Photovoltaic energy storage system scheduling method, system and equipment

Abstract

The invention discloses a photovoltaic energy storage system scheduling method, system and equipment, and the method comprises the steps: firstly, setting test time, dividing the test time into a plurality of time periods, calculating the photovoltaic end generation power of each time period, and calculating the photovoltaic end generation power of each time period; the method comprises the steps of obtaining load end electricity consumption power, exchange power between an optical energy storage system and a power grid end and energy storage end charging and discharging power in each time period, establishing an electric power balance relation, then constructing constraint conditions according to the electric power balance relation, and taking maximum photovoltaic electric energy consumption as a target function to obtain optimal energy storage power consumption. And finally, according to the constraint condition and the objective function, carrying out charging and discharging scheduling on the energy storage end of the photovoltaic energy storage system. By adopting the method, the charging and discharging scheduling of the photovoltaic energy storage system can be optimized, the dependence on the power grid is reduced, the power grid can be balanced, the stability of the power grid can be improved, and the photovoltaic consumption rate and the utilization rate of the photovoltaic energy storage system can be improved.

Description

Technical Field

[0001] The present 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 Art

[0002] Photovoltaic absorption capacity refers to the amount of solar photovoltaic power generation that the power system can accept and effectively utilize. When the photovoltaic power generation system is connected to the power grid, due to the certain stability and frequency control requirements of the power grid itself, the access to photovoltaic power generation needs to be subject to certain restrictions and cannot exceed the power range that the power grid can safely and economically absorb. Exceeding this capacity may cause problems such as voltage fluctuations and frequency instability. Photovoltaic energy storage system refers to a device system used in photovoltaic power generation systems to store, convert and release cyclic electrical energy through electrochemical batteries or electromagnetic energy storage media. Introducing a photovoltaic energy storage system in a photovoltaic power generation system can effectively smooth the volatility of photovoltaic power generation and improve the utilization rate of electricity. Generally, the photovoltaic absorption rate and the utilization rate of the energy storage system are improved by dispatching the photovoltaic energy storage system.

[0003] At present, the scheduling of photovoltaic energy storage systems includes: considering the electricity price at the load end, adopting the method of peak shaving and valley filling to reduce peak power consumption and increase valley power consumption; adjusting the charging and discharging times of energy storage equipment based on the day-ahead load forecast of the distribution network and the photovoltaic power generation forecast to reduce the peak-valley difference of the critical load; adjusting the charging and discharging of the energy storage system based on weather, power generation, load size, power consumption period, etc. However, the above existing photovoltaic energy storage system scheduling methods cannot effectively handle the charging and discharging of the energy storage end under different scenarios, and cannot effectively improve the photovoltaic absorption rate and energy storage system utilization rate. 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] In order to solve the above technical problems, an embodiment of the present invention provides a photovoltaic energy storage system scheduling method, comprising: Setting a test time, dividing the test time into several time periods, and calculating the photovoltaic power generation power in each time period; Obtain the load power consumption, the exchange power between the solar energy storage system and the grid, and the charging and discharging power of the energy storage end in each time period; Establishing a power balance relationship according to the photovoltaic power generation, load power, exchange power between the photovoltaic energy storage system and the grid, and energy storage charging and discharging power in each time period; Constructing constraint conditions according to the power balance relationship, and taking maximizing photovoltaic power consumption as the objective function; According to the constraint conditions and the objective function, the energy storage end of the photovoltaic energy storage system is charged and discharged.

[0006] Optionally, the power balance relationship is: ; in, Indicates time period The photovoltaic power generation power; Indicates time period The exchange power between the photovoltaic energy storage system and the grid. A positive value indicates that the photovoltaic end takes power from the grid, and a negative value indicates that the photovoltaic end sends power back to the grid. Indicates time period The load end power consumption, Indicates time period The charging and discharging power of the energy storage end, charging is a positive value and discharging is a negative value.

[0007] Optionally, the constraints include energy storage end capacity constraints, energy storage end charging and discharging power constraints, transformer reverse overload constraints, and photovoltaic end power generation constraints.

[0008] Optionally, the objective function is ; in, Indicates the maximum value of photovoltaic power consumption; Indicates time period The actual photovoltaic power generation work, , Indicates the maximum power generation allowed by the photovoltaic end; Indicates time period The power sent back from the photovoltaic end to the grid end, when When it is a positive value, the result is 0, indicating that the photovoltaic power generation is insufficient and all the photovoltaic power generation is consumed, and it is necessary to take power from the grid; when When it is a negative value, is a positive value, the result is , indicating that the photovoltaic power generation is sufficient and is fed back to the grid, and part of the power sent to the grid is not consumed; M represents the total number of time periods into which the test time is divided.

[0009] Optionally, the performing charging and discharging scheduling on the energy storage end of the photovoltaic energy storage system according to the constraint condition and the objective function includes: When the total charge amount of the energy storage end during the test time is greater than the capacity of the energy storage end, the time for the energy storage end to act as electricity is determined according to the difference between the photovoltaic power generation power and the load power, and the energy storage end is charged and discharged; When the total charge amount of the energy storage terminal during the test time is less than or equal to the capacity of the energy storage terminal, the charge and discharge state of the energy storage terminal is determined and the charge and discharge of the energy storage terminal is executed while considering the balancing of the grid load or economic benefits.

[0010] Optionally, when the total charge amount of the energy storage end during the test time is greater than the capacity of the energy storage end, the time for the energy storage end to act as electricity is determined according to the difference between the photovoltaic end power generation and the load end power consumption, and the energy storage end is charged and discharged, including: When the total charge amount of the energy storage terminal during the test time is greater than the capacity of the energy storage terminal, If the difference between the photovoltaic power generation and the load power consumption is greater than a first set value, the energy storage end starts charging until the energy storage end capacity constraint condition is violated or when the difference between the photovoltaic power generation and the load power consumption is less than 0, the energy storage end stops charging; If the difference between the photovoltaic power generation and the load power consumption is greater than the second set value, the energy storage end starts discharging, and when the difference between the photovoltaic power generation and the load power consumption is less than 0, the energy storage end stops discharging; If the photovoltaic power generation power is equal to 0, the energy storage end is discharged until the total charge amount of the energy storage end during the test time is 0, and the energy storage end stops discharging.

[0011] Optionally, when the total charge amount of the energy storage terminal during the test time is less than or equal to the capacity of the energy storage terminal, the charge and discharge state of the energy storage terminal is determined while considering the balancing of the grid load or economic benefits, and the charge and discharge of the energy storage terminal is performed, including: When the total charge amount of the energy storage terminal during the test time is less than or equal to the capacity of the energy storage terminal, If the load of the power grid is balanced, the energy storage end starts discharging when the output power of the power grid reaches 70% of the peak value during the period when the power generation of the photovoltaic end is insufficient or the photovoltaic end is not generating power. If economic benefits are taken into consideration, during the period of photovoltaic power generation, the charging and discharging states of the energy storage end are switched according to the power generation power of the photovoltaic end. During the period of no photovoltaic power generation, the energy storage end is charged by drawing electricity from the grid.

[0012] As an improvement of the above solution, the photovoltaic energy storage system scheduling method further includes: Based on the objective function, the photovoltaic consumption rate and the energy storage terminal utilization rate are calculated; The energy storage end of the photovoltaic energy storage system is re-scheduled for charging and discharging according to the photovoltaic absorption rate and the energy storage end utilization rate.

[0013] In order to solve the above technical problems, an embodiment of the present invention further provides a photovoltaic energy storage system scheduling system, including: A first power acquisition module is used to set a test time, divide the test time into a number of time periods, and calculate the photovoltaic power generation power in each time period; The second power acquisition module is used to obtain the load-side power consumption, the exchange power between the solar energy storage system and the grid side, and the energy storage side charging and discharging power in each time period; A power balance relationship establishment module, used to establish a power balance relationship according to the photovoltaic power generation, load power, exchange power between the photovoltaic energy storage system and the grid, and energy storage charging and discharging power in each time period; An objective function construction module is used to construct constraint conditions according to the power balance relationship and take maximizing photovoltaic power consumption as the objective function; The scheduling module is used to schedule the charging and discharging of the energy storage end of the photovoltaic energy storage system according to the constraint conditions and the objective function.

[0014] To solve the above technical problems, an embodiment of the present invention further 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, and when the processor executes the computer program, it implements the photovoltaic energy storage system scheduling method as described in any one of the above.

[0015] Compared with the prior art, the photovoltaic energy storage system scheduling method, system and device provided in the embodiments of the present invention provide an analysis basis for the balance between photovoltaic, energy storage, load and power grid by measuring the photovoltaic power generation in different time periods and the load power in different time periods, thereby improving the accuracy of the analysis; further, by considering various constraints, the actual photovoltaic power generation is determined, the photovoltaic power consumption is calculated, and then, on the basis of maximizing photovoltaic consumption, according to the energy storage and the capacity of the energy storage, the charging and discharging time points of the energy storage under different scenarios are formulated, the charging and discharging operations of the energy storage are optimized, the photovoltaic power generation is maximized, the dependence on the power grid is reduced, it is helpful to balance the power grid and improve its stability, and further improve the photovoltaic consumption rate and the utilization rate of the energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solution of the present invention, the drawings used in the implementation mode will be briefly introduced below. Obviously, the drawings described below are only some implementation modes of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 is a flow chart of a photovoltaic energy storage system scheduling method provided by an embodiment of the present invention; Figure 2is another flow chart of a photovoltaic energy storage system scheduling method provided by an embodiment of the present invention; Figure 3 It is a structural block diagram of a photovoltaic energy storage system scheduling system provided by an embodiment of the present invention; Figure 4 It is a structural block diagram of a terminal device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] It should be noted that a photovoltaic power generation system generally includes a photovoltaic end, an energy storage end, a load end and a grid end. The electric energy generated by the photovoltaic end is first supplied to the load end, and the excess is provided to the energy storage end. The electric energy exceeding the energy storage end is uploaded to the grid. If the power uploaded to the grid far exceeds the transformer load, it will cause the connected transformer to be reversely overloaded. At this time, it is necessary to limit the photovoltaic power generation power to ensure that the transformer is not overloaded. When the electric energy generated by the photovoltaic end cannot meet the demand of the load end, it will first be supplemented by the energy storage end and provided to the load end. If the sum of the electric energy of the photovoltaic end and the energy storage end still cannot meet the demand of the load end, the photovoltaic end, the energy storage end and the grid end will jointly provide electric energy to the load end.

[0020] See also Figure 1 , Figure 1 : is a flow chart of a photovoltaic energy storage system scheduling method provided by an embodiment of the present invention, the photovoltaic energy storage system scheduling method comprises steps S1 to S5: S1. Setting a test time, dividing the test time into several time periods, and calculating the photovoltaic power generation power in each time period; Exemplarily, one day is used as the test time, and then one day is divided into M time periods, where M is a positive integer greater than or equal to 1. In the embodiment of the present invention, M=24, that is, one hour is used as a time period, and the remaining value calculation methods of M are similar, and are not repeated here.

[0021] Mark any time period as ,but The value range is 1, 2, 3...24, which can be expressed as: ; Any time of day , the power generation of photovoltaic , can be calculated by the following formula: (1); In formula (1), It is in the time period The solar irradiance (unit: W / m²) can be derived by measuring the current generated by the photovoltaic cell, or by obtaining the solar irradiance through satellite remote sensing data; A is the area of ​​the photovoltaic module (unit: m²); It is the photovoltaic conversion efficiency under standard test conditions (STC, i.e. solar irradiance of 1000 W / m², cell temperature of 25°C, air mass (AM) of 1.5), which is usually 15-25%; is the temperature coefficient of the PV module (unit: 1 / °C); is the temperature under standard test conditions, usually 25°C; in, refers to the time period The actual operating temperature of the photovoltaic module at this time, in °C, can be adjusted by the ambient temperature and solar irradiance To estimate, the estimation formula is: (2); In formula (2), is the nominal operating temperature of a PV module, typically 45-50°C.

[0022] In addition, all time periods are aggregated The power generation of photovoltaic , we can get the power generation of the photovoltaic end ,Right now: (3).

[0023] S2, obtaining the load-side power consumption, the exchange power between the solar energy storage system and the grid, and the energy storage-side charging and discharging power in each time period; Understandably, the load power consumption at different time periods in a day can be obtained based on historical data. , the exchange power between the optical energy storage system and the grid And the charging and discharging power of the energy storage end .

[0024] For example, the power consumption at the load end can be measured by the power consumption data monitored and recorded by an electric meter or smart meter; the exchange power between the energy storage system and the grid can be obtained by monitoring the power exchange between the photovoltaic system and the grid through equipment such as photovoltaic inverters; 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.

[0025] S3, establishing a power balance relationship according to the photovoltaic power generation, load power, exchange power between the photovoltaic energy storage system and the grid, and charge and discharge power of the energy storage end in each time period; For example, in any time period , the photovoltaic power generation system maintains power balance, that is, the photovoltaic power generation , energy storage end charging and discharging power , the exchange power between the optical energy storage system and the grid , Load end power Maintain a balance between the two, as shown in the following formula: (4); in, Indicates time period The photovoltaic power generation power; Indicates time period The exchange power between the photovoltaic energy storage system and the grid. A positive value indicates that the photovoltaic end takes power from the grid, and a negative value indicates that the photovoltaic end sends power back to the grid. Indicates time period The load end power consumption, Indicates time period The charging and discharging power of the energy storage end, charging is a positive value and discharging is a negative value.

[0026] It is worth noting that the power balance relationship established by the embodiment of the present invention can illustrate that the photovoltaic end, the energy storage end, and the power grid end can all provide electric energy to the load end. Among them, the photovoltaic end provides electric energy, the energy storage end and the power grid end can both receive and output electric energy. The photovoltaic end power generation and the load end power consumption 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 to maximize the photovoltaic power consumption rate, improve the overall performance and economic benefits of the system, and ensure the stability of the power grid.

[0027] For example, according to the balance equation (4), the following scenarios can be classified: 1. When When the photovoltaic power generation is higher than the load power demand, the excess power of photovoltaic power generation will be provided to the energy storage end for charging. .

[0028] 2. When , When the peak period of photovoltaic power generation is reached, the excess power generated by photovoltaic power generation will be provided to the energy storage terminal for charging. The charging power of the energy storage terminal has reached the maximum value, and the excess power generated by photovoltaic power generation will be fed back to the power grid. is negative.

[0029] 3. When ,and When , it means that the photovoltaic power generation is lower than the load power demand or the photovoltaic power generation is not working, and the energy storage end is not turned on for discharge or the remaining energy at the energy storage end is 0. At this time, the photovoltaic power generation is insufficient, and the photovoltaic power generation + the power grid jointly supply the load end with electricity, or the power grid alone supplies the load end with electricity. Is positive.

[0030] 4. When ,and When the photovoltaic power generation is lower than the load power demand or the photovoltaic power generation is not working, the energy storage end starts to discharge, and the photovoltaic power generation + energy storage end discharge jointly supply the load end power, or the energy storage end alone supplies the load end power. When it is 0, the power grid does not work.

[0031] 5. When When the power of photovoltaic power generation + energy storage discharge is lower than the load power consumption, photovoltaic power generation + energy storage discharge + power grid will jointly supply power to the load end.

[0032] S4, constructing constraint conditions according to the power balance relationship, and taking maximizing photovoltaic power consumption as the objective function; Specifically, the constraints include energy storage end capacity constraints, energy storage end charging and discharging power constraints, transformer reverse overload constraints, and photovoltaic end power generation constraints.

[0033] For example, due to the capacity of the energy storage end is limited, the maximum capacity of the energy storage terminal can be set to , the maximum charging power and the maximum discharging power are both , in the time period The remaining energy at the energy storage end is , then the energy storage capacity constraint is , the charging and discharging power constraint condition of the energy storage end is .

[0034] It should be noted that in the second case mentioned above, photovoltaic power generation is fed back to the grid. In order to prevent the transformer from being overloaded due to power transmission, it is necessary to construct the transformer reverse overload constraint condition: (5); in, Indicates the maximum allowable reverse power of the transformer, usually the rated power 80% of the total cost, as shown in the following formula: (6); From this, the maximum power generation allowed by the photovoltaic terminal can be calculated as: (7); When the photovoltaic power generation exceeds the maximum power allowed by the photovoltaic end, the photovoltaic power generation needs to be adjusted so that it does not exceed the maximum power allowed. Can be adjusted to: (8); That is, in a period of time If the photovoltaic power generation power is greater than the maximum power generation power allowed by the photovoltaic end, it is necessary to control the photovoltaic power generation power to decrease so that the photovoltaic power generation power is less than the maximum power generation power allowed by the photovoltaic end. The actual photovoltaic power generation power is the minimum value between the maximum power generation power allowed by the photovoltaic end and the photovoltaic power generation power.

[0035] It should be noted that if the photovoltaic power generation is not fed back to the grid, but is all used at the load end and the energy storage end, all the photovoltaic power generation can be absorbed. If the photovoltaic power generation is fed back to the grid, part of the electricity sent to the grid will not be absorbed.

[0036] Taking the maximum photovoltaic power consumption as the goal, the objective function constructed by the embodiment of the present invention is as shown in the following formula: (9); From the actual photovoltaic power The power absorbed is the power minus the power that is not absorbed. The sum of the absorbed power in all time periods is the maximum value of photovoltaic power absorption.

[0037] In formula (9), Indicates the maximum value of photovoltaic power consumption; Indicates time period The actual photovoltaic power generation work, , Indicates the maximum power generation allowed by the photovoltaic end; Indicates time period The power sent back from the photovoltaic end to the grid end, when When it is a positive value, the result is 0, indicating that the photovoltaic power generation is insufficient and all the photovoltaic power generation is consumed, and it is necessary to take power from the grid; when When it is a negative value, is a positive value, the result is , indicating that the photovoltaic power generation is sufficient and is fed back to the grid, and part of the power sent to the grid is not consumed; M represents the total number of time periods into which the test time is divided.

[0038] S5. According to the constraint conditions and the objective function, the energy storage end of the photovoltaic energy storage system is charged and discharged.

[0039] It should be noted that in order to maximize the consumption of photovoltaic power, it is necessary to control the charging and discharging time points of the energy storage end, so that the photovoltaic power generation in any time period is all used for charging the energy storage end and electricity consumption at the load end, and the energy storage end is controlled to discharge at a suitable time point. That is, by controlling the charging and discharging time points of the energy storage end, the photovoltaic consumption of the photovoltaic end can be dispatched.

[0040] Specifically, the charging and discharging scheduling of the energy storage end of the photovoltaic energy storage system according to the constraint condition and the objective function includes: When the total charge amount of the energy storage end during the test time is greater than the capacity of the energy storage end, the time for the energy storage end to act as electricity is determined according to the difference between the photovoltaic power generation power and the load power, and the energy storage end is charged and discharged; When the total charge amount of the energy storage terminal during the test time is less than or equal to the capacity of the energy storage terminal, the charge and discharge state of the energy storage terminal is determined and the charge and discharge of the energy storage terminal is executed while considering the balancing of the grid load or economic benefits.

[0041] In an optional embodiment, when the total charge amount of the energy storage end during the test time is greater than the capacity of the energy storage end, the time for the energy storage end to act as electricity is determined according to the difference between the photovoltaic power generation power and the load power, and the energy storage end is charged and discharged, including: When the total charge amount of the energy storage terminal during the test time is greater than the capacity of the energy storage terminal, If the difference between the photovoltaic power generation and the load power consumption is greater than a first set value, the energy storage end starts charging until the energy storage end capacity constraint condition is violated or when the difference between the photovoltaic power generation and the load power consumption is less than 0, the energy storage end stops charging; If the difference between the photovoltaic power generation and the load power consumption is greater than the second set value, the energy storage end starts discharging, and when the difference between the photovoltaic power generation and the load power consumption is less than 0, the energy storage end stops discharging; If the photovoltaic power generation power is equal to 0, the energy storage end is discharged until the total charge amount of the energy storage end during the test time is 0, and the energy storage end stops discharging.

[0042] In an optional embodiment, when the total charge amount of the energy storage terminal at the test time is less than or equal to the capacity of the energy storage terminal, the charge and discharge state of the energy storage terminal is determined while considering the balancing of the grid load or economic benefits, and the charge and discharge of the energy storage terminal is performed, including: When the total charge amount of the energy storage terminal during the test time is less than or equal to the capacity of the energy storage terminal, If the load of the power grid is balanced, the energy storage end starts discharging when the output power of the power grid reaches 70% of the peak value during the period when the power generation of the photovoltaic end is insufficient or the photovoltaic end is not generating power. If economic benefits are taken into consideration, during the period of photovoltaic power generation, the charging and discharging states of the energy storage end are switched according to the power generation power of the photovoltaic end. During the period of no photovoltaic power generation, the energy storage end is charged by drawing electricity from the grid.

[0043] It should be noted that during the photovoltaic power generation period, that is, during the light period, the value of the energy storage end charging power is equal to the actual photovoltaic end power generation The electric energy exceeding the load end power consumption and the maximum charge and discharge power of the energy storage end The minimum value of the two is as follows: (10); Among them, the actual photovoltaic power generation The difference obtained by subtracting the load end power consumption is the actual photovoltaic power generation power. Electrical energy that exceeds the electrical power consumed by the load at the load end.

[0044] When the actual photovoltaic power generation When the power consumption of the energy storage end is much greater than that of the load end, the energy storage end reaches the maximum charging power. At this time, the excess power is fed back to the grid, as shown in the following formula: (11); It should be noted that the amount of chargeable energy storage terminal using photovoltaic power in a day is the total charge amount of the energy storage terminal during the test time, as shown in the following formula: (12); Exemplarily, the total charge amount of the energy storage terminal during the test time is compared with the capacity of the energy storage terminal, and according to the comparison result, a scheduling strategy for the photovoltaic energy storage system is formulated for different scenarios.

[0045] Scenario 1: When the total charge amount of the energy storage terminal exceeds the capacity of the energy storage terminal during the day, that is: (13); The scheduling strategy of the photovoltaic energy storage system can be: discharge the energy storage end during the daytime when the photovoltaic output is insufficient, keep the energy storage end in a charging or full state during the rest of the time, and discharge again at night.

[0046] Exemplarily, it can be set that when the difference between the photovoltaic power generation and the load power is greater than value A, the energy storage end starts charging; when the difference between the photovoltaic power generation and the load power is less than 0, the energy storage end stops charging; when the difference between the load power and the photovoltaic power generation is greater than value B, the energy storage end starts discharging, and when the difference between the load power and the photovoltaic power generation is less than 0, the energy storage end stops discharging. When photovoltaic power generation stops at night, the energy storage end discharges directly, or during the peak power consumption period at night, the energy storage end starts discharging until E=0. This avoids frequent charging and discharging switching of the energy storage end when the photovoltaic power generation is comparable to the load during the day, thereby protecting the energy storage end.

[0047] Scenario 2: When the total charge amount of the energy storage terminal during the day is less than the capacity of the energy storage terminal, that is: (14); This means that the capacity of the energy storage end is sufficient to store the excess power generated by the photovoltaic end during the day, and that discharging during any period of insufficient photovoltaic output can maximize the absorption capacity. At this time, the optimized scheduling should consider balancing the grid load or improving economic benefits.

[0048] Exemplarily, in the case of considering balancing the grid load, the scheduling strategy of the photovoltaic energy storage system is: during the period of insufficient photovoltaic output or the period of no photovoltaic output, the energy storage end is set to start discharging when the grid output reaches 70% of the peak value to achieve the purpose of peak shaving.

[0049] Exemplarily, taking economic benefits into consideration, the scheduling strategy of the photovoltaic energy storage system is as follows: during the photovoltaic output period, the energy storage end switches between charging and discharging states according to the photovoltaic output; during the photovoltaic non-output period, when the electricity price is at the valley price, the energy storage end draws electricity from the grid for charging.

[0050] In an optional embodiment, the photovoltaic energy storage system scheduling method further includes: Based on the objective function, the photovoltaic consumption rate and the energy storage terminal utilization rate are calculated; The energy storage end of the photovoltaic energy storage system is re-scheduled for charging and discharging according to the photovoltaic absorption rate and the energy storage end utilization rate.

[0051] Exemplarily, based on maximizing photovoltaic power consumption (i.e., the objective function), the photovoltaic consumption rate and the energy storage utilization rate are calculated by the following formula: Photovoltaic absorption rate (15); Energy storage utilization (16); Wherein, T is the total test time, which is in hours in this embodiment, T is 24, and M is 24.

[0052] For specific implementation, see Figure 2 , Figure 2 is another flow chart of a photovoltaic energy storage system scheduling method provided by an embodiment of the present invention, such as Figure 2 As shown, the photovoltaic energy storage system scheduling method specifically includes the following steps: S201, setting a test period; S202, determine whether the current period is in the test period, if so, proceed to the next step, if not, execute S218; S203, setting a split value M for the test period, splitting the test period into M time periods; S204, calculating the photovoltaic power generation power in each time period; S205, calculating the photovoltaic power generation during the test period; S206, obtaining load-side power consumption in different time periods; S207, setting constraints, including the maximum capacity of the energy storage terminal, the maximum charge and discharge power of the energy storage terminal, the reverse overload constraint of the transformer, and the maximum power generation power of the photovoltaic terminal; S208, determining whether the photovoltaic power generation power is less than the maximum photovoltaic power generation power, if so, proceed to the next step, if not, execute S210; S209, setting the photovoltaic end power generation to the actual photovoltaic end power generation, and executing S211; S210, adjusting the maximum power generation power of the photovoltaic terminal to the actual photovoltaic power generation power; S211, setting the maximum objective function of photovoltaic power consumption according to the actual photovoltaic power generation power; S212, calculating the photovoltaic power generation power exceeding the load end power consumption during the photovoltaic power generation period as the first data; S213, calculating the minimum value between the first data and the maximum charging and discharging power of the energy storage end as the charging power of the energy storage end; S214, calculating the total charge amount of the energy storage terminal during the test period; S215, determine whether the total charge amount of the energy storage end is greater than the capacity of the energy storage end, if so, proceed to the next step, if not, execute S217; S216, executing the scheduling strategy of scenario 1, and proceeding to S218; S217, executing the scheduling strategy of scenario 2; S218. Calculate the photovoltaic consumption rate and energy storage utilization rate; S209: Determine whether the photovoltaic consumption rate and the energy storage utilization rate meet the preset requirements. If so, terminate the scheduling; if not, enter S202.

[0053] For example, in scenario 1, the photovoltaic system provides sufficient power to the energy storage terminal during the test time, and the energy storage terminal discharges when conditions permit. The scheduling strategy includes steps SA1 to SA7: SA1: Determine whether the difference between the photovoltaic power generation and the load power is greater than the first set value. If so, the energy storage end starts charging until , stop charging and go to the next step; if not, go directly to the next step; SA2: Determine whether the difference between the photovoltaic power generation and the load power is less than 0. If so, the energy storage end stops charging and proceeds to the next step. If not, return to SA1. SA3, determine whether the difference between the load-side power consumption and the photovoltaic-side power generation is greater than the second set value. If so, the energy storage end starts discharging and proceeds to the next step; if not, return to SA2; SA4: Determine whether the difference between the load-side power consumption and the photovoltaic-side power generation is less than 0. If so, the energy storage end stops discharging and returns to SA1; if not, proceed to the next step. SA5, determine whether the photovoltaic power generation is equal to 0, if so, go to the next step; if not, return to SA1; SA6, the energy storage end continues to discharge until E=0; SA7, end.

[0054] For example, in scenario 2, the photovoltaic output is insufficient, and all photovoltaic power generation is used by the load or energy storage end, which can achieve full absorption. The energy storage end charging cannot reach the maximum capacity of the energy storage end. At this time, there is no need to consider the absorption problem, only the role of energy storage needs to be considered. Its scheduling strategies include SB1 to SB4: SB1, determine whether to consider economic benefits, if so, proceed to the next step and execute the first dispatching strategy, if not, execute SB3, consider balancing the power grid load and execute the second dispatching strategy; SB2, the first dispatching strategy includes: during the photovoltaic power output period, the energy storage end switches between charging and discharging states according to the photovoltaic power output; during the photovoltaic power output period, when the electricity price is at the valley price, the energy storage end takes electricity from the grid for charging, and executes SB4; SB3. The second dispatching strategy includes: in the period of insufficient photovoltaic output or the period of no photovoltaic output, the energy storage end starts discharging when the grid output reaches 70% of the peak value; SB4, end.

[0055] It should be noted that in step SB2, the energy storage end can discharge at any time when the photovoltaic output is insufficient. Combined with the peak and valley electricity prices, the energy storage end is charged when the photovoltaic output is insufficient and the electricity price is at a valley value, and is discharged when the photovoltaic output is insufficient and the electricity price is at a peak value.

[0056] In summary, a photovoltaic energy storage system scheduling method provided by an embodiment of the present invention provides an analysis basis for the balance between photovoltaic, energy storage, load and power grid by measuring the photovoltaic power generation in different time periods and the load power in different time periods, thereby improving the accuracy of the analysis; further, by considering various constraints, the actual photovoltaic power generation is determined, and the photovoltaic power consumption is calculated. Then, on the basis of maximizing photovoltaic consumption, according to the energy storage and the capacity of the energy storage, the charging and discharging time points of the energy storage under different scenarios are formulated, the charging and discharging operations of the energy storage are optimized, the photovoltaic power generation is maximized, the dependence on the power grid is reduced, it is helpful to balance the power grid and improve its stability, and further improve the photovoltaic consumption rate and the utilization rate of the energy storage system.

[0057] On the basis of the above-mentioned method items, the present invention provides corresponding embodiments of the system items.

[0058] See also Figure 3 , Figure 3 : is a structural block diagram of a photovoltaic energy storage system scheduling system provided by an embodiment of the present invention. The photovoltaic energy storage system scheduling system includes: 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 in each time period; The second power acquisition module 22 is used to obtain the load-side power consumption, the exchange power between the solar energy storage system and the grid side, and the energy storage side charging and discharging power in each time period; The power balance relationship establishment module 23 is used to establish a power balance relationship according to the photovoltaic power generation, load power, exchange power between the photovoltaic energy storage system and the grid, and energy storage charging and discharging power in each time period; An objective function construction module 24 is used to construct constraint conditions according to the power balance relationship and take maximizing photovoltaic power consumption as the objective function; The scheduling module 25 is used to schedule the charging and discharging of the energy storage end of the photovoltaic energy storage system according to the constraint conditions and the objective function.

[0059] Specifically, the scheduling module 25 includes: The first scheduling unit is used to determine the time for the energy storage end to act as electricity according to the difference between the photovoltaic end power generation and the load end power consumption when the total charge amount of the energy storage end during the test time is greater than the capacity of the energy storage end, and to perform charging and discharging of the energy storage end; The second scheduling unit is used to determine the charging and discharging state of the energy storage end and execute the charging and discharging of the energy storage end while considering balancing the grid load or economic benefits when the total charging amount of the energy storage end during the test time is less than or equal to the capacity of the energy storage end.

[0060] Specifically, the first scheduling unit is specifically used to: When the total charge amount of the energy storage terminal during the test time is greater than the capacity of the energy storage terminal, If the difference between the photovoltaic power generation and the load power consumption is greater than a first set value, the energy storage end starts charging until the energy storage end capacity constraint condition is violated or when the difference between the photovoltaic power generation and the load power consumption is less than 0, the energy storage end stops charging; If the difference between the photovoltaic power generation and the load power consumption is greater than the second set value, the energy storage end starts discharging, and when the difference between the photovoltaic power generation and the load power consumption is less than 0, the energy storage end stops discharging; If the photovoltaic power generation power is equal to 0, the energy storage end is discharged until the total charge amount of the energy storage end during the test time is 0, and the energy storage end stops discharging.

[0061] Specifically, the second scheduling unit is specifically used to: When the total charge amount of the energy storage terminal during the test time is less than or equal to the capacity of the energy storage terminal, If the load of the power grid is balanced, the energy storage end starts discharging when the output power of the power grid reaches 70% of the peak value during the period when the power generation of the photovoltaic end is insufficient or the photovoltaic end is not generating power. If economic benefits are taken into consideration, during the period of photovoltaic power generation, the charging and discharging states of the energy storage end are switched according to the power generation power of the photovoltaic end. During the period of no photovoltaic power generation, the energy storage end is charged by drawing electricity from the grid.

[0062] As an improvement of the above solution, the photovoltaic energy storage system scheduling system further includes an optimization scheduling module for: Based on the objective function, the photovoltaic consumption rate and the energy storage terminal utilization rate are calculated; The energy storage end of the photovoltaic energy storage system is re-scheduled for charging and discharging according to the photovoltaic absorption rate and the energy storage end utilization rate.

[0063] It should be noted that a photovoltaic energy storage system scheduling system provided in an embodiment of the present invention is used to execute all process steps of a photovoltaic energy storage system scheduling method in the above embodiment, and the working principles and beneficial effects of the two correspond one to one, so they will not be repeated.

[0064] The embodiment of the present invention also provides a terminal device, such as Figure 4, which is a block diagram of a terminal device provided by 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, the photovoltaic energy storage system scheduling method described in any of the above embodiments is implemented.

[0065] In addition, an embodiment of the present invention further provides a computer-readable storage medium, which includes a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute the photovoltaic energy storage system scheduling method described in any of the above embodiments.

[0066] When the processor 31 executes the computer program, the steps in the above photovoltaic energy storage system scheduling method embodiment are implemented, for example: Figure 1 Alternatively, when the processor 31 executes the computer program, the functions of each module in the photovoltaic energy storage system scheduling system embodiment are realized, for example Figure 3 The functions of each module of the photovoltaic energy storage system dispatching system are shown.

[0067] 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 implement the present invention. The one or more modules / units can be a series of computer program instruction segments that can implement specific functions, and the instruction segments are used to describe the execution process of the computer program in the terminal device.

[0068] The processor 31 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor, or the processor 31 may be any conventional processor. The processor 31 is the control center of the terminal device, and various parts of the terminal device are connected using various interfaces and lines.

[0069] The memory 32 mainly includes a program storage area and a data storage area, wherein the program storage area can store an operating system, an application 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 memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, and a flash card (Flash Card), etc., or the memory 32 can also be other volatile solid-state storage devices.

[0070] It should be noted that the above terminal device may include, but is not limited to, a processor and a memory. Those skilled in the art will understand that Figure 4 The structural block diagram shown is only a structural example of the above-mentioned terminal device and does not constitute a structural limitation of the above-mentioned terminal device. The above-mentioned terminal device may include more or fewer components than shown in the figure, or combine certain components, or different components.

[0071] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A photovoltaic energy storage system scheduling method, characterized in that: include: Setting a test time, dividing the test time into several time periods, and calculating the photovoltaic power generation power in each time period; Obtain the load power consumption, the exchange power between the solar energy storage system and the grid, and the charging and discharging power of the energy storage end in each time period; Establishing a power balance relationship according to the photovoltaic power generation, load power, exchange power between the photovoltaic energy storage system and the grid, and charge and discharge power of the energy storage end in each time period; Constructing constraint conditions according to the power balance relationship, and taking maximizing photovoltaic power consumption as the objective function; According to the constraint conditions and the objective function, the energy storage end of the photovoltaic energy storage system is charged and discharged.

2. The photovoltaic energy storage system scheduling method according to claim 1, characterized in that: The power balance relationship is: ； in, Indicates time period The photovoltaic power generation power; Indicates time period The exchange power between the photovoltaic energy storage system and the grid. A positive value indicates that the photovoltaic end takes power from the grid, and a negative value indicates that the photovoltaic end sends power back to the grid. Indicates time period The load end power consumption, Indicates time period The charging and discharging power of the energy storage end, charging is a positive value and discharging is a negative value.

3. The photovoltaic energy storage system scheduling method according to claim 2, characterized in that: The constraints include energy storage capacity constraints, energy storage charging and discharging power constraints, transformer reverse overload constraints, and photovoltaic power generation constraints.

4. The photovoltaic energy storage system scheduling method according to claim 3, characterized in that: The objective function is ； in, Indicates the maximum value of photovoltaic power consumption; Indicates time period The actual photovoltaic power generation work, , Indicates the maximum power generation allowed by the photovoltaic end; Indicates time period The power sent back from the photovoltaic end to the grid end, when When it is a positive value, the result is 0, indicating that the photovoltaic power generation is insufficient and all the photovoltaic power generation is consumed, and it is necessary to take power from the grid; when When it is a negative value, is a positive value, the result is , indicating that the photovoltaic power generation is sufficient and is fed back to the grid, and part of the power sent to the grid is not consumed; M represents the total number of time periods into which the test time is divided.

5. The photovoltaic energy storage system scheduling method according to any one of claims 1 or 4, characterized in that: The charging and discharging scheduling of the energy storage end of the photovoltaic energy storage system according to the constraint condition and the objective function includes: When the total charge amount of the energy storage end during the test time is greater than the capacity of the energy storage end, the time for the energy storage end to act as electricity is determined according to the difference between the photovoltaic power generation power and the load power, and the energy storage end is charged and discharged; When the total charge amount of the energy storage terminal during the test time is less than or equal to the capacity of the energy storage terminal, the charge and discharge state of the energy storage terminal is determined and the charge and discharge of the energy storage terminal is executed while considering the balancing of the grid load or economic benefits.

6. The photovoltaic energy storage system scheduling method according to claim 5, characterized in that: When the total charge amount of the energy storage end during the test time is greater than the capacity of the energy storage end, the time for the energy storage end to act as electricity is determined according to the difference between the photovoltaic power generation power and the load power, and the energy storage end is charged and discharged, including: When the total charge amount of the energy storage terminal during the test time is greater than the capacity of the energy storage terminal, If the difference between the photovoltaic power generation and the load power consumption is greater than a first set value, the energy storage end starts charging until the energy storage end capacity constraint condition is violated or when the difference between the photovoltaic power generation and the load power consumption is less than 0, the energy storage end stops charging; If the difference between the photovoltaic power generation and the load power consumption is greater than the second set value, the energy storage end starts discharging, and when the difference between the photovoltaic power generation and the load power consumption is less than 0, the energy storage end stops discharging; If the photovoltaic power generation power is equal to 0, the energy storage end is discharged until the total charge amount of the energy storage end during the test time is 0, and the energy storage end stops discharging.

7. The photovoltaic energy storage system scheduling method according to claim 6, characterized in that: When the total charge amount of the energy storage terminal during the test time is less than or equal to the capacity of the energy storage terminal, the charge and discharge state of the energy storage terminal is determined while considering the load balance of the power grid or the economic benefit, and the charge and discharge of the energy storage terminal is performed, including: When the total charge amount of the energy storage terminal during the test time is less than or equal to the capacity of the energy storage terminal, If the load of the power grid is balanced, the energy storage end starts discharging when the output power of the power grid reaches 70% of the peak value during the period when the power generation of the photovoltaic end is insufficient or the photovoltaic end is not generating power. If economic benefits are taken into consideration, during the period of photovoltaic power generation, the charging and discharging states of the energy storage end are switched according to the power generation power of the photovoltaic end. During the period of no photovoltaic power generation, the energy storage end is charged by drawing electricity from the grid.

8. The photovoltaic energy storage system scheduling method according to claim 1, characterized in that: The method further comprises: Based on the objective function, the photovoltaic consumption rate and the energy storage terminal utilization rate are calculated; The energy storage end of the photovoltaic energy storage system is re-scheduled for charging and discharging according to the photovoltaic absorption rate and the energy storage end utilization rate.

9. A photovoltaic energy storage system scheduling system, characterized in that: include: A first power acquisition module is used to set a test time, divide the test time into a number of time periods, and calculate the photovoltaic power generation power in each time period; The second power acquisition module is used to obtain the load-side power consumption, the exchange power between the solar energy storage system and the grid side, and the energy storage side charging and discharging power in each time period; A power balance relationship establishment module, used to establish a power balance relationship according to the photovoltaic power generation, load power, exchange power between the photovoltaic energy storage system and the grid, and energy storage charging and discharging power in each time period; An objective function construction module is used to construct constraint conditions according to the power balance relationship and take maximizing photovoltaic power consumption as the objective function; The scheduling module is used to schedule the charging and discharging of the energy storage end of the photovoltaic energy storage system according to the constraint conditions and the objective function.

10. A terminal device, characterized in that: The method comprises a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, the photovoltaic energy storage system scheduling method according to any one of claims 1 to 8 is implemented.

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