Automatic power generation control method for tower type photo-thermal power station

Abstract

The invention provides an automatic power generation control method for a tower-type photo-thermal power station based on a wind and light energy base. According to the method, the tower-type photo-thermal power station serving as a high-quality adjusting device of the wind and light energy base serves as a research object. The automatic power generation control requirement of the tower type photo-thermal power station based on the application scene is greater in the aspects of quick response, stable adjustment and the like, and the power generation power instruction fluctuation is greatly influenced by the real-time fluctuation of wind and light resources. On this basis, a self-updating historical data evolution model is created on the basis of receiving power command data of the photo-thermal power plant to predict the power command, and the predicted value is used for feed-forward compensation of the hot molten salt conditioning loop in combination with the set specific conditioning function device. The power instruction trend factor can be effectively responded in advance of the control loop, the relative lag of the steam generation system is compensated from the setting mechanism, and the rapidity and stability of automatic power generation control of the tower type photo-thermal power station are improved. Meanwhile, in order to avoid control deviation in the hot molten salt adjusting process and ensure the reliability of the control effect, a steam pocket pressure PID controller is arranged on an outer loop of the hot molten salt pump adjusting loop so as to ensure the steam supply capacity and the heat storage capacity on the overall performance of the system.

Description

Technical Field

[0001] The present application relates to a tower-type solar thermal power station, and particularly to an automatic power generation control method for a tower-type solar thermal power station. Background Art

[0002] Most of the existing tower-type solar thermal power stations combined with wind and light energy bases are dedicated to solving the power coordination problem between different power stations, which is to solve the matching problem of different energy stations from a large perspective. From the bottom layer, although the tower-type solar thermal power station has a faster response speed compared with coal power, etc., its response speed is still insufficient compared with photovoltaic power generation and wind power generation. In order to suppress the strong volatility of photovoltaic and wind power generation to the greatest extent, the automatic power generation control method of the tower-type solar thermal power station proposed by the present invention is placed in the energy base environment, and the entire energy base has a unified power coordination control method. After receiving the power command requirement, the tower-type solar thermal power station mainly solves the problem of quickly responding to power changes, coordinating and stabilizing the molten salt and water vapor circuits, so as to improve the reliable and rapid adjustment function of the tower-type solar thermal power station in the energy base and contribute to the overall stability of the energy base as an energy body.

[0003] The solar thermal power station is usually equipped with a thermal energy storage system, and the solar energy collection and power generation of molten salt thermal energy can be decoupled. After the heat collection, the thermal energy storage device has sufficient heat, and the heat exchange between the molten salt and the water vapor pipeline only requires the deployment of two-phase media, greatly reducing the system control elements and enabling the system to start and stop quickly. This enables the solar thermal power station to play an important role in the rapid peak shaving function. At the same time, wind turbines, photovoltaic power stations, etc. in the energy base have strong uncertainties, and the real-time changes in weather will affect the power generation capacity of the units at any time. This poses a high requirement for the power tracking ability of the solar thermal power station, and it is necessary to meet various requirements such as rapidity, foresight, and stability. For the solar thermal power station, the adjustment of the power control loop can be adjusted by the main steam regulating valve at any time, and it can respond quickly. However, the steam and water production loop has a large lag and time delay compared with the power loop. The response time of the steam turbine generator to power is about 0.1 s level, and the response time of the molten salt system to the steam parameter requirement is between dozens of seconds and hundreds of seconds. Therefore, an automatic power generation control method for a tower-type solar thermal power station is needed, aiming to reduce the lag and inertia effects of the steam generation system, enhance the time matching of the steam generation system to respond to the power generation power requirement, and then increase the overall load response speed of the unit. Summary of the Invention

[0004] The purpose of the present application is to provide a solution rapid sub-packaging system, which solves the problem of too long time limit in the process of sub-packaging a large number of solutions into multiple liquid storage bags.

[0005] The present application discloses an automatic power generation control system for a tower-type solar thermal power station. The solar thermal power station is completely decoupled from the heat collection unit. The control system includes: a steam-water system, a molten salt system, a unit power regulation loop, a hot molten salt pump regulation loop, and a feed water pump regulation loop, where:

[0006] The feed water pump in the steam-water system and the hot molten salt pump in the molten salt system are equipped with frequency modulation devices. The control system is equipped with a steam drum pressure detection meter, a steam drum water level detection meter, a feed water flow monitoring meter, a steam pressure detection meter at the turbine inlet, a molten salt main pipe flow detection meter, and a power generation power detection meter;

[0007] The unit power regulation loop is configured in the steam-water system and is provided with a unit PID controller. The input of the PID controller is configured as the difference between the corrected value of the solar thermal power station power command set value and the unit power detection value;

[0008] The hot molten salt pump regulation loop is arranged in the molten salt system. It is equipped with a loop PID controller and is connected to the molten salt main pipe flow detection meter. The hot molten salt pump regulation loop is configured as a closed-loop regulation loop based on the balance of the molten salt heat capacity and the steam consumption demand driven by the current power command demand. A molten salt flow PID controller is arranged in the closed-loop regulation loop. The molten salt flow PID controller controls the hot molten salt flow. The molten salt flow set value of the molten salt flow PID controller is calculated based on the steam turbine first-stage pressure set value and the output of the steam drum pressure PID controller is accumulated;

[0009] The feed water pump regulation loop includes a steam drum water level PID control loop and a feed water flow PID control loop. The steam drum water level PID control loop is connected to the steam drum water level detection meter. The feed water flow PID control loop is connected to the steam drum pressure detection meter; A cascade control system is formed between the steam drum water level PID control loop and the feed water flow control loop to control the steam drum water level to remain at the set value;

[0010] During use, the unit power regulation loop in the control system responds to the power generation power demand first; the feed water pump regulation loop responds to the steam drum water level regulation demand; the hot molten salt pump regulation loop balances power generation and steam-water production;

[0011] The control system is further equipped with a monitoring prediction correction device. The monitoring prediction correction device is configured with a feedforward function. The monitoring prediction correction device uses the power command historical data as the input for power command prediction and outputs it with a gain function as the feedforward command for the path.

[0012] Optionally, in a preferred example, the corrected value of the power command set value includes high / low limit and maximum rate limit functions and accumulates the corresponding power regulation amount of unit frequency modulation.

[0013] Optionally, in a preferred example, the gain function calculates the feedforward path gain coefficient according to the coupling effect on the salt vapor side for power command time dimension correction adaptively.

[0014] Optionally, in a preferred example, the control system is further configured with a feedforward function adjustment function. The feedforward function adjustment function has the ability to monitor the matching of the heat of the molten salt being converted into the steam pressure of the first stage of the steam turbine during the operation of the entire control system, which is achieved through the adjustment function F3. The feedforward function adjustment function uses the inverse function of the F1 function for the detection of the molten salt flow rate at a certain moment before the current moment to obtain the steam turbine first stage pressure value based on the molten salt flow rate, and calculates the difference measurement parameter by taking the difference from the steam turbine first stage pressure detection value; Subsequently, the difference measurement parameter value is input into the adjustment function F3 to dynamically adjust the strength of the feedforward effect of the monitoring and prediction correction device.

[0015] Optionally, in a preferred example, the adjustment function F3 is specifically as follows:

[0016]

[0017] where a and b are the large value and small value of the gain function segmentation characteristics determined according to the system operation and debugging characteristics; K1 and K2 are the set feedforward path gain adjustment values, and K1 > K2 > 0, and x is the difference measurement parameter.

[0018] Optionally, in a preferred example, the molten salt flow rate set value is specifically obtained through the F1 function, and the F1 function is as follows:

[0019]

[0020] where: P C1 is the steam turbine first stage pressure detection value, P M is the regulating valve inlet pressure detection value, P MS is the regulating valve inlet pressure set value; P C1S is the steam turbine first stage pressure set value, which is calculated based on the linear correlation between the regulating valve inlet pressure and the steam turbine first stage pressure.

[0021] Optionally, in a preferred example, the specific working steps of the monitoring and prediction correction device are as follows:

[0022] 1) Group the historical data of the current moment and several consecutive previous marked time tags. The data grouping is done by taking pairs, that is, taking the actual value of the power command P t at time t as a pair of data 1, and using it as the predicted value at time t - 1.

[0023] Take the k historical data from time (t - 1) to time (t - k) and sequentially form an array P t-1Data 2 as paired data.

[0024] 2) Set up a mapping matrix for fitting the mapping relationship between corresponding historical data and predicted data. The mapping matrix is calculated from the aforementioned historical data set.

[0025] 3) Calculate the mapping matrix at time t, construct the power array at time t by taking k historical data from time t to time (t - k - 1), and calculate the power prediction value at time t + 1.

[0026] Among them, the mapping matrix β is as follows

[0027] P X β = P fm

[0028] Among them, P is the historical data matrix, β is the historical data fitting coefficient matrix, and P fm is the shifted matrix of matrix P.

[0029] 4) Use the result obtained in 3) and calculate the aforementioned data according to the steps of 1) to 3).

[0030] 5) Calculate the correction value of the power change to the molten salt flow regulation loop as follows:

[0031]

[0032] Optionally, in a preferred example, the monitoring and prediction correction device is configured at the power command of the solar thermal power plant.

[0033] Optionally, in a preferred example, the feed water pump regulation loop and the unit power regulation loop respond independently to demands.

[0034] The advantages of this application include;

[0035] 1) Set up a self-updating historical data evolution model based on the power command data received by the solar thermal power plant to predict the power command. The predicted value is combined with the set specific regulation function device for feed-forward compensation of the molten salt regulation loop, which can effectively respond to the power command trend factor in advance in the control loop, compensating for the relative lag of the steam generation system from the setting mechanism and improving the rapidity and stability of the automatic generation control of the tower-type solar thermal power plant.

[0036] 2) To avoid control deviation during the molten salt regulation process and ensure the reliability of its control effect, a steam drum pressure PID controller is set in the outer loop of the molten salt pump regulation loop to ensure the steam supply capacity and heat storage capacity in terms of the overall system performance.

[0037] The description of this application records a large number of technical features, which are distributed in various technical solutions. If all possible combinations of technical features (i.e., technical solutions) of this application are to be listed, the description will become overly lengthy. To avoid this problem, each technical feature disclosed in the above-mentioned invention content of this application, each technical feature disclosed in the following various embodiments and examples, and each technical feature disclosed in the drawings can be freely combined with each other to form various new technical solutions (all of these technical solutions should be regarded as having been recorded in this specification), unless the combination of such technical features is technically infeasible. For example, in one example, features A + B + C are disclosed, and in another example, features A + B + D + E are disclosed. Features C and D are equivalent technical means that perform the same function, and only one of them can be used technically and it is impossible to use both at the same time. Feature E can be combined with feature C technically. Then, the solution of A + B + C + D should not be regarded as having been recorded because it is technically infeasible, while the solution of A + B + C + E should be regarded as having been recorded. Brief Description of the Drawings

[0038] Figure 1 is a schematic diagram of the principle system of the power generation island of a tower-type solar thermal power station applicable to the present invention;

[0039] Figure 2 is a schematic diagram of the automatic power generation control strategy of a tower-type solar thermal power station according to an embodiment of the present invention. Detailed Embodiments

[0040] After in-depth research and extensive screening, the inventor of the present application has developed an automatic power generation control method for a tower-type solar thermal power station based on a wind-solar energy base. Compared with the prior art, this application takes the tower-type solar thermal power station, which is a high-quality regulating device for the wind-solar energy base, as the research object. Based on the requirements of the automatic power generation control of the tower-type solar thermal power station in this application scenario, the requirements in terms of rapid response and stable regulation are greater, and the fluctuation of its power generation power command is greatly affected by the real-time fluctuation of the wind-solar resources. Based on this, a self-updating historical data evolution model is created based on the power command data received by the solar thermal power station to predict the power command. The predicted value, combined with the set specific regulating function device, is used for the feed-forward compensation of the molten salt regulation loop, which can effectively respond to the power command trend factor ahead of the control loop, compensating for the relative lag of the steam generation system from the setting mechanism and improving the rapidity and stability of the automatic power generation control of the tower-type solar thermal power station. At the same time, in order to avoid control deviation during the molten salt regulation process and ensure the reliability of its control effect, a steam drum pressure PID controller is set in the outer loop of the molten salt pump regulation loop to ensure the steam supply capacity and heat storage capacity in terms of the overall system performance.

[0041] Terms

[0042] Tower-type solar thermal power station

[0043] The tower-type solar thermal power station described in the present invention is a solar thermal power station configured with a sufficient thermal energy storage system and completely decoupled from the heat collection unit. The schematic diagram of the principle system of its power generation island is as shown in Figure 2 . The main equipment of its steam-water system includes condensate recovery tank, condensate pump, low-pressure heater, deaerator, feed water pump, high-pressure heater, preheater, evaporator, steam drum, superheater, reheater, etc. The main equipment of the molten salt system includes cold salt tank, hot salt tank, hot molten salt pump, temperature-adjusting salt pump, etc. The generator set includes steam turbine and its supporting regulating device, generator, etc. The purpose of the present invention is to solve the balance of molten salt, water and power generation power, and the configured feed water pump and hot molten salt pump are configured with frequency modulation devices. The main monitoring points set in the system include steam drum pressure detection gauge P A1 , steam drum water level detection gauge L A1 , feed water flow monitoring gauge F A1 , steam turbine inlet steam pressure detection gauge PM, molten salt main pipe flow detection gauge F HS , power generation power detection gauge P W . The above settings are only for describing the control strategy requirements and do not represent the specific quantity. The quantity setting is considered according to the redundancy setting principle of the applied system.

[0044] Calculation of the set value of molten salt flow

[0045] The set value of the molten salt flow mentioned in this application is mainly calculated according to the following two methods: 1. Calculate the steam turbine first-stage pressure set value according to Equation 1; 2. Calculate the molten salt flow set value by the F1 function according to the characteristics of the unit and its thermal system.

[0046]

[0047] Where: P C1 is the steam turbine first-stage pressure detection value, P M is the regulating valve inlet pressure detection value, P MS is the regulating valve inlet pressure set value. According to the linear correlation between the regulating valve inlet pressure and the steam turbine first-stage pressure, the steam turbine first-stage pressure set value P C1S is calculated.

[0048] The above-mentioned regulating valve inlet pressure set value P MS is the correction value in response to the set value of the solar thermal power station power command, which is determined by the function F2 according to the characteristics of the steam turbine generator set. F2(M D ) can usually be a piecewise linear function. For higher control accuracy, this function needs to be verified and provided by the steam turbine generator supplier.

[0049] Monitoring prediction correction device

[0050] The monitoring and prediction correction device of the present invention groups a number of historical data before the current moment with the data corresponding to the data array of the corresponding time tag data, and fits the predicted value according to the historical data evolution rule. Specifically:

[0051] 1) Group the historical data of the current moment and several marked time tags sequentially before it. The specific grouping method is as follows;

[0052]

[0053] 2) The data grouping is done by taking pairs. That is, take the actual value P of the power command at time t t as the paired data 1 and use it as the predicted value at time t-1.

[0054] Take the k historical data from time (t-1) to time (t-k) and sequentially form an array P t-1 as the paired data 2.

[0055] 3) Set the mapping matrix β to fit the mapping relationship between the corresponding historical data and the predicted data. The mapping matrix β is calculated from the aforementioned historical data set.

[0056] 4) Calculate the mapping matrix β at time t. Take the k historical data from time t to time (t-k-1) to construct the power array at time t, and calculate the power predicted value at time t+1

[0057] Among them, the mapping matrix β is calculated according to Equation 2

[0058] P X β = P fm Equation 2

[0059] P is the historical data matrix,

[0060] P is m historical data starting from the previous moment of the current moment, i.e., time t-1. Each one corresponds to a sample size of a certain historical moment. For example, P t-1 = [P t-1 P t-2 …P t-k is a set of k data marked by the value at time t-1.

[0061]

[0062] P t is the actual value of the power command at time t, and P t-1 is the actual value of the power command at time t-1, and so on.

[0063] is the fitting coefficient 1 at time t. The predicted value at time t+1 corresponding to time t is P tData inheritance weight value; For the fitting coefficient 2 at time t, the predicted value at time t + 1 corresponding to time t is P t-1 Data inheritance weight value; and so on.

[0064] Then Equation 4 is obtained:

[0065]

[0066] Where: Is the predicted power value at time t + 1

[0067] Note: When the mapping matrix β does not exist, such as when the data in the historical data matrix P is a constant value, or a step instruction is triggered and lasts for a certain period of time, etc., all take

[0068] Calculate the predicted power value at time t + 2 in the same way Calculate the correction value of the power change to the molten salt flow regulation loop according to the following formula:

[0069]

[0070] In order to effectively track the dynamic characteristics of the conversion of the heat of the molten salt into the steam pressure of the first stage of the steam turbine during the operation of the entire system, the function F3(x) is set to monitor the matching of the conversion of the heat of the molten salt into the steam pressure of the first stage of the steam turbine during the operation of the entire control system, so as to dynamically adjust the strength of the feedforward action of the monitoring prediction correction device. The detected value F of the molten salt flow at τ time before the current time HS Use the inverse function of the F1 function to obtain the first-stage pressure value of the steam turbine based on the molten salt flow and compare it with the detected value P of the first-stage pressure of the steam turbine C1 Find the difference, and this difference signal is the input variable of the function F3(x), and perform the following functions:

[0071]

[0072] Where a and b are the large value and small value of the piecewise characteristic of the gain function determined according to the system operation and debugging characteristics; K1 and K2 are the set gain adjustment values of the feedforward path, and K1 > K2 > 0.

[0073] The function F3(x) enables the salt-steam side coupling effect determined by the overall internal characteristics of the system to be monitored in real time, and uses this performance characteristic for real-time correction of the molten salt flow regulation loop, enhancing the intercommunication and self-correction performance of the system.

[0074] To make the purpose, technical solution and advantages of this application clearer, the following will further describe the implementation manner of this application in detail with reference to the accompanying drawings.

[0075] Embodiment

[0076] As shown in an embodiment of the present application Figures 1-2 The automatic power generation control system of the tower-type solar thermal power station in this embodiment is characterized in that the solar thermal power station is completely decoupled from the heat collection unit. The control system includes: a steam-water system, a molten salt system, a unit power regulation loop, a hot molten salt pump regulation loop, and a feed water pump regulation loop, where:

[0077] The feed water pump in the steam-water system and the hot molten salt pump in the molten salt system are equipped with frequency modulation devices. The control system is equipped with a steam drum pressure detection table, a steam drum water level detection table, a feed water flow monitoring table, a steam pressure detection table at the inlet of the steam turbine, a molten salt main pipe flow detection table, and a power generation power detection table;

[0078] The unit power regulation loop is configured in the steam-water system and is provided with a unit PID controller. The input of the PID controller is configured as the difference between the corrected value of the solar thermal power station power command set value and the unit power detection value. The corrected value of the power command set value includes high / low limit and maximum rate limit functions and accumulates the corresponding power regulation amount of unit frequency modulation.

[0079] The hot molten salt pump regulation loop is arranged in the molten salt system. It is equipped with a loop PID controller and is connected to the molten salt main pipe flow detection table. The hot molten salt pump regulation loop is configured as a closed-loop regulation loop based on the balance of molten salt heat capacity and steam demand driven by the current power command demand. A molten salt flow PID controller is set in the closed-loop regulation loop. The molten salt flow PID controller controls the hot molten salt flow. The set value of the hot molten salt flow of the molten salt flow PID controller is calculated based on the steam turbine first-stage pressure set value and accumulates the output of the steam drum pressure PID controller;

[0080] The feed water pump regulation loop includes a steam drum water level PID control loop and a feed water flow PID control loop. The steam drum water level PID control loop is connected to the steam drum water level detection table. The feed water flow PID control loop is connected to the steam drum pressure detection table; A cascade control system is formed between the steam drum water level PID control loop and the feed water flow control loop to control the steam drum water level to remain at the set value;

[0081] During use, the unit power regulation loop in the control system responds to the power generation power demand first; the feed water pump regulation loop responds to the steam drum water level regulation demand; the hot molten salt pump regulation loop balances power generation and steam production; the feed water pump regulation loop and the unit power regulation loop respond to demands independently.

[0082] The control system is further configured with a monitoring prediction correction device, which is configured with a feedforward function. The monitoring prediction correction device takes the historical data of the power command as input, is used for power command prediction, and outputs it with a gain function as the feedforward command of the path.

[0083] Optionally, in one embodiment, the gain function calculates the feedforward path gain coefficient according to the coupling effect on the salt vapor side to perform power command time dimension correction adaptively.

[0084] Optionally, in one embodiment, the control system is further configured with a feedforward function adjustment function, which has the ability to monitor the matching of the heat conversion of the molten salt into the steam pressure of the first stage of the steam turbine during the operation of the entire control system. It is realized through the adjustment function F3. The feedforward function adjustment function takes the detection of the molten salt flow rate at a certain moment before the current moment and applies the inverse function of the F1 function to obtain the steam turbine first stage pressure value based on the molten salt flow rate, and calculates the difference measurement parameter with the steam turbine first stage pressure detection value; Subsequently, the difference measurement parameter value is input into the adjustment function F3 to dynamically adjust the strength of the feedforward action of the monitoring prediction correction device. The specific form of the adjustment function F3 is as follows:

[0085]

[0086] Where a and b are the large value and small value of the gain function segmentation characteristics determined according to the system operation and debugging characteristics; K1 and K2 are the set feedforward path gain adjustment values, and K1>K2>0, and x is the difference measurement parameter.

[0087] Optionally, in one embodiment, the set value of the molten salt flow rate is specifically obtained through the F1 function, and the specific form of the F1 function is as follows:

[0088]

[0089] Where: P C1 is the steam turbine first stage pressure detection value, P M is the regulating valve inlet pressure detection value, P MS is the regulating valve inlet pressure set value; P C1S is the steam turbine first stage pressure set value, which is calculated according to the linear correlation between the regulating valve inlet pressure and the steam turbine first stage pressure.

[0090] In this embodiment, the specific working steps of the monitoring prediction correction device are as follows:

[0091] 1) Group the historical data of the current moment and several consecutive previous marked time tags. The data grouping is performed by taking pairs, that is, taking the actual value P of the power command at time t t as the paired data 1 and using it as the predicted value at time t-1.

[0092] Take the k historical data from time (t - 1) to time (t - k) and sequentially form an array P t-1 As the data 2 of paired data.

[0093] 2) Set up a mapping matrix for fitting the mapping relationship between the corresponding historical data and the predicted data. The mapping matrix is calculated from the aforementioned historical data set.

[0094] 3) Calculate the mapping matrix at time t. Take the k historical data from time t to time (t - k - 1) to construct the power array at time t, and calculate the power prediction value at time t + 1

[0095] Among them, the mapping matrix β is as follows

[0096] P X β = P fm

[0097] Where P is the historical data matrix, β is the historical data fitting coefficient matrix, and P fm is the shifted matrix of matrix P.

[0098] Specifically, in this embodiment, P is m historical data starting from the previous moment of the current moment, i.e., time t - 1, and each corresponds to a set of sample sizes at a certain historical moment. Such as P t-1 = [P t-1 P t-2 …P t-k is a set of k data marked by the value at time t - 1.

[0099]

[0100] P t is the actual value of the power command at time t, and P t-1 is the actual value of the power command at time t - 1, and so on.

[0101] is the fitting coefficient 1 at time t, and the predicted value at time t + 1 corresponding to time t is P t data inheritance weight;

[0102] is the fitting coefficient 2 at time t, and the predicted value at time t + 1 corresponding to time t is P t-1 data inheritance weight; and so on.

[0103] Then equation 4 is obtained:

[0104]

[0105] Among them: is the power prediction value at time t + 1

[0106] It should be noted that when the mapping matrix β does not exist, such as when the data in the historical data matrix P is a constant value, or when a step instruction is triggered and lasts for a certain period of time, etc., all take

[0107] 4) Calculate the power prediction value at time t + 2 in the same way

[0108] 5) Calculate the correction value of the power change to the molten salt flow regulation loop according to the following formula:

[0109]

[0110] In order to effectively track the dynamic characteristics of the conversion of the heat of molten salt into the steam pressure of the first stage of the steam turbine during the operation of the entire system, the function F3(x) is set to monitor the matching of the conversion of the heat of molten salt into the steam pressure of the first stage of the steam turbine during the operation of the entire control system, so as to dynamically adjust the strength of the feedforward action of the monitoring prediction correction device. The detected value F of the molten salt flow at time τ before the current time HS Use the inverse function of the F1 function to obtain the steam turbine first-stage pressure value based on the molten salt flow and compare it with the detected value P of the steam turbine first-stage pressure C1 Find the difference, and this difference signal is the input variable of the function F3(x).

[0111] It should be noted that in the application documents of this patent, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including one" does not exclude the existence of additional identical elements in the process, method, article or device including the said element. In the application documents of this patent, if it is mentioned that a certain action is performed according to a certain element, it means at least performing the action according to the said element, including two cases: performing the action only according to the said element, and performing the action according to the said element and other elements. Expressions such as multiple, multiple times, multiple types, etc. include 2, 2 times, 2 types, and more than 2, more than 2 times, more than 2 types.

[0112] This specification includes combinations of various embodiments described herein. A separate reference to "an embodiment" or a particular embodiment, etc. does not necessarily refer to the same embodiment; however, unless indicated to be mutually exclusive or clearly mutually exclusive to those skilled in the art, these embodiments are not mutually exclusive. It should be noted that, unless the context clearly indicates otherwise or requires, the word "or" is used in a non-exclusive sense in this specification.

[0113] All documents mentioned in this application are considered to be incorporated herein by reference in their entirety so that they can be used as a basis for modification if necessary. In addition, it should be understood that after reading the above disclosure of this application, those skilled in the art can make various changes or modifications to this application, and these equivalent forms also fall within the scope of protection claimed in this application.

Claims

1. An automatic power generation control system for a tower-type solar thermal power station, characterized in that: The solar thermal power station is completely decoupled from the heat collection unit, and the control system includes: a steam-water system, a molten salt system, a unit power regulation loop, a hot molten salt pump regulation loop and a feed water pump regulation loop, wherein: The feed water pump in the steam-water system and the hot molten salt pump in the molten salt system are equipped with a frequency modulation device, and the control system is equipped with a drum pressure detection meter, a drum water level detection meter, a feed water flow monitoring meter, a turbine inlet steam pressure detection meter, a hot molten salt main pipe flow detection meter and a power generation detection meter; The unit power regulating loop is configured in the steam-water system and is provided with a unit PID controller, and the input of the PID controller is configured as the difference between the correction value of the power instruction setting value of the solar thermal power station and the unit power detection value; The hot molten salt pump regulating loop is arranged in the molten salt system, and is connected to the hot molten salt main pipe flow detection meter. The hot molten salt pump regulating loop is configured as a closed-loop regulating loop based on the balance between the molten salt heat capacity and the steam demand driven by the current power instruction demand. A molten salt flow PID controller is arranged in the closed-loop regulating loop. The hot molten salt flow PID controller controls the hot molten salt flow. The hot molten salt flow set value of the hot molten salt flow PID controller is calculated based on the first-stage pressure set value of the steam turbine and the output of the drum pressure PID controller is accumulated; The feedwater pump regulating loop includes a drum water level PID control loop and a feedwater flow PID control loop, the drum water level PID control loop is connected to the drum water level detection meter, and the feedwater flow PID control loop is connected to the drum pressure detection meter; a cascade control system is formed between the drum water level PID control loop and the feedwater flow control loop to control the drum water level to maintain a set value; The control system is also equipped with a monitoring prediction correction device, which is equipped with a feedforward instruction. The monitoring prediction correction device uses power instruction history data as input for power instruction prediction and outputs it in combination with a feedforward gain function as a feedforward instruction for the path; When in use, the unit power regulation loop in the control system responds to the power generation demand in advance; the feed water pump regulation loop responds to the drum water level regulation demand; the molten salt pump regulation loop balances power generation and steam-water production through the drum water level according to the feedforward instructions of the monitoring, prediction and correction device.

2. The automatic power generation control system of a tower type solar thermal power plant according to claim 1, characterized in that: The power command setting value correction value includes high / low limit and maximum rate limit functions and accumulates the power adjustment amount corresponding to the unit frequency regulation.

3. The automatic power generation control system of a tower type CSP power station according to claim 1, characterized in that: The gain function F3(x) calculates the feedforward path gain coefficient according to the salt-steam side coupling effect to adaptively correct the power command time dimension.

4. The automatic power generation control system of a tower type CSP power station according to claim 1, characterized in that: The control system is also equipped with a feedforward function adjustment function, which has the ability to monitor the conversion of molten salt heat into the first-stage steam pressure of the steam turbine during the operation of the entire control system. It is achieved through the adjustment function F3. The feedforward function adjustment function uses the inverse function of the F1 function to detect the molten salt flow at a certain moment before the current moment to obtain the first-stage pressure value of the steam turbine based on the molten salt flow and calculate the difference measurement parameter with the first-stage pressure detection value of the steam turbine; then the difference measurement parameter value is input into the adjustment function F3 to dynamically adjust the strength of the feedforward effect of the monitoring prediction and correction device.

5. The automatic power generation control system of a tower type CSP power station according to claim 4, characterized in that: The adjustment function F3 is specifically as follows: Where a and b are the maximum and minimum values ​​of the segmented characteristics of the gain function determined according to the system operation and debugging characteristics; K1 and K2 are the gain adjustment values ​​for setting the feedforward path, and K1>K2>0, and x is the difference measurement parameter.

6. The automatic power generation control system of a tower type CSP power station according to claim 1, characterized in that: The molten salt flow rate setting value is also specifically obtained through the F1 function, and the F1 function is as follows: Where: P C1 is the first stage pressure detection value of the steam turbine, P M P is the detection value of the inlet pressure of the regulating valve, MS Regulating valve inlet pressure setting value; P C1S is the set value of the first-stage pressure of the steam turbine, which is calculated based on the linear correlation between the regulating valve inlet pressure and the first-stage pressure of the steam turbine.

7. The automatic power generation control system of a tower type CSP power station according to claim 1, characterized in that: The specific working steps of the monitoring prediction correction device are: 1) Group the historical data with time tags at the current moment and the previous moments in sequence. The data groups are taken in pairs, i.e., the actual value of the power command P at moment t is taken. t is the paired data 1, which is the predicted value at time t-1. Take k historical data from time (t-1) to time (tk) and form an array P in sequence t-1 Data 2 as paired data. 2) Setting a mapping matrix for fitting the mapping relationship between the corresponding historical data and the predicted data. The mapping matrix is ​​calculated based on the aforementioned historical data set. 3) Calculate the mapping matrix at time t, take k historical data from time t to time (tk-1) to construct the power array at time t, and calculate the power prediction value at time t+1 Among them, the mapping matrix β is as follows P×β=P fm Where P is the historical data matrix, β is the historical data fitting coefficient matrix, P fm is the backward shift matrix of matrix P. 4) Based on 3) And the above data is calculated according to steps 1) to 3) 5) Calculate the correction value of the power change to the hot molten salt flow regulation loop as follows:

8. The automatic power generation control system of a tower type CSP power station according to claim 1, characterized in that: The monitoring, predicting and correcting device is configured at the power instruction of the CSP power station.

9. The automatic power generation control system of a tower type solar thermal power plant according to claim 1, characterized in that: The feed water pump regulation circuit and the unit power regulation circuit respond to demand independently of each other.

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