Simulation method and system for thermal power generating unit under wide load operation conditions

Abstract

Provided in the present application are a simulation method and system for a thermal power generating unit under wide load operation conditions. The method comprises: on the basis of an operating mechanism of a steam turbine of a thermal power generating unit, constructing a single-reheat steam turbine model using a power natural overshoot coefficient calculation method (S201); collecting a plurality of pieces of preset influencing data affecting the steam turbine of the thermal power generating unit, and determining, by means of time domain analysis and frequency domain analysis, an influence relationship between the influencing data and the single-reheat steam turbine model, and on the basis of the influence relationship, determining an influence condition, and on the basis of the influence condition, adjusting the single-reheat steam turbine model to obtain a reconstructed single-reheat steam turbine model (S202); on the basis of the configuration of a governing system of the thermal power generating unit, performing analysis to obtain a power-valve position conversion coefficient and a correction coefficient, and constructing, by means of the power-valve position conversion coefficient and the correction coefficient, a governing system model (S203); and by means of the reconstructed single-reheat steam turbine model and the governing system model, performing target simulation processing (S204).

Description

Simulation Method and System for Thermal Power Units Operating Under Wide Load Technical Field

[0001] This application relates to the field of power system stability analysis, such as a simulation method and system for thermal power units operating under wide load conditions. Background Technology

[0002] With the large-scale grid connection of new energy sources and their increasing share of power generation year by year, the "high-energy-consuming and high-polluting" characteristics of the new power system are becoming increasingly prominent. Improving the system's regulation and support capabilities faces numerous constraints, and safe and stable operation faces significant risks and challenges. To address these issues, thermal power units are transforming into support-oriented and regulation-oriented power sources, significantly expanding their load operating range through flexibility upgrades, making ultra-low load operation the norm. Generally, operating at 50% or above rated load is considered normal operating condition, while operating at 50% or below is considered deep peak-shaving operating condition.

[0003] By establishing a grid-connected model of the steam turbine and its regulating system using field measurement data and simulation identification, this model can be used to analyze the dynamic response characteristics of the power system under various disturbances in steady state, and is an important means of power system stability analysis. The accuracy and applicability of the model directly affect the results of power system stability analysis. Currently, commonly used models are mainly for units operating under conventional conditions. Under deep peak-shaving conditions, the simulation accuracy of the original models decreases. Therefore, it is necessary to reconstruct the steam turbine grid-connected model to adapt to the characteristics of wide-load operation of the unit, and to provide engineering application methods for the model to improve its simulation accuracy and broaden its applicability.

[0004] Currently, the commonly used turbine and governor models in power system stability analysis are the Bonneville Power Administration (BPA) models provided in the "PSD-ST Transient Stability Program User Manual". Since the main turbine models currently in service in China are single reheat turbines, the commonly used turbine and regulating system models are the single reheat turbine model (TB card), the electro-hydraulic servo system model (GA / GA+ card), and the regulating system model (GJ / GJ+ card), with their transfer functions shown in Figures 1A to 1C, respectively.

[0005] In Figure 1A, S is the Laplace operator. To achieve the per-unit value of the high-regulating valve opening, T CH T is the volumetric time constant of the high-pressure cylinder front chamber. RH T is the reheater volume time constant. CO F is the volumetric time constant of the steam chamber in the low-pressure connecting pipe. HP F IP FLP These represent the percentage of total engine power accounted for by the high, medium, and low-power cylinders, respectively. P is the natural overshoot coefficient for the high-pressure cylinder power. M This represents the per-unit value of the turbine output power. In Figure 1B, S is the Laplace operator, and P... CV To comprehensively regulate the per-unit value of the valve position command, K P K D K I For the proportional coefficient, derivative coefficient, and integral coefficient of the high-pressure regulating valve servo card, T C T is the shut-off time of the hydraulic actuator. O P is the start time of the hydrator. MAX P represents the per-unit value of the maximum prime mover output power (maximum stroke of the hydraulic motor or maximum valve opening). MIN P is the per-unit value of the minimum prime mover output power (minimum stroke of the hydraulic motor or minimum opening of the control valve), T2 is the time constant of the linear variable differential transformer (LVDT) in the hydraulic motor stroke feedback loop, and P is the minimum per-unit value of the prime mover output power (minimum stroke of the hydraulic motor or minimum opening of the control valve). GV Here, VELopen is the per-unit value of the high-pressure regulating valve opening, VELclose is the per-unit value of the overspeed closing coefficient, and VELclose is the per-unit value of the overspeed opening coefficient. In Figure 1C, S is the Laplace operator. The difference between the rated speed and the actual speed, TW delay T1 is the pure delay time of the frequency input signal, and T2 is the time constant of the speed measurement circuit. TW2 is the time constant of an inertial element corresponding to the power feedback signal. delay DP is the pure delay time after the frequency signal is amplified. UP / DP DOWN The per-unit value for limiting the rise / fall rate of the input PID signal after the frequency signal is amplified, TW2-PID delay TP is the pure delay time of the frequency signal after amplification and input to the PID controller. delay The pure delay time of the power feedback signal. This represents the per-unit value of the turbine power feedback signal under load control conditions. This represents the per-unit value of the turbine power feedback signal under regulating stage pressure control conditions. This is the per-unit value for the power setpoint. Select the switching coefficient for the control method. This is the amplification factor for the rotational speed deviation. For load control feedforward coefficients, The time constant of the first-order inertial element in power feedback. This refers to the proportional element ratio in a PID controller. This refers to the integral factor in a PID controller. This is the factor of the derivative element in the PID controller. The per-unit value of the overall regulating valve position command.

[0006] The BPA model significantly simplifies real steam turbine systems. While it performs well in simulating units operating under conventional pure condensing conditions, its performance is poor for units operating under deep peak-shaving and heating conditions due to factors such as main steam pressure variations, valve nonlinearity, unit heating, and low-pressure cylinder disconnection. Therefore, the BPA model cannot meet the simulation requirements of thermal power units operating under wide load conditions. Summary of the Invention

[0007] This application provides a simulation method and system for thermal power units operating under wide loads, which meets the simulation requirements of thermal power units operating under wide loads and the requirements of power system simulation, and significantly improves simulation accuracy and efficiency, greatly reducing the difficulty of engineering applications.

[0008] The simulation method for wide-load operation thermal power units provided in this application includes: constructing a single reheat turbine model based on the operating mechanism of the thermal power unit turbine and using a method for calculating the natural power overshoot coefficient; collecting multiple preset influence data affecting the thermal power unit turbine, and determining the influence relationship of the influence data on the single reheat turbine model through time-domain analysis and frequency-domain analysis; determining the influence conditions based on the influence relationship, and adjusting the single reheat turbine model according to the influence conditions to obtain a single reheat turbine reconfiguration model; analyzing and obtaining the power-valve position conversion coefficient and correction coefficient based on the configuration structure of the thermal power unit's regulation system; constructing a regulation system model using the power-valve position conversion coefficient and the correction coefficient; and performing target simulation processing using the single reheat turbine reconfiguration model and the regulation system model.

[0009] This application also provides a simulation system for thermal power units operating under wide loads. The system includes a turbine reconfiguration module, a regulation module, and a simulation module. The turbine reconfiguration module is configured to construct a single reheat turbine model based on the operating mechanism of the thermal power unit turbine and using a power natural overshoot coefficient calculation method; collect multiple preset influence data affecting the thermal power unit turbine, and determine the influence relationship of the influence data on the single reheat turbine model through time-domain and frequency-domain analysis; determine the influence conditions based on the influence relationship, and adjust the single reheat turbine model according to the influence conditions to obtain a single reheat turbine reconfiguration model. The regulation module is configured to analyze and obtain the power-valve position conversion coefficient and correction coefficient based on the configuration structure of the thermal power unit's regulation system, and construct a regulation system model using the power-valve position conversion coefficient and the correction coefficient. The simulation module is configured to perform target simulation processing using the single reheat turbine reconfiguration model and the regulation system model.

[0010] This application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-described method.

[0011] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method.

[0012] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the above-described method.

[0013] This application starts from the perspective of the operating mechanism of the steam turbine of thermal power unit, and considers the factors that have the greatest impact on the simulation accuracy of the model when the thermal power unit is operating under wide load. It reconstructs the single reheat steam turbine model and the regulation system model in the traditional BPA model and forms an application method; thereby improving the simulation accuracy and the applicable range of operating conditions of the model. Attached Figure Description

[0014] Figure 1A is a schematic diagram of the transfer function of a single reheat steam turbine model in related technologies;

[0015] Figure 1B is a schematic diagram of the transfer function of the electro-hydraulic servo system model in the related technology;

[0016] Figure 1C is a schematic diagram of the transfer function of the regulation system model in the related technology;

[0017] Figure 2 is a flowchart illustrating a simulation method for thermal power units operating under wide loads according to an embodiment of this application;

[0018] Figure 3 is a schematic diagram of the construction process of a single reheat steam turbine model provided in an embodiment of this application;

[0019] Figure 4A is a flowchart illustrating the adjustment of the turbine model corresponding to the main steam pressure variation factors provided in an embodiment of this application;

[0020] Figure 4B is a model of a steam drum furnace provided in an embodiment of this application;

[0021] Figure 4C is a simplified model diagram of the main steam pressure factor provided in an embodiment of this application;

[0022] Figure 5A is a schematic flowchart of the turbine model for adjusting valve nonlinearity factors provided in an embodiment of this application;

[0023] Figure 5B is a schematic diagram of the DEH valve control logic provided in an embodiment of this application;

[0024] Figure 5C is a schematic diagram of the relationship between the lift and flow characteristics of a steam turbine regulating valve provided in an embodiment of this application;

[0025] Figure 5D is a schematic diagram of the actual flow characteristic curve of the regulating valve assembly provided in an embodiment of this application;

[0026] Figure 5E is a schematic diagram of the actual flow characteristic curves of various high-pressure regulating valves provided in an embodiment of this application;

[0027] Figure 5F is a simplified model diagram of the valve nonlinearity factor provided in an embodiment of this application;

[0028] Figure 6A is a flowchart illustrating the adjustment of the turbine model corresponding to the unit heating factors provided in an embodiment of this application;

[0029] Figure 6B is a schematic diagram of the steam quantity-electric power operating condition of a thermal power unit provided in an embodiment of this application;

[0030] Figure 7A is a schematic diagram of the process of adjusting the turbine model under the low-pressure cylinder cut-off condition provided in an embodiment of this application;

[0031] Figure 7B is a schematic diagram of the process for adjusting a steam turbine model under high and low bypass heating conditions according to an embodiment of this application;

[0032] Figure 8 is a schematic diagram of the heating factors of the unit provided in an embodiment of this application;

[0033] Figure 9 is a logic diagram of a low bypass heating condition provided in an embodiment of this application;

[0034] Figure 10 is a logic diagram of the low-pressure cylinder cut-off condition provided in an embodiment of this application;

[0035] Figure 11 is a logical schematic diagram of a single reheat turbine reconfiguration model provided in an embodiment of this application;

[0036] Figure 12A is a schematic diagram of time-domain analysis (regulator stage pressure comparison) of the main steam pressure factor provided in an embodiment of this application;

[0037] Figure 12B is a schematic diagram of time-domain analysis (power comparison) of the main steam pressure factor provided in an embodiment of this application;

[0038] Figure 13A is a schematic diagram of time-domain analysis (regulatory stage pressure comparison) of valve nonlinearity factors provided in an embodiment of this application;

[0039] Figure 13B is a schematic diagram of time-domain analysis (power comparison) of valve nonlinearity factors provided in an embodiment of this application;

[0040] Figure 14 is a schematic diagram of the influence of valve nonlinearity on the frequency domain characteristics of the system according to an embodiment of this application;

[0041] Figure 15 is a schematic diagram showing the effect of the natural overmodulation coefficient on the frequency domain characteristics of the system according to an embodiment of this application;

[0042] Figure 16 is a schematic diagram showing the effect of the work ratio correction coefficient provided in an embodiment of this application on the frequency domain characteristics of the system.

[0043] Figure 17 is a schematic diagram of the power-valve position conversion coefficient acquisition process provided in an embodiment of this application;

[0044] Figure 18 is a schematic diagram of the transfer function of the reconfiguration model of the adjustment system provided in an embodiment of this application;

[0045] Figure 19 is a schematic diagram of the experimental process for measuring and modeling thermal power unit parameters according to an embodiment of this application;

[0046] Figure 20 is a schematic diagram comparing the simulation results of the integrated valve position command provided in an embodiment of this application;

[0047] Figure 21 is a schematic diagram comparing the simulation results of the regulating stage pressure provided in an embodiment of this application;

[0048] Figure 22 is a schematic diagram comparing the simulation results of the unit power provided in an embodiment of this application;

[0049] Figure 23 is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0050] Furthermore, the steps shown in the flowchart in 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 flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0051] Please refer to Figure 2. The simulation method for wide-load operation thermal power units provided in this application includes:

[0052] S201, a single reheat turbine model is constructed based on the operating mechanism of the steam turbine of the thermal power unit using the calculation method of the power natural overshoot coefficient;

[0053] S202, the influence correlation of multiple preset influence data affecting the steam turbine of the thermal power unit on the single reheat steam turbine model is analyzed by time domain and frequency domain. The influence conditions are determined according to the influence correlation and the single reheat steam turbine model is adjusted to obtain the single reheat steam turbine reconfiguration model.

[0054] S203, Based on the configuration structure analysis of the regulating system of the thermal power unit, the power-valve position conversion coefficient and the correction coefficient are obtained, and the regulating system model is constructed using the power-valve position conversion coefficient and the correction coefficient;

[0055] S204, target simulation processing is performed using the single reheat turbine reconfiguration model and the regulation system model.

[0056] In practical application, this application first establishes a single reheat turbine model from a mechanistic perspective, considering factors such as main steam pressure variations, valve nonlinearity, unit heating, and flexibility modifications. The impact of the added components on the model simulation results is analyzed from both time and frequency domain perspectives. Then, by summarizing the configuration structure of actual thermal power unit control systems, power-valve position conversion coefficients and proportional-integral-derivative (PID) controller correction coefficients are added, resulting in a control system model that more closely approximates the actual unit. Finally, engineering application methods for the reconstructed model are presented, including methods for obtaining large-scale data on equivalent valve position curves corresponding to valve flow characteristics and methods for measuring and calculating the heating coefficient. The specific implementation process of each step will be detailed in subsequent embodiments and will not be elaborated upon here.

[0057] Please refer to Figure 3. In one embodiment of this application, constructing a single reheat turbine model based on the power natural overshoot coefficient calculation method includes:

[0058] S301 calculates the power natural overshoot coefficients corresponding to the two parts of the high-pressure cylinder divided by the first extraction point.

[0059] S302 constructs a single reheat turbine model based on the calculated power natural overshoot coefficient.

[0060] For example, the work done by a steam turbine is determined by both the flow rate and enthalpy drop of the steam passing through the flow path. However, the models in related technologies do not consider the effect of enthalpy drop. Therefore, this application uses a power natural overshoot coefficient to correct this problem. In practical applications, the power of a simple steam turbine unit can be expressed as:

[0061]

[0062] in: This refers to the steam flow rate at the inlet of the turbine stage;

[0063] This refers to the isentropic enthalpy drop of steam within the turbine stage;

[0064] For the thermal efficiency of the turbine stage;

[0065] First, consider traffic. The change. Assuming the turbine consists of a single pressure stage, according to the principle of variable operating conditions for turbine pressure stage groups, we have:

[0066]

[0067] in: For varying operating parameters (steam flow rate, inlet steam pressure, and inlet steam temperature), ignoring the change in inlet steam temperature during the varying operating conditions, then:

[0068]

[0069] make Define the intake and exhaust steam pressure ratio ,have:

[0070]

[0071] Next, consider the isentropic enthalpy drop. The change in enthalpy. The enthalpy drop of the steam in the turbine's flow path is the expansion work of a unit constant flow of working fluid. Assuming that there are no flow rate changes caused by steam extraction or other factors inside the turbine, then for an isentropic process, we have:

[0072]

[0073] in: Specific volume of steam; The process adiabatic index is used for superheated steam. .therefore:

[0074]

[0075] Therefore, the change in the isentropic enthalpy drop of the series is as follows:

[0076]

[0077] Similarly If we ignore the change in steam inlet temperature, then we have:

[0078]

[0079] If we ignore the change in stage efficiency under varying operating conditions, then:

[0080]

[0081] make ,right Differentiating and rearranging the above equation, we get:

[0082]

[0083] in This is called the power natural overshoot coefficient.

[0084] The calculation method in related technologies treats the high-pressure cylinder as a pressure stage, and the pressure ratio is the ratio of the high-pressure cylinder exhaust pressure to the regulating stage pressure. The natural overshoot coefficient calculated by this method deviates too much from the simulation fitting value and is too small. To avoid this, this application improves the calculation method for the high-pressure cylinder power overshoot coefficient, wherein the natural overshoot coefficient is represented by the symbol... The improved solution is shown below:

[0085] Divide the high-pressure cylinder into two parts with the first extraction point as the dividing point. The first part is from the high-pressure cylinder inlet to the first extraction point, denoted by subscript 1. The second part is from the first extraction point to the high-pressure cylinder exhaust port, denoted by subscript 2. The natural overshoot coefficient of the high-pressure cylinder can be calculated by the following formula:

[0086]

[0087] in, This is the work ratio coefficient. These are the natural overtuning coefficients for the first and second parts, respectively.

[0088]

[0089] in, The first part is the pressure ratio, which is numerically equal to the ratio of the pressure at the extraction point to the pressure at the inlet of the high-pressure cylinder.

[0090]

[0091] in, The second pressure ratio is numerically equal to the ratio of the pressure at the high-pressure cylinder exhaust port to the pressure at the extraction port.

[0092]

[0093] in, These represent the work done in the first part and the second part, respectively.

[0094]

[0095] in, This refers to the steam flow rate at the high-pressure cylinder inlet. To regulate leakage flow, The enthalpy of the steam at the inlet. The enthalpy of the steam after the regulating stage, This is the enthalpy of vapor extracted from the pump.

[0096]

[0097] in, This refers to the steam extraction flow rate of the first-stage heater. This is the enthalpy value of the high-pressure cylinder exhaust steam.

[0098] In one embodiment of this application, the influencing conditions include main steam pressure variation factors, valve nonlinearity factors, unit heating factors, and flexibility modification factors. Figure 4A is a flowchart illustrating the adjustment of the turbine model corresponding to the main steam pressure variation factors provided in one embodiment of this application. Referring to Figure 4A, in one embodiment of this application, adjusting the single reheat turbine model through preset influencing conditions to obtain a single reheat turbine reconfiguration model includes:

[0099] S401 When the influencing condition is affected by the change in main steam pressure, construct the main steam adjustment function based on the influence of steam flow on the main steam pressure.

[0100] S402 adjusts the single reheat turbine model using the main steam adjustment function to obtain the single reheat turbine reconfiguration model.

[0101] The main steam adjustment function, constructed based on the influence of steam flow rate on main steam pressure, includes: constructing an integral function and an inertial function based on the steam flow rate at the turbine's state, and then constructing the main steam adjustment function based on the integral function and the inertial function. The integral function corresponds to a scenario where, due to a change in the steam flow rate entering the turbine, an imbalance arises between the heat carried away by the steam flowing into the turbine per unit time and the heat generated by fuel combustion, leading to a change in the pressure of the boiler drum, and where the heat from the fuel is greater than the heat carried away by the steam flow rate. The inertial function is a proportionality coefficient-based inertial function constructed when the boiler drum pressure is constant and the main steam pressure changes due to a change in the steam flow rate entering the turbine.

[0102] For example, in practical work, the mathematical model of the boiler body includes several modules such as the combustion system, water-cooled walls, evaporation heating surfaces, and superheaters.

[0103] Combustion system:

[0104] Combustion and heat release are complex chemical and physical changes. In the analysis and design of the furnace-machine coordinated control system, if the combustion regulation system is designed reasonably and combustion is stable, the combustion and heat release process can be approximated as a first-order inertial process with a delay.

[0105]

[0106] in, For combustion rate instructions, The heat released during fuel combustion The pure time delay of the combustion and heat release process, This is a time constant, which can vary depending on the system design.

[0107] Water-cooled walls:

[0108]

[0109] in, S is the heat released during fuel combustion. G T1 is the total effective heat absorption of the boiler's heating surface (expressed in units of steam flow rate), and T2 is the time constant of the boiler's heat transfer process.

[0110] Evaporation heating surface:

[0111] The heat absorbed by the evaporating heating surface is used to heat the feedwater to saturated steam. Considering the energy storage in the boiler drum, the drum pressure P... d This reflects the amount of heat absorbed by the boiler (the amount of steam produced), S G superheated steam S at the superheater inlet F Balance:

[0112]

[0113] Among them, C B This represents the heat storage coefficient of the steam drum.

[0114] Superheater model:

[0115] Because the superheater has a relatively small volume, this application considers the resistance characteristics of the superheater, and its volumetric characteristics are incorporated into the volumetric characteristics of the boiler drum. Therefore, the superheater drum pressure P... d and main steam pressure P T The pressure and the steam flow rate S entering the turbine F There is a square root relationship between them:

[0116]

[0117] Among them, K sh This is the resistance coefficient of the superheater pipes.

[0118] The above results in the schematic diagram of the boiler drum model, as shown in Figure 4B. Since the boiler drum model requires additional inputs and has a complex structure, this application simplifies the boiler and its control system model to a main steam pressure model with main steam flow as the input to reduce model complexity. The simplification steps are as follows: Ideally, the main steam pressure is mainly affected by the drum pressure and steam flow. The drum pressure is mainly affected by the heat released from fuel combustion and the steam flow entering the turbine. Near a given operating condition, the fuel heat can be considered essentially constant, and the main steam pressure is mainly affected by changes in flow rate. This effect can be divided into two parts: The first part is that when the steam flow entering the turbine changes, an imbalance occurs between the heat carried away by the steam flowing into the turbine per unit time and the heat generated by fuel combustion, causing a change in the boiler drum pressure. When the fuel heat is greater than the heat carried away by the steam flow, the drum pressure increases; conversely, it decreases. This part of the effect can be described by an integral term, where... The first part represents the heat storage time constant; the second part is that, when the steam drum pressure is constant, changing the steam flow rate into the turbine will cause changes in the pressure loss between the steam drum and the turbine steam inlet, thus leading to changes in the main steam pressure. For example, when the steam flow rate increases, the pressure loss increases and the main steam pressure decreases; when the main steam flow rate decreases, the pressure loss decreases and the main steam pressure increases. This part of the effect can be described by a first-order inertial element with a proportionality coefficient, where... The time constant of the inertial element, This is the proportionality coefficient. The simplified model corresponding to the main steam pressure factor is shown in Figure 4C.

[0119] Figure 5A is a flowchart illustrating the adjustment of the turbine model corresponding to the valve nonlinearity factor according to an embodiment of this application. Referring to Figure 5A, in one embodiment of this application, adjusting the single reheat turbine model through preset influence conditions to obtain a reconfigurable single reheat turbine model includes:

[0120] S501 When the influencing condition is a valve nonlinear influence, a valve management function is constructed based on the correlation between the measured regulating stage pressure, the measured main steam pressure, and the total valve position command;

[0121] S502 adjusts the single reheat turbine model according to the valve management function to obtain the single reheat turbine reconfiguration model.

[0122] The process of constructing a valve management function based on the correlation between the measured regulating stage pressure, main steam pressure, and total valve position command includes: obtaining the actual equivalent valve position based on the ratio between the measured regulating stage pressure and the measured main steam pressure; constructing a valve linearity function curve based on the correlation between the actual equivalent valve position and the total valve position command; and constructing a valve management function based on the valve linearity function curve.

[0123] For example, in practical operation, most steam turbine units are controlled by four high-pressure regulating valves equipped with independent servo control mechanisms to control the steam supply to the unit. There are two types of steam distribution regulation methods: single-valve regulation and sequential valve regulation. Each high-pressure regulating valve of the unit has 24 nozzles of equal area. In the sequential valve method, the opening sequence of each regulating valve is as follows: GV1 and GV4 open simultaneously, followed by GV2, and finally GV3.

[0124] Taking the above-mentioned type of unit as an example, the valve control function in the control logic configuration of the Digital Electro-Hydraulic Control System (DEH) is implemented through a proportional bias factor and three flow functions. The specific logic flow is shown in Figure 5B below. This is the back pressure correction function; This is the proportional bias factor that controls the valve opening sequence in sequence valve mode. This is the flow distribution function for sequential valves (also used to adjust valve overlap, also known as the overlap function). This is a function to correct the flow command. This is the flow characteristic function of each valve in single-valve mode (the inherent flow characteristic of the control valve).

[0125] Normally, without considering and The impact on the unit's flow characteristics. The former refers to the correction of turbine output by the unit's back pressure, while the latter refers to the inherent flow properties of the turbine's regulating valves. The main consideration is the flow distribution function. and flow command correction function The impact of this is significant. During the opening process of the high-pressure regulating valve in a steam turbine unit, the valve opening area changes. The theoretical steam flow rate through the valve is calculated using the valve's nominal area (nominal diameter) and upstream and downstream parameters. Then, based on the flow characteristic curve obtained from experiments, i.e., the relationship between the characteristic flow ratio (the ratio of actual flow to theoretical flow), pressure loss, and the valve's relative lift, the third parameter can be determined once two of these conditions are known. In commonly used steam turbine unit inlet valve flow characteristic curves, one uses the diffuser throat diameter as the nominal diameter; the other uses the diameter of the sealing ring where the valve core contacts the valve seat. The former is more common. The theoretical flow rate has two definitions: one is the critical flow rate calculated using upstream parameters and the throat area. The characteristic flow ratio calculated according to this definition is always less than 1. The calculation formula is as follows:

[0126]

[0127] In the formula: The theoretical flow rate through the valve is expressed in kg / s.

[0128] The nominal area of ​​the valve throat, in units of ;

[0129] The steam pressure before the valve, in Pa;

[0130] The specific volume of steam entering the valve is expressed in kg / m³. 3 ;

[0131] This is the Pengtaimen coefficient.

[0132] When the pressure ratio across the valve is constant, the relationship between valve opening and flow rate is linear when the relative valve lift L (valve lift) / D (nominal diameter) is less than 0.2. When the relative lift exceeds 0.2, the flow rate increases very slowly. When L / D exceeds 0.3, the flow area of ​​the valve is already limited by the area of ​​the diffuser; further increasing the valve opening will not increase the flow area or flow rate. Therefore, the flow characteristic curve at this point is a horizontal line, as shown in Figure 5C. Figure 5C is a schematic diagram of the relationship between the lift and flow characteristics of a turbine regulating valve provided in an embodiment of this application. The actual flow characteristics of the regulating valve group and the actual flow characteristic curves of each regulating valve obtained through experiments using the above method are shown in Figures 5D and 5E. Figure 5D is a schematic diagram of the actual flow characteristic curve of the regulating valve group provided in an embodiment of this application. Figure 5E is a schematic diagram of the actual flow characteristic curves of each high-pressure regulating valve provided in an embodiment of this application.

[0133] The flow characteristic curve of a valve reflects the relationship between the turbine's flow command and the actual flow. Theoretically, the flow command and the actual flow characteristic should be equal. However, as shown in Figure 5D, the linearity of the valve flow characteristic curve is often poor in actual systems, which leads to a serious decline in the turbine's frequency regulation performance and may even cause accidents. The model established in this application can take into account the nonlinear effects of the valve flow characteristic. To reduce the complexity of the model, the valve management module is simplified into a valve linearity correction function to achieve 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 obtained actual equivalent valve position as the ordinate and the measured total valve position command as the abscissa. The valve linearity function is used to replace the valve management module and substituted into the model for simulation. The simplified model corresponding to the valve nonlinearity factor is shown in Figure 5F. In the above embodiments, the engineering method for obtaining the equivalent valve position can be achieved through relevant technologies, which will not be described in detail here.

[0134] Figure 6A is a flowchart illustrating the adjustment of the turbine model corresponding to the unit heating factors provided in an embodiment of this application. Referring to Figure 6A, in one embodiment of this application, adjusting the single reheat turbine model through preset influence conditions to obtain a single reheat turbine reconfiguration model includes:

[0135] S601 When the influencing condition is the impact of unit heating and flexibility modification, construct the extraction steam heating function based on the correlation between main steam flow, extraction steam flow and turbine power.

[0136] S602 adjusts the single reheat turbine model according to the extraction steam heating function to obtain the single reheat turbine reconfiguration model.

[0137] For example, after steam is extracted from the turbine for heating, the amount of steam used for power generation in the cylinder after the extraction point will change, and the turbine power will vary due to the same change in the regulating valve. Therefore, the impact of steam extraction for heating on the turbine power needs to be considered, as shown in Figure 6B below. Figure 6B is a schematic diagram of the steam quantity-electric power operating condition of a thermal power unit provided in an embodiment of this application.

[0138] Represents the setpoint operating condition line for steam extraction flow;

[0139] Represents the condensing steam operating condition line;

[0140] This represents the minimum stable combustion evaporation capacity of the boiler;

[0141] Represents the maximum steam inlet flow rate;

[0142] Represents the condensate setpoint operating condition line;

[0143] Represents the back pressure operating condition line;

[0144] Represents the minimum condensate flow rate operating condition line;

[0145] Represents the electric power coordinate axis;

[0146] The axis representing steam volume;

[0147] This represents the maximum output of the steam turbine generator.

[0148] Through mechanism and data analysis, it can be found that under the same main steam flow rate, the turbine power decreases with the increase of extraction steam flow rate; under the same extraction steam rate, the main steam flow rate and turbine power still have a linear relationship. Therefore, a model considering the influence of extraction steam heating can be established as follows:

[0149]

[0150] in, For turbine power, The constant coefficient, Main steam pressure, This refers to the opening degree of the steam turbine valves. This is the coefficient representing the influence of steam extraction rate on turbine power. This refers to the amount of steam extracted.

[0151] In one embodiment of this application, the flexibility modification factor corresponds to the low-pressure cylinder cutoff condition and the high- and low-pressure bypass heating condition. Figure 7A is a flowchart illustrating the adjustment of the turbine model under the low-pressure cylinder cutoff condition provided in one embodiment of this application. Referring to Figure 7A, adjusting the single reheat turbine model through preset influence conditions to obtain the single reheat turbine reconfiguration model includes:

[0152] S701 When the influencing conditions are the effects of unit heating and flexibility modification, the power cut-off curve of the turbine when the low-pressure cylinder is cut off is obtained by calculating the turbine's operating data when the low-pressure cylinder is cut off based on the turbine's thermal balance calculation.

[0153] S702 constructs a low-pressure cylinder cutoff function based on the cutoff curve, and adjusts the single reheat turbine model according to the low-pressure cylinder cutoff function to obtain a single reheat turbine reconfiguration model.

[0154] Figure 7B is a flowchart illustrating the adjustment of a turbine model under high and low bypass heating conditions according to an embodiment of this application. Referring to Figure 7B, adjusting the single reheat turbine model using preset influence conditions to obtain a single reheat turbine reconfiguration model includes:

[0155] S703 When the influencing conditions are unit heating factors and flexibility modification factors, the bypass curve of high and low bypass heating on turbine power is obtained based on the turbine thermal balance calculation of the turbine's operating data when the turbine is heated by high and low bypasses.

[0156] S704 constructs a bypass function based on the bypass curve, and adjusts the single reheat turbine model according to the bypass function to obtain a single reheat turbine reconfiguration model.

[0157] For example, when the low-pressure cylinder of a steam turbine is disconnected, it retains only a minimum cooling steam flow and does no work. Therefore, the modeling principle and process for the low-pressure cylinder disconnection condition are similar to the extraction steam heating influence model. However, it requires combining steam turbine thermal balance calculations and low-pressure cylinder disconnection operation data to obtain the influence curve of low-pressure cylinder disconnection on steam turbine power. The form of this curve is similar to the curve of extraction steam turbine power affected by extraction steam volume. After obtaining the influence curve of low-pressure cylinder disconnection on steam turbine power, a low-pressure cylinder disconnection influence model can be established using a method similar to the extraction steam heating influence model.

[0158] When a steam turbine is heated by high-pressure and low-pressure bypass systems, the steam flow rates in the high-pressure, intermediate-pressure, and low-pressure cylinders will decrease accordingly. As the extraction steam volume changes with the high-pressure and low-pressure bypass heating, the turbine power decreases. Therefore, the modeling principle and process for high-pressure and low-pressure bypass heating are similar to those for extraction steam heating. However, it requires combining turbine thermal balance calculations and high-pressure and low-pressure bypass heating operation data to obtain the influence curves of high-pressure and low-pressure bypass heating on turbine power. The form of these curves is similar to the curves showing the influence of extraction steam turbine power on extraction steam volume. After obtaining the influence curves of high-pressure and low-pressure bypass heating on turbine power, a similar method to the extraction steam heating influence model can be used to establish the high-pressure and low-pressure bypass heating influence model.

[0159] According to thermodynamic principles, the work done by steam entering each stage of the cylinder is equal to the product of the steam flow rate and the enthalpy difference before and after the blades, as shown in the following formula:

[0160]

[0161] In the formula, This represents the amount of work done before and after the blade. This is the mass flow rate of the steam passing through the blade. This represents the enthalpy value per unit mass of steam before it flows through the blades. This represents the enthalpy value per unit mass of steam after it flows through the blades.

[0162] The following relationship exists between the enthalpy values ​​per unit mass of steam before and after flowing through the blades:

[0163]

[0164] In the formula This represents the enthalpy per unit mass of steam flowing through the blades under ideal conditions (an isentropic process). This refers to the efficiency of the steam turbine blades.

[0165] For a given steam turbine, the steam state before and after each stage of the blades does not change significantly under varying operating conditions. Therefore, for the sake of simplifying calculations, when calculating the turbine power, it is generally assumed that the work done by a unit mass of steam flowing through each stage of the turbine blades is the same. Thus, the amount of work done by steam in each stage of the turbine is consistent with the change in the mass flow rate of steam entering each stage, as shown in the following formula:

[0166]

[0167] In the formula, For the total amount of work done, , , These are the work done by the high-pressure cylinder, steam flow rate, and enthalpy change, respectively. , , These are the work done by the intermediate-pressure cylinder, steam flow rate, and enthalpy change, respectively. , , These are the work done by the low-pressure cylinder, steam flow rate, and enthalpy change, respectively.

[0168] For units operating under pure condensing conditions, the flow rates through the high-pressure cylinder, intermediate-pressure cylinder, and low-pressure cylinder remain essentially constant. Therefore, the total flow rate entering the turbine is... And since their respective enthalpy changes are constant, normalizing both sides of the above equation yields the following equation:

[0169]

[0170] and:

[0171]

[0172] In the formula, , , These represent the power ratios of the high, medium, and low pressure cylinders, respectively.

[0173] As can be seen from the above formula, since the enthalpy drop of each stage of the turbine blades remains basically constant and the flow rate is basically the same for a specific turbine, there is a certain relationship between the work done by each stage of the turbine blades, i.e., the corresponding work ratio, even if the unit is operating under varying conditions. , , It is certain.

[0174] However, for special operating conditions such as low-pressure bypass heating, high-pressure bypass heating, and low-pressure cylinder cutoff, the work ratio of each cylinder will no longer be equal to that of the others. , , The reason is that steam extraction causes the steam flow rate through each cylinder to no longer be basically consistent, and the work done by each cylinder needs to be calculated by the following formula:

[0175]

[0176] Under low-pressure bypass heating conditions, the steam splits into two parts after exiting the reheater. One part enters the intermediate-pressure cylinder to perform work, while the other part is drawn into the low-pressure cylinder bypass for heating. This portion of steam no longer performs work and can be excluded from power calculations. , Substituting the values, we can obtain the work done by each cylinder as shown in the following formula:

[0177]

[0178] In the formula, For low bypass heating flow correction factor, .

[0179] Under heating conditions, steam splits into two parts after exiting the intermediate-pressure cylinder. One part enters the low-pressure cylinder to perform work, while the other part is drawn into the heat exchanger for heating. This latter part of the steam is excluded from power calculations. , Therefore, the work done by each cylinder is shown in the following formula:

[0180]

[0181] In the formula, This is the heating flow rate correction factor. .

[0182] Under low-pressure cylinder cutoff conditions, after steam exits the intermediate-pressure cylinder, a small portion enters the low-pressure cylinder to maintain operation, while the majority is bypassed by the low-pressure cylinder and drawn into the heat exchanger for heating. Analogous to heating conditions, this portion of steam is excluded when calculating power output. , Therefore, the work done by each cylinder is shown in the following formula:

[0183]

[0184] In the formula, This is the correction factor for the low-pressure cylinder cutoff flow rate. .

[0185] Since it is assumed that the enthalpy drop of steam before and after flowing through the blades is constant, the flow correction coefficient is... , , Numerically, they are respectively equal to the work ratio coefficient. , , It needs to be determined by fitting actual data.

[0186] Based on the above principles, the influencing factors of unit heating and flexibility modification are shown in Figures 8 to 10, where Figure 8 is a schematic diagram of the unit heating factors provided in an embodiment of this application. In Figure 8, This is the heating flow rate correction factor. To shut off the heating supply, This is a heating switch; Figure 9 is a schematic diagram of the logic circuit under low bypass heating conditions provided in an embodiment of this application. In Figure 9, For low bypass heating flow correction factor, For low-voltage bypass heating shut-off switch, This is a low-pressure bypass heating switch; Figure 10 is a logic diagram of the low-pressure cylinder cut-off condition provided in an embodiment of this application. In Figure 10, This is the correction factor for the low-pressure cylinder cutoff flow rate. For low-pressure cylinder cutoff switch, The low-pressure cylinder is cut off by the shut-off switch.

[0187] Therefore, a single reheat turbine model, also known as a single reheat turbine reconfiguration model, can be constructed and generated through the above embodiments. Please refer to Figure 11 for details. To comprehensively regulate the per-unit value of the valve position command, To adjust the valve opening per unit value, The main steam pressure per unit value This is the per-unit value for the regulating stage pressure. The steam volume time constant is The reheat volumetric time constant is... The time constant of the cross tube, This is the natural overshoot coefficient for the high-pressure cylinder. This is the power ratio coefficient for the high-pressure cylinder. This is the proportional coefficient for the work done by the intermediate pressure cylinder. This is the power ratio coefficient for the low-pressure cylinder. For low bypass heating flow correction factor, This is the heating flow rate correction factor. This is the correction factor for the low-pressure cylinder cutoff flow rate. This is the per-unit power value of the steam turbine. For low-voltage bypass heating shut-off switch, This is a low-voltage bypass heating switch. To shut off the heating supply, For heating switch, For low-pressure cylinder cutoff switch, To cut off the low-pressure cylinder shut-off switch, the actuator can adopt the structure shown in Figure 1B.

[0188] In one embodiment of this application, the influence correlation of multiple preset influence data affecting the steam turbine of a thermal power unit through time-domain and frequency-domain analysis on a single reheat steam turbine model includes: analyzing the influence conditions on the simulation accuracy of the single reheat steam turbine reconstruction model through time-domain and frequency-domain analysis; and determining the influence correlation based on the comparison result of the simulation accuracy influence and a preset threshold.

[0189] In the time domain: Please refer to Figures 12A and 12B. Figure 12A is a schematic diagram of the time domain analysis (regulator stage pressure comparison) corresponding to the main steam pressure factor provided in an embodiment of this application, and Figure 12B is a schematic diagram of the time domain analysis (power comparison) corresponding to the main steam pressure factor provided in an embodiment of this application. Figures 12A and 12B show the simulation results of the model for regulator stage pressure and power under 20% rated load conditions of a 315MW subcritical unit, before and after considering the main steam pressure, and the comparison results of the actual regulator stage pressure and power. As can be seen from Figures 12A and 12B, considering the influence of the main steam pressure can make the model have higher simulation accuracy. In actual process, the main steam pressure will change to a certain extent with the change of valve opening, and weaken the influence of valve opening on regulator stage pressure. For example, when the valve opening increases, the steam flow increases, the pressure loss increases, the steam drum pressure remains unchanged temporarily, and the main steam pressure decreases. Ultimately, the change in flow rate entering the turbine is smaller in the short period of time after the valve is activated compared to the change in flow rate when the main steam pressure is constant. Please refer to Figures 13A and 13B. Figure 13A is a schematic diagram of time-domain analysis (regulator stage pressure comparison) corresponding to valve nonlinearity factors provided in an embodiment of this application, and Figure 13B is a schematic diagram of time-domain analysis (power comparison) corresponding to valve nonlinearity factors provided in an embodiment of this application. Figures 13A and 13B show the simulation results of the model for regulator stage pressure and power under 80% rated load conditions of a 600MW subcritical unit before and after considering valve nonlinearity, and the comparison results with the actual regulator stage pressure and power. As can be seen from the figures, considering the influence of valve nonlinearity can make the model have higher simulation accuracy. As can be seen from Figures 13A and 13B, after considering valve nonlinearity factors, the model can more realistically reflect the correspondence between the comprehensive valve position command and the flow rate. This capability is reflected in the model simulation results as a more accurate reflection of the gain effect obtained by the steam flow rate entering the turbine when the comprehensive valve position command changes by a unit amplitude, avoiding the situation where the simulation results for the flow rate (regulator stage pressure) change are too large or too small due to the ideal assumption that "the command and the flow rate are linearly related".

[0190] In the frequency domain: Frequency domain analysis was performed on the system, with the valve nonlinear module selected for both closing and enabling. The changes in the system's frequency domain characteristics are shown in Figure 14. As can be seen from Figure 14, when the system frequency disturbance is greater than 0.004... At this time, valve nonlinearity will have a certain impact on the amplitude-frequency characteristics of the system. When the system frequency disturbance is within 0.001... -0.02 When the valve nonlinearity is between 0.004 and 0.004, it will have a certain impact on the phase frequency characteristics of the system. Therefore, considering all factors, it is recommended that the frequency disturbance be greater than 0.004. That is, the power grid disturbance frequency is greater than 0.0006. The influence of valve nonlinearity is considered. Frequency domain analysis is performed on the system, and the power natural overshoot coefficient values ​​obtained from the new and old natural overshoot coefficient calculation methods are selected respectively. The changes in the system's frequency domain characteristics are shown in Figure 15. As can be seen from Figure 15, when the system frequency disturbance is greater than 0.08... At this time, the natural overmodulation factor will have a certain impact on the amplitude-frequency characteristics of the system. When the system frequency disturbance is within 0.02... -0.3 When the frequency disturbance is between 0.08 and 0.08, the natural overmodulation factor will have a certain impact on the phase-frequency characteristics of the system. Therefore, considering all factors, it is recommended to limit the frequency disturbance when it is greater than 0.08. That is, the power grid disturbance frequency is greater than 0.0127. The influence of the natural overshoot coefficient is considered. Frequency domain analysis is performed on the system. Taking the low-pressure cylinder work ratio correction coefficient under heating conditions as an example, the frequency domain characteristics of the system change when the correction coefficient module is turned off / on are shown in Figure 16. As can be seen from Figure 16, when the system frequency disturbance is within 0.001... -0.1 When the frequency disturbance is between 0.001, the work ratio correction factor will affect the amplitude-frequency characteristics of the system. -0.8 When the work ratio correction factor is between 0.00016 and 0.00016, it will have a certain impact on the phase frequency characteristics of the system, that is, the main affected frequency band is 0.00016. -0.1274 between.

[0191] Please refer to Figure 17. In one embodiment of this application, the power-valve position conversion coefficient obtained from the configuration structure analysis of the regulating system of the thermal power unit includes:

[0192] S1701 calls up the historical control system operation data of the thermal power unit according to the configuration structure of the thermal power unit's regulation system;

[0193] S1702 analyzes the historical control system operation data to obtain the proportional relationship between the input and output of the thermal power unit, and obtains the power-valve position conversion coefficient through the proportional relationship.

[0194] For example, in practical work, this application analyzes the situation where there is a large deviation between the PID controller parameters in the control system model and the actual PID controller parameters in the actual control system, based on previous simulations:

[0195] First, it's necessary to clarify the position and role of the control system in the closed-loop model: essentially, it's a set of algorithms. Taking a traditional control system model as an example, the input consists of three parts: the primary frequency regulation loop, the actual load command signal, and the power feedback signal. The output is the comprehensive valve position command. The correspondence between input and output is characterized by parameters in the control system, such as the integral and proportional coefficients in a PID controller. Therefore, when the simulation results of the control system parameters deviate significantly from the actual values, it means that even when the parameters in the control system model match the actual values, the comprehensive valve position command obtained from the model simulation is inconsistent with the actual comprehensive valve position command. This deviation could be caused by either the input data or the input-output correspondence.

[0196] To eliminate the influence of input data, this application used actual data from a primary frequency modulation test to conduct a test. The input value of the primary frequency modulation loop was obtained by using the slip and the primary frequency modulation function, and was used together with the actual load command and actual power data as input to the control system model. By adjusting the PID controller parameter values, a good matching relationship was achieved between the simulated value and the actual value of the integrated valve position command. The results showed that when the output signal was close to the actual value, the PID controller parameters had a large deviation from the actual value, thus eliminating the possibility that the input signal was the main cause of the deviation. The analysis then examines potential issues in the input-output relationship. It notes that in actual control systems, the input signal is the power value (theoretically ranging from 0 to rated power), and the output signal is the comprehensive valve position command value (theoretically ranging from 0 to 100). In the model, the control system input signal is the per-unit power value (theoretically ranging from 0 to 1), and the output signal is the per-unit comprehensive valve position command value (theoretically ranging from 0 to 1). Therefore, it's easy to see that the use of per-unit scaling in the model alters the proportional relationship between the control system's input and output. This application names this proportional relationship the power-valve position conversion coefficient, which is numerically equal to the ratio of the unit's rated power value (MW) to the comprehensive valve position command value (%), denoted by the symbol B. In traditional control system models, B is masked as a deviation of the PID controller parameters. Furthermore, the actual control system loop contains a correction coefficient module, which this application refers to as the PID correction coefficient, denoted by the symbol A. In traditional control system models, the correction coefficient is not reflected. When participating in the calculation, it plays a similar role to the PID controller parameter. Therefore, in traditional control system models, the correction coefficient is also masked as a deviation of the PID controller parameter.

[0197] The transfer function of the reconfiguration model of the regulation system is shown in Figure 18, where S is the Laplace operator. The difference between the rated speed and the actual speed, TW delay T1 is the pure delay time of the frequency input signal, and T2 is the time constant of the speed measurement circuit. TW2 is the time constant of an inertial element corresponding to the power feedback signal. delay DP is the pure delay time after the frequency signal is amplified. UP / DP DOWN The per-unit value for limiting the rise / fall rate of the input PID signal after the frequency signal is amplified, TW2-PID delay TP is the pure delay time of the frequency signal after amplification and input to the PID controller. delay The pure delay time of the power feedback signal. This represents the per-unit value of the turbine power feedback signal under load control conditions. This represents the per-unit value of the turbine power feedback signal under regulating stage pressure control conditions. This is the per-unit value for the power setpoint. Switch to control mode selection. This is the amplification factor for the rotational speed deviation. For load control feedforward coefficients, The time constant of the first-order inertial element in power feedback. This refers to the proportional element ratio in a PID controller. This refers to the integral factor in a PID controller. This is the factor of the derivative element in the PID controller. To comprehensively regulate the per-unit value of the valve position command, This is the power-valve position conversion factor. This is the PID correction coefficient.

[0198] In one embodiment of this application, target simulation processing using the single reheat turbine reconfiguration model and the regulation system model includes: static test simulation processing or load disturbance test simulation processing using the single reheat turbine reconfiguration model and the regulation system model.

[0199] For example, in practical work, the reconstructed single reheat turbine model and regulating system model described above can be used to optimize and write engineering application schemes for the measurement and modeling of turbine and regulating system parameters. The experimental process logic can be referred to Figure 19, which is a schematic diagram of the experimental flow logic for the measurement and modeling of thermal power unit parameters provided in an embodiment of this application. The specific experimental flow is as follows:

[0200] 1. Unit Introduction;

[0201] 2. Experimental objective:

[0202] The purpose of testing the parameters of steam turbine units and their speed control systems is to provide real and reliable experimental data for long-term stability simulation analysis in power systems.

[0203] 3. Test content:

[0204] A. The identification parameters of the steam turbine generator set control system are shown in Table 1.

[0205] Table 1

[0206]

[0207] B. The identification parameters of the turbine generator set actuator are shown in Table 2.

[0208] Table 2

[0209]

[0210] C. The identification parameters of the steam turbine generator set are shown in Table 3.

[0211] Table 3

[0212]

[0213] 4. Test Items and Methods

[0214] 1) Test items: Static test, load disturbance test;

[0215] 2) Test methods:

[0216] 2.1 Static Test:

[0217] Test conditions and requirements: a) The regulating system has been accepted, the unit is in a shutdown and cooling state, and there is no residual steam pressure in the main and reheat steam pipelines; b) After the regulating steam valve is set, 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 turbine is ready for braking, and the oil temperature and oil pressure are within the normal range; e) The turbine vacuum system is not in operation.

[0218] Experimental procedure:

[0219] a) High-frequency gate large opening step disturbance test

[0220] Step 1: The valve is under single-valve control, and the valve position is 0%.

[0221] Step 2: Set the valve position command to 100%;

[0222] Step 3: Hold for 5 seconds, then set the valve position command to 0%;

[0223] Step 4: Continue for 5 seconds, and record the "static test waveform data" throughout the process at a sampling frequency of 1000Hz. The parameter names are shown in Table 4.

[0224] b) High-adjustment gate small-opening step disturbance test

[0225] Step 1: The valve is under single-valve control, and the valve position is at 50%.

[0226] Step 2: Set the valve position command to 55%;

[0227] Step 3: Hold for 5 seconds, then set the valve position command to 50%.

[0228] Step 4: Hold for 5 seconds to set the valve position command to 45%;

[0229] Step 5: Hold for 5 seconds, then set the valve position command to 50%.

[0230] Step 6: Continue for 5 seconds, and record the "static test waveform data" throughout the process at a sampling frequency of 1000Hz. The parameter names are shown in Table 4.

[0231] After the high-frequency gate step test is completed, query the control system logic record "Control System Setting Data", see Table 5.

[0232] 2.2 Load Disturbance Test

[0233] Test conditions and requirements: a) Primary frequency regulation test has been completed and the primary frequency regulation test function is in operation; b) Automatic Generation Control (AGC) is deactivated; c) Load disturbance test under deep peak shaving conditions for heating units should be conducted separately under heating and pure condensing conditions; d) The load disturbance test conditions should include the lowest load condition for deep peak shaving certification of the unit; e) It is advisable to conduct load disturbance tests 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.

[0234] Experimental procedure:

[0235] a) Wiring before testing

[0236] Connect the measurement points of the "load disturbance test waveform data" to the high-speed waveform recorder as required. The parameter names and requirements are shown in Table 6.

[0237] b) Disturbance test under coordinated control system (CCS) mode

[0238] AGC control was disengaged, and the unit operated stably under test conditions. CCS coordinated control was then activated. During the test, the unit's reference speed was changed to generate a speed deviation, thereby initiating a frequency regulation action to achieve a step change in load. A ±9 rpm load disturbance test was conducted. At the engineer's station, the thermal engineers set the slip: first, a +9 rpm slip was set, maintained for 1 minute, then restored, and maintained for 1 minute after restoration; then a -9 rpm slip was set, maintained for 1 minute, then restored, and maintained for 1 minute after restoration.

[0239] During the test, “Load Disturbance Test Record Data” was recorded. The parameter names are shown in Table 7.

[0240] c) Disturbance test of Digital Electro-Hydraulic Control System (DEH) under valve control mode

[0241] With AGC control disengaged and the unit operating stably under test conditions, CCS coordination control was also disengaged, and DEH was set to valve control mode. During the test, the unit's base speed was changed to generate a speed deviation, thereby initiating a frequency regulation action to achieve a step change in load. A ±6 rpm load disturbance test was conducted. At the engineer's station, the thermal engineers set the slip: first +6 rpm slip, maintained for 1 minute, then restored, maintained for 1 minute, then -6 rpm slip, maintained for 1 minute, then restored, and maintained for 1 minute.

[0242] During the test, “Load Disturbance Test Record Data” was recorded. The parameter names are shown in Table 7.

[0243] d) Valve flow characteristic fitting data acquisition

[0244] Query the power plant's Supervisory Information System (SIS) and collect "SIS historical data." Parameter names and requirements are shown in Table 8. The data sampling accuracy is 1 minute / point, and the data volume should be at least one week's worth. The data must cover the integrated valve position and active power, including modeling tests and nearby operating conditions.

[0245] The required data collection is divided into five parts: static test waveform data, control system setting data, load disturbance test waveform data, load disturbance test record data, and SIS historical data.

[0246] The static test waveform data are shown in Table 4.

[0247] Table 4

[0248]

[0249] The control system settings are shown in Table 5.

[0250] Table 5

[0251]

[0252] The waveform data from the load disturbance test are shown in Table 6.

[0253] Table 6

[0254]

[0255] The load disturbance test data are shown in Table 7.

[0256] Table 7

[0257]

[0258] The historical SIS data used to fit the valve flow characteristic curve is shown in Table 8.

[0259] Table 8

[0260]

[0261] Based on the measured results of a Harbin 630MW subcritical, single-reheat, three-cylinder, four-exhaust, single-shaft, condensing turbine unit operating at 20% rated power Pe under coordinated control power closed-loop mode, this application uses the wide-load operation thermal power unit simulation method provided in this application. Using actual slip and actual load commands as inputs to the closed-loop model, the simulation results of each part of the reconstructed model (referred to as the simplified model) and the traditional BPA model are compared with actual data. The comparison objects include integrated valve position commands, regulating stage pressure, and power. Identification parameters can be found in Tables 9 to 11. The simulation results are shown in Figures 20 and 22. Figure 20 is a schematic diagram comparing the simulation results of integrated valve position commands provided in an embodiment of this application; Figure 21 is a schematic diagram comparing the simulation results of regulating stage pressure provided in an embodiment of this application; Figure 22 is a schematic diagram comparing the simulation results of unit power provided in an embodiment of this application.

[0262] Table 9

[0263]

[0264] Table 10

[0265]

[0266] Table 11

[0267]

[0268] Similarly, Equation 32 was used to calculate the goodness of fit between the simulated curve and the measured curve, and the results are shown in Table 12:

[0269]

[0270] In the formula, These are actual measured data. for The mean, This is the simulation result data.

[0271] Table 12

[0272]

[0273] Analysis of the above results shows that the closed-loop simulation accuracy of the simplified model established in this application is generally higher than that of the BPA model, which is reflected in the simplified model's... The values ​​are all above 0.9829, while the BPA model's... The maximum value is 0.8451.

[0274] This application also provides a simulation system for thermal power units operating under wide loads. The system includes: a turbine reconfiguration module, a regulation module, and a simulation module. The turbine reconfiguration module is configured to construct a single reheat turbine model based on the operating mechanism of the thermal power unit turbine using a power natural overshoot coefficient calculation method. It analyzes the influence correlation of multiple preset influence data affecting the thermal power unit turbine on the single reheat turbine model through time and frequency domain analysis, determines the influence conditions based on the influence correlation, and adjusts the single reheat turbine model to obtain a single reheat turbine reconfiguration model. The regulation module is configured to obtain the power-valve position conversion coefficient and correction coefficient based on the configuration structure analysis of the thermal power unit's regulation system, and construct a regulation system model using the power-valve position conversion coefficient and the correction coefficient. The simulation module is configured to perform target simulation processing using the single reheat turbine reconfiguration model and the regulation system model.

[0275] In the above embodiments, the turbine reconfiguration module includes a construction unit and an adjustment unit; the construction unit is configured to calculate the power natural overshoot coefficient corresponding to the two parts divided into two parts by the first extraction point of the high-pressure cylinder; and construct a single reheat turbine model based on the calculated power natural overshoot coefficient. The influencing conditions include main steam pressure variation, valve nonlinearity, unit heating, and flexibility modification. The regulating unit is configured to construct an integral function and an inertial function based on the steam flow rate at the turbine's current state when the influencing condition is main steam pressure variation. A main steam adjustment function is then constructed based on these integral and inertial functions. The integral function is the corresponding integral function constructed when the steam flow rate entering the turbine changes, causing an imbalance between the heat carried away by the steam flowing into the turbine per unit time and the heat generated by fuel combustion, resulting in a change in the boiler pressure and the fuel heat being greater than the heat carried away by the steam flow. The inertial function is the corresponding inertial function with a proportional coefficient constructed when the boiler pressure is constant and the main steam pressure changes due to a change in the steam flow rate entering the turbine. When the influencing condition is valve nonlinearity, the actual equivalent valve is obtained based on the ratio between the measured regulating stage pressure and the measured main steam pressure. The system constructs a valve linearity function curve based on the correlation between the actual equivalent valve position and the total valve position command, and then constructs a valve management function based on the valve linearity function curve. When the influencing conditions are unit heating factors and flexibility modification factors, an extraction steam heating function is constructed based on the correlation between the main steam flow, extraction steam flow, and turbine power. When the influencing conditions are unit heating factors and flexibility modification factors, an extraction steam power cut-off curve is obtained based on the turbine's operating data during low-pressure cylinder cut-off, calculated using turbine thermal balance, and a low-pressure cylinder cut-off function is constructed based on the cut-off curve. Furthermore, a bypass curve is obtained based on the turbine's operating data during high- and low-pressure bypass heating, calculated using turbine thermal balance, and a bypass function is constructed based on the bypass curve. Finally, the single reheat turbine model is adjusted based on the main steam adjustment function, the valve management function, the extraction steam heating function, and the bypass function to obtain a single reheat turbine reconfiguration model.

[0276] In another embodiment of this application, the turbine reconfiguration module includes a verification module, which is configured to analyze the impact of the influencing conditions on the simulation accuracy of the single reheat turbine reconfiguration model through time and frequency domain analysis; and determine the influence correlation based on the comparison result of the simulation accuracy impact and a preset threshold. The regulation module includes a coefficient extraction unit, which is configured to call the historical control system operation data of the thermal power unit according to the configuration structure of the thermal power unit's regulation system; analyze the historical control system operation data to obtain the proportional relationship between the input and output of the thermal power unit, and obtain the power-valve position conversion coefficient through the proportional relationship. The simulation module is configured to perform static test simulation processing or load disturbance test simulation processing through the single reheat turbine reconfiguration model and the regulation system model.

[0277] Since the principle behind this system's problem-solving approach is similar to the simulation method for thermal power units operating under wide loads, the implementation of this system can be found in the implementation of the simulation method for thermal power units operating under wide loads, and the repetitive parts will not be repeated.

[0278] The beneficial technical effects of this application are as follows: from the perspective of mechanism, it considers the factors that have the greatest impact on the simulation accuracy of the model when the unit is running under wide loads, and reconstructs the single reheat turbine model and the regulation system model in the traditional BPA model to form an application method; thus improving the simulation accuracy and the applicable range of operating conditions of the model.

[0279] This application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-described method.

[0280] This application also provides a computer-readable storage medium storing a computer program that performs the above-described methods.

[0281] This application also provides a computer program product, including a computer program / instructions that, when executed by a processor, implement the steps of the above-described method.

[0282] Figure 23 is a schematic diagram of the physical structure of an electronic device provided in an embodiment of this application. As shown in Figure 23, the electronic device includes: a processor 501, a memory 502, and a bus 503.

[0283] The processor 501 and the memory 502 communicate with each other via the bus 503.

[0284] The processor 501 is configured to call program instructions in the memory 502 to execute the methods provided in the above-described method embodiments.

[0285] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described simulation method for thermal power units operating under wide load conditions.

[0286] This application also provides a computer program product, which includes a computer program that, when executed by a processor, implements the above-described simulation method for thermal power units operating under wide load conditions.

[0287] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage, compact disc read-only memory (CD-ROM), optical storage, etc.) containing computer-usable program code.

[0288] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create a system for implementing the functions specified in one or more blocks of the flowchart illustrations and / or one or more blocks of the block diagrams.

[0289] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including an instruction system that implements the functions specified in one or more flowcharts and / or one or more block diagrams.

[0290] These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, such that the instructions, which execute on the computer or other programmable apparatus, provide steps for implementing the functions specified in one or more flowcharts and / or one or more block diagrams.

[0291] In the wide-load operation simulation method of thermal power units in this application embodiment, the on-site sensors of the thermal power unit (including main steam pressure sensor, steam flow sensor, extraction steam flow sensor, and power transmitter) collect data on main steam pressure, steam flow, extraction steam volume, and actual turbine power under wide-load conditions. This data is directly transmitted to the Coordinated Control System (CCS) for storage. The CCS, as the overall coordination center of the unit, is responsible for integrating and recording various operating data, providing a foundation for subsequent analysis. The actual data stored in the CCS is sent to the simulation computer, which performs time-domain and frequency-domain analysis on the "actual data collected by the sensors" and the "output data of the initial model of the single reheat turbine" to determine the influence relationship between various influencing data (such as main steam pressure fluctuations and extraction steam flow changes) and the single reheat turbine model. Then, combined with the historical operating condition data stored in the CCS, the preset influencing conditions (main steam pressure change factors, valve nonlinearity factors, unit heating factors, and flexibility modification factors) are determined. Based on the determined influencing conditions, real-time sensor data (such as main steam pressure and extraction valve opening data) transmitted by CCS are retrieved on the simulation computer to adjust the initial model parameters of the single reheat turbine and obtain the reconfigurable model of the single reheat turbine. The "configuration structure of the thermal power unit's regulating system" (including the valve position control logic built into DEH, the turbine power feedback link, and the electro-hydraulic valve control logic configuration) is retrieved from the Digital Electro-hydraulic Control System (DEH). Simultaneously, historical operating data of the regulating system stored in DEH (such as valve position commands under different loads, corresponding turbine power, and valve opening feedback data) are extracted. This data is analyzed on the simulation computer to calculate the power-valve position conversion coefficient and correction coefficient. Based on these two coefficients, the regulating system model is constructed on the simulation computer. The single reheat turbine reconfiguration model and the regulation system model are linked in the simulation computer to carry out target simulation processing: During static tests, the valve position command data of the regulation system is obtained through DEH to verify the matching degree between the model output power and the actual power recorded by CCS; During load disturbance tests, the simulated power data of the model is fed back to CCS, and the actual regulation response data (such as unit power and main steam pressure changes) recorded by CCS are compared to complete the accurate simulation of a wide load range.

Claims

1. A simulation method for thermal power units operating under wide load conditions, comprising: Based on the operating mechanism of steam turbines in thermal power units, a single reheat steam turbine model is constructed using the method of calculating the natural power overshoot coefficient. Multiple preset influence data affecting the steam turbine of the thermal power unit are collected. Through time domain analysis and frequency domain analysis, the influence relationship of the influence data on the single reheat steam turbine model is determined. The influence conditions are determined according to the influence relationship, and the single reheat steam turbine model is adjusted according to the influence conditions to obtain a single reheat steam turbine reconfiguration model. Based on the configuration structure of the regulating system of the thermal power unit, the power-valve position conversion coefficient and the correction coefficient are obtained through analysis; and the regulating system model is constructed using the power-valve position conversion coefficient and the correction coefficient. The target simulation is performed using the single reheat turbine reconfiguration model and the regulation system model.

2. The simulation method for thermal power units operating under wide loads according to claim 1, wherein, The method for calculating the natural power overshoot coefficient is used to construct a single reheat turbine model, which includes: The high-pressure cylinder is divided into two parts with one extraction as the dividing point, and the power natural over-adjustment coefficients corresponding to the two parts after the division are calculated respectively. Based on the power natural overshoot coefficients corresponding to the two split parts, a single reheat turbine model is constructed.

3. The simulation method for wide-load operation of thermal power units according to claim 1, wherein, The influencing factors include: main steam pressure variation factors, valve nonlinearity factors, unit heating factors, and flexibility modification factors.

4. The simulation method for wide-load operation of thermal power units according to claim 3, wherein, The step of adjusting the single reheat turbine model according to the influencing conditions to obtain a single reheat turbine reconfiguration model includes: In response to the determination that the influencing conditions are the main steam pressure variation factors, the single reheat turbine model is adjusted in the following manner to obtain a single reheat turbine reconfiguration model: Based on the influence of main steam pressure on main steam flow rate, a main steam adjustment function is constructed. The single reheat turbine model is adjusted by the main steam adjustment function to obtain a single reheat turbine reconfiguration model.

5. The simulation method for thermal power units operating under wide loads according to claim 4, wherein, The main steam adjustment function, constructed based on the influence of main steam pressure on main steam flow rate, includes: Based on the different operating conditions caused by the change in the main steam flow rate entering the turbine, an integral function and an inertial function are constructed respectively, and a main steam adjustment function is constructed based on the integral function and the inertial function; The integral function is applied to the first operating condition where the main steam flow rate changes and the heat of the boiler fuel is greater than the heat carried away by the steam, and is used to characterize the pressure change law of the boiler under the first operating condition. The inertia function is a function with a proportionality coefficient, applied to the second operating condition where the main steam flow rate changes when the steam drum pressure is constant, and used to characterize the main steam pressure change pattern under the second operating condition.

6. The simulation method for wide-load operation of thermal power units according to claim 3, wherein, The step of adjusting the single reheat turbine model according to the influencing conditions to obtain a single reheat turbine reconfiguration model includes: In response to determining that the influencing condition is the valve nonlinearity factor, the single reheat turbine model is adjusted in the following manner to obtain a single reheat turbine reconfiguration model: Based on the correspondence between the measured regulating stage pressure and the measured main steam pressure and the total valve position command, a valve management function is constructed; The single reheat turbine model is adjusted according to the valve management function to obtain a single reheat turbine reconfiguration model.

7. The simulation method for wide-load operation of thermal power units according to claim 6, wherein, The valve management function is constructed based on the correspondence between the measured regulating stage pressure and main steam pressure and the total valve position command, and includes: The actual equivalent valve position is obtained based on the ratio between the measured regulating stage pressure and the measured main steam pressure. Based on the correspondence between the actual equivalent valve position and the total valve position command, a valve linearity function curve is constructed; Based on the valve linearity function curve, construct the valve management function.

8. The simulation method for thermal power units operating under wide loads according to claim 3, wherein, The step of adjusting the single reheat turbine model according to the influencing conditions to obtain a single reheat turbine reconfiguration model includes: In response to determining that the influencing conditions are the unit heating factors and the flexibility modification factors, the single reheat turbine model is adjusted in the following manner to obtain a single reheat turbine reconfiguration model: Based on the causal relationship between main steam flow rate, extraction steam flow rate, and turbine power, an extraction steam heating function is constructed. The single reheat turbine model is adjusted according to the extraction steam heating function to obtain a single reheat turbine reconfiguration model.

9. The simulation method for thermal power units operating under wide loads according to claim 3, wherein, The flexibility modification factors correspond to the low-pressure cylinder cut-off condition and the high and low bypass heating condition.

10. The simulation method for wide-load operation of thermal power units according to claim 9, wherein, The step of adjusting the single reheat turbine model through the influencing conditions to obtain a single reheat turbine reconfiguration model includes: In response to determining that the influencing conditions are the unit heating factors and the flexibility modification factors, the single reheat turbine model is adjusted in the following manner to obtain a single reheat turbine reconfiguration model: Based on the principle of steam turbine thermal balance, the operating data of the steam turbine under the condition of low-pressure cylinder cut-off is calculated to obtain the power cut-off curve of the steam turbine under the condition of low-pressure cylinder cut-off. Construct a low-pressure cylinder cutoff function based on the cutoff curve; The single reheat turbine model is adjusted according to the low-pressure cylinder cutoff function to obtain a single reheat turbine reconfiguration model.

11. The simulation method for thermal power units operating under wide loads according to claim 9, wherein, The step of adjusting the single reheat turbine model through the influencing conditions to obtain a single reheat turbine reconfiguration model includes: In response to determining that the influencing conditions are the unit heating factors and the flexibility modification factors, the single reheat turbine model is adjusted in the following manner to obtain a single reheat turbine reconfiguration model: Based on the principle of steam turbine thermal balance, the operating data of the steam turbine under the high and low bypass heating conditions are calculated to obtain the bypass curve of the steam turbine power under the high and low bypass heating conditions. Construct a bypass function based on the bypass curve; The single reheat turbine model is adjusted according to the bypass function to obtain a single reheat turbine reconfiguration model.

12. The simulation method for wide-load operation of thermal power units according to claim 1, wherein, The determination of the influence relationship of the influencing data on the single reheat turbine model through time-domain and frequency-domain analysis includes: The impact of the influencing data on the simulation accuracy of the single reheat turbine reconfiguration model was determined through time-domain and frequency-domain analysis. The degree of influence is compared with the preset threshold of the single reheat turbine reconfiguration model, and the influence relationship is determined based on the comparison result.

13. The simulation method for thermal power units operating under wide loads according to claim 1, wherein, The power-valve position conversion coefficient obtained by analyzing the configuration structure of the thermal power unit's regulation system includes: Based on the configuration structure of the thermal power unit's regulation system, call up the historical control system operation data of the thermal power unit; The proportional relationship between the input and output of the thermal power unit is obtained by analyzing the historical control system operation data, and the power-valve position conversion coefficient is obtained through the proportional relationship.

14. The simulation method for thermal power units operating under wide loads according to claim 1, wherein, The target simulation processing using the single reheat turbine reconfiguration model and the regulation system model includes: Static test simulation or load disturbance test simulation is performed using the single reheat turbine reconfiguration model and the regulation system model.

15. A simulation system for a thermal power unit operating under wide load conditions, comprising: a turbine reconfiguration module, a regulation module, and a simulation module; The turbine reconfiguration module is configured to: construct a single reheat turbine model based on the operating mechanism of the thermal power unit turbine and using a power natural overshoot coefficient calculation method; collect multiple preset influence data affecting the thermal power unit turbine, and determine the influence relationship of the influence data on the single reheat turbine model through time domain analysis and frequency domain analysis; determine the influence conditions based on the influence relationship, and adjust the single reheat turbine model according to the influence conditions to obtain a single reheat turbine reconfiguration model; The regulation module is configured to analyze and obtain the power-valve position conversion coefficient and correction coefficient based on the configuration structure of the regulation system of the thermal power unit; and to construct a regulation system model using the power-valve position conversion coefficient and the correction coefficient. The simulation module is configured to perform target simulation processing using the single reheat turbine reconfiguration model and the regulation system model.

16. The wide-load operation thermal power unit simulation system according to claim 15, wherein, The turbine reconfiguration module includes a construction unit, which is configured to split the high-pressure cylinder into two parts with one extraction as the dividing point, calculate the power natural overshoot coefficients corresponding to the two parts after the split, and construct a single reheat turbine model based on the power natural overshoot coefficients corresponding to the two parts after the split.

17. The wide-load operation thermal power unit simulation system according to claim 15, wherein, The influencing conditions include main steam pressure variation factors, valve nonlinearity factors, unit heating factors, and flexibility modification factors; the turbine reconfiguration module also includes a regulating unit; The adjustment unit is configured to perform at least one of the following: In response to the determination that the influencing condition is the main steam pressure change factor, the single reheat turbine model is adjusted in the following manner to obtain a single reheat turbine reconfiguration model: Based on different operating conditions caused by changes in the steam flow rate entering the turbine, an integral function and an inertial function are constructed respectively, and a main steam adjustment function is constructed based on the integral function and the inertial function; wherein, the integral function is applied to a first operating condition where the steam flow rate changes and the heat of the boiler fuel is greater than the heat carried away by the steam, and is used to characterize the boiler pressure change law under the first operating condition; the inertial function is a function with a proportional coefficient, applied to a second operating condition where the steam flow rate changes when the boiler pressure is constant, and is used to characterize the main steam pressure change law under the second operating condition; the single reheat turbine model is adjusted using the main steam adjustment function to obtain a single reheat turbine reconfiguration model; In response to the determination that the influencing condition is the valve nonlinearity factor, the single reheat turbine model is adjusted in the following manner to obtain a single reheat turbine reconfiguration model: The actual equivalent valve position is obtained based on the ratio between the measured regulating stage pressure and the measured main steam pressure; a valve linearity function curve is constructed based on the correspondence between the actual equivalent valve position and the total valve position command; a valve management function is constructed based on the valve linearity function curve; and the single reheat turbine model is adjusted based on the valve management function to obtain a single reheat turbine reconfiguration model. In response to the determination that the influencing conditions are the unit heating factors and the flexibility modification factors, the single reheat turbine model is adjusted in the following manner to obtain a single reheat turbine reconfiguration model: an extraction steam heating function is constructed based on the causal relationship between the main steam flow rate, extraction steam flow rate, and turbine power; the single reheat turbine model is adjusted based on the extraction steam heating function to obtain a single reheat turbine reconfiguration model. In response to the determination that the influencing conditions are the unit heating factors and the flexibility modification factors, the single reheat turbine model is adjusted in the following manner to obtain a single reheat turbine reconfiguration model: The turbine's operating data under low-pressure cylinder cut-off conditions is calculated based on the turbine's thermal balance principle to obtain the turbine power cut-off curve under the low-pressure cylinder cut-off condition; a low-pressure cylinder cut-off function is constructed based on the cut-off curve; and the single reheat turbine model is adjusted based on the low-pressure cylinder cut-off function to obtain a single reheat turbine reconfiguration model. In response to the determination that the influencing conditions are the unit heating factors and the flexibility modification factors, the single reheat turbine model is adjusted in the following manner to obtain a single reheat turbine reconfiguration model: based on the turbine thermal balance principle, the turbine's operating data under high and low bypass heating conditions is calculated to obtain the bypass curve of the turbine power under the high and low bypass heating conditions; a bypass function is constructed based on the bypass curve; the single reheat turbine model is adjusted based on the bypass function to obtain a single reheat turbine reconfiguration model.

18. The wide-load operation thermal power unit simulation system according to claim 15, wherein, The turbine reconfiguration module includes a verification module, which is configured to determine the degree of influence of the influencing data on the simulation accuracy of the single reheat turbine reconfiguration model through time domain analysis and frequency domain analysis; compare the degree of influence with a preset threshold of the single reheat turbine reconfiguration model; and determine the influence relationship based on the comparison result.

19. The wide-load operation thermal power unit simulation system according to claim 15, wherein, The regulation module includes a coefficient extraction unit, which is configured to: retrieve historical control system operation data of the thermal power unit according to the configuration structure of the regulation system of the thermal power unit; analyze the historical control system operation data to obtain the proportional relationship between the input and output of the thermal power unit; and obtain the power-valve position conversion coefficient through the proportional relationship.

20. The wide-load operation thermal power unit simulation system according to claim 15, wherein, The simulation module is configured to perform static test simulation or load disturbance test simulation using the single reheat turbine reconfiguration model and the regulation system model.

21. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the method of any one of claims 1 to 14.

22. A computer-readable storage medium storing a computer program that, when executed by a processor, implements the method of any one of claims 1 to 14.

23. A computer program product comprising a computer program that, when executed by a processor, implements the method of any one of claims 1 to 14.

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