CN-121997732-A - Parameter identification and evaluation method for speed regulation system of deep peak regulation thermal power unit

CN121997732ACN 121997732 ACN121997732 ACN 121997732ACN-121997732-A

Abstract

The invention relates to a parameter identification and evaluation method for a speed regulation system of a deep peak regulation thermal power unit, which comprises the steps of establishing a simulation model of a steam turbine and a speed regulation system thereof, comprising a speed regulator, an actuating mechanism and a steam turbine model, acquiring static and dynamic test data of the unit, preprocessing and normalizing, calculating partial parameters and an on-off time constant of the motor in the speed regulator and the actuating mechanism model based on the static test data of the unit, identifying PID parameters of the speed regulator and the actuating mechanism model by adopting an intelligent identification method, acquiring valve flow characteristics based on the dynamic test data of the unit under different deep peak regulation operating conditions, identifying the parameters of the steam turbine model by adopting an intelligent identification method, substituting the identification parameters into the simulation model to operate, and taking the fitting goodness of simulation and actual measurement output data as an evaluation index to evaluate an identification result, thereby establishing the deep peak regulation thermal power unit model suitable for simulation analysis of the power system. The simulation precision and adaptability of the unit model under the deep peak shaving working condition are effectively improved.

Inventors

JIA BIN
YANG YANPING
ZHANG JIAMING
YUN JIE
AO QI
DUAN XUEYOU
LI XIAOBO
WEI CHAO
WANG LI
CHEN ZHONG
WANG RUOXU
XIN SHIHONG
ZHANG FENGFENG

Assignees

内蒙古电力(集团)有限责任公司内蒙古电力科学研究院分公司

Dates

Publication Date: 20260508
Application Date: 20260120

Claims (10)

1. The method for identifying and evaluating the parameters of the speed regulation system of the deep peak regulation thermal power unit is characterized by comprising the following steps of: S1, establishing a simulation model of a steam turbine and a speed regulation system thereof on a simulation platform, wherein the simulation model comprises a speed regulator model, an execution mechanism model and a steam turbine model; s2, acquiring static and rotational speed disturbance dynamic test data of a unit under a set working condition, carrying out pretreatment including denoising and smoothing on the test data, and normalizing the pretreated data to obtain actual measurement input and output data of a speed regulator model, an actuator model and a steam turbine model; S3, calculating and acquiring limiting, dead zone and delay link parameters in a speed regulator model and an actuator model and an on-off time constant of an oil motor in the actuator model based on unit static test data; s4, based on the static test data of the unit, identifying and acquiring PID parameters of a speed regulator model and an execution mechanism model by adopting an intelligent identification method; s5, performing piecewise linear fitting based on unit rotating speed disturbance dynamic test data under different depth peak shaving operation conditions, obtaining valve flow characteristics, and establishing a nonlinear relation among a throttle opening, main steam pressure and steam flow; s6, based on unit rotating speed disturbance dynamic test data and valve flow characteristics under different deep peak regulation operation conditions, an intelligent identification method is adopted to identify and acquire relevant parameters of a steam turbine model; S7, substituting the identified parameters into a simulation model, operating the simulation model to obtain model output data, and using the fitting goodness of the model output data and the actually measured output data as an evaluation index to evaluate the model parameter identification result, so as to establish a deep peak regulation thermal power unit model suitable for simulation analysis of the power system.
2. The method for identifying and evaluating parameters of a speed regulation system of a deep peak-shaving thermal power unit according to claim 1, wherein in the step S1, the input of a speed regulator model is a power set value, a rotation speed set value, unit active power and unit rotation speed, and the input is a door regulating opening command through a power feedforward and controller control link; The input of the execution mechanism model is a door opening command, and the output is the door opening through a controller and a servomotor link; The input of the steam turbine model is main steam flow calculated based on the opening degree of a valve and main steam pressure, the output is mechanical power, and the steam turbine model considers valve flow characteristics.
3. The method for identifying and evaluating parameters of the speed regulation system of the deep peak-shaving thermal power unit according to claim 1, wherein in the step S3, based on input and output data of large step full-open and large step full-closed disturbance of the opening degree of a regulating valve of an actuating mechanism in static test data of the unit, the opening and closing time constant of an oil engine in an actuating mechanism model is calculated, and the calculation formula of the opening and closing time constant of the oil engine is as follows: Wherein T is the opening and closing time constant of the oil engine, P max and P min are the maximum value and the minimum value of the opening of the valve respectively, deltat is the time required by the full-step full-opening or full-closing stroke section of the opening of the valve, deltaP y is the opening variation corresponding to the full-step full-opening or full-closing stroke section of the opening of the valve, deltaP y is the opening increase of the valve when the oil engine is opened, T is the opening time constant of the oil engine, deltaP y is the opening decrease of the valve when the oil engine is closed, and T is the closing time constant of the oil engine.
4. The method for identifying and evaluating parameters of a speed regulation system of a deep peak-shaving thermal power unit according to claim 1 is characterized in that in the step S4, based on input and output data of small step disturbance of opening degree of a regulating gate of an actuating mechanism in static test data of the unit, an intelligent identification method is adopted to identify and obtain parameters of PID controllers of a speed regulator model and the actuating mechanism model, an objective function f of the intelligent identification method aims at solving a minimum mean square error R MSE , and an expression of the objective function f is as follows: wherein n is the total number of data points calculated by the objective function, y i and The method comprises the steps of respectively obtaining the ith measured output data and model output data, setting a governor model, wherein y refers to a governor opening instruction output by the governor model, and setting y refers to a governor opening output by an actuator model.
5. The method for identifying and evaluating parameters of a thermal power generating unit speed regulation system with deep peak regulation according to claim 1, wherein in step S5, based on unit rotational speed disturbance dynamic test data under different deep peak regulation operation conditions, valve flow characteristics are obtained, and the method specifically comprises the following steps: For a steam turbine model, set output of a set under different depth peak-shaving operation points is P g1 、P g2 、…、P gn respectively, a set output interval [ P gi ,P gj ] is selected, a linear fitting relation is established, and an expression of steam flow G s is as follows: Wherein, G sn and P Tn are the main steam flow and the main steam pressure under the rated working condition respectively, F () is the valve flow characteristic function; And performing piecewise linear fitting on the operation points with different depths to generate nonlinear corresponding relations among the opening degree P GV of the regulating valve, the main steam pressure P T and the steam flow G s , so as to realize nonlinear fitting, wherein in a unit output interval [ P gi ,P gj ], the linear fitting expression of the valve flow characteristic function is as follows: Wherein F i( P GV ) is a valve flow characteristic function in a unit output interval [ P gi ,P gj ], and a 0 and a 1 are fitting coefficients.
6. The method for identifying and evaluating parameters of a speed regulation system of a deep peak shaving thermal power generating unit according to claim 1, wherein in step S6, a first-order inertia link is identified based on unit rotational speed disturbance dynamic test data under different deep peak shaving operation conditions, and according to regulation stage steam pressure and reheat steam pressure data measured by unit rotational speed disturbance dynamic test under different deep peak shaving operation conditions Wherein s is a complex variable, P zr is regulating stage steam pressure, P t is reheat steam pressure, and then, according to the data of the opening degree of a regulating valve, main steam pressure and unit output mechanical power measured by a unit rotating speed disturbance dynamic test under different deep peak regulating operation conditions, the high-pressure steam chamber volume time constant T ch and the natural overshoot coefficient lambda of high-pressure cylinder power are obtained through identification.
7. The method for identifying and evaluating parameters of a thermal power generating unit speed regulation system with deep peak regulation according to claim 1, wherein in step S7, the expression of the goodness of fit R 2 is: in the formula, The average of all measured output data.
8. The method for identifying and evaluating parameters of the speed regulation system of the deep peak shaving thermal power generating unit according to claim 1, wherein the intelligent identification method is a quantum particle swarm optimization algorithm QPSO.
9. A computer device comprising at least one processor, at least one memory, and computer program instructions stored in the memory, which when executed by the processor, implement the method of any of claims 1-8.
10. A computer readable storage medium having stored thereon computer program instructions, which when executed by a processor, implement the method of any of claims 1-8.

Description

Parameter identification and evaluation method for speed regulation system of deep peak regulation thermal power unit Technical Field The invention belongs to the technical field of operation control of electric power systems, and particularly relates to a method for identifying and evaluating parameters of a deep peak shaving thermal power unit based on measured data. Background Under the proposal and guidance of the 'double carbon' strategy, the development goal of the electric power system in China is to construct a novel electric power system taking new energy as a main body. Along with the expansion of the grid-connected scale of the new energy, the randomness and the fluctuation of the new energy bring the problems of low frequency modulation quality, large output fluctuation and the like of the series-parallel system. In order to improve the defect of the flexible peak regulation capability of the system, china is greatly advancing the thermal power flexibility improvement project. Typical model parameters of the thermal power generating unit obtained based on rated working conditions are not suitable for deep peak shaving working conditions, and simulation calculation results of the typical model parameters have larger deviation from actual running states. The reason is that the typical model does not fully consider the nonlinear links in the steam turbine and the speed regulation system thereof, but carries out simple linear fitting treatment on the steam turbine, so that the influence of the ignored nonlinear links is more obvious when the peak regulation depth of the unit varies in a large range. At present, china is working on building a novel power system mainly based on new energy. With the large-scale grid connection of new energy sources such as wind power, photovoltaic and the like, the inherent randomness and fluctuation of the new energy sources bring serious challenges to the frequency modulation quality and the power stability of a power grid. In order to improve the flexible regulation capability of the power system, the thermal power unit has become a necessary choice for deep peak regulation operation. However, the typical model parameters of the thermal power generating unit obtained based on the rated working condition have obvious deviation between the simulation result and the actual running state when the unit is in the low-load and large-range deep peak-shaving working condition. The main reason for this deviation is that the existing typical model fails to fully consider the nonlinear links (such as valve flow characteristics) in the steam turbine and its speed regulation system, and a simple linearization process is often adopted. When the peak regulation depth of the unit varies in a large range, the ignored nonlinear influences are more remarkable, so that the accuracy of the work such as simulation analysis, primary frequency modulation characteristic evaluation, control strategy optimization and the like based on the model is reduced. Therefore, by combining actual measurement data of the unit under the actual deep peak regulation working condition, a simulation model of the steam turbine and a speed regulation system thereof, which can accurately reflect dynamic characteristics under different peak regulation depths, is finely built, key parameters of the simulation model are rapidly and accurately identified, and the simulation model has important significance in improving the simulation precision of a power grid and optimizing the operation and control strategy of the unit. Disclosure of Invention The invention aims to overcome the defects of the prior art and provides a method for identifying and evaluating parameters of a speed regulation system of a deep peak shaving thermal power generating unit. In order to achieve the purpose, the invention adopts the following technical scheme that the method for identifying and evaluating the parameters of the speed regulation system of the deep peak-shaving thermal power unit comprises the following steps: S1, establishing a simulation model of a steam turbine and a speed regulation system thereof on a simulation platform, wherein the simulation model comprises a speed regulator model, an execution mechanism model and a steam turbine model; s2, acquiring static and rotational speed disturbance dynamic test data of a unit under a set working condition, carrying out pretreatment including denoising and smoothing on the test data, and normalizing the pretreated data to obtain actual measurement input and output data of a speed regulator model, an actuator model and a steam turbine model; S3, calculating and acquiring limiting, dead zone and delay link parameters in a speed regulator model and an actuator model and an on-off time constant of an oil motor in the actuator model based on unit static test data; s4, based on the static test data of the unit, identifying and acquiring PID parameters of a speed regulator model and an exe