Response control method, device and system of photo-thermal and photo-voltaic combined power station

Abstract

The present application relates to the field of photo-thermal photovoltaic power generation, and discloses a response control method of a photo-thermal photovoltaic power station, which comprises the following steps: obtaining a power system demand sequence and a photovoltaic output prediction sequence within a set time length; constructing a target function, taking the minimum of the demand deviation and the output adjustment step as the optimization goal, and solving the target function to obtain a photo-thermal output plan sequence; compensating the current output plan value according to the output difference between the current photovoltaic output prediction value and the actual value to obtain a current output set value; if the difference between the current output set value and the output set value at the last moment is beyond the step response capability of the closed-loop control algorithm, then the power system demand sequence and the photovoltaic output prediction sequence within the set time length are re-obtained; otherwise, the closed-loop control algorithm controls the photo-thermal system according to the current output set value. The present application can make the photo-thermal system compensate the fluctuation of the photovoltaic system in a timely manner.

Description

Technical Field

[0001] This invention relates to the field of concentrated solar power (CSP) and photovoltaic (PV) power generation, specifically to a response control method, apparatus, and system for a combined CSP and PV power plant. Background Technology

[0002] In recent years, my country's new energy power generation industry has developed rapidly. Photovoltaic (PV) power generation is a major form of utilizing solar energy resources. However, compared to traditional hydropower and coal-fired power generation, PV power generation is characterized by randomness, fluctuation, and intermittency, making its electricity difficult to absorb. Currently, there is also a concentrated solar power (CSP) technology, which first absorbs and stores solar thermal energy, then uses the stored heat to drive a steam turbine, thereby generating electricity. Thermal storage devices enable flexible power generation regulation capabilities, and combined CSP-PV power plants are beneficial for improving PV utilization efficiency.

[0003] However, the power generation process of a solar thermal system requires a certain amount of high-temperature molten salt to flow through a heat exchanger and exchange heat with a water system, generating high-temperature, high-pressure steam to drive a steam turbine and ultimately produce electricity. This results in a relatively long adjustment time after the solar thermal system responds to changes in power generation demand, meaning that solar thermal systems exhibit a large time lag. In contrast, changes in sunlight intensity directly affect the power generation of a photovoltaic system, meaning that photovoltaic systems exhibit instantaneous changes.

[0004] When a solar thermal-photovoltaic (CTP) combined power plant participates in peak shaving, the large lag in the CTP system makes it difficult to adjust in real time according to the instantaneous changes in the photovoltaic system, thus making it difficult for the CTP-PV combined power plant to adjust its final output power according to the power system demand. Summary of the Invention

[0005] Based on the above description, the present invention provides a response control method, device and system for a solar thermal-photovoltaic combined power plant, so that when the solar thermal-photovoltaic combined power plant participates in peak shaving, the solar thermal system can compensate for the fluctuations of the photovoltaic system in a timely manner, and the total output power of the two can follow the power system demand more smoothly.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0007] For combined solar thermal and photovoltaic power plants, which include both solar thermal and photovoltaic systems, the response control methods include:

[0008] Obtain the power system demand sequence and photovoltaic output prediction sequence within a set time period; wherein, the time step of the power system demand sequence and photovoltaic output prediction sequence is greater than or equal to the adjustment time required for the closed-loop control algorithm of the solar thermal system to reach steady state from the response change;

[0009] An objective function is constructed based on the power system demand sequence, photovoltaic output prediction sequence, and solar thermal output sequence. The optimization objectives are to minimize the supply-demand deviation and the output adjustment step size. The objective function is solved to obtain the solar thermal output planning sequence. The supply-demand deviation is the deviation obtained by subtracting the power system demand from the sum of photovoltaic output and solar thermal output. The output adjustment step size is the difference between the solar thermal system output at two adjacent moments in the solar thermal output sequence. The maximum value of the output adjustment step size is within the step response capability of the closed-loop control algorithm.

[0010] The difference between the current photovoltaic output prediction value and the current actual photovoltaic output value in the photovoltaic output prediction sequence is used to compensate the current planned output value in the solar thermal output plan sequence in order to obtain the current output setpoint of the closed-loop control algorithm.

[0011] If the difference between the current output setpoint and the previous output setpoint is outside the step response capability of the closed-loop control algorithm, then the power system demand sequence and photovoltaic output prediction sequence within the set time period are reacquired.

[0012] Otherwise, the closed-loop control algorithm controls the solar thermal system based on the current output setpoint.

[0013] Through the above technical solution, the output state of the solar thermal system is allocated at the strategy level using the photovoltaic output prediction sequence, allowing the solar thermal system a relatively long adjustment time. Ultimately, the output state of the solar thermal system is matched with that of the photovoltaic system in a general direction, meaning that their total output can meet the power system's demand. The supply-demand deviation, used as the optimization objective in this invention's technical solution, reflects the strategy-level matching control between the large lag of the solar thermal system and the instability of the photovoltaic system. Furthermore, the maximum output adjustment step size, also an optimization objective, is within the step response capability of the closed-loop control algorithm. Its function is to enable the closed-loop control algorithm of the solar thermal system at the execution level to control the output state of the solar thermal system allocated at the strategy level. Regardless of the prediction method used to predict solar irradiance, the prediction results will always contain errors. The present invention, after obtaining the photovoltaic output prediction sequence, compensates for the current planned output value in the solar thermal output plan sequence based on the output difference between the current predicted photovoltaic output value and the actual photovoltaic output value within the control cycle of the solar thermal system using a closed-loop control algorithm. This compensation obtains the current output setpoint for the closed-loop control algorithm, thereby compensating for prediction deviations when specifically controlling the solar thermal system. This improves the solar thermal system's ability to compensate for the instability of the photovoltaic system. Furthermore, because the optimization process for obtaining the current planned output value aims to minimize the supply-demand deviation, the compensated solar thermal system not only compensates for the instability of the photovoltaic system but also ensures that the total output of both the solar thermal and photovoltaic systems meets the power system's requirements. However, this compensation for the current planned output value adjusts the magnitude of the planned output value. This causes the current output adjustment step size to exceed the step response capability of the closed-loop control algorithm, leading to instability or excessive oscillations in the solar thermal system. Therefore, if the difference between the current output setpoint and the previous output setpoint is outside the step response capability of the closed-loop control algorithm, the power system demand sequence and photovoltaic output prediction sequence within the set time period are re-acquired. That is, the solar thermal output plan sequence is re-optimized and calculated to ensure the stability of the solar thermal system. In addition, if the current output adjustment step size exceeds the step response capability of the closed-loop control algorithm, it also indicates that there is a large deviation between the photovoltaic output prediction sequence and the actual photovoltaic output. This is often caused by the prediction algorithm's inability to handle sudden weather factors. In this case, re-acquiring the photovoltaic output prediction sequence is also beneficial to obtain a more accurate photovoltaic output prediction sequence, which is conducive to a more accurate allocation of the solar thermal system's output status at the strategy level.

[0014] Based on the above technical solution, the present invention can be further improved as follows.

[0015] Furthermore, the objective function is:

[0016] ;

[0017] in, The index of the parameter in the sequence. The total number of parameters in the sequence. The first in the photothermal output sequence item, The first in the photovoltaic power output prediction sequence item, The first in the power system demand sequence item, To adjust the coefficient, , To ensure the smoothness of the output adjustment step size during the optimization process, To adjust the step length for power output, , .

[0018] The above technical solution allows for adjustments to the supply-demand imbalance and output step size based on demand.

[0019] Furthermore, the difference between the current photovoltaic output forecast value and the current actual photovoltaic output value in the photovoltaic output forecast sequence is used to compensate the current planned output value in the solar thermal output plan sequence, in order to obtain the current output setpoint for the closed-loop control algorithm, including:

[0020] Obtain the output difference between the current predicted photovoltaic output and the current actual photovoltaic output, as well as the rate of change of the output difference;

[0021] The weighted sum of the output difference and the rate of change is calculated based on the first weight of the output difference and the second weight of the rate of change; wherein the first weight is set in accordance with the proportional parameter in PID control theory, and the second weight is set in accordance with the derivative parameter in PID control theory.

[0022] The sum of the weighted average and the current planned output value is determined as the current output setting value.

[0023] The above technical solution can be used to obtain the current output setting value of the closed-loop control algorithm.

[0024] Furthermore, the closed-loop control algorithm controls the solar thermal system based on the current output setpoint, including:

[0025] At the start of the time step corresponding to the current output setting value, record the first actual output value of the solar thermal system;

[0026] At the end of the time step corresponding to the current output setting value, record the second actual output value of the solar thermal system;

[0027] The difference between the first actual output value and the second actual output value is determined as the actual output adjustment value;

[0028] The difference between the current output setting value and the output setting value of the previous cycle is determined as the set output adjustment value;

[0029] The difference between the set output adjustment value and the actual output adjustment value is determined as the adjustment loss value;

[0030] The degree of importance attached to the smoothness of the output adjustment step size is determined by the adjustment loss value during the optimization process; the larger the adjustment loss value, the higher the importance attached to smoothness, and the smaller the adjustment loss value, the lower the importance attached to smoothness.

[0031] The above technical solution enables the smoothness of the solar thermal output planning sequence to match the operating conditions of the solar thermal system. For example, if a valve on the molten salt flow path is opened too small due to an anomaly, or if start-up and shutdown operations are performed due to low solar thermal system output, the actual output adjustment value of the solar thermal system will be reduced. In this case, increasing the smoothness emphasis in the objective function, i.e., improving... In order to obtain a more balanced solar thermal output plan sequence, the solar thermal system can execute and achieve the output state allocated at the strategy level under the control of the closed-loop control algorithm.

[0032] Furthermore, in the process of obtaining the photovoltaic power output prediction sequence, the confidence level of each item in the photovoltaic power output prediction sequence is also obtained.

[0033] Based on the first weight of the difference and the second weight of the rate of change, calculate the weighted sum of the difference and the rate of change, including:

[0034] The first scaling factor is determined based on the confidence level of the current photovoltaic power output forecast; wherein, the first scaling factor is less than 1, and the first scaling factor is positively correlated with the confidence level of the current photovoltaic power output forecast;

[0035] The second scaling factor is determined based on the confidence level of the current photovoltaic power output forecast; wherein the second scaling factor is less than the first scaling factor, and the second scaling factor is positively correlated with the confidence level of the current photovoltaic power output forecast.

[0036] Calculate the first product of the difference, the first weight, and the first scaling factor, and the second product of the rate of change, the second weight, and the second scaling factor;

[0037] The sum of the first product and the second product is determined as the weighted sum.

[0038] The above technical solutions can reduce noise caused by low confidence levels, thereby compensating for the current output plan value with a more stable and conservative strategy, obtaining a more stable and conservative current output setting value, and enabling the solar thermal system to more robustly match and compensate for the unstable characteristics of the photovoltaic system.

[0039] In addition, a conservative and prudent strategy can make it difficult for the solar thermal system to respond to the deviation between the actual photovoltaic output and the predicted photovoltaic output, resulting in a smaller actual output adjustment value and a larger adjustment loss value. This conservative and prudent strategy, combined with the correction of the smoothing emphasis based on the adjustment loss value, can achieve a smoother power output (i.e., total output) of the solar thermal-photovoltaic combined power plant at the cost of a larger instantaneous deviation.

[0040] Furthermore, the confidence level of the current photovoltaic power output forecast is determined as the first scaling factor; and the power of the confidence level of the current photovoltaic power output forecast is determined as the second scaling factor.

[0041] Furthermore, response control methods for combined solar thermal and photovoltaic power plants also include:

[0042] Obtain several differences between the predicted photovoltaic power output and the actual photovoltaic power output in the photovoltaic power output prediction sequence up to the current moment;

[0043] If the sum of several differences is greater than or equal to the set deviation threshold, the power system demand sequence and photovoltaic output prediction sequence within the set time period are reacquired.

[0044] The above technical solution statistically analyzes the residual between the output state represented by the photovoltaic output prediction sequence and the actual photovoltaic output state. This residual is used to represent the cumulative inaccuracy of the existing photovoltaic output prediction sequence over time. If the sum of several differences is greater than or equal to a set deviation threshold, the photovoltaic output prediction sequence is re-acquired in a timely manner to avoid further amplification of the large cumulative inaccuracy in the closed-loop control algorithm. Ultimately, this enables the output states of both the solar thermal system and the photovoltaic system to more accurately follow the power system demand and meet the power system requirements.

[0045] Secondly, the present invention also provides a response control device for a solar thermal-photovoltaic combined power plant, the solar thermal-photovoltaic combined power plant including a solar thermal system and a photovoltaic system; the response control device includes:

[0046] The data acquisition module is used to acquire the power system demand sequence and photovoltaic output prediction sequence within a set time period; wherein, the time step of the power system demand sequence and photovoltaic output prediction sequence is greater than or equal to the adjustment time required for the closed-loop control algorithm of the solar thermal system to reach a steady state from the response change;

[0047] The optimization and solution module is used to construct an objective function based on the power system demand sequence, photovoltaic output prediction sequence, and solar thermal output sequence. The optimization objectives are to minimize the supply-demand deviation and the output adjustment step size. The objective function is then solved to obtain the solar thermal output plan sequence. The supply-demand deviation is the deviation obtained by subtracting the power system demand from the sum of photovoltaic output and solar thermal output. The output adjustment step size is the difference between the solar thermal system output at two adjacent moments in the solar thermal output sequence. The maximum value of the output adjustment step size is within the step response capability of the closed-loop control algorithm.

[0048] The compensation module is used to compensate the current planned output value in the solar thermal output plan sequence based on the output difference between the current predicted photovoltaic output value and the current actual photovoltaic output value in the photovoltaic output prediction sequence, so as to obtain the current output setpoint of the closed-loop control algorithm.

[0049] The first rollback module is used to reacquire the power system demand sequence and photovoltaic output prediction sequence within a set time period if the difference between the current output setpoint and the output setpoint at the previous moment is beyond the step response capability of the closed-loop control algorithm.

[0050] The control module is used to control the solar thermal system according to the current output setpoint if the difference between the current output setpoint and the output setpoint at the previous moment is within the step response capability of the closed-loop control algorithm.

[0051] Thirdly, the present invention also provides a response control device for a solar thermal-photovoltaic combined power plant, including a processor and a memory storing program instructions, wherein the processor is configured to execute the response control method for the solar thermal-photovoltaic combined power plant provided in the foregoing embodiments when executing the program instructions.

[0052] Fourthly, the present invention also provides a response control system for a solar thermal-photovoltaic combined power plant, including the response control device for the solar thermal-photovoltaic combined power plant provided in the foregoing embodiments.

[0053] Compared with the prior art, the technical solution of this application has the following beneficial technical effects:

[0054] 1. When a solar thermal-photovoltaic combined power plant participates in peak shaving, the solar thermal system can compensate for the fluctuations of the photovoltaic system in a timely manner, so that the total output power of the two can follow the power system demand more smoothly.

[0055] 2. Adaptive adjustments are made based on the inaccuracy of photovoltaic power output predictions, enabling the response control method to maintain a certain degree of robustness even under high or unstable prediction inaccuracies. Attached Figure Description

[0056] Figure 1 A schematic flowchart illustrating a response control method for a solar thermal-photovoltaic combined power plant provided in an embodiment of the present invention;

[0057] Figure 2 A schematic flowchart illustrating a response control method for a solar thermal-photovoltaic combined power plant provided in an embodiment of the present invention;

[0058] Figure 3 A schematic flowchart illustrating a response control method for a solar thermal-photovoltaic combined power plant provided in an embodiment of the present invention;

[0059] Figure 4 This is a schematic diagram of a response control device for a solar thermal-photovoltaic combined power plant provided in an embodiment of the present invention.

[0060] Figure reference numerals: 41, Data acquisition module; 42, Optimization solution module; 43, Compensation module; 44, First rollback module; 45, Control module. Detailed Implementation

[0061] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be more thorough and complete.

[0062] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0063] Example 1:

[0064] The solar thermal-photovoltaic combined power plant in this embodiment includes a solar thermal system and a photovoltaic system.

[0065] refer to Figure 1 The response control methods for combined solar thermal and photovoltaic power plants include:

[0066] S101. Obtain the power system demand sequence and photovoltaic output forecast sequence within a set time period.

[0067] Among them, the time step of the power system demand sequence and the photovoltaic output prediction sequence is greater than or equal to the adjustment time required for the closed-loop control algorithm of the solar thermal system to reach a steady state from the response change, so that the solar thermal output plan sequence calculated in subsequent steps can be stably executed by the closed-loop control algorithm of the solar thermal system.

[0068] The closed-loop control algorithm in this embodiment of the invention refers to a closed-loop control algorithm adapted to the photothermal system. The adjustment time required for the closed-loop control algorithm to reach a steady state from the response change is not only related to the algorithm itself, but also to the parameters of the molten salt subsystem and the steam subsystem of the photothermal system.

[0069] The adjustment time can be obtained from the instruction manual of the solar thermal system, or it can be obtained by observing historical data on the adjustment of the solar thermal system's output.

[0070] The set duration can be 3 times, 6 times, 9 times, 12 times, 15 times, 18 times, 21 times, or 24 times the adjustable duration.

[0071] In some application scenarios, if the duration is adjusted to 10 minutes, the set duration can be 30 minutes, 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, or 4 hours.

[0072] Peak shaving refers to adjusting the power generation at the generating end in real time according to the load changes at the load end of the power system, so that the power generation at the generating end just meets the power demand at the load end. The power system is connected to several load ends, and the above-mentioned power system demand is the overall power demand at the load end reflected by the power system as a whole.

[0073] Generally, photovoltaic (PV) power output prediction sequences are obtained using existing neural network models. Since irradiance exhibits certain temporal characteristics, the PV power output prediction sequence also possesses specific temporal characteristics. Therefore, Long Short-Term Memory (LSTM) networks and their variants can be used to obtain the PV power output prediction sequence. However, this invention focuses on obtaining the result of the "PV power output prediction sequence," without limiting the acquisition process. Those skilled in the art can use appropriate neural network models or other models based on experience to obtain the PV power output prediction sequence, which will not be elaborated upon here.

[0074] S102. Construct an objective function based on the power system demand sequence, photovoltaic power output forecast sequence, and solar thermal power output sequence. Take the minimum supply-demand deviation and power output adjustment step size as the optimization objective, and solve the objective function to obtain the solar thermal power output plan sequence.

[0075] Among them, the supply-demand deviation is the deviation obtained by subtracting the power system demand from the sum of photovoltaic output and solar thermal output, and the output adjustment step size is the difference between the solar thermal system output at two adjacent moments in the solar thermal output sequence.

[0076] For example, the objective function could be:

[0077] ;

[0078] in, The index of the parameter in the sequence. The total number of parameters in the sequence. The first in the photothermal output sequence item, The first in the photovoltaic power output prediction sequence item, The first in the power system demand sequence item, To adjust the coefficient, , To ensure the smoothness of the output adjustment step size during the optimization process, To adjust the step length for power output, , .

[0079] The constraints include: the maximum value of the output adjustment step size must be within the step response capability of the closed-loop control algorithm. Here, step response capability refers to the ability of the closed-loop control algorithm to bring the system output to a stable state within the expected time after a step change in the setpoint.

[0080] In other words, when the step change is the maximum value mentioned above, the closed-loop control algorithm can bring the system output to a stable state within the expected time. When the step change exceeds the maximum value mentioned above, the closed-loop control algorithm cannot bring the system output to a stable state within the expected time, or the stability effect of the system output within the expected time is not ideal.

[0081] In addition, the constraints of the objective function also include the heat reserve constraint of the solar thermal system, and the solar thermal output cannot exceed the heat reserve of the solar thermal system.

[0082] As further explanation, the photothermal output sequence refers to a sequence with unknown parameters that has not been solved; the photothermal output plan sequence refers to a sequence with specific parameters after solving.

[0083] S103. Compensate the current output plan value in the solar thermal output plan sequence based on the output difference between the current photovoltaic output prediction value and the current actual photovoltaic output value in the photovoltaic output prediction sequence, so as to obtain the current output setpoint of the closed-loop control algorithm.

[0084] The current output plan value becomes the current output set value after compensation.

[0085] In this embodiment of the invention, "current X" can be any item in each sequence, and the specific item it refers to depends on the control cycle of the closed-loop control algorithm. For example, in the first control cycle of the closed-loop control algorithm after calculating the solar thermal output plan sequence, the current photovoltaic output prediction value refers to the first item in the photovoltaic output prediction sequence, and the current output plan value refers to the first item in the solar thermal output plan sequence; ...; in the k-th control cycle of the closed-loop control algorithm after calculating the solar thermal output plan sequence, the current photovoltaic output prediction value refers to the k-th item in the photovoltaic output prediction sequence, and the current output plan value refers to the k-th item in the solar thermal output plan sequence.

[0086] Furthermore, the difference between the current photovoltaic output forecast value and the current actual photovoltaic output value in the photovoltaic output forecast sequence is used to compensate the current planned output value in the solar thermal output plan sequence, in order to obtain the current output setpoint for the closed-loop control algorithm, including:

[0087] Obtain the output difference between the current predicted photovoltaic output and the current actual photovoltaic output, as well as the rate of change of the output difference;

[0088] The weighted sum of the output difference and the rate of change is calculated based on the first weight of the output difference and the second weight of the rate of change; wherein the first weight is set in accordance with the proportional parameter in PID control theory, and the second weight is set in accordance with the derivative parameter in PID control theory.

[0089] The sum of the weighted average and the current planned output value is determined as the current output setting value.

[0090] S104. If the difference between the current output setpoint and the output setpoint at the previous moment is outside the step response capability of the closed-loop control algorithm, then the power system demand sequence and photovoltaic output prediction sequence within the set time period are reacquired.

[0091] S105. If the difference between the current output setpoint and the output setpoint at the previous moment is within the step response capability of the closed-loop control algorithm, then the closed-loop control algorithm controls the solar thermal system according to the current output setpoint.

[0092] Furthermore, the closed-loop control algorithm controls the solar thermal system based on the current output setpoint, including: recording the first actual output value of the solar thermal system at the beginning of the time step corresponding to the current output setpoint; recording the second actual output value of the solar thermal system at the end of the time step corresponding to the current output setpoint; determining the difference between the first and second actual output values ​​as the actual output adjustment value; determining the difference between the current output setpoint and the output setpoint of the previous cycle as the set output adjustment value; determining the difference between the set output adjustment value and the actual output adjustment value as the adjustment loss value; and adjusting the smoothness of the output adjustment step during the optimization process based on the adjustment loss value; wherein, the larger the adjustment loss value, the higher the smoothness emphasis, and the smaller the adjustment loss value, the lower the smoothness emphasis.

[0093] Furthermore, the degree of importance for smoothing is determined by dividing the adjusted loss value by the set output adjustment value. For example, the degree of importance for smoothing is determined by dividing the adjusted loss value by the set output adjustment value. Alternatively, the smoothing priority can be determined by using the natural constant as the base and the quotient of the adjusted loss value divided by the set output adjustment value as the exponent. .

[0094] Example 2:

[0095] The solar thermal-photovoltaic combined power plant in this embodiment includes a solar thermal system and a photovoltaic system.

[0096] refer to Figure 2 The response control methods for combined solar thermal and photovoltaic power plants include:

[0097] S201. Obtain the power system demand sequence, photovoltaic output forecast sequence, and the confidence level of each item in the photovoltaic output forecast sequence within a set time period.

[0098] S202. Construct an objective function based on the power system demand sequence, photovoltaic output forecast sequence, and solar thermal output sequence. Take the minimum supply-demand deviation and output adjustment step size as the optimization objective, and solve the objective function to obtain the solar thermal output plan sequence.

[0099] S203. Obtain the output difference between the current photovoltaic power output prediction value and the current photovoltaic power output actual value, as well as the rate of change of the difference.

[0100] S204. Determine the first scaling factor based on the confidence level of the current photovoltaic output forecast.

[0101] The first scaling factor is less than 1, and it is positively correlated with the confidence level of the current photovoltaic power output prediction.

[0102] Furthermore, the confidence level of the current photovoltaic output forecast is determined as the first scaling factor.

[0103] S205. Determine the second scaling factor based on the confidence level of the current photovoltaic power output forecast.

[0104] The second scaling factor is smaller than the first scaling factor, and the second scaling factor is positively correlated with the confidence level of the current photovoltaic power output forecast.

[0105] Furthermore, the power of the confidence level of the current photovoltaic output forecast is determined as the second scaling factor.

[0106] S206. Calculate the first product of the output force difference, the first weight and the first scaling factor, and the second product of the rate of change, the second weight and the second scaling factor.

[0107] S207. Determine the sum of the first product and the second product as a weighted sum.

[0108] S208. The sum of the weighted sum and the current planned output value is determined as the current output setting value.

[0109] S209. If the difference between the current output setpoint and the output setpoint at the previous moment is outside the step response capability of the closed-loop control algorithm, then the power system demand sequence and photovoltaic output prediction sequence within the set time period are reacquired.

[0110] S210. If the difference between the current output setpoint and the output setpoint at the previous moment is within the step response capability of the closed-loop control algorithm, then the closed-loop control algorithm controls the solar thermal system according to the current output setpoint.

[0111] Example 3:

[0112] The solar thermal-photovoltaic combined power plant in this embodiment includes a solar thermal system and a photovoltaic system.

[0113] refer to Figure 3 The response control methods for combined solar thermal and photovoltaic power plants include:

[0114] S301. Obtain the power system demand sequence and photovoltaic output forecast sequence within a set time period.

[0115] S302. Construct an objective function based on the power system demand sequence, photovoltaic output forecast sequence, and solar thermal output sequence. Take the minimum supply-demand deviation and output adjustment step size as the optimization objective, and solve the objective function to obtain the solar thermal output plan sequence.

[0116] S303. Obtain several differences between the predicted photovoltaic output value and the actual photovoltaic output value in the photovoltaic output prediction sequence up to the current time.

[0117] S304. If the sum of several differences is greater than or equal to the set deviation threshold, then the power system demand sequence and photovoltaic output prediction sequence within the set time period are reacquired.

[0118] S305. If the sum of several differences is less than the set deviation threshold, the current output plan value in the solar thermal output plan sequence is compensated based on the output difference between the current photovoltaic output prediction value and the current actual photovoltaic output value in the photovoltaic output prediction sequence, so as to obtain the current output set value of the closed-loop control algorithm.

[0119] S306. If the difference between the current output setpoint and the output setpoint at the previous moment is outside the step response capability of the closed-loop control algorithm, then the power system demand sequence and photovoltaic output prediction sequence within the set time period are reacquired.

[0120] S307. If the difference between the current output setpoint and the output setpoint at the previous moment is within the step response capability of the closed-loop control algorithm, the closed-loop control algorithm controls the solar thermal system according to the current output setpoint.

[0121] Example 4:

[0122] The solar thermal-photovoltaic combined power plant in this embodiment includes a solar thermal system and a photovoltaic system.

[0123] refer to Figure 4 The response control device of the solar thermal-photovoltaic combined power plant includes a data acquisition module 41, an optimization solution module 42, a compensation module 43, a first backoff module 44, and a control module 45.

[0124] The data acquisition module 41 is used to acquire the power system demand sequence and photovoltaic output prediction sequence within a set time period; wherein, the time step of the power system demand sequence and photovoltaic output prediction sequence is greater than or equal to the adjustment time required for the closed-loop control algorithm of the solar thermal system to reach a steady state from the response change.

[0125] The optimization solution module 42 is used to construct an objective function based on the power system demand sequence, photovoltaic output prediction sequence, and solar thermal output sequence. The objective function is to minimize the supply-demand deviation and the output adjustment step size, and then solve the objective function to obtain the solar thermal output plan sequence. The supply-demand deviation is the deviation obtained by subtracting the power system demand from the sum of photovoltaic output and solar thermal output. The output adjustment step size is the difference between the solar thermal system output at two adjacent moments in the solar thermal output sequence. The maximum value of the output adjustment step size is within the step response capability of the closed-loop control algorithm.

[0126] The compensation module 43 is used to compensate the current output plan value in the solar thermal output plan sequence based on the output difference between the current photovoltaic output prediction value and the current actual photovoltaic output value in the photovoltaic output prediction sequence, so as to obtain the current output set value of the closed-loop control algorithm.

[0127] The first rollback module 44 is used to reacquire the power system demand sequence and photovoltaic output prediction sequence within a set time period if the difference between the current output setpoint and the output setpoint at the previous moment is outside the step response capability of the closed-loop control algorithm.

[0128] The control module 45 is used to control the solar thermal system according to the current output setpoint if the difference between the current output setpoint and the output setpoint at the previous moment is within the step response capability of the closed-loop control algorithm.

[0129] Furthermore, the compensation module 43 includes an acquisition unit, a calculation unit, and a first determination unit.

[0130] The acquisition unit is used to obtain the output difference between the current photovoltaic output prediction value and the current photovoltaic output actual value, as well as the rate of change of the difference.

[0131] The calculation unit is used to calculate the weighted sum of the output difference and the rate of change based on the first weight of the output difference and the second weight of the rate of change; wherein, the first weight is set in accordance with the proportional parameter in PID control theory, and the second weight is set in accordance with the derivative parameter in PID control theory.

[0132] The first determining unit is used to determine the sum of the weighted sum and the current planned output value as the current output setting value.

[0133] Furthermore, the control module 45 includes a first recording unit, a second recording unit, a second determining unit, a third determining unit, a fourth determining unit, and an adjustment unit.

[0134] The first recording unit is used to record the first actual output value of the solar thermal system at the start of the time step corresponding to the current output setting value.

[0135] The second recording unit is used to record the second actual output value of the photothermal system when the time step corresponding to the current output setting value ends.

[0136] The second determining unit is used to determine the difference between the first actual output value and the second actual output value as the actual output adjustment value.

[0137] The third determining unit is used to determine the difference between the current output setting value and the output setting value of the previous cycle as the set output adjustment value.

[0138] The fourth determining unit is used to determine the difference between the set output adjustment value and the actual output adjustment value as the adjustment loss value.

[0139] The adjustment unit is used to adjust the smoothness emphasis of the output adjustment step size during the optimization process according to the adjustment loss value; the larger the adjustment loss value, the higher the smoothness emphasis, and the smaller the adjustment loss value, the lower the smoothness emphasis.

[0140] Furthermore, the data acquisition module 41 is also used to acquire the confidence level of each item in the photovoltaic power output prediction sequence.

[0141] Correspondingly, the calculation unit is specifically used for: determining a first scaling factor based on the confidence level of the current photovoltaic power output prediction value; wherein the first scaling factor is less than 1 and is positively correlated with the confidence level of the current photovoltaic power output prediction value; determining a second scaling factor based on the confidence level of the current photovoltaic power output prediction value; wherein the second scaling factor is less than the first scaling factor and is positively correlated with the confidence level of the current photovoltaic power output prediction value; calculating a first product of the difference, the first weight, and the first scaling factor, and a second product of the rate of change, the second weight, and the second scaling factor; and determining the sum of the first product and the second product as a weighted sum.

[0142] Furthermore, the confidence level of the current photovoltaic output forecast is determined as the first scaling factor.

[0143] Furthermore, the power of the confidence level of the current photovoltaic output forecast is determined as the second scaling factor.

[0144] Furthermore, the response control device of the solar thermal-photovoltaic combined power plant also includes a statistics module and a second backoff module.

[0145] The statistics module is used to obtain several differences between the predicted photovoltaic power output value and the actual photovoltaic power output value in the photovoltaic power output prediction sequence up to the current time.

[0146] The second rollback module is used to reacquire the power system demand sequence and photovoltaic output prediction sequence within a set time period if the sum of several differences is greater than or equal to a set deviation threshold.

[0147] Example 5:

[0148] A response control device for a solar thermal-photovoltaic combined power plant includes a processor and a memory storing program instructions. The processor is configured to execute the response control method for the solar thermal-photovoltaic combined power plant as provided in the foregoing embodiments when executing the program instructions.

[0149] Example 6:

[0150] A response control system for a solar thermal-photovoltaic combined power plant includes the response control device for the solar thermal-photovoltaic combined power plant provided in the foregoing embodiments.

[0151] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A response control method for a solar thermal-photovoltaic combined power plant, wherein the solar thermal-photovoltaic combined power plant includes a solar thermal system and a photovoltaic system; characterized in that, The response control method includes: Obtain the power system demand sequence and photovoltaic output prediction sequence within a set time period; wherein the time step of the power system demand sequence and the photovoltaic output prediction sequence is greater than or equal to the adjustment time required for the closed-loop control algorithm of the solar thermal system to reach a steady state from the response change; An objective function is constructed based on the power system demand sequence, the photovoltaic output prediction sequence, and the solar thermal output sequence. The optimization objectives are to minimize the supply-demand deviation and the output adjustment step size. The objective function is then solved to obtain the solar thermal output planning sequence. The supply-demand deviation is the deviation obtained by subtracting the power system demand from the sum of the photovoltaic output and the solar thermal output. The output adjustment step size is the difference in solar thermal system output between two adjacent moments in the solar thermal output sequence. The maximum value of the output adjustment step size is within the step response capability of the closed-loop control algorithm. The difference between the current photovoltaic output prediction value and the current actual photovoltaic output value in the photovoltaic output prediction sequence is used to compensate the current output plan value in the solar thermal output plan sequence in order to obtain the current output setpoint of the closed-loop control algorithm. If the difference between the current output setpoint and the output setpoint at the previous moment is beyond the step response capability of the closed-loop control algorithm, then the power system demand sequence and the photovoltaic output prediction sequence within the set time period are reacquired. Otherwise, the closed-loop control algorithm controls the solar thermal system based on the current output setpoint.

2. The response control method according to claim 1, characterized in that, The objective function is: ； in, The index of the parameter in the sequence. The total number of parameters in the sequence. The first in the photothermal output sequence item, The first in the photovoltaic output prediction sequence item, The first in the power system demand sequence item, To adjust the coefficient, , To ensure the smoothness of the output adjustment step size during the optimization process, Adjust the step size for the output force. , .

3. The response control method according to claim 1 or 2, characterized in that, The difference between the current photovoltaic output prediction value and the current actual photovoltaic output value in the photovoltaic output prediction sequence is used to compensate the current planned output value in the solar thermal output planning sequence to obtain the current output setpoint of the closed-loop control algorithm, including: Obtain the output difference between the current predicted photovoltaic output value and the current actual photovoltaic output value, as well as the rate of change of the output difference; The weighted sum of the output difference and the rate of change is calculated based on the first weight of the output difference and the second weight of the rate of change; wherein the first weight is set in accordance with the proportional parameter in PID control theory and the second weight is set in accordance with the derivative parameter in PID control theory. The sum of the weighted sum and the current planned output value is determined as the current output setting value.

4. The response control method according to claim 3, characterized in that, The closed-loop control algorithm controls the solar thermal system according to the current output setpoint, including: At the start of the time step corresponding to the current output setting value, the first actual output value of the photothermal system is recorded; When the time step corresponding to the current output setting value ends, the second actual output value of the photothermal system is recorded; The difference between the first actual output value and the second actual output value is determined as the actual output adjustment value; The difference between the current output setting value and the output setting value of the previous cycle is determined as the set output adjustment value; The difference between the set output adjustment value and the actual output adjustment value is determined as the adjustment loss value; The degree of importance attached to the smoothness of the output adjustment step size during the adjustment and optimization process based on the adjustment loss value; wherein, the larger the adjustment loss value, the higher the degree of importance attached to smoothness, and the smaller the adjustment loss value, the lower the degree of importance attached to smoothness.

5. The response control method according to claim 3, characterized in that, In the process of obtaining the photovoltaic power output prediction sequence, the confidence level of each item in the photovoltaic power output prediction sequence is also obtained. Calculate a weighted sum of the difference and the rate of change based on a first weight of the difference and a second weight of the rate of change, including: A first scaling factor is determined based on the confidence level of the current photovoltaic power output prediction value; wherein, the first scaling factor is less than 1, and the first scaling factor is positively correlated with the confidence level of the current photovoltaic power output prediction value; A second scaling factor is determined based on the confidence level of the current photovoltaic power output prediction value; wherein the second scaling factor is less than the first scaling factor, and the second scaling factor is positively correlated with the confidence level of the current photovoltaic power output prediction value; Calculate the first product of the difference, the first weight, and the first scaling factor, and the second product of the rate of change, the second weight, and the second scaling factor; The sum of the first product and the second product is determined as the weighted sum.

6. The response control method according to claim 5, characterized in that, The confidence level of the current photovoltaic output prediction value is determined as the first scaling factor; The power of the confidence level of the current photovoltaic output prediction is used as the second scaling factor.

7. The response control method according to claim 1 or 2, characterized in that, Also includes: Obtain several differences between the predicted photovoltaic output value and the actual photovoltaic output value in the photovoltaic output prediction sequence up to the current time. If the sum of the aforementioned differences is greater than or equal to a set deviation threshold, then the power system demand sequence and the photovoltaic output prediction sequence within the set time period are reacquired.

8. A response control device for a solar thermal-photovoltaic combined power plant, the solar thermal-photovoltaic combined power plant comprising a solar thermal system and a photovoltaic system; characterized in that, The response control device includes: The data acquisition module is used to acquire the power system demand sequence and the photovoltaic output prediction sequence within a set time period; wherein, the time step of the power system demand sequence and the photovoltaic output prediction sequence is greater than or equal to the adjustment time required for the closed-loop control algorithm of the solar thermal system to reach a steady state from the response change; The optimization solution module is used to construct an objective function based on the power system demand sequence, the photovoltaic output prediction sequence, and the solar thermal output sequence. The objective function is to minimize the supply-demand deviation and the output adjustment step size, and then solve the objective function to obtain the solar thermal output plan sequence. The supply-demand deviation is the deviation obtained by subtracting the power system demand from the sum of the photovoltaic output and the solar thermal output. The output adjustment step size is the difference between the solar thermal system output at two adjacent moments in the solar thermal output sequence. The maximum value of the output adjustment step size is within the step response capability of the closed-loop control algorithm. The compensation module is used to compensate the current planned output value in the solar thermal output plan sequence based on the output difference between the current predicted photovoltaic output value and the current actual photovoltaic output value in the photovoltaic output prediction sequence, so as to obtain the current output setting value of the closed-loop control algorithm. The first rollback module is used to reacquire the power system demand sequence and the photovoltaic output prediction sequence within the set time period if the difference between the current output set value and the output set value at the previous moment is outside the step response capability of the closed-loop control algorithm. The control module is configured to control the solar thermal system according to the current output setpoint if the difference between the current output setpoint and the output setpoint at the previous moment is within the step response capability of the closed-loop control algorithm.

9. A response control device for a solar thermal-photovoltaic combined power plant, comprising a processor and a memory storing program instructions, characterized in that, The processor is configured to execute the response control method of the solar thermal-photovoltaic combined power plant as described in any one of claims 1 to 7 when executing the program instructions.

10. A response control system for a solar thermal-photovoltaic combined power plant, characterized in that, Includes the response control device for a solar thermal-photovoltaic combined power plant as described in claim 8 or 9.

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