A photovoltaic energy storage system scheduling method, system and device

Abstract

The application discloses a photovoltaic energy storage system scheduling method, system and device, wherein the method first divides a test time into a plurality of time periods by setting the test time, calculates photovoltaic terminal power generation power of each time period, and obtains load terminal power consumption power of each time period, exchange power between a photovoltaic energy storage system and a power grid terminal, and energy storage terminal charging and discharging power, establishes a power balance relationship, then constructs a constraint condition according to the power balance relationship, and takes maximum photovoltaic power consumption as an objective function, and finally performs charging and discharging scheduling on the energy storage terminal of the photovoltaic energy storage system according to the constraint condition and the objective function. The application can optimize the charging and discharging scheduling of the photovoltaic energy storage system, reduce the dependence on the power grid, help balance the power grid and improve the stability of the power grid, thereby improving the photovoltaic power consumption rate and the utilization rate of the photovoltaic energy storage system.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic energy storage system control technology, and in particular to a photovoltaic energy storage system scheduling method, system and equipment. Background Technology

[0002] Photovoltaic (PV) absorption capacity refers to the amount of solar photovoltaic (PV) power that a power system can accept and effectively utilize. When a PV power generation system is connected to the grid, the grid's stability and frequency control requirements limit the amount of PV power that can be absorbed safely and economically. Exceeding this capacity may lead to voltage fluctuations and frequency instability. A PV energy storage system is a device system used in PV power generation systems to cyclically store, convert, and release electrical energy through electrochemical cells or electromagnetic energy storage media. Introducing a PV energy storage system into a PV power generation system can effectively mitigate the volatility of PV power generation and improve energy utilization. Generally, the PV absorption rate and energy storage system utilization rate are improved through the scheduling of the PV energy storage system.

[0003] Current methods for scheduling photovoltaic (PV) energy storage systems include: considering load-side electricity prices and employing peak shaving and valley filling to reduce peak electricity consumption and increase valley electricity consumption; adjusting the number of charge-discharge cycles of energy storage devices based on day-ahead load forecasts of the distribution network and PV power generation forecasts to reduce the peak-valley difference in load; and adjusting the charging and discharging of the energy storage system based on weather, power generation, load size, and electricity consumption periods. However, these existing PV energy storage system scheduling methods cannot effectively address the charging and discharging of energy storage devices under different scenarios, and cannot effectively improve the PV absorption rate and the utilization rate of the energy storage system. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a photovoltaic energy storage system scheduling method, system and equipment, which can realize the charging and discharging scheduling of the energy storage end under different scenarios, and effectively improve the photovoltaic absorption rate and the utilization rate of the energy storage system.

[0005] To address the above technical problems, embodiments of the present invention provide a photovoltaic energy storage system scheduling method, comprising:

[0006] Set a test time, divide the test time into several time periods, and calculate the photovoltaic power generation power in each time period;

[0007] The system acquires the load power consumption, the power exchange between the photovoltaic energy storage system and the grid, and the charging and discharging power of the energy storage system for each time period.

[0008] A power balance relationship is established based on the photovoltaic power generation, load power consumption, power exchange between the photovoltaic energy storage system and the grid, and the charging and discharging power of the energy storage system for each time period.

[0009] Based on the power balance relationship, constraints are constructed, and the objective function is to maximize the consumption of photovoltaic power.

[0010] Based on the constraints and the objective function, the charging and discharging of the energy storage end of the photovoltaic energy storage system is scheduled.

[0011] Optionally, the power balance relationship is as follows:

[0012] ;

[0013] in, Indicates time period The photovoltaic power generation capacity; Indicates time period The exchange power between the photovoltaic energy storage system and the grid is represented by a positive value, indicating that the photovoltaic system draws power from the grid, and a negative value, indicating that the photovoltaic system feeds power back to the grid. Indicates time period The power consumption at the load end, Indicates time period The charging and discharging power of the energy storage terminal is positive when charging and negative when discharging.

[0014] Optionally, the constraints include energy storage capacity constraints, energy storage charging and discharging power constraints, transformer reverse overload constraints, and photovoltaic power generation constraints.

[0015] Optionally, the objective function is

[0016] ;

[0017] in, This represents the maximum value of photovoltaic power consumption; Indicates time period The actual photovoltaic power generation capacity , Indicates the maximum allowable power generation of the photovoltaic module; Indicates time period The electricity fed back from the internal photovoltaic terminal to the grid terminal, when When the value is positive, the result is 0, indicating insufficient power generation at the photovoltaic end, all photovoltaic power generation is consumed, and power needs to be drawn from the grid; when... When it is negative, If the value is positive, the result is taken as... , indicating that the photovoltaic power generation is sufficient and fed back to the grid, and the portion of the power fed to the grid is not consumed; M represents the total number of time periods into which the test time is divided.

[0018] Optionally, the step of scheduling the charge and discharge of the energy storage terminal of the photovoltaic energy storage system according to the constraints and the objective function includes:

[0019] When the total charging amount of the energy storage terminal during the test period is greater than the capacity of the energy storage terminal, the time for the energy storage terminal to act as electricity is determined based on the difference between the power generation of the photovoltaic terminal and the power consumption of the load terminal, and the charging and discharging of the energy storage terminal is executed.

[0020] When the total charge of the energy storage terminal during the test period is less than or equal to the capacity of the energy storage terminal, the charging and discharging state of the energy storage terminal is determined and the charging and discharging of the energy storage terminal is executed, taking into account the balancing of grid load or economic benefits.

[0021] Optionally, when the total charging amount of the energy storage terminal during the test time is greater than the capacity of the energy storage terminal, the time for the energy storage terminal to act as electricity is determined based on the difference between the power generation of the photovoltaic terminal and the power consumption of the load terminal, and the energy storage terminal charging and discharging is performed, including:

[0022] When the total charge of the energy storage device during the test period is greater than the capacity of the energy storage device,

[0023] If the difference between the photovoltaic power generation and the load power consumption is greater than the first set value, the energy storage terminal will start charging until the energy storage terminal capacity constraint is violated or the difference between the photovoltaic power generation and the load power consumption is less than 0, at which point the energy storage terminal will stop charging.

[0024] If the difference between the power generated by the photovoltaic terminal and the power consumed by the load terminal is greater than the second set value, the energy storage terminal will start discharging until the difference between the power generated by the photovoltaic terminal and the power consumed by the load terminal is less than 0, at which point the energy storage terminal will stop discharging.

[0025] If the photovoltaic power generation is equal to 0, then the energy storage terminal discharges until the total charge of the energy storage terminal during the test time is 0, at which point the energy storage terminal stops discharging.

[0026] Optionally, when the total charging amount of the energy storage terminal during the test period is less than or equal to the capacity of the energy storage terminal, the charging and discharging state of the energy storage terminal is determined, and the charging and discharging of the energy storage terminal is executed, taking into account the balancing of grid load or economic benefits, including:

[0027] When the total charge of the energy storage device during the test period is less than or equal to the capacity of the energy storage device,

[0028] If grid load balancing is taken into account, the energy storage terminal will start discharging when the grid output power reaches 70% of its peak value during periods when the photovoltaic power generation is insufficient or when the photovoltaic power generation is not at all.

[0029] If economic benefits are taken into consideration, during the period when the photovoltaic power generation is in operation, the charging and discharging states of the energy storage terminal are switched according to the power generation of the photovoltaic power generation. During the period when the photovoltaic power generation is not in operation, the energy storage terminal draws power from the grid to charge.

[0030] As an improvement to the above solution, the photovoltaic energy storage system scheduling method further includes:

[0031] Based on the objective function, the photovoltaic absorption rate and energy storage utilization rate are calculated.

[0032] Based on the photovoltaic absorption rate and the energy storage utilization rate, the charging and discharging schedule of the energy storage terminal of the photovoltaic energy storage system is re-executed.

[0033] To address the above technical problems, embodiments of the present invention also provide a photovoltaic energy storage system scheduling system, comprising:

[0034] The first power acquisition module is used to set the test time, divide the test time into several time periods, and calculate the photovoltaic power generation power of each time period.

[0035] The second power acquisition module is used to acquire the load power consumption, the power exchange between the photovoltaic energy storage system and the grid, and the charging and discharging power of the energy storage end for each time period.

[0036] The power balance relationship establishment module is used to establish a power balance relationship based on the photovoltaic power generation, load power consumption, power exchange between the photovoltaic energy storage system and the grid, and the charging and discharging power of the energy storage end for each time period.

[0037] The objective function construction module is used to construct constraints based on the power balance relationship, with the objective function being to maximize the consumption of photovoltaic power.

[0038] The scheduling module is used to schedule the charging and discharging of the energy storage terminal of the photovoltaic energy storage system according to the constraints and the objective function.

[0039] To address the above technical problems, this invention provides a terminal device including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements the photovoltaic energy storage system scheduling method described in any of the above embodiments.

[0040] Compared with existing technologies, the photovoltaic energy storage system scheduling method, system, and equipment provided in this invention provide an analytical basis for the balance between photovoltaic, energy storage, load, and power grid by calculating the photovoltaic power generation and load power consumption at different time periods, thereby improving the accuracy of the analysis. Furthermore, by considering various constraints, the actual photovoltaic power generation is determined, and the photovoltaic power consumption is calculated. Then, based on maximizing photovoltaic consumption, the charging and discharging time points of the energy storage terminal are determined according to the energy storage capacity and the energy storage terminal, optimizing the charging and discharging operation of the energy storage terminal, maximizing the utilization of photovoltaic power generation, reducing dependence on the power grid, helping to balance the power grid and improve its stability, and further improving the photovoltaic consumption rate and the utilization rate of the energy storage system. Attached Figure Description

[0041] To more clearly illustrate the technical solution of the present invention, the accompanying 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.

[0042] Figure 1 This is a flowchart of a photovoltaic energy storage system scheduling method provided in an embodiment of the present invention;

[0043] Figure 2 This is another flowchart of a photovoltaic energy storage system scheduling method provided in an embodiment of the present invention;

[0044] Figure 3 This is a structural block diagram of a photovoltaic energy storage system scheduling system provided in an embodiment of the present invention;

[0045] Figure 4 This is a structural block diagram of a terminal device provided in an embodiment of the present invention. Detailed Implementation

[0046] 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.

[0047] It should be noted that a photovoltaic power generation system generally includes a photovoltaic (PV) end, an energy storage end, a load end, and a grid end. The electricity generated by the PV end is first supplied to the load end, and any excess is supplied to the energy storage end. The excess electricity from the energy storage end is then fed into the grid. If the power fed into the grid far exceeds the transformer load, it will cause the connected transformer to be overloaded in reverse. In this case, the PV power generation capacity needs to be limited to ensure that the transformer is not overloaded. When the electricity generated by the PV end cannot meet the demand of the load end, the energy storage end first supplements the load end with electricity. If the sum of the electricity generated by the PV end and the energy storage end still cannot meet the demand of the load end, the PV end, the energy storage end, and the grid end jointly provide electricity to the load end.

[0048] See Figure 1 , Figure 1 This is a flowchart of a photovoltaic energy storage system scheduling method provided by an embodiment of the present invention, the photovoltaic energy storage system scheduling method including steps S1 to S5:

[0049] S1. Set the test time, divide the test time into several time periods, and calculate the photovoltaic power generation power of each time period;

[0050] For example, a day is used as the test period, and then the day is divided into M time periods, where M is a positive integer greater than or equal to 1. In this embodiment of the invention, M=24, that is, one hour is one time period. The calculation method for other values ​​of M is similar and will not be described in detail.

[0051] Mark any time period as ,but The value range of is 1, 2, 3...24, which can be represented as:

[0052] ;

[0053] Any time period of day Photovoltaic power generation It can be calculated using the following formula:

[0054] (1);

[0055] In equation (1), During the time period Solar irradiance (unit: W / m²) can be derived by measuring the current generated by photovoltaic cells, or obtained through satellite remote sensing data; A is the area of ​​the photovoltaic module (unit: m²). This refers to the photovoltaic conversion efficiency under standard test conditions (STC, i.e., solar irradiance of 1000 W / m², cell temperature of 25°C, and air quality (AM) of 1.5), which is typically 15-25%. It is the temperature coefficient of a photovoltaic module (unit: 1 / °C). This is the temperature under standard testing conditions, typically 25°C;

[0056] in, It refers to a time period The actual operating temperature of the photovoltaic module, expressed in °C, is such that its size can be determined by the ambient temperature. and solar irradiance To estimate, the estimation formula is:

[0057] (2);

[0058] In equation (2), This is the nominal operating temperature of the photovoltaic module, typically 45-50°C.

[0059] In addition, all time periods are summarized. Photovoltaic power generation The amount of electricity generated by the photovoltaic end can be obtained. ,Right now:

[0060] (3).

[0061] S2. Obtain the load power consumption, the power exchange between the photovoltaic energy storage system and the grid, and the charging and discharging power of the energy storage end for each time period;

[0062] Understandably, historical data can be used to obtain the load power consumption at different times of the day. Power exchange between the photovoltaic energy storage system and the grid and the charging and discharging power of the energy storage end .

[0063] For example, the power consumption at the load end can be measured by monitoring and recording the power consumption data of the electricity meter or smart meter; the power exchange between the energy storage system and the grid end can be obtained by monitoring the power exchange between the photovoltaic system and the grid through equipment such as photovoltaic inverters; and the charging and discharging status of the energy storage system can be obtained through the monitoring equipment of the energy storage system, thereby knowing the charging and discharging power of the energy storage end.

[0064] S3. Establish a power balance relationship based on the photovoltaic power generation, load power consumption, power exchange between the photovoltaic energy storage system and the grid, and the charging and discharging power of the energy storage end for each time period.

[0065] For example, in any time period The photovoltaic power generation system maintains power balance, that is, the power generation of the photovoltaic end. Energy storage terminal charging and discharging power Power exchange between the photovoltaic energy storage system and the grid Power consumption at the load end They maintain a balance, as shown in the following equation:

[0066] (4);

[0067] in, Indicates time period The photovoltaic power generation capacity; Indicates time period The exchange power between the photovoltaic energy storage system and the grid is represented by a positive value, indicating that the photovoltaic system draws power from the grid, and a negative value, indicating that the photovoltaic system feeds power back to the grid. Indicates time period The power consumption at the load end, Indicates time period The charging and discharging power of the energy storage terminal is positive when charging and negative when discharging.

[0068] It is worth noting that the power balance relationship established in the embodiments of the present invention can illustrate that the photovoltaic end, energy storage end, and grid end can all provide power to the load end. Among them, the photovoltaic end provides power, while the energy storage end and the grid end can both receive and output power. The power generation of the photovoltaic end and the power consumption of the load end are dynamically changing. The scheduling strategy needs to be dynamically adjusted according to different scenarios to ensure that the system always operates in the optimal state, so as to maximize the photovoltaic power absorption rate, improve the overall performance and economic benefits of the system, and ensure the stability of the power grid.

[0069] For example, based on the balance relation (4), the following scenarios can be identified:

[0070] 1. When When photovoltaic power generation exceeds the load demand, the excess electricity generated by photovoltaic power generation is supplied to the energy storage terminal for charging. .

[0071] 2. When , At this time, representing the peak period of photovoltaic power generation, the excess electricity generated by photovoltaic power generation is supplied to the energy storage terminal for charging. When the charging power of the energy storage terminal has reached its maximum, the excess electricity generated by photovoltaic power generation will be fed back to the grid. It is negative.

[0072] 3. When ,and This indicates that photovoltaic (PV) power generation is below the load demand or the PV system is not generating power, while the energy storage system is not discharging or has zero remaining energy. In this case, the PV power generation is insufficient, and the load is supplied with power by a combination of PV power generation and the grid, or solely by the grid. It is positive.

[0073] 4. When ,and When photovoltaic power generation is below the load demand or the photovoltaic system is not generating power, the energy storage device starts discharging. In this case, the photovoltaic power generation and the energy storage device discharge together supply power to the load, or the energy storage device alone supplies power to the load. If the value is 0, the power grid will not generate power.

[0074] 5. When When the power output of photovoltaic power generation and energy storage discharge is lower than the power consumption of the load, the power supply to the load is jointly provided by photovoltaic power generation, energy storage discharge, and the power grid.

[0075] S4. Construct constraints based on the power balance relationship, and take maximizing photovoltaic power consumption as the objective function;

[0076] Specifically, the constraints include energy storage capacity constraints, energy storage charging and discharging power constraints, transformer reverse overload constraints, and photovoltaic power generation constraints.

[0077] For example, due to the capacity of the energy storage end It is finite; the maximum capacity of the energy storage terminal can be set as... The maximum charging power and maximum discharging power are both During the time period The remaining energy at the energy storage end is Then the capacity constraint condition of the energy storage end is: The energy storage terminal charging and discharging power constraint is: .

[0078] It should be noted that in the second scenario described above, where photovoltaic power is fed back to the grid, in order to prevent the transformer from being overloaded in reverse, it is necessary to construct reverse overload constraints on the transformer:

[0079] (5);

[0080] in, This indicates the maximum allowable reverse power of the transformer, typically the rated power. 80%, as shown in the following formula:

[0081] (6);

[0082] Therefore, the maximum allowable power generation at the photovoltaic end can be calculated as follows:

[0083] (7);

[0084] When the photovoltaic (PV) power generation exceeds the maximum allowable power output at the PV terminal, adjustments need to be made to ensure it does not exceed this maximum allowable value. Therefore, the actual PV power output... It can be adjusted to:

[0085] (8);

[0086] That is, within a time period If the photovoltaic power generation is greater than the maximum allowed photovoltaic power generation, then it is necessary to control the photovoltaic power generation to decrease so that the photovoltaic power generation is less than the maximum allowed photovoltaic power generation. The actual photovoltaic power generation is the minimum value between the maximum allowed photovoltaic power generation and the photovoltaic power generation.

[0087] It should be noted that photovoltaic power generation is not fed back to the grid; it is used entirely for load and energy storage, and all photovoltaic power generation can be absorbed. If photovoltaic power generation is fed back to the grid, the portion of the electricity sent to the grid is not absorbed.

[0088] With the goal of maximizing the absorption of photovoltaic power, the objective function constructed in this embodiment of the invention is shown in the following formula:

[0089] (9);

[0090] From actual photovoltaic power generation Subtracting the power that was not absorbed from the total power consumption gives the absorbed power. The sum of the absorbed power over all time periods is the maximum value of photovoltaic power absorption.

[0091] In equation (9), This represents the maximum value of photovoltaic power consumption; Indicates time period The actual photovoltaic power generation capacity , Indicates the maximum allowable power generation of the photovoltaic module; Indicates time period The electricity fed back from the internal photovoltaic terminal to the grid terminal, when When the value is positive, the result is 0, indicating insufficient power generation at the photovoltaic end, all photovoltaic power generation is consumed, and power needs to be drawn from the grid; when... When it is negative, If the value is positive, the result is taken as... , indicating that the photovoltaic power generation is sufficient and fed back to the grid, and the portion of the power fed to the grid is not consumed; M represents the total number of time periods into which the test time is divided.

[0092] S5. Based on the constraints and the objective function, perform charge and discharge scheduling on the energy storage end of the photovoltaic energy storage system.

[0093] It should be noted that, in order to maximize the absorption of photovoltaic power, it is necessary to control the charging and discharging time of the energy storage terminal, so that all the power generated by the photovoltaic terminal at any given time is used for charging the energy storage terminal and for power consumption by the load terminal, and the energy storage terminal is controlled to discharge at a certain appropriate time. That is, by controlling the charging and discharging time of the energy storage terminal, the photovoltaic absorption capacity of the photovoltaic terminal can be scheduled.

[0094] Specifically, the step of scheduling the charging and discharging of the energy storage terminal of the photovoltaic energy storage system according to the constraints and the objective function includes:

[0095] When the total charging amount of the energy storage terminal during the test period is greater than the capacity of the energy storage terminal, the time for the energy storage terminal to act as electricity is determined based on the difference between the power generation of the photovoltaic terminal and the power consumption of the load terminal, and the charging and discharging of the energy storage terminal is executed.

[0096] When the total charge of the energy storage terminal during the test period is less than or equal to the capacity of the energy storage terminal, the charging and discharging state of the energy storage terminal is determined and the charging and discharging of the energy storage terminal is executed, taking into account the balancing of grid load or economic benefits.

[0097] In one optional embodiment, when the total charging amount of the energy storage terminal during the test time is greater than the capacity of the energy storage terminal, the time for the energy storage terminal to act as electricity is determined based on the difference between the power generation of the photovoltaic terminal and the power consumption of the load terminal, and the energy storage terminal charging and discharging is performed, including:

[0098] When the total charge of the energy storage device during the test period is greater than the capacity of the energy storage device,

[0099] If the difference between the photovoltaic power generation and the load power consumption is greater than the first set value, the energy storage terminal will start charging until the energy storage terminal capacity constraint is violated or the difference between the photovoltaic power generation and the load power consumption is less than 0, at which point the energy storage terminal will stop charging.

[0100] If the difference between the power generated by the photovoltaic terminal and the power consumed by the load terminal is greater than the second set value, the energy storage terminal will start discharging until the difference between the power generated by the photovoltaic terminal and the power consumed by the load terminal is less than 0, at which point the energy storage terminal will stop discharging.

[0101] If the photovoltaic power generation is equal to 0, then the energy storage terminal discharges until the total charge of the energy storage terminal during the test time is 0, at which point the energy storage terminal stops discharging.

[0102] In one optional embodiment, when the total charging amount of the energy storage terminal during the test time is less than or equal to the capacity of the energy storage terminal, the charging and discharging state of the energy storage terminal is determined, and the charging and discharging of the energy storage terminal is performed, taking into account the balancing of grid load or economic benefits. This includes:

[0103] When the total charge of the energy storage device during the test period is less than or equal to the capacity of the energy storage device,

[0104] If grid load balancing is taken into account, the energy storage terminal will start discharging when the grid output power reaches 70% of its peak value during periods when the photovoltaic power generation is insufficient or when the photovoltaic power generation is not at all.

[0105] If economic benefits are taken into consideration, during the period when the photovoltaic power generation is in operation, the charging and discharging states of the energy storage terminal are switched according to the power generation of the photovoltaic power generation. During the period when the photovoltaic power generation is not in operation, the energy storage terminal draws power from the grid to charge.

[0106] It should be noted that during photovoltaic power generation, i.e., during periods of sunshine, the charging power at the energy storage end is equal to the actual power generated by the photovoltaic end. Electrical energy exceeding the power consumption at the load end, and the maximum charging and discharging power at the energy storage end. The minimum of the two is shown in the following formula:

[0107] (10);

[0108] Among them, the actual photovoltaic power generation The difference between the power consumption at the load end and the actual photovoltaic power generation is the result of subtracting the power consumption at the load end. Electrical energy exceeding the power consumption of the load end.

[0109] When the actual photovoltaic power generation When the power consumption is much greater than the load power, the energy storage end reaches its maximum charging power, that is, when At this time, excess power is fed back to the power grid, as shown in the following formula:

[0110] (11);

[0111] It should be noted that the amount of electricity that the energy storage device can charge using photovoltaic power throughout the day, i.e., the total amount of electricity charged by the energy storage device during the test period, is shown in the following formula:

[0112] (12);

[0113] For example, the total charging amount of the energy storage terminal during the test time is compared with the capacity of the energy storage terminal, and a scheduling strategy for the photovoltaic energy storage system is formulated according to different scenarios based on the comparison results.

[0114] Scenario 1:

[0115] When the total charging amount at the energy storage terminal during the day exceeds the capacity of the energy storage terminal, that is:

[0116] (13);

[0117] The scheduling strategy for a photovoltaic energy storage system can be as follows: during periods of insufficient photovoltaic output during the day, the energy storage device will discharge; during other periods, the energy storage device will be in a charging or fully charged state; and at night, the energy storage device will discharge again.

[0118] For example, the system can be configured to start charging when the difference between the photovoltaic (PV) power generation and the load power consumption is greater than value A; stop charging when the difference is less than 0; and start discharging when the difference is greater than value B, stopping discharging when the difference is less than 0. At night, when PV power generation stops, the energy storage device directly discharges, or during peak nighttime electricity consumption, it begins discharging until E=0. This avoids frequent charging and discharging switching of the energy storage device when PV power generation and load are roughly equal during the day, thus protecting the energy storage device.

[0119] Scenario 2:

[0120] When the total charging amount at the energy storage terminal during the day is less than the capacity of the energy storage terminal, that is:

[0121] (14);

[0122] This indicates that the capacity of the energy storage terminal is sufficient to store the excess power generated by the photovoltaic terminal throughout the day, and the discharge during any period when the photovoltaic output is insufficient can maximize the absorption capacity. At this time, the optimized scheduling should consider balancing the grid load or improving economic efficiency.

[0123] For example, when considering the balancing of grid load, the scheduling strategy of the photovoltaic energy storage system is as follows: during periods when the photovoltaic output is insufficient or when the photovoltaic output is not at all, the energy storage terminal is set to start discharging when the grid output reaches 70% of the peak value, so as to achieve the purpose of peak shaving.

[0124] For example, considering economic benefits, the scheduling strategy of the photovoltaic energy storage system is as follows: during the photovoltaic output period, the energy storage terminal switches between charging and discharging states according to the photovoltaic output; during the photovoltaic non-output period, when the electricity price is at the off-peak price, the energy storage terminal draws electricity from the grid for charging.

[0125] In one optional embodiment, the photovoltaic energy storage system scheduling method further includes:

[0126] Based on the objective function, the photovoltaic absorption rate and energy storage utilization rate are calculated.

[0127] Based on the photovoltaic absorption rate and the energy storage utilization rate, the charging and discharging schedule of the energy storage terminal of the photovoltaic energy storage system is re-executed.

[0128] For example, based on maximizing photovoltaic power consumption (i.e., the objective function), the photovoltaic consumption rate and energy storage utilization rate are calculated using the following formulas:

[0129] Photovoltaic absorption rate (15);

[0130] Energy storage utilization rate (16);

[0131] Where T is the total test time, which is in hours in this embodiment. T is 24 and M is 24.

[0132] For specific implementation, please refer to Figure 2 , Figure 2 This is another flowchart of a photovoltaic energy storage system scheduling method provided in an embodiment of the present invention, as shown below. Figure 2 As shown, the photovoltaic energy storage system scheduling method specifically includes the following steps:

[0133] S201. Set the test period;

[0134] S202. Determine whether the current time period is within the test period. If yes, proceed to the next step. If no, execute S218.

[0135] S203. Set the test period splitting value M to divide the test period into M time periods;

[0136] S204. Calculate the photovoltaic power generation at each time period;

[0137] S205. Calculate the photovoltaic power generation during the test period;

[0138] S206. Obtain the power consumption at the load end during different time periods;

[0139] S207. Set constraints, including the maximum capacity of the energy storage terminal, the maximum charging and discharging power of the energy storage terminal, the reverse heavy load constraint of the transformer, and the maximum power generation of the photovoltaic terminal.

[0140] S208. Determine whether the photovoltaic power generation is less than the maximum photovoltaic power generation. If yes, proceed to the next step. If no, execute S210.

[0141] S209. Set the photovoltaic power generation to the actual photovoltaic power generation and execute S211.

[0142] S210. Adjust the maximum power generation of the photovoltaic terminal to the actual photovoltaic power generation.

[0143] S211. Set the objective function for maximizing photovoltaic power consumption based on the actual photovoltaic power generation.

[0144] S212. During the calculation of photovoltaic power generation, the photovoltaic power generation power exceeding the power consumption at the load end is taken as the first data.

[0145] S213. Calculate the minimum value between the first data and the maximum charging and discharging power of the energy storage terminal, and use it as the charging power of the energy storage terminal.

[0146] S214. Calculate the total charging amount of the energy storage terminal during the test period;

[0147] S215. Determine whether the total charging amount of the energy storage terminal is greater than the energy storage terminal capacity. If yes, proceed to the next step. If no, execute S217.

[0148] S216. Execute the scheduling strategy of Scenario 1 and proceed to S218;

[0149] S217. Implement the scheduling strategy for Scenario 2;

[0150] S218. Calculate the photovoltaic absorption rate and the energy storage utilization rate;

[0151] S209. Determine whether the photovoltaic absorption rate and energy storage utilization rate meet the preset requirements. If yes, end the dispatch; otherwise, proceed to S202.

[0152] For example, in Scenario 1, the photovoltaic system provides ample power to the energy storage device during the testing period, and the energy storage device discharges when conditions permit. Its scheduling strategy includes steps SA1 to SA7:

[0153] SA1. Determine if the difference between the photovoltaic power generation and the load power consumption is greater than a first set value. If so, the energy storage unit begins charging until... If the charging stops, proceed to the next step; otherwise, proceed directly to the next step.

[0154] SA2. Determine if the difference between the photovoltaic power generation and the load power consumption is less than 0. If yes, stop charging at the energy storage end and proceed to the next step; otherwise, return to SA1.

[0155] SA3. Determine whether the difference between the power consumption at the load end and the power generation at the photovoltaic end is greater than the second set value. If yes, the energy storage end starts discharging and proceeds to the next step; otherwise, return to SA2.

[0156] SA4. Determine if the difference between the power consumption at the load end and the power generation at the photovoltaic end is less than 0. If yes, the energy storage end stops discharging and returns to SA1; otherwise, proceed to the next step.

[0157] SA5. Determine if the photovoltaic power generation is equal to 0. If yes, proceed to the next step; otherwise, return to SA1.

[0158] SA6, the energy storage terminal continues to discharge until E=0;

[0159] SA7, End.

[0160] For example, in Scenario 2, the photovoltaic output is insufficient, and all photovoltaic power generation is utilized by loads or energy storage, achieving full grid integration. However, the charging capacity of the energy storage cannot reach its maximum capacity. In this case, grid integration is not a concern; only the role of energy storage needs to be considered, and its scheduling strategies include SB1 to SB4:

[0161] SB1. Determine whether economic benefits should be considered. If yes, proceed to the next step and execute the first dispatching strategy. If no, execute SB3, consider balancing the grid load, and execute the second dispatching strategy.

[0162] SB2, the first scheduling strategy includes: during the photovoltaic output period, the energy storage terminal switches between charging and discharging states according to the photovoltaic output; during the photovoltaic non-output period, when the electricity price is at the off-peak price, the energy storage terminal draws power from the grid for charging, and executes SB4;

[0163] SB3, the second dispatch strategy includes: during periods when photovoltaic output is insufficient or when photovoltaic output is not at all, the energy storage terminal is set to start discharging when the grid output reaches 70% of its peak value;

[0164] SB4, End.

[0165] It should be noted that in step SB2, the energy storage terminal can discharge at any time when the photovoltaic output is insufficient. Combined with peak and off-peak electricity prices, the energy storage terminal is charged when the photovoltaic output is insufficient and the electricity price is at its lowest point, and the energy storage terminal discharges when the photovoltaic output is insufficient and the electricity price is at its highest point.

[0166] In summary, the photovoltaic energy storage system scheduling method provided by this invention provides an analytical basis for the balance between photovoltaic, energy storage, load, and power grid by calculating the photovoltaic power generation and load power consumption at different time periods, thereby improving the accuracy of the analysis. Furthermore, by considering various constraints, the actual photovoltaic power generation is determined, and the photovoltaic power consumption is calculated. Then, based on maximizing photovoltaic consumption, the charging and discharging time points of the energy storage terminal are determined according to the energy storage capacity of the energy storage terminal under different scenarios, optimizing the charging and discharging operation of the energy storage terminal, maximizing the utilization of photovoltaic power generation, reducing dependence on the power grid, helping to balance the power grid and improve its stability, and further improving the photovoltaic consumption rate and the utilization rate of the energy storage system.

[0167] Based on the above method items, the present invention provides corresponding system items embodiments.

[0168] See Figure 3 , Figure 3 This is a structural block diagram of a photovoltaic energy storage system scheduling system provided in an embodiment of the present invention. The photovoltaic energy storage system scheduling system includes:

[0169] The first power acquisition module 21 is used to set the test time, divide the test time into several time periods, and calculate the photovoltaic power generation power of each time period.

[0170] The second power acquisition module 22 is used to acquire the load power consumption, the power exchange between the photovoltaic energy storage system and the grid, and the charging and discharging power of the energy storage end for each time period.

[0171] The power balance relationship establishment module 23 is used to establish a power balance relationship based on the photovoltaic power generation, load power consumption, power exchange between the photovoltaic energy storage system and the grid, and the charging and discharging power of the energy storage end for each time period.

[0172] Objective function construction module 24 is used to construct constraints based on the power balance relationship, and take maximizing photovoltaic power consumption as the objective function;

[0173] The scheduling module 25 is used to perform charge and discharge scheduling of the energy storage end of the photovoltaic energy storage system according to the constraints and the objective function.

[0174] Specifically, the scheduling module 25 includes:

[0175] The first scheduling unit is used to determine the time for the energy storage terminal to act as electricity based on the difference between the power generation of the photovoltaic terminal and the power consumption of the load terminal when the total charging amount of the energy storage terminal during the test time is greater than the capacity of the energy storage terminal, and to execute the charging and discharging of the energy storage terminal.

[0176] The second scheduling unit is used to determine the charging and discharging state of the energy storage terminal and execute the charging and discharging of the energy storage terminal when the total charging amount of the energy storage terminal during the test time is less than or equal to the capacity of the energy storage terminal, taking into account the balancing of grid load or economic benefits.

[0177] Specifically, the first scheduling unit is used for:

[0178] When the total charge of the energy storage device during the test period is greater than the capacity of the energy storage device,

[0179] If the difference between the photovoltaic power generation and the load power consumption is greater than the first set value, the energy storage terminal will start charging until the energy storage terminal capacity constraint is violated or the difference between the photovoltaic power generation and the load power consumption is less than 0, at which point the energy storage terminal will stop charging.

[0180] If the difference between the power generated by the photovoltaic terminal and the power consumed by the load terminal is greater than the second set value, the energy storage terminal will start discharging until the difference between the power generated by the photovoltaic terminal and the power consumed by the load terminal is less than 0, at which point the energy storage terminal will stop discharging.

[0181] If the photovoltaic power generation is equal to 0, then the energy storage terminal discharges until the total charge of the energy storage terminal during the test time is 0, at which point the energy storage terminal stops discharging.

[0182] Specifically, the second scheduling unit is used for:

[0183] When the total charge of the energy storage device during the test period is less than or equal to the capacity of the energy storage device,

[0184] If grid load balancing is taken into account, the energy storage terminal will start discharging when the grid output power reaches 70% of its peak value during periods when the photovoltaic power generation is insufficient or when the photovoltaic power generation is not at all.

[0185] If economic benefits are taken into consideration, during the period when the photovoltaic power generation is in operation, the charging and discharging states of the energy storage terminal are switched according to the power generation of the photovoltaic power generation. During the period when the photovoltaic power generation is not in operation, the energy storage terminal draws power from the grid to charge.

[0186] As an improvement to the above solution, the photovoltaic energy storage system scheduling system further includes an optimized scheduling module, used for:

[0187] Based on the objective function, the photovoltaic absorption rate and energy storage utilization rate are calculated.

[0188] Based on the photovoltaic absorption rate and the energy storage utilization rate, the charging and discharging schedule of the energy storage terminal of the photovoltaic energy storage system is re-executed.

[0189] It should be noted that the photovoltaic energy storage system scheduling system provided in this embodiment of the invention is used to execute all the process steps of the photovoltaic energy storage system scheduling method in the above embodiment. The working principles and beneficial effects of the two are one-to-one, so they will not be described again.

[0190] This invention also provides a terminal device, such as... Figure 4 The diagram shown is a structural block diagram of a terminal device provided in an embodiment of the present invention. The terminal device includes a processor 31, a memory 32, and a computer program stored in the memory 32 and configured to be executed by the processor 31. When the processor 31 executes the computer program, it implements the photovoltaic energy storage system scheduling method as described in any of the above embodiments.

[0191] In addition, embodiments of the present invention also provide a computer-readable storage medium, the computer-readable storage medium including a stored computer program, wherein, when the computer program is executed, it controls the device where the computer-readable storage medium is located to execute the photovoltaic energy storage system scheduling method as described in any of the above embodiments.

[0192] When the processor 31 executes the computer program, it implements the steps in the above-described embodiments of the photovoltaic energy storage system scheduling method, for example... Figure 1 All steps of the photovoltaic energy storage system scheduling method shown. Alternatively, when the processor 31 executes the computer program, it implements the functions of each module in the above-described photovoltaic energy storage system scheduling system embodiment, for example... Figure 3 The functions of each module in the photovoltaic energy storage system scheduling system are shown.

[0193] Preferably, the computer program can be divided into one or more modules / units, which are stored in the memory 32 and executed by the processor 31 to complete the present invention. The one or more modules / units can be a series of computer program instruction segments capable of performing specific functions, which describe the execution process of the computer program in the terminal device.

[0194] The processor 31 can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor, or the processor 31 can be any conventional processor. The processor 31 is the control center of the terminal device, connecting various parts of the terminal device through various interfaces and lines.

[0195] The memory 32 mainly includes a program storage area and a data storage area. The program storage area can store the operating system, applications required for at least one function, etc., and the data storage area can store related data, etc. In addition, the memory 32 can be a high-speed random access memory, or a non-volatile memory, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, and a flash card, etc., or the memory 32 can also be other volatile solid-state storage devices.

[0196] It should be noted that the aforementioned terminal devices may include, but are not limited to, processors and memory, as will be understood by those skilled in the art. Figure 4The structural block diagram shown is merely a structural example of the terminal device described above and does not constitute a limitation on the structure of the terminal device. The terminal device may include more or fewer components than shown, or combine certain components, or use different components.

[0197] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for scheduling a photovoltaic energy storage system, characterized in that, include: Set a test time, divide the test time into several time periods, and calculate the photovoltaic power generation power in each time period; The system acquires the load power consumption, the power exchange between the photovoltaic energy storage system and the grid, and the charging and discharging power of the energy storage system for each time period. A power balance relationship is established based on the photovoltaic power generation, load power consumption, power exchange between the photovoltaic energy storage system and the grid, and the charging and discharging power of the energy storage system for each time period. Based on the power balance relationship, constraints are constructed, and the objective function is to maximize the consumption of photovoltaic power. Based on the constraints and the objective function, the charging and discharging of the energy storage end of the photovoltaic energy storage system is scheduled. Wherein, the objective function is ； in, This represents the maximum value of photovoltaic power consumption; Indicates time period The actual photovoltaic power generation capacity , Indicates the maximum allowable power generation of the photovoltaic module; Indicates time period The electricity fed back from the internal photovoltaic terminal to the grid terminal, when When the value is positive, the result is 0, indicating insufficient power generation at the photovoltaic end, all photovoltaic power generation is consumed, and power needs to be drawn from the grid; when... When it is negative, If the value is positive, the result is taken as... , indicating that the photovoltaic power generation is sufficient and fed back to the grid, and the part of the power fed to the grid is not consumed; M represents the total number of time periods into which the test time is divided; The constraints include a transformer reverse overload constraint, which is as follows: ； in, This indicates that the maximum allowable reverse power of the transformer is 80% of the transformer's rated power; therefore, ； ； Indicates time period The power consumption at the load end, This indicates the maximum charging power or maximum discharging power of the energy storage device. Indicates time period The photovoltaic power generation capacity; The step of scheduling the charging and discharging of the energy storage terminal of the photovoltaic energy storage system according to the constraints and the objective function includes: When the total charging amount of the energy storage terminal during the test period is greater than the capacity of the energy storage terminal, the time for the energy storage terminal to act as electricity is determined based on the difference between the power generation of the photovoltaic terminal and the power consumption of the load terminal, and the charging and discharging of the energy storage terminal is executed. When the total charge of the energy storage terminal during the test period is less than or equal to the capacity of the energy storage terminal, the charging and discharging state of the energy storage terminal is determined and the charging and discharging of the energy storage terminal is executed, taking into account the balancing of grid load or economic benefits.

2. The photovoltaic energy storage system scheduling method as described in claim 1, characterized in that, The power balance relationship is as follows: ； in, Indicates time period The photovoltaic power generation capacity; Indicates time period The exchange power between the photovoltaic energy storage system and the grid is represented by a positive value, indicating that the photovoltaic system draws power from the grid, and a negative value, indicating that the photovoltaic system feeds power back to the grid. Indicates time period The power consumption at the load end, Indicates time period The charging and discharging power of the energy storage terminal is positive when charging and negative when discharging.

3. The photovoltaic energy storage system scheduling method as described in claim 2, characterized in that, The constraints include energy storage capacity constraints, energy storage charging and discharging power constraints, and photovoltaic power generation constraints.

4. The photovoltaic energy storage system scheduling method as described in claim 3, characterized in that, When the total charging amount of the energy storage terminal during the test period is greater than the capacity of the energy storage terminal, the time for the energy storage terminal to act as power is determined based on the difference between the power generated by the photovoltaic terminal and the power consumed by the load terminal, and the charging and discharging of the energy storage terminal is performed, including: When the total charge of the energy storage device during the test period is greater than the capacity of the energy storage device, If the difference between the photovoltaic power generation and the load power consumption is greater than the first set value, the energy storage terminal will start charging until the energy storage terminal capacity constraint is violated or the difference between the photovoltaic power generation and the load power consumption is less than 0, at which point the energy storage terminal will stop charging. If the difference between the power generated by the photovoltaic terminal and the power consumed by the load terminal is greater than the second set value, the energy storage terminal will start discharging until the difference between the power generated by the photovoltaic terminal and the power consumed by the load terminal is less than 0, at which point the energy storage terminal will stop discharging. If the photovoltaic power generation is equal to 0, then the energy storage terminal discharges until the total charge of the energy storage terminal during the test time is 0, at which point the energy storage terminal stops discharging.

5. The photovoltaic energy storage system scheduling method as described in claim 4, characterized in that, When the total charging amount of the energy storage terminal during the test period is less than or equal to the capacity of the energy storage terminal, the charging and discharging state of the energy storage terminal is determined, and the charging and discharging of the energy storage terminal is executed, taking into account the balancing of grid load or economic benefits, including: When the total charge of the energy storage device during the test period is less than or equal to the capacity of the energy storage device, If grid load balancing is taken into account, the energy storage terminal will start discharging when the grid output power reaches 70% of its peak value during periods when the photovoltaic power generation is insufficient or when the photovoltaic power generation is not at all. If economic benefits are taken into consideration, during the period when the photovoltaic power generation is in operation, the charging and discharging states of the energy storage terminal are switched according to the power generation of the photovoltaic power generation. During the period when the photovoltaic power generation is not in operation, the energy storage terminal draws power from the grid to charge.

6. The photovoltaic energy storage system scheduling method as described in claim 1, characterized in that, The method further includes: Based on the objective function, the photovoltaic absorption rate and energy storage utilization rate are calculated. Based on the photovoltaic absorption rate and the energy storage utilization rate, the charging and discharging schedule of the energy storage terminal of the photovoltaic energy storage system is re-executed.

7. A photovoltaic energy storage system dispatching system, characterized in that, include: The first power acquisition module is used to set the test time, divide the test time into several time periods, and calculate the photovoltaic power generation power of each time period. The second power acquisition module is used to acquire the load power consumption, the power exchange between the photovoltaic energy storage system and the grid, and the charging and discharging power of the energy storage end for each time period. The power balance relationship establishment module is used to establish a power balance relationship based on the photovoltaic power generation, load power consumption, power exchange between the photovoltaic energy storage system and the grid, and the charging and discharging power of the energy storage end for each time period. The objective function construction module is used to construct constraints based on the power balance relationship, with the objective function being to maximize the consumption of photovoltaic power. The scheduling module is used to schedule the charging and discharging of the energy storage terminal of the photovoltaic energy storage system according to the constraints and the objective function. Wherein, the objective function is ； in, This represents the maximum value of photovoltaic power consumption; Indicates time period The actual photovoltaic power generation capacity , Indicates the maximum allowable power generation of the photovoltaic module; Indicates time period The electricity fed back from the internal photovoltaic terminal to the grid terminal, when When the value is positive, the result is 0, indicating insufficient power generation at the photovoltaic end, all photovoltaic power generation is consumed, and power needs to be drawn from the grid; when... When it is negative, If the value is positive, the result is taken as... , indicating that the photovoltaic power generation is sufficient and fed back to the grid, and the part of the power fed to the grid is not consumed; M represents the total number of time periods into which the test time is divided; The constraints include a transformer reverse overload constraint, which is as follows: ； in, This indicates that the maximum allowable reverse power of the transformer is 80% of the transformer's rated power; therefore, ； ； Indicates time period The power consumption at the load end, This indicates the maximum charging power or maximum discharging power of the energy storage device. Indicates time period The photovoltaic power generation capacity; Specifically, the scheduling module is used for: When the total charging amount of the energy storage terminal during the test period is greater than the capacity of the energy storage terminal, the time for the energy storage terminal to act as electricity is determined based on the difference between the power generation of the photovoltaic terminal and the power consumption of the load terminal, and the charging and discharging of the energy storage terminal is executed. When the total charge of the energy storage terminal during the test period is less than or equal to the capacity of the energy storage terminal, the charging and discharging state of the energy storage terminal is determined and the charging and discharging of the energy storage terminal is executed, taking into account the balancing of grid load or economic benefits.

8. A terminal device, characterized in that, The system includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor, when executing the computer program, implements the photovoltaic energy storage system scheduling method as described in any one of claims 1 to 6.

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