CN-121997591-A - Deep peak-shaving thermal power unit steam turbine considering heat supply working condition and speed regulation system simulation modeling method thereof

CN121997591ACN 121997591 ACN121997591 ACN 121997591ACN-121997591-A

Abstract

The invention relates to a deep peak regulation thermal power unit steam turbine considering heat supply working conditions and a speed regulation system simulation modeling method thereof, belonging to the technical field of operation control of an electric power system. The method comprises the steps of constructing a system model consisting of a speed regulator module, an actuating mechanism module, a steam turbine module and a boiler module, wherein the speed regulator module processes power and rotation speed deviation and outputs a throttle opening command, the steam turbine module receives the throttle opening and main steam pressure output by the boiler at the same time to calculate mechanical power, establishing a steam turbine module model considering heat supply working conditions, wherein the steam turbine module model comprises a heat supply steam extraction module, initializing balance calculation of model parameter assignment and model variable, setting scenes such as set frequency given disturbance, set power disturbance and steam extraction disturbance, verifying simulation characteristics under different peak-regulating depths in a step mode, and verifying simulation characteristics under different working conditions.

Inventors

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

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: 20260123

Claims (10)

1. A deep peak regulation thermal power unit steam turbine taking heat supply conditions into consideration and a speed regulation system simulation modeling method thereof are characterized by comprising the following steps: S1, a deep peak-shaving thermal power generating unit steam turbine taking heat supply conditions into consideration and a speed regulation system thereof are used for constructing a system model consisting of a speed regulator module, an executing mechanism module, a steam turbine module and a boiler module, wherein power deviation and rotation speed deviation are input to the speed regulator module, a door regulation opening instruction output by the speed regulator module is used as input of the executing mechanism module, and the output of the executing mechanism module controls the door regulation opening; s2, building a turbine module model considering heat supply working conditions, wherein the model comprises a turbine heat supply and steam extraction module; s3, assigning values to the model parameters and carrying out model variable initialization balance calculation; s4, setting a set frequency given disturbance, a set power disturbance and a steam extraction flow disturbance scene; S5, verifying simulation characteristics under different working conditions, and outputting a model simulation result.
2. The simulation modeling method for the deep peak-shaving thermal power unit steam turbine taking heating conditions into consideration is characterized in that the speed regulator module comprises a valve position control mode and a coordination control mode, wherein the coordination control mode obtains a set valve opening value based on a set value of a set rotation speed and a difference value of a set rotation speed and a set power difference value, through a proportional-integral-derivative controller and a power feedforward control function, and takes primary frequency modulation speed limitation and primary frequency modulation amplitude upper limit and lower limit under different peak-shaving depths into consideration.
3. The simulation modeling method of the deep peak shaving thermal power generating unit steam turbine taking heat supply conditions into consideration as well as a speed regulation system thereof according to claim 1, wherein the steam turbine module takes the influence of main steam pressure change output by the boiler module on input steam flow into consideration, and establishes a nonlinear relation among mechanical power, a valve opening and main steam pressure, and main steam flow Q T and steam flow per unit value entering the steam turbine The expressions of (2) are respectively: Wherein Q sn and The main steam flow and the main steam pressure under the rated working condition are respectively, P T is the main steam pressure, P GV is the opening degree of the shutter as a function of the opening degree of the shutter.
4. The simulation modeling method of the deep peak shaving thermal power unit steam turbine and the speed regulation system thereof taking the heat supply condition into consideration as claimed in claim 3, wherein the nonlinear relation is characterized in that a piecewise linear fitting relation is established according to different deep peak shaving operation points, nonlinear corresponding relations among the opening degree P GV of the regulating valve, the main steam pressure P T and the input steam flow are generated, the nonlinear relation is approximately piecewise linear fitted, and the unit output interval [ P gi ,P gj ], The linear fit expression is: Wherein, P gj and P gi respectively correspond to the power up value and the power down value of the output section of the unit, and a 0 and a 1 are fitting coefficients.
5. The simulation modeling method for the deep peak shaving thermal power unit steam turbine taking heat supply conditions into consideration and the speed regulation system thereof according to claim 1 is characterized in that a steam turbine module establishes a steam turbine heat supply and steam extraction module model when the heat supply conditions are considered, wherein the steam turbine module comprises a steam extraction volume link, a butterfly valve oil motor link and a proportional-integral controller link, and the heat supply conditions have a heat balance relation: Wherein Q IP is the steam flow of the outlet of the medium pressure cylinder, Q LP is the low pressure steam inlet flow, and Q ES is the heat supply steam extraction flow.
6. The simulation modeling method for the deep peak shaving thermal power generating unit steam turbine and the speed regulation system thereof taking heating conditions into consideration as claimed in claim 1, wherein the variable initialization balance calculation is performed based on differential equations, and is characterized in that for typical first-order differential equations: Wherein x 2 is input quantity, x 1 is feedback quantity; The transfer function obtained by carrying out Laplace transform is as follows: at the initial time and after transition process under disturbance condition, entering a new steady state, making the right side of the equation Equal to 0, such that x 2 =x 1 .
7. The simulation modeling method for the deep peak-shaving thermal power unit steam turbine taking heat supply conditions into consideration and the speed regulation system thereof is characterized in that a set frequency given disturbance and a set power disturbance are set for a speed regulator module, a steam extraction flow instruction disturbance scene is set for the steam turbine module, the disturbance setting mode is step disturbance, simulation characteristics are verified under different conditions, and a model simulation result is output.
8. The deep peak shaving thermal power unit turbine taking heat supply conditions into consideration and the simulation modeling method for the speed regulation system thereof according to claim 1, wherein the turbine module introduces a natural overshoot factor of the power of the high-pressure cylinder To reflect the overshoot characteristic of the high pressure cylinder output in the dynamic process, and the turbine module model comprises the power coefficients of the high pressure cylinder, the medium pressure cylinder and the low pressure cylinder, thereby meeting the requirements of 。
9. A deep peak shaving thermal power unit steam turbine and its speed regulation system simulation modeling system taking into account heating conditions, characterized by comprising a memory, a processor and computer program instructions stored on the memory and executable by the processor, the steps of the method according to any one of claims 1-8 being enabled when the processor runs the computer program instructions.
10. A computer readable storage medium having stored thereon computer program instructions executable by a processor, which when executed by the processor are capable of carrying out the steps of the method according to any one of claims 1-8.

Description

Deep peak-shaving thermal power unit steam turbine considering heat supply working condition and speed regulation system simulation modeling method thereof Technical Field The invention belongs to the technical field of operation control of electric power systems, and particularly relates to a deep peak regulation thermal power unit turbine taking heat supply conditions into consideration and a speed regulation system simulation modeling method thereof. Background Along with the expansion of the grid-connected scale of new energy, in order to solve the problems of large system power fluctuation and the like caused by randomness and fluctuation of the new energy, the thermal power unit has the characteristics of large installed capacity, stable frequency response and the like, and is still an important supporting power supply for grid frequency modulation and peak shaving. But the thermal power generating unit simulation model and parameters established based on typical working conditions in the power system are difficult to be suitable for deep peak shaving working conditions. Therefore, a model capable of accurately reflecting the operating characteristics of the deep peak shaving working condition of the unit is needed to be established. The nonlinear relation in the steam turbine and the speed regulation system of the steam turbine is not fully considered in the typical model of the thermal power unit, and the nonlinear relation is simply and linearly fitted, so that when the peak regulation depth of the unit is widely changed, the ignored nonlinear relation has more obvious influence on the response of the unit. The flow characteristics of the steam turbine valve and the main steam pressure have certain influence on the power response of the thermal power unit participating in primary frequency modulation. Taking into account the non-linear nature of the valve flow, and establishing a primary frequency modulation model of the unit participating in the power grid. Through analysis and optimization of the flow characteristics of the turbine valve, the primary frequency modulation simulation response of the unit is more accurate. The simulation model for the heat supply working condition of the thermal power generating unit is not considered in the simulation analysis of the power system. It is needed to provide a deep peak shaving thermal power unit steam turbine taking heat supply conditions into consideration and a speed regulation system simulation modeling method thereof, and a thermal power unit participation power grid primary frequency modulation dynamic model under the deep peak shaving conditions is established. Disclosure of Invention The invention aims to provide a deep peak-shaving thermal power unit turbine taking heat supply conditions into consideration and a speed regulation system simulation modeling method thereof, In order to achieve the purpose, the technical scheme of the invention is that the deep peak regulation thermal power unit turbine taking the heat supply condition into consideration and the speed regulation system simulation modeling method thereof comprise the following steps: S1, a deep peak-shaving thermal power generating unit steam turbine taking heat supply conditions into consideration and a speed regulation system thereof are used for constructing a system model consisting of a speed regulator module, an executing mechanism module, a steam turbine module and a boiler module, wherein power deviation and rotation speed deviation are input to the speed regulator module, a door regulation opening instruction output by the speed regulator module is used as input of the executing mechanism module, and the output of the executing mechanism module controls the door regulation opening; s2, building a turbine module model considering heat supply working conditions, wherein the model comprises a turbine heat supply and steam extraction module; s3, assigning values to the model parameters and carrying out model variable initialization balance calculation; s4, setting a set frequency given disturbance, a set power disturbance and a steam extraction flow disturbance scene; S5, verifying simulation characteristics under different working conditions, and outputting a model simulation result. Further, the speed regulator module comprises a valve position control mode and a coordination control mode, wherein the coordination control mode obtains a set value of a throttle opening through a proportional-integral-differential controller and a power feedforward control function based on a set value of a set rotation speed and a set rotation speed difference value and a set value of a power and a set active power difference value, and the speed regulator module considers a primary frequency modulation rate limit and upper and lower primary frequency modulation amplitude limits under different peak modulation depths. Further, the steam turbine module considers the influence of the pressure c