select to turn off / enable the correction coefficient module respectively. The frequency domain characteristics of the system change as follows: Fig.16 As shown by Fig.16 It can be seen that when the system frequency disturbance is between 0.001rad / sec-0.1rad / sec, the work proportion correction coefficient will affect the amplitude-frequency characteristics of the system. When the system frequency disturbance is between 0.001rad / sec-0.8rad / sec, the work proportion correction coefficient will have a certain impact on the phase-frequency characteristics of the system, that is, the main affected frequency band is between 0.00016Hz-0.1274Hz.

[0198] Please refer to Fig.17 As shown, in one embodiment of the present application, the power valve position conversion coefficient is obtained according to the configuration structure analysis of the regulation system of the thermal power unit, including:

[0199] S1701 calls the historical control system operation data of the thermal power unit according to the configuration structure of the regulation system of the thermal power unit;

[0200] S1702 obtains the proportional relationship between the input and output of the thermal power unit according to the historical control system operation data analysis, and obtains the power valve position conversion coefficient through the proportional relationship.

[0201] Specifically, in actual work, the present application analyzes the situation in which the PID controller parameters in the control system model and the PID controller parameters in the actual control system have large deviations according to the problem that the PID controller parameters in the previous simulation process have large deviations:

[0202] First, it is necessary to clarify the position and role of the control system in the closed-loop model: it is essentially a set of algorithms. Taking the traditional control system model as an example, the input consists of three parts, namely the primary frequency modulation loop, the actual load command signal and the power feedback signal, and the output is the comprehensive valve position command. The corresponding relationship between the input and the output is characterized by the parameters in the control system, such as the integral link coefficient and the proportional link coefficient in the PID controller. Therefore, when the simulation results of the control system parameters have a large deviation from the actual value, that is, when the parameters in the control system model are consistent with the actual value, the comprehensive valve position command obtained by the model simulation is inconsistent with the actual comprehensive valve position command. This deviation may be caused by any one of the input data and the input-output correspondence.

[0203] In order to eliminate the influence of input data, the present invention uses actual data from a primary frequency modulation test for testing, and obtains the input value of the primary frequency modulation loop with slip and primary frequency modulation functions, and uses the actual data of the actual load command and power as the input of the control system model. By adjusting the PID controller parameter value, the simulation value and the actual value of the comprehensive valve position command can obtain a better matching relationship. The results show that when the output signal is close to the actual value, the PID controller parameter has a large deviation from the actual value, thereby eliminating the possibility that the input signal is the main cause of the deviation. After that, the possible problems in the input-output relationship are analyzed. It is noted that in the actual control system, the input signal is the value of power (its theoretical range is 0-rated power), and the output signal is the value of the comprehensive valve position instruction (its theoretical range is 0-100). In the model, the control system input signal is the per-unit value of power (its theoretical range is 0-1), and the output signal is the per-unit value of the comprehensive valve position instruction (its theoretical range is 0-1). Therefore, it is not difficult to find that since the model uses per-unit processing, the corresponding proportional relationship between the input and output of the control system has changed. The present invention names this proportional relationship as the power-valve position conversion coefficient, which is numerically equal to the ratio of the rated power value (MW) of the unit to the comprehensive valve position instruction value (%), represented by the symbol B. In the traditional control system model, B is masked as the deviation of the PID controller parameters. In addition, there is a correction coefficient module in the actual control system loop. The present invention calls this correction coefficient the PID correction coefficient, represented by the symbol A. It is not reflected in the traditional control system model. The correction coefficient will play a similar role to the PID controller parameters when participating in the calculation. Therefore, in the traditional control system model, the correction coefficient will also be obscured as a deviation of the PID controller parameters.

[0204] Adjust the system reconstruction model as Fig.18 As shown, in Fig.18 Where S is the Laplace operator, Δω is the difference between the rated speed and the actual speed, TW delayis the pure delay time of the frequency input signal, T1 is the time constant of the speed measurement link, T R is the time constant of an inertia link corresponding to the power feedback signal, TW2 delay is the pure delay time after the frequency signal is amplified, DP UP / DP DOWN It is the rising / falling rate limit per unit value of the input PID signal after the frequency signal is amplified. delay It is the pure delay time of the frequency signal after amplification and input into PID, TP delay is the pure delay time of the power feedback signal, P E is the per unit value of the turbine power feedback signal under load control conditions, P M1 is the per unit value of the turbine power feedback signal under the regulating stage pressure control condition, P REF is the power setting value per unit, K 0 is the control mode selection switch, K 1 is the speed deviation magnification factor, K 2 is the load control feedforward coefficient, T R is the time constant of the first-order inertia link in power feedback, K P is the multiple of the proportional link in the PID controller, K I is the integral factor multiple in the PID controller, K D is the multiple of the differential link in the PID controller, P CV is the per-unit value of the comprehensive adjustment valve position command, B is the power-valve position conversion coefficient, and A is the PID correction coefficient.

[0205] In one embodiment of the present application, performing target simulation processing through the single reheat steam turbine reconstruction model and the regulation system model includes: performing static test simulation processing or load disturbance test simulation processing through the single reheat steam turbine reconstruction model and the regulation system model.

[0206] Specifically, in actual work, the above-mentioned reconstructed single reheat steam turbine reconstruction model and regulation system model can be used to rewrite the actual measurement and modeling engineering application scheme of steam turbine and its regulation system parameters. The test process logic can be referred to Fig.19 The specific test process is as follows:

[0207] 1. Brief introduction of the unit;

[0208] 2. Test purpose:

[0209] The purpose of testing the parameters of steam turbine units and their speed control systems is to provide real and reliable test data for simulation analysis of the medium- and long-term stability of power systems.

[0210] 3. Test content:

[0211] A. The identification parameters of the steam turbine generator control system are shown in Table 1.

[0212] Table 1

[0213]

[0214] B. The identification parameters of the steam turbine generator set actuator are shown in Table 2.

[0215] Table 2

[0216]

[0217] C. The identification parameters of the steam turbine generator set are shown in Table 3.

[0218] Table 3

[0219]

[0220] 4. Test items and methods

[0221] 1) Test items: static test, load disturbance test;

[0222] 2) Test methods:

[0223] 1. Static test:

[0224] Test conditions and requirements: a) The control system has been accepted, the unit is in shutdown and cooling state, and there is no residual steam pressure in the main and reheat steam pipes; b) After the adjustment of the steam valve is completed, the step characteristics of the actuator are qualified, the overshoot should not exceed 20%, and the number of oscillations should not exceed 3 times. c) The lubricating oil system and fire-resistant oil system are working normally; d) The steam turbine has the conditions for locking, and the oil temperature and oil pressure are within the normal range; e) The steam turbine vacuum system is not put into operation.

[0225] Test process:

[0226] a) High-pressure door large opening step disturbance test

[0227] Step 1: The valve is in single valve control and the valve position is 0%;

[0228] Step2 Set the valve position command to 100%;

[0229] Step 3 Continue for 5 seconds and then set the valve position command to 0;

[0230] Step 4: Continue for 5 seconds and record the “static test waveform data” of the whole process at a sampling frequency of 1000 Hz. The parameter names are shown in Table 4.

[0231] b) High-pressure valve small opening step disturbance test

[0232] Step 1 The valve is in single valve control and the valve position is 50%;

[0233] Step2 Set the valve position command to 55%;

[0234] Step 3 Continue for 5 seconds and then set the valve position command to 50%;

[0235] Step 4 Continue for 5 seconds and set the valve position command to 45%;

[0236] Step 5 Continue for 5 seconds and then set the valve position command to 50%;

[0237] Step 6: Continue for 5 seconds and record the “static test waveform data” of the whole process at a sampling frequency of 1000 Hz. The parameter names are shown in Table 4.

[0238] After the high-voltage door step test is completed, query the control system logic record "control system setting data", see Table 5.

[0239] 2. Load disturbance test

[0240] Test conditions and requirements: a) The primary frequency regulation test has been completed and the primary frequency regulation test function has been put into operation; b) Release AGC control; c) The load disturbance test under the deep peak regulation condition of the heating unit should be carried out under the heating condition and the pure condensing condition respectively; d) The load disturbance test condition should include the minimum load condition for the deep peak regulation certification of the unit; e) It is advisable to carry out load disturbance test under typical conditions of 50% rated load and below. The selection of the test load condition point can be consistent with the requirements of the primary frequency regulation test.

[0241] Test process:

[0242] a) Wiring before testing

[0243] Connect the “load disturbance test recording data” measuring point to the high-speed recorder as required. The parameter names and requirements are shown in Table 6.

[0244] b) Disturbance test under CCS coordination mode

[0245] Release AGC control, and the unit stably operates under the test condition, and put into CCS coordinated control. During the test, by changing the unit reference speed, a speed deviation is generated, so that a frequency modulation action is performed once to achieve a step change in load. Conduct a ±9rpm load disturbance test. The thermal engineer sets the slip at the engineer station, first setting the slip to +9rpm, maintaining for 1 minute, recovering, maintaining for 1 minute, and then setting the slip to -9rpm, maintaining for 1 minute, recovering, and maintaining for 1 minute.

[0246] During the test, record the “load disturbance test record data”. The parameter names are shown in Table 7.

[0247] c) Disturbance test under DEH valve control mode

[0248] Release AGC control, and the unit stably operates in the test condition, release CCS coordinated control, and DEH is in valve control mode. During the test, by changing the unit reference speed, a speed deviation is generated, so that a frequency modulation action is performed once to achieve a step change in load. Conduct a ±6rpm load disturbance test. The thermal engineer sets the slip at the engineer station, first setting the slip to +6rpm, maintaining it for 1 minute, recovering it, maintaining it for 1 minute, and then setting the slip to -6rpm, maintaining it for 1 minute, recovering it, and maintaining it for 1 minute.

[0249] During the test, record the “load disturbance test record data”. The parameter names are shown in Table 7.

[0250] d) Valve flow characteristic fitting data collection

[0251] Query the power plant SIS system and collect "SIS historical data". The parameter names and requirements are shown in Table 8. The data accuracy is 1 minute per point, and the data volume is at least one week of data. The data requires comprehensive valve position and active power to cover modeling tests and nearby operating conditions.

[0252] The required collected data are divided into five parts: static test recording data, control system setting data, load disturbance test recording data, load disturbance test record data, and SIS historical data.

[0253] The static test recording data is shown in Table 4.

[0254] Table 4

[0255]

[0256] The control system setting data is shown in Table 5.

[0257] Table 5

[0258]

[0259] The recorded data of the load disturbance test are shown in Table 6.

[0260] Table 6

[0261]

[0262] The load disturbance test record data is shown in Table 7.

[0263] Table 7

[0264]

[0265] The SIS historical data used to fit the valve flow characteristic curve is shown in Table 8.

[0266] Table 8

[0267]

[0268] Aiming at the measured results of coordinated control of power closed-loop mode under 20%Pe heating condition of a Harbin Steam 630MW subcritical, single intermediate reheat, three-cylinder four-exhaust, single-shaft, condensing unit, the simulation method of wide load operation thermal power unit provided by this application is used. The actual slip and actual load instructions are used as closed-loop model inputs. The simulation results of each part of the reconstructed model of this application (referred to as the simplified model) and the traditional BPA model are compared with the actual data, including the comprehensive valve position instruction, regulating stage pressure, and power. The identification parameters can be referred to as shown in Tables 9 to 11. The simulation results are as follows Figure 20 to Figure 22 shown.

[0269] Table 9

[0270]

[0271] Table 10

[0272]

[0273] Table 11

[0274]

[0275] Similarly, the goodness of fit between the simulation curve and the measured curve is calculated using formula 32, and the results are shown in Table 12:

[0276] (Formula 32)

[0277] In the formula, is the measured data, for The mean of It is the simulation result data.

[0278] Table 12

[0279]

[0280] The above results show that the closed-loop simulation accuracy of the simplified model built by the present invention is higher than that of the BPA model as a whole, which is reflected in the R 2 The values ​​are all above 0.9829, and the R 2 The maximum value is 0.8451.

[0281] The present application also provides a simulation system for a wide-load operation thermal power unit, the system comprising: a turbine reconstruction module, a regulation module and a simulation module; the turbine reconstruction module is used to construct a single reheat steam turbine model according to the operating mechanism of the thermal power unit steam turbine using a power natural overregulation coefficient calculation method; the influence correlation of multiple preset influence data affecting the thermal power unit steam turbine on the single reheat steam turbine model is analyzed through time domain and frequency domain, the influence condition is determined according to the influence correlation, and the single reheat steam turbine model is adjusted to obtain a single reheat steam turbine reconstruction model; the regulation module is used to obtain a power valve position conversion coefficient and a correction coefficient according to the configuration structure analysis of the regulation system of the thermal power unit, and a regulation system model is constructed through the power valve position conversion coefficient and the correction coefficient; the simulation module is used to perform target simulation processing through the single reheat steam turbine reconstruction model and the regulation system model.

[0282] In the above embodiment, the steam turbine reconstruction module includes a construction unit and an adjustment unit; the construction unit is used to respectively calculate the power natural overmodulation coefficient corresponding to the two parts of the high-pressure cylinder divided by one extraction as the dividing point; and a single reheat steam turbine model is constructed according to the calculated power natural overmodulation coefficient. The influencing conditions include the influence of main steam pressure change, valve nonlinearity, and the influence of unit heating and flexibility transformation; the regulating unit is used to construct an integral function and an inertia function respectively according to the state of the steam flow in the turbine when the influencing condition is the influence of the main steam pressure change, and construct a main steam adjustment function according to the integral function and the inertia function; wherein the integral function is the corresponding integral function constructed when the steam flow entering the turbine changes, the heat carried away by the steam flowing into the turbine per unit time and the heat generated by the fuel combustion are unbalanced, resulting in a change in the pressure of the drum boiler, and the fuel heat is greater than the heat carried away by the steam flow; the inertia function is the corresponding inertia function with a proportional coefficient constructed when the drum pressure is constant and the steam flow entering the turbine is changed, resulting in a change in the main steam pressure; when the influencing condition is the nonlinear influence of the valve, the actual equivalent valve is obtained according to the ratio between the measured regulating stage pressure and the measured main steam pressure. According to the correlation between the actual equivalent valve position and the total valve position instruction, a valve linearity function curve is constructed, and a valve management function is constructed according to the valve linearity function curve; when the influencing condition is the influence of unit heating and flexibility transformation, an extraction heating function is constructed according to the correlation between main steam flow, extraction flow and turbine power; when the influencing condition is the influence of unit heating and flexibility transformation, the operation data of the steam turbine when the low-pressure cylinder is cut off is calculated according to the thermal balance of the steam turbine to obtain a cut-off curve of the low-pressure cylinder cut-off for the turbine power, and a low-pressure cylinder cut-off function is constructed according to the cut-off curve; and, according to the thermal balance of the steam turbine, the operation data of the steam turbine when the high and low bypass heating is calculated to obtain a bypass curve of the high and low bypass heating for the turbine power, and a bypass function is constructed according to the bypass curve; the single reheat turbine model is adjusted according to the main steam adjustment function, the valve management function, the extraction heating function and the bypass function to obtain a single reheat turbine reconstruction model.

[0283] In another embodiment of the present application, the steam turbine reconstruction module includes a verification module, which is used to analyze the influence of the influencing conditions on the simulation accuracy of the single reheat steam turbine reconstruction model through time domain and frequency domain; and determine the influence association according to the comparison result of the simulation accuracy influence and the preset threshold. The regulation module includes a coefficient extraction unit, which is used to call the historical control system operation data of the thermal power unit according to the configuration structure of the regulation system of the thermal power unit; obtain the proportional relationship between the input and output of the thermal power unit according to the historical control system operation data analysis, and obtain the power valve position conversion coefficient through the proportional relationship. The simulation module includes: performing static test simulation processing or load disturbance test simulation processing through the single reheat steam turbine reconstruction model and the regulation system model.

[0284] Since the principle of solving the problem of this system is similar to the simulation method of the wide-load operation thermal power unit, the implementation of this system can refer to the implementation of the simulation method of the wide-load operation thermal power unit, and the repeated parts will not be repeated.

[0285] The beneficial technical effects of the present application are as follows: starting from the mechanism point of view, the factors that have the greatest impact on the model simulation accuracy when the unit is operating at wide load are taken into consideration, the single reheat turbine model and the regulation system model in the traditional BPA model are reconstructed and an application method is formed; the simulation accuracy and the applicable scope of the operating conditions of the model are improved.

[0286] The present application also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above method when executing the computer program.

[0287] The present application also provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program for executing the above method.

[0288] The present application also provides a computer program product, comprising a computer program / instruction, which implements the steps of the above method when executed by a processor.

[0289] Fig.23 A schematic diagram of the physical structure of an electronic device provided in an embodiment of the present invention, such as Fig.23 As shown, the electronic device includes: a processor (processor) 501, a memory (memory) 502 and a bus 503.

[0290] The processor 501 and the memory 502 communicate with each other via a bus 503 .

[0291] The processor 501 is used to call the program instructions in the memory 502 to execute the methods provided by the above method embodiments.

[0292] An embodiment of the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the above-mentioned wide-load operation thermal power unit simulation method is implemented.

[0293] An embodiment of the present invention further provides a computer program product, which includes a computer program. When the computer program is executed by a processor, the above-mentioned wide-load operation thermal power unit simulation method is implemented.

[0294] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0295] The present invention is described with reference to the flowchart and / or block diagram of the method, device (system), and computer program product according to the embodiment of the present invention. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the process and / or box in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a system for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0296] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction system that implements the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0297] These computer program instructions may also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, whereby the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0298] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A simulation method for a thermal power unit operating at a wide load, characterized in that: The method comprises: According to the operation mechanism of the steam turbine of thermal power unit, a single reheat steam turbine model is constructed by using the power natural overregulation coefficient calculation method. Analyze the influence correlation of multiple preset influence data affecting the steam turbine of the thermal power unit on the single reheat steam turbine model through time domain and frequency domain, determine the influence condition according to the influence correlation and adjust the single reheat steam turbine model to obtain the single reheat steam turbine reconstruction model; According to the configuration structure analysis of the regulation system of the thermal power unit, a power valve position conversion coefficient and a correction coefficient are obtained, and a regulation system model is constructed by the power valve position conversion coefficient and the correction coefficient; Performing target simulation processing through the single reheat steam turbine reconstruction model and the regulation system model; The influencing conditions include the influence of main steam pressure change, valve nonlinearity, and unit heating and flexibility transformation; The single reheat steam turbine model is adjusted by a preset influencing condition to obtain a single reheat steam turbine reconstruction model, comprising: when the influencing condition is affected by the change of main steam pressure, a main steam adjustment function is constructed according to the influence of the main steam pressure on the steam flow rate; the single reheat steam turbine model is adjusted by the main steam adjustment function to obtain a single reheat steam turbine reconstruction model; When the influencing condition is the nonlinear influence of the valve, the actual equivalent valve position is obtained according to the ratio between the measured regulating stage pressure and the measured main steam pressure, a valve linearity function curve is constructed according to the correlation between the actual equivalent valve position and the total valve position instruction, and a valve management function is constructed according to the valve linearity function curve; When the influencing conditions are the influence of unit heating and flexibility transformation, an extraction steam heating function is constructed according to the correlation between the main steam flow, the extraction steam flow and the turbine power; When the influencing conditions are the influence of the unit heating and flexibility transformation, the operation data of the steam turbine when the low-pressure cylinder is cut off is calculated according to the thermal balance of the steam turbine to obtain the cut-off curve of the low-pressure cylinder cut-off on the steam turbine power, and the low-pressure cylinder cut-off function is constructed according to the cut-off curve; and the operation data of the steam turbine when the high-low bypass heating is calculated according to the thermal balance of the steam turbine to obtain the bypass curve of the high-low bypass heating on the steam turbine power, and the bypass function is constructed according to the bypass curve; The single reheat steam turbine model is adjusted according to the main steam adjustment function, the valve management function, the extraction heat supply function and the bypass function to obtain a single reheat steam turbine reconstruction model.

2. The method for simulating a thermal power unit under wide load operation according to claim 1, characterized in that: The single reheat steam turbine model is constructed based on the power natural overregulation coefficient calculation method, including: Calculate the power natural overmodulation coefficients corresponding to the two parts of the high-pressure cylinder divided by one draw as the dividing point; A single reheat steam turbine model is constructed based on the calculated power natural overregulation coefficient.

3. The method for simulating a thermal power unit under wide load operation according to claim 1, characterized in that: The main steam adjustment function is constructed based on the influence of steam flow on the main steam pressure, including: constructing an integral function and an inertia function according to the state of the steam flow in the steam turbine, and constructing a main steam adjustment function according to the integral function and the inertia function; The integral function is a corresponding integral function constructed when the steam flow rate entering the steam turbine changes, an imbalance occurs between the heat carried away by the steam flowing into the steam turbine per unit time and the heat generated by the combustion of the fuel, resulting in a change in the pressure of the drum boiler, and the fuel heat is greater than the heat carried away by the steam flow rate; The inertia function is an inertia function with a proportional coefficient that is constructed when the steam drum pressure is constant and the steam flow entering the steam turbine is changed, resulting in a change in the main steam pressure.

4. The method for simulating a thermal power unit under wide load operation according to claim 1, characterized in that: The impact of flexible transformation includes the impact of low-pressure cylinder removal and the impact of high and low bypass heating.

5. The method for simulating a thermal power unit under wide load operation according to claim 1, characterized in that: The influence of multiple preset influence data on the single reheat steam turbine model on the thermal power unit steam turbine through time domain and frequency domain analysis includes: Analyze the influence of the influencing conditions on the simulation accuracy of the single reheat steam turbine reconstruction model through time domain and frequency domain; The impact association is determined according to a comparison result of the simulation accuracy impact and a preset threshold.

6. The method for simulating a thermal power unit under wide load operation according to claim 1, characterized in that: According to the configuration structure analysis of the regulation system of the thermal power unit, the power valve position conversion coefficient includes: Call the historical control system operation data of the thermal power unit according to the configuration structure of the regulation system of the thermal power unit; The proportional relationship between the input and output of the thermal power unit is obtained according to the analysis of the historical control system operation data, and the power valve position conversion coefficient is obtained through the proportional relationship.

7. The method for simulating a thermal power unit under wide load operation according to claim 1, characterized in that: Performing target simulation processing by using the single reheat steam turbine reconstruction model and the regulation system model includes: Static test simulation processing or load disturbance test simulation processing is performed through the single reheat steam turbine reconstruction model and the regulation system model.

8. A wide load operation thermal power unit simulation system, characterized in that: The system comprises: a steam turbine reconstruction module, a regulation module and a simulation module; The steam turbine reconstruction module is used to construct a single reheat steam turbine model according to the operation mechanism of the steam turbine of the thermal power unit by using the power natural overmodulation coefficient calculation method; analyze the influence association of multiple preset influence data affecting the steam turbine of the thermal power unit on the single reheat steam turbine model through time domain and frequency domain, determine the influence condition according to the influence association, and adjust the single reheat steam turbine model to obtain the single reheat steam turbine reconstruction model; The regulating module is used to obtain a power valve position conversion coefficient and a correction coefficient according to the configuration structure analysis of the regulating system of the thermal power unit, and to construct a regulating system model through the power valve position conversion coefficient and the correction coefficient; The simulation module is used to perform target simulation processing through the single reheat steam turbine reconstruction model and the regulation system model; The steam turbine reconstruction module includes a regulating unit; the influencing conditions include the influence of main steam pressure change, valve nonlinearity, and the influence of unit heating and flexibility transformation; The regulating unit is used for constructing an integral function and an inertia function respectively according to the state of the steam flow in the steam turbine when the influencing condition is the influence of the main steam pressure change, and constructing a main steam adjustment function according to the integral function and the inertia function; wherein the integral function is a corresponding integral function constructed when the steam flow entering the steam turbine changes, an imbalance occurs between the heat taken away by the steam flowing into the steam turbine per unit time and the heat generated by the fuel combustion, resulting in a change in the pressure of the drum boiler, and the heat of the fuel is greater than the heat taken away by the steam flow; the inertia function is a corresponding inertia function with a proportional coefficient constructed when the main steam pressure changes due to a change in the steam flow entering the steam turbine when the drum pressure is constant; The regulating unit is also used for obtaining the actual equivalent valve position according to the ratio between the measured regulating stage pressure and the measured main steam pressure when the influencing condition is the nonlinear influence of the valve, constructing a valve linearity function curve according to the correlation between the actual equivalent valve position and the total valve position instruction, and constructing a valve management function according to the valve linearity function curve; when the influencing condition is the influence of unit heating and flexibility transformation, constructing an extraction heating function according to the correlation between the main steam flow, the extraction flow and the turbine power; when the influencing condition is the influence of unit heating and flexibility transformation When the influence of the low-pressure cylinder is cut off, the operation data of the steam turbine is calculated according to the thermal balance of the steam turbine to obtain the cut-off curve of the low-pressure cylinder cut-off on the turbine power, and the low-pressure cylinder cut-off function is constructed according to the cut-off curve; and the bypass curve of the high and low bypass heating to the turbine power is obtained according to the thermal balance of the steam turbine to obtain the operation data of the steam turbine when the high and low bypass heating is carried out, and the bypass function is constructed according to the bypass curve; the single reheat steam turbine model is adjusted according to the main steam adjustment function, the valve management function, the extraction heating function and the bypass function to obtain the single reheat steam turbine reconstruction model.

9. The wide load operation thermal power unit simulation system according to claim 8, characterized in that: The steam turbine reconstruction module also includes a construction unit, which is used to respectively calculate the power natural overmodulation coefficients corresponding to the two parts of the high-pressure cylinder divided by one extraction as the dividing point; and construct a single reheat steam turbine model according to the calculated power natural overmodulation coefficients.

10. The wide load operation thermal power unit simulation system according to claim 8, characterized in that: The steam turbine reconstruction module includes a verification module, which is used to analyze the influence of the influencing conditions on the simulation accuracy of the single reheat steam turbine reconstruction model through time domain and frequency domain; and determine the influence association based on the comparison result of the simulation accuracy influence and a preset threshold.

11. The wide load operation thermal power unit simulation system according to claim 8, characterized in that: The regulation module includes a coefficient extraction unit, which is used to call the historical control system operation data of the thermal power unit according to the configuration structure of the regulation system of the thermal power unit; obtain the proportional relationship between the input and output of the thermal power unit according to the analysis of the historical control system operation data, and obtain the power valve position conversion coefficient through the proportional relationship.

12. The wide load operation thermal power unit simulation system according to claim 8, characterized in that: The simulation module includes: performing static test simulation processing or load disturbance test simulation processing through the single reheat steam turbine reconstruction model and the regulation system model.

13. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 7 is implemented.

14. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

15. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instructions are executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

Images