Considering the grid-connected requirements of photovoltaic power station and the energy storage calling method of energy storage state of charge

Abstract

The application discloses a method for calling energy storage considering grid-connection requirements of a photovoltaic power station and a state of charge of energy storage, and belongs to the field of grid-connection of photovoltaic power stations. The method for calling energy storage utilizes photovoltaic predicted output data, considers three situations of long-time scale exceeding, long-time scale not exceeding but short-time scale exceeding, and long-time scale and short-time scale both not exceeding, adopts a calling method for controlling deviation of energy storage and recovering the state of charge of energy storage, and can meet the grid-connection requirements of the photovoltaic power station while taking into account the recovery of the state of charge of the energy storage, thereby prolonging the service life of the energy storage battery.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic power plant grid connection, and in particular to an energy storage dispatch method that takes into account the grid connection requirements of photovoltaic power plants and the energy storage state of charge. Background Technology

[0002] With the continuous growth of renewable energy, a large number of photovoltaic (PV) power plants are being connected to the grid. The unpredictability and volatility of PV power generation pose numerous challenges to the grid, impacting the safety, stability, and reliability of the power system. To a certain extent, to ensure the safe and stable operation of the power system, PV power plants connecting to the grid need to meet certain grid connection regulations and requirements, necessitating the monitoring and control of power fluctuations. Due to the technical requirements for grid connection, excessive fluctuations when PV power plants are connected can cause power overflow or deficit. To address this issue, utilizing the energy storage systems configured in PV power plants can serve as an important supplementary measure. By leveraging the "energy time-shifting" characteristics of energy storage to smooth out fluctuations in PV power generation, the output of PV power plants can be kept within the acceptable power range of the grid, improving the reliability and stability of the power system and mitigating the problems brought about by renewable energy integration. Therefore, research on integrating PV power plants into the power system using energy storage technology is essential.

[0003] According to the State Grid's Q / GDW617-2011 "Technical Regulations for Photovoltaic Power Plant Grid Connection," power limits for grid connection are set for photovoltaic power plants of different sizes. Specifically, for small photovoltaic power plants (0.4kV), the maximum output change in 1 minute is 0.2MW, and the maximum output change in 10 minutes is the installed capacity; for medium-sized photovoltaic power plants (10-35kV), the maximum output change in 1 minute is the installed capacity / 5, and the maximum output change in 10 minutes is the installed capacity; for large photovoltaic power plants (66kV), the maximum output change in 1 minute is the installed capacity / 10, and the maximum output change in 10 minutes is the installed capacity / 3.

[0004] To ensure that photovoltaic power plants meet the maximum active power output variation requirements stipulated by grid connection technology, the following methods are currently used: (1) Controlling the power output of photovoltaic power plants to meet the maximum active power output variation acceptable to the grid, avoiding overload or underload of the grid. However, this method may cause curtailment when photovoltaic fluctuations and output are too large. (2) Using power electronics and intelligent control technology to control and regulate photovoltaic power plants, improve response speed and control accuracy, and use intelligent control systems to monitor and control the power generation of photovoltaic power plants. However, this method is more dependent on hardware and software equipment and the control algorithm is generally more complex. (3) Strengthening grid management and planning, improving grid capacity and stability, and creating better conditions for the grid connection of photovoltaic power plants. However, this method is more dependent on external factors. (4) Using energy storage systems to balance the fluctuations of photovoltaic power generation, thereby meeting the grid's requirements for the grid connection of photovoltaic power plants. Currently, using energy storage to balance the output fluctuations of photovoltaic power plants to meet grid connection requirements requires consideration of both short-term and long-term time scale factors, and currently, there is little consideration for energy storage state-of-charge recovery to extend the life of energy storage batteries. Summary of the Invention

[0005] The purpose of this invention is to provide an energy storage dispatch method that takes into account the grid connection requirements of photovoltaic power plants and the state of charge of energy storage, so as to meet the grid connection requirements of photovoltaic power plants while also taking into account the recovery of the state of charge of energy storage and extending the life of energy storage batteries.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] An energy storage dispatch method considering the grid connection requirements of photovoltaic power plants and the state of charge of energy storage includes:

[0008] Obtain the maximum output change of the photovoltaic power station at the first time scale and the maximum output change at the second time scale; wherein the second time scale is n times the first time scale, and n is a positive integer;

[0009] Based on the actual output of the photovoltaic power station at the current moment, combined with environmental parameters and the historical actual output of the photovoltaic power station, a photovoltaic power output prediction sequence for the second time scale starting from the current moment is predicted; wherein, the photovoltaic power output prediction sequence includes n photovoltaic power output predictions for the first time scale;

[0010] Determine whether the photovoltaic predicted output of the nth time scale of the photovoltaic predicted output sequence is within the acceptable power range of the power grid over a long time scale to obtain a first determination result; the acceptable power range of the power grid over a long time scale is determined by the maximum output change in the second time scale.

[0011] If the first judgment result indicates no, then based on the rated power of the energy storage configured in the photovoltaic power station, the energy storage control deviation configured in the photovoltaic power station is invoked within the second time scale.

[0012] If the first judgment result indicates yes, then it is determined whether the photovoltaic predicted output of each first time scale other than the nth in the photovoltaic predicted output sequence is within the acceptable power range of the grid in the short time scale, and a second judgment result is obtained; the acceptable power range of the grid in the short time scale is determined by the maximum output change in the first time scale.

[0013] If the second judgment result indicates no, then the energy storage control deviation configured in the photovoltaic power station is invoked according to the rated power of the energy storage configured in the photovoltaic power station;

[0014] If the second judgment result indicates yes, then the state of charge of the energy storage configured in the photovoltaic power station is restored according to the current state of charge of the energy storage and the reference state of charge.

[0015] Optionally, based on the current actual output of the photovoltaic power station, combined with environmental parameters and the historical actual output of the photovoltaic power station, a photovoltaic power output sequence for the second time scale starting from the current moment is predicted, specifically including:

[0016] Based on the current actual output of the photovoltaic power station, combined with solar radiation, temperature, humidity, cloud cover, and the historical actual output of the photovoltaic power station, the photovoltaic power output sequence for the second time scale starting from the current time t is predicted as [P] using time series forecasting, artificial neural network, autoregressive moving average model, support vector machine, or wavelet analysis. f (t+T s ),P f (t+2T s ),…,P f (t+T l )]; where T s As the first time scale, T l For the second time scale, T l =nT s ;P f (t+T s ), P f (t+2T s ) and P f (t+T l ) are the photovoltaic power outputs predicted for the 1st, 2nd, and nth first time scales starting from the current time t.

[0017] Optionally, the acceptable power range for the power grid over a long time scale is [P]. r (t)-P l P r (t)+P l In the formula, P r (t) represents the actual output of the photovoltaic power station at time t, P lThis represents the maximum output change on the second time scale;

[0018] The acceptable power range for the short-time scale of the power grid is [P] r (t+iT s -T s )-P s P r (t+iT s -T s )+P s In the formula, P r (t+iT s -T s P represents the actual output of the photovoltaic power station at the (i-1)th time scale starting from the current time t. s Let i be the maximum output change in the first time scale, i = 1, 2, ..., n.

[0019] Optionally, based on the rated power of the energy storage configured in the photovoltaic power station, the control deviation of the energy storage configured in the photovoltaic power station is invoked within the second time scale, specifically including:

[0020] Obtain the rated power P of the energy storage configured in the photovoltaic power station rated ;

[0021] According to the rated power P rated Using the formula Determine the energy storage output for each of the first time scales within the second time scale; where P st (t+iT s P represents the energy storage output at the i-th time scale within the second time scale. f (t+iT s P represents the predicted photovoltaic output at the i-th first time scale starting from the current time t. r (t+iT s () represents the actual output of the photovoltaic power station at the i-th first time scale starting from the current time t;

[0022] Based on the energy storage output of each first time scale within the second time scale, the energy storage control deviation configured for the photovoltaic power station is invoked.

[0023] Optionally, based on the current state of charge (SOC) of the energy storage and a reference SOC, the SOC of the energy storage configured in the photovoltaic power station is restored, specifically including:

[0024] Obtain the rated energy capacity E of the energy storage configured in the photovoltaic power station. rated This is beneficial for reducing the reference state of charge (SOC) of energy storage lifetime degradation. ref And the current state of charge (SOC(t)) of the energy storage;

[0025] According to the rated power Prated The rated energy capacity E rated The reference state of charge (SOC) ref And the state of charge SOC(t), using the formula Determine the energy storage output when the predicted photovoltaic output for the first time scale is not within the acceptable power range of the grid for the short time scale; where P st (t+jT s ) represents the energy storage output when the predicted photovoltaic output value at the j-th time scale starting from the current time t is not within the acceptable power range of the grid in the short time scale, and λ is the energy storage state of charge recovery coefficient, 0≤λ≤1;

[0026] Based on the photovoltaic power output predicted at the first time scale, when it is not within the acceptable power range of the grid at the short time scale, the energy storage output is called upon to control the energy storage deviation configured in the photovoltaic power station.

[0027] An energy storage dispatch system that considers the grid connection requirements of photovoltaic power plants and the state of charge of energy storage includes:

[0028] The maximum output change acquisition module is used to acquire the maximum output change of the photovoltaic power station in the first time scale and the maximum output change in the second time scale; wherein the second time scale is n times the first time scale, and n is a positive integer;

[0029] The output prediction module is used to predict the photovoltaic power generation sequence at the second time scale starting from the current moment, based on the actual output of the photovoltaic power station at the current moment, combined with environmental parameters and the historical actual output of the photovoltaic power station; wherein, the photovoltaic power generation sequence includes n photovoltaic power generation predictions at the first time scale;

[0030] The first judgment module is used to determine whether the photovoltaic predicted output of the nth first time scale of the photovoltaic predicted output sequence is within the acceptable power range of the grid over a long time scale, and to obtain a first judgment result; the acceptable power range of the grid over a long time scale is determined by the maximum output change in the second time scale.

[0031] The first energy storage call module is used to call the energy storage control deviation configured in the photovoltaic power station within a second time scale according to the rated power of the energy storage configured in the photovoltaic power station if the first judgment result indicates no.

[0032] The second judgment module is used to determine whether the photovoltaic predicted output of each first time scale other than the nth one in the photovoltaic predicted output sequence is within the acceptable power range of the grid in the short time scale if the first judgment result indicates yes, and obtain the second judgment result; the acceptable power range of the grid in the short time scale is determined by the maximum output change in the first time scale.

[0033] The second energy storage call module is used to call the energy storage control deviation configured in the photovoltaic power station according to the rated power of the energy storage configured in the photovoltaic power station if the second judgment result indicates no;

[0034] The energy storage recovery module is used to restore the state of charge of the energy storage configured in the photovoltaic power station based on the current state of charge and the reference state of charge of the energy storage if the second judgment result indicates yes.

[0035] An electronic device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the energy storage call method described above, which takes into account the grid connection requirements of a photovoltaic power plant and the state of charge of the energy storage.

[0036] A computer-readable storage medium having a computer program stored thereon, which, when executed, implements the energy storage recall method as described above, taking into account the grid connection requirements of a photovoltaic power plant and the state of charge of the energy storage.

[0037] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0038] This invention discloses an energy storage dispatch method that considers the grid connection requirements of photovoltaic power plants and the state of charge of energy storage. It utilizes photovoltaic predicted output data and considers three scenarios: exceeding limits on a long-term scale, not exceeding limits on a long-term scale but exceeding limits on a short-term scale, and not exceeding limits on either a long-term or short-term scale. It adopts a dispatch method that calls for energy storage control deviations and restores the state of charge of energy storage. This method can meet the grid connection requirements of photovoltaic power plants while also taking into account the restoration of the state of charge of energy storage, thus extending the life of energy storage batteries. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 A flowchart of an energy storage dispatching method that considers the grid connection requirements of photovoltaic power plants and the state of charge of energy storage, provided in an embodiment of the present invention;

[0041] Figure 2 A schematic diagram of an energy storage dispatching method that considers the grid connection requirements of photovoltaic power plants and the state of charge of energy storage, provided in an embodiment of the present invention. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0044] This application proposes a method for energy storage initiation that addresses the power overflow or deficit caused by excessive fluctuations when photovoltaic power plants are connected to the grid. This method utilizes configured energy storage to meet the technical requirements for grid connection of photovoltaic power plants. Furthermore, to extend the lifespan of energy storage, it considers restoring the state of charge of energy storage under certain conditions.

[0045] like Figure 1 As shown in the figure, an energy storage dispatching method considering the grid connection requirements of photovoltaic power plants and the state of charge of energy storage proposed in this embodiment of the invention includes:

[0046] Step S1: Obtain the maximum output change of the photovoltaic power station at the first time scale and the maximum output change at the second time scale; wherein the second time scale is n times the first time scale, and n is a positive integer.

[0047] According to the technical requirements for grid connection of photovoltaic power plants, the short time scale T is read. s The maximum change in output is P s Long-term timescale T l The maximum change in output is P l T l =nT s Taking the current "Technical Regulations for Photovoltaic Power Plant Grid Connection" as an example, the maximum output change is specified for the short time scale of 1 minute and the long time scale of 10 minutes, so n is 10.

[0048] Step S2: Based on the actual output of the photovoltaic power station at the current moment, combined with environmental parameters and the historical actual output of the photovoltaic power station, predict the photovoltaic power output sequence for the second time scale starting from the current moment; wherein, the photovoltaic power output sequence includes n photovoltaic power outputs for the first time scale.

[0049] The current time is t, and the actual output of the photovoltaic power station is P. r (t), based on solar radiation, temperature, humidity, cloud cover, and historical operating data of the power station, predict the next long-term time scale T. l The photovoltaic power output prediction sequence is [P]f (t+T s ), P f (t+2T s ), ..., P f (t+T l )]. P f (t+T s ), P f (t+2T s ) and P f (t+T l ) are the photovoltaic power outputs predicted for the 1st, 2nd, and nth first time scales starting from the current time t.

[0050] Specifically, historical operating data of the power station refers to the actual output data of the photovoltaic power station over a past period. This data allows for the prediction of future photovoltaic output by combining past output data. Depending on the available historical data, one or two years' worth of data can be used; if only two months' worth of data is available, then two months' worth of data should be used.

[0051] There are many existing photovoltaic forecasting methods. This invention combines data to select one of the existing photovoltaic forecasting methods. It does not innovate photovoltaic forecasting methods and chooses traditional methods. For example, one can choose (1) time series forecasting method: the most classic, systematic and widely used forecasting method. It uses past time series data for statistical analysis to infer the development trend of things and makes curve fitting predictions based on the change law of a single time series; (2) artificial neural network method: the input layer is the existing solar radiation, temperature, humidity, cloud cover and other weather information, and the output is the power plant operation output data. The existing data is divided into training set and test set for neural network training. After determining the weight of each layer in the neural network, the future solar radiation, temperature, humidity, cloud cover and other weather information can be input to predict the future output. Other methods that can be used include: (3) autoregressive moving average model method, (4) support vector machine method, (5) wavelet analysis method, etc.

[0052] Step S3: Determine whether the photovoltaic predicted output of the nth first time scale of the photovoltaic predicted output sequence is within the acceptable power range of the grid over a long time scale, and obtain a first judgment result; the acceptable power range of the grid over a long time scale is determined by the maximum output change in the second time scale.

[0053] Determining the long time scale T l The predicted photovoltaic power output P f (t+T l Whether it is within the acceptable power range of the power grid, i.e., whether it meets P r (t)-P l ≤P f (t+Tl )≤P r (t)+P l .

[0054] Step S4: If the first judgment result indicates no, then according to the rated power of the energy storage configured in the photovoltaic power station, the energy storage control deviation configured in the photovoltaic power station is called in the second time scale.

[0055] Reference Figure 2 Before activating the energy storage, it is also necessary to read the rated power P of the energy storage configured in the photovoltaic power station. rated Rated energy capacity is E rated The reference state of charge (SOC) is beneficial for reducing the degradation of energy storage lifespan. ref The current state of charge (SOC(t)) of the energy storage.

[0056] If the long time scale T l If the predicted photovoltaic output exceeds the limit, the energy storage control deviation will be activated, and the energy storage output P will be reduced. st (t+xT s The following equation applies (where x = 1, 2, ..., n):

[0057]

[0058] That is, if the time period exceeds the limit, it is necessary to go from time t to time t+T. l During this period, the energy storage control deviation was addressed, and the timescale for real-time energy storage deployment is T. s For example, suppose time t is 0, T l For 10 minutes, T s The time interval is 1 minute. If the predicted output at time 10 minutes exceeds the limit, the energy storage will adjust the control deviation according to the real-time output at times 1, 2, 3, ... 10 minutes.

[0059] Step S5: If the first judgment result indicates yes, then determine whether the photovoltaic predicted output of each first time scale other than the nth in the photovoltaic predicted output sequence is within the acceptable power range of the grid in the short time scale, and obtain the second judgment result; the acceptable power range of the grid in the short time scale is determined by the maximum output change in the first time scale.

[0060] If the long time scale T l If the predicted photovoltaic power output does not exceed the limit, then the short-term time scale T is determined. s The predicted photovoltaic power output P f (t+iT s Whether it is within the acceptable power range of the power grid, i.e., whether it meets P r (t+iT s -T s )-Ps ≤P f (t+iT s )≤P r (t+iT s -T s )+P s Among them, iT s Representing the long time scale T l The i-th short time scale T traversed below s The initial value of i is 1.

[0061] Step S6: If the second judgment result indicates no, then the energy storage control deviation configured in the photovoltaic power station is called according to the rated power of the energy storage configured in the photovoltaic power station.

[0062] If the short timescale T s If the predicted photovoltaic output exceeds the limit, the energy storage control deviation will be activated, and the energy storage output P will be reduced. st (t+iT s The following equation must be satisfied:

[0063]

[0064] Step S7: If the second judgment result indicates yes, then restore the state of charge of the energy storage configured in the photovoltaic power station according to the current state of charge of the energy storage and the reference state of charge.

[0065] If the short timescale T s If the predicted photovoltaic output does not exceed the limit, the energy storage will be restored to its state of charge, and the energy storage output P will be restored. st (t+iT s (where λ is the energy storage state of charge recovery coefficient, 0≤λ≤1) satisfies the following formula:

[0066]

[0067] For steps S5 to S7, traverse the time scale T. l All short timescales T s .

[0068] After performing the above steps, update the current time t = t + T. l If t ≤ the time period T during which energy storage needs to be called all To proceed to the next long-term timescale T l The calculation is to repeat the above steps, or to end the process if the steps are not repeated.

[0069] This invention aims to propose an energy storage dispatch method that considers both the grid connection requirements of photovoltaic power plants and the state of charge of energy storage. It considers three scenarios: photovoltaic predicted output exceeding limits on a long-term time scale, not exceeding limits on a long-term time scale but exceeding limits on a short-term time scale, and not exceeding limits on either a long-term or short-term time scale. The method employs a dispatch method that addresses energy storage control deviations and restores the state of charge of energy storage. This approach considers both the grid connection requirements of photovoltaic power plants and the restoration of the state of charge of energy storage, thus achieving a scientific and efficient solution to the energy storage dispatch problem when meeting the grid connection requirements of photovoltaic power plants.

[0070] The main technical advantages of this invention are as follows:

[0071] (1) This invention proposes an energy storage dispatch method that takes into account the grid connection requirements of photovoltaic power plants. It can meet the requirements of the maximum acceptable change in active power output of the grid under short and long time scales when photovoltaic power plants are connected to the grid, and avoid overload or underload of the grid.

[0072] (2) This invention proposes an energy storage call method that takes into account the energy storage state of charge, which can restore the energy storage state of charge when the output of the photovoltaic power station does not exceed the limit, so that the energy storage is kept at the reference state of charge as much as possible, and the deep charge and discharge are reduced, thereby reducing the energy storage life decay.

[0073] (3) This invention proposes an energy storage dispatch method that considers the grid connection requirements of photovoltaic power plants and the state of charge of energy storage. It utilizes photovoltaic predicted output data and considers three situations: exceeding the limit on a long time scale, not exceeding the limit on a long time scale but exceeding the limit on a short time scale, and not exceeding the limit on either a long or short time scale. It adopts a dispatch method that calls energy storage control deviation and restores the state of charge of energy storage, which can meet the grid connection requirements of photovoltaic power plants while taking into account the restoration of the state of charge of energy storage.

[0074] In order to execute the methods corresponding to the above embodiments and achieve the corresponding functions and technical effects, an energy storage dispatch system considering the grid connection requirements of photovoltaic power plants and the state of charge of energy storage is provided below, characterized in that it includes:

[0075] The maximum output change acquisition module is used to acquire the maximum output change of the photovoltaic power station in the first time scale and the maximum output change in the second time scale; wherein the second time scale is n times the first time scale, and n is a positive integer;

[0076] The output prediction module is used to predict the photovoltaic power generation sequence at the second time scale starting from the current moment, based on the actual output of the photovoltaic power station at the current moment, combined with environmental parameters and the historical actual output of the photovoltaic power station; wherein, the photovoltaic power generation sequence includes n photovoltaic power generation predictions at the first time scale;

[0077] The first judgment module is used to determine whether the photovoltaic predicted output of the nth first time scale of the photovoltaic predicted output sequence is within the acceptable power range of the grid over a long time scale, and to obtain a first judgment result; the acceptable power range of the grid over a long time scale is determined by the maximum output change in the second time scale.

[0078] The first energy storage call module is used to call the energy storage control deviation configured in the photovoltaic power station within a second time scale according to the rated power of the energy storage configured in the photovoltaic power station if the first judgment result indicates no.

[0079] The second judgment module is used to determine whether the photovoltaic predicted output of each first time scale other than the nth one in the photovoltaic predicted output sequence is within the acceptable power range of the grid in the short time scale if the first judgment result indicates yes, and obtain the second judgment result; the acceptable power range of the grid in the short time scale is determined by the maximum output change in the first time scale.

[0080] The second energy storage call module is used to call the energy storage control deviation configured in the photovoltaic power station according to the rated power of the energy storage configured in the photovoltaic power station if the second judgment result indicates no;

[0081] The energy storage recovery module is used to restore the state of charge of the energy storage configured in the photovoltaic power station based on the current state of charge and the reference state of charge of the energy storage if the second judgment result indicates yes.

[0082] The energy storage dispatch system that considers the grid connection requirements of photovoltaic power plants and the state of charge of energy storage provided in this embodiment of the invention has a similar working principle and beneficial effects to the energy storage dispatch method that considers the grid connection requirements of photovoltaic power plants and the state of charge of energy storage described in the above embodiments. Therefore, it will not be described in detail here. For details, please refer to the introduction of the above method embodiments.

[0083] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, it implements the energy storage call method as described above, which takes into account the grid connection requirements of photovoltaic power plants and the state of charge of energy storage.

[0084] Furthermore, when the computer program in the aforementioned memory is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory, random access memory, magnetic disks, or optical disks.

[0085] Furthermore, the present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed, it implements the aforementioned energy storage call method that takes into account the grid connection requirements of photovoltaic power plants and the state of charge of energy storage.

[0086] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0087] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for energy storage dispatch considering the grid connection requirements of photovoltaic power plants and the state of charge of energy storage, characterized in that, include: Obtain the maximum output change of the photovoltaic power station at the first time scale and the maximum output change at the second time scale; wherein the second time scale is n times the first time scale, and n is a positive integer; Based on the current actual output of the photovoltaic power station, combined with environmental parameters and the historical actual output of the photovoltaic power station, a photovoltaic power output sequence for the second time scale starting from the current moment is predicted; wherein, the photovoltaic power output sequence includes n photovoltaic power outputs for the first time scale; Determine whether the photovoltaic predicted output of the nth time scale of the photovoltaic predicted output sequence is within the acceptable power range of the grid over a long time scale to obtain a first determination result; the acceptable power range of the grid over a long time scale is determined by the maximum output change in the second time scale. If the first judgment result indicates no, then based on the rated power of the energy storage configured in the photovoltaic power station, the energy storage control deviation configured in the photovoltaic power station is invoked within the second time scale. If the first judgment result indicates yes, then it is determined whether the photovoltaic predicted output of each first time scale other than the nth in the photovoltaic predicted output sequence is within the acceptable power range of the grid in the short time scale, and a second judgment result is obtained; the acceptable power range of the grid in the short time scale is determined by the maximum output change in the first time scale. If the second judgment result indicates no, then the energy storage control deviation configured in the photovoltaic power station is invoked according to the rated power of the energy storage configured in the photovoltaic power station. If the second judgment result indicates yes, then the state of charge of the energy storage configured in the photovoltaic power station is restored according to the current state of charge of the energy storage and the reference state of charge.

2. The energy storage dispatch method considering the grid connection requirements of photovoltaic power plants and the state of charge of energy storage according to claim 1, characterized in that, Based on the current actual output of the photovoltaic power station, combined with environmental parameters and the historical actual output of the photovoltaic power station, the photovoltaic power output sequence for the second time scale starting from the current moment is predicted, specifically including: Based on the current actual output of the photovoltaic power station, combined with solar radiation, temperature, humidity, cloud cover, and the historical actual output of the photovoltaic power station, the photovoltaic power output sequence for the second time scale starting from the current time t is predicted as [P] using time series forecasting, artificial neural network, autoregressive moving average model, support vector machine, or wavelet analysis. f (t+T s ),P f (t+2T s ),…,P f (t+T l )]; where T s As the first time scale, T l For the second time scale, T l =nT s ;P f (t+T s ), P f (t+2T s ) and P f (t+T l ) are the photovoltaic power outputs predicted for the 1st, 2nd, and nth first time scales starting from the current time t.

3. The energy storage dispatch method considering the grid connection requirements of photovoltaic power plants and the state of charge of energy storage according to claim 2, characterized in that, The acceptable power range for the power grid over a long time scale is [P] r (t)-P l P r (t)+P l In the formula, P r (t) represents the actual output of the photovoltaic power station at time t, P l This represents the maximum output change on the second time scale; The acceptable power range for the short-time scale of the power grid is [P] r (t+iT s -T s )-P s P r (t+iT s -T s )+P s In the formula, P r (t+iT s -T s P represents the actual output of the photovoltaic power station at the (i-1)th time scale starting from the current time t. s Let i be the maximum output change in the first time scale, i = 1, 2, ..., n.

4. The energy storage dispatch method considering the grid connection requirements of photovoltaic power plants and the state of charge of energy storage according to claim 3, characterized in that, Based on the rated power of the energy storage configured in the photovoltaic power station, the control deviation of the energy storage configured in the photovoltaic power station is applied within the second time scale, specifically including: Obtain the rated power P of the energy storage configured in the photovoltaic power station rated ; According to the rated power P rated Using the formula Determine the energy storage output for each of the first time scales within the second time scale; where P st (t+iT s P represents the energy storage output at the i-th time scale within the second time scale. f (t+iT s P represents the predicted photovoltaic output at the i-th first time scale starting from the current time t. r (t+iT s () represents the actual output of the photovoltaic power station at the i-th first time scale starting from the current time t; Based on the energy storage output of each first time scale within the second time scale, the energy storage control deviation configured for the photovoltaic power station is invoked.

5. The energy storage dispatch method considering the grid connection requirements of photovoltaic power plants and the state of charge of energy storage according to claim 4, characterized in that, Based on the current state of charge (SOC) and reference SOC of the energy storage, the SOC of the energy storage configured in the photovoltaic power station is restored, specifically including: Obtain the rated energy capacity E of the energy storage configured in the photovoltaic power station. rated This is beneficial for reducing the reference state of charge (SOC) of energy storage lifetime degradation. ref And the current state of charge (SOC(t)) of the energy storage; According to the rated power P rated The rated energy capacity E rated The reference state of charge (SOC) ref And the state of charge SOC(t), using the formula Determine the energy storage output when the predicted photovoltaic output for the first time scale is not within the acceptable power range of the grid for the short time scale; where P st (t+jT s ) represents the energy storage output when the predicted photovoltaic output value at the j-th time scale starting from the current time t is not within the acceptable power range of the grid in the short time scale, and λ is the energy storage state of charge recovery coefficient, 0≤λ≤1; Based on the photovoltaic power output predicted at the first time scale, when it is not within the acceptable power range of the grid at the short time scale, the energy storage output is called upon to control the energy storage deviation configured in the photovoltaic power station.

6. An energy storage dispatch system that considers the grid connection requirements of photovoltaic power plants and the state of charge of energy storage, characterized in that, include: The maximum output change acquisition module is used to acquire the maximum output change of the photovoltaic power station in the first time scale and the maximum output change in the second time scale; wherein the second time scale is n times the first time scale, and n is a positive integer; The output prediction module is used to predict the photovoltaic power generation sequence at the second time scale starting from the current moment, based on the actual output of the photovoltaic power station at the current moment, combined with environmental parameters and the historical actual output of the photovoltaic power station; wherein, the photovoltaic power generation sequence includes n photovoltaic power generation predictions at the first time scale; The first judgment module is used to determine whether the photovoltaic predicted output of the nth first time scale of the photovoltaic predicted output sequence is within the acceptable power range of the grid over a long time scale, and to obtain a first judgment result; the acceptable power range of the grid over a long time scale is determined by the maximum output change in the second time scale. The first energy storage call module is used to call the energy storage control deviation configured in the photovoltaic power station within a second time scale according to the rated power of the energy storage configured in the photovoltaic power station if the first judgment result indicates no. The second judgment module is used to determine whether the photovoltaic predicted output of each first time scale other than the nth one in the photovoltaic predicted output sequence is within the acceptable power range of the grid in the short time scale if the first judgment result indicates yes, and obtain the second judgment result; the acceptable power range of the grid in the short time scale is determined by the maximum output change in the first time scale. The second energy storage call module is used to call the energy storage control deviation configured in the photovoltaic power station according to the rated power of the energy storage configured in the photovoltaic power station if the second judgment result indicates no; The energy storage recovery module is used to restore the state of charge of the energy storage configured in the photovoltaic power station based on the current state of charge and the reference state of charge of the energy storage if the second judgment result indicates yes.

7. An electronic device, characterized in that, It includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the energy storage call method as described in any one of claims 1 to 5, which takes into account the grid connection requirements of the photovoltaic power plant and the energy storage state of charge.

8. A computer-readable storage medium, characterized in that, It stores a computer program, which, when executed, implements the energy storage call method as described in any one of claims 1 to 5, taking into account the grid connection requirements of the photovoltaic power station and the energy storage state of charge.

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