A virtual power plant peak shaving control method and device based on sodium ion energy storage

Abstract

The present invention discloses a virtual power plant peak shaving control method and device based on sodium ion energy storage, and relates to the technical field of virtual power plant planning and optimal scheduling. The present invention first obtains the maximum peak load obtained by load forecasting of the virtual power plant in the target period, and determines the load reduction capacity of the sodium ion energy storage system, so as to determine the maximum peak load setting value of the virtual power plant in the target period. Subsequently, the sodium ion energy storage system is charged during the low electricity price period, and the sodium ion energy storage system is put on standby during the stable electricity price period. During the peak electricity price period, it is judged that no peak shaving is needed in the future to carry out discharge arbitrage. When it is judged that peak shaving may be needed in the future, the charge state of the sodium ion energy storage system is maintained or supplemented; finally, during the peak electricity consumption period, the sodium ion energy storage system is discharged to the load to carry out peak shaving control, and the peak shaving control is completed. After the peak shaving control is completed, the power grid is charged in time. The present invention ensures the optimal economy while improving the peak shaving effect.

Description

Technical Field

[0001] The present invention relates to the technical field of virtual power plant planning and optimization scheduling, and in particular to a virtual power plant peak shaving control method and device based on sodium ion energy storage. Background Art

[0002] Generally, in the peak shaving control of virtual power plants, the energy storage system can be used to balance the supply and demand of the power grid during peak and valley hours, reducing the pressure on the power grid during peak hours. At present, the peak shaving control method based on lithium-ion energy storage is relatively mature, but the peak shaving control method suitable for the high discharge rate and low charge rate characteristics of sodium-ion battery energy storage, especially the peak shaving control method of virtual power plants based on sodium-ion energy storage, is still lacking in optimization.

[0003] Compared with traditional lithium batteries, sodium-ion batteries have abundant reserves of raw materials and low prices; they have a wider operating temperature range and can operate stably for a long time in an environment of -40℃-80℃. The internal resistance of sodium-ion batteries is higher than that of lithium-ion batteries, and the electrode materials have high thermal stability, and perform better in short-circuit and thermal runaway safety tests. In addition, the outstanding advantages of sodium-ion batteries are their high discharge rate and low charge rate capabilities. They currently have a discharge capacity of more than 3C rate and have great potential in the field of peak shaving control. Compared with lithium-ion batteries, sodium-ion batteries have high-rate discharge characteristics. Under the same maximum discharge power conditions, the configuration capacity of the sodium-ion battery energy storage system is much lower than that of lithium-ion battery energy storage, which can effectively reduce the initial investment cost of the system.

[0004] However, due to the reduced capacity configuration of the sodium-ion battery energy storage system, the full-power discharge duration is short, and the high-rate discharge characteristics of the sodium-ion battery charge and discharge ratio result in a high charge and discharge time ratio. As a result, the management of sodium-ion energy storage is more difficult when performing peak shaving control of virtual power plants based on sodium-ion energy storage. Considering the economy of time-of-use electricity prices, the complexity of sodium-ion energy storage management is further increased. The current virtual power plant peak shaving control is difficult to take into account both peak shaving effects and economy. Summary of the invention

[0005] Based on this, it is necessary to provide a peak shaving control method and device for a virtual power plant based on sodium ion energy storage to address the above technical problems.

[0006] The present invention adopts the following technical solutions:

[0007] The present invention provides a peak shaving control method for a virtual power plant based on sodium ion energy storage, which first obtains the maximum peak load obtained by load forecasting of the virtual power plant in the target period, and determines the load reduction capacity of the sodium ion energy storage system, and determines the maximum peak load setting value of the virtual power plant in the target period according to the difference between the maximum peak load and the load reduction capacity. Subsequently, based on the time-of-use electricity price, the sodium ion energy storage system can be charged during the low electricity price period, and the sodium ion energy storage system can be put on standby during the stable electricity price period. During the peak electricity price period, if it is determined that no peak shaving control is needed in the future, discharge arbitrage can be carried out, and if it is determined that peak shaving control may be needed in the future, the charge state of the sodium ion energy storage system can be maintained or supplemented; finally, during the peak electricity consumption period, the sodium ion energy storage system is discharged to the load for peak shaving control, and the peak shaving control is completed. After the peak shaving control is completed, the system is charged in time through the power grid.

[0008] The present invention provides a virtual power plant peak shaving control device based on sodium ion energy storage, comprising:

[0009] An acquisition module is used to obtain the maximum peak load obtained by load forecasting of the virtual power plant in the target period, and determine the load reduction capacity of the sodium-ion energy storage system, and determine the maximum peak load setting value of the virtual power plant in the target period according to the difference between the maximum peak load and the load reduction capacity;

[0010] The valley control module is used to charge the sodium-ion energy storage system through the power grid during the daily low electricity price period when the load data of the current control cycle of the virtual power plant is less than or equal to the maximum peak load setting value;

[0011] The normal control module is used to put the sodium ion energy storage system into standby mode when the load data of the current control cycle of the virtual power plant is less than or equal to the maximum peak load setting value during the daily stable electricity price period;

[0012] Peak control module, used during the peak electricity price period of each day, when the load data of the current control cycle of the virtual power plant is less than or equal to the maximum peak load setting value, if it is predicted that peak shaving control will be required for the rest of the day, the sodium ion energy storage system will be put into standby mode or charged through the grid according to its charge state; if it is predicted that peak shaving control is not required for the rest of the day, the sodium ion energy storage system will be discharged to the load for arbitrage;

[0013] The peak shaving control module is used to discharge the load through the sodium ion energy storage system to perform peak shaving control when it is determined that the power consumption is at a peak based on the load data of the current control cycle of the virtual power plant and the maximum peak load setting value, and to charge through the power grid after the peak shaving control.

[0014] The present invention provides a computer-readable storage medium, wherein the storage medium stores a computer program, and when the computer program is executed by a processor, the virtual power plant peak shaving control method based on sodium ion energy storage is implemented.

[0015] The present invention provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned peak shaving control method of a virtual power plant based on sodium ion energy storage when executing the program.

[0016] At least one of the above technical solutions adopted by the present invention can achieve the following beneficial effects:

[0017] When the present invention performs peak shaving control on a virtual power plant based on sodium ion energy storage, the maximum peak load setting value of the virtual power plant in the target period is first determined according to the difference between the maximum peak load predicted by the virtual power plant in the target period and the load reduction capacity of the sodium ion energy storage system, and this is used as the peak shaving warning line. Based on this, when the load data of the current control cycle of each day is less than or equal to the maximum peak load setting value, it indicates that the current power consumption pressure is small. Then, based on the economy of time-of-use electricity prices, the sodium ion energy storage system is charged during the low electricity price period, the sodium ion energy storage system is put on standby during the stable electricity price period, and during the peak electricity price period, the sodium ion energy storage system is discharged for arbitrage when no peak shaving control is required in the future, thereby ensuring the best economy. At the same time, by maintaining or supplementing the charge state of the sodium ion energy storage system when it is judged that peak shaving control may be required in the future during the peak electricity price period, and discharging to the load through the sodium ion energy storage system during the peak electricity consumption period for peak shaving control and charging in time through the power grid after the peak shaving control is completed, so as to cope with potential continuous multiple waves of peak electricity consumption, the peak shaving effect is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0019] Figure 1 A schematic flow chart of a peak shaving control method for a virtual power plant based on sodium ion energy storage provided by the present invention;

[0020] Figure 2 A schematic diagram of a virtual power plant peak shaving method program flow provided by the present invention;

[0021] Figure 3 A schematic diagram of a virtual power plant peak shaving control device based on sodium ion energy storage provided by the present invention. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. 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 making creative work are within the scope of protection of the present invention.

[0023] At present, compared with lithium-ion batteries, sodium-ion batteries have high-rate discharge characteristics. Under the same maximum discharge power conditions, the configuration capacity of the sodium-ion battery energy storage system is much lower than that of lithium-ion battery energy storage, which can effectively reduce the initial investment cost of the system. However, due to the reduced system capacity configuration, the full-power discharge duration is shorter; the difference in the charge and discharge rates of sodium-ion batteries leads to a high charge and discharge time ratio, which brings about the problem of rapid energy replenishment of sodium-ion energy storage; on the other hand, the time-of-use electricity price policy is conducive to improving the economy of the system, but it increases the complexity of control. The above problems require further adjustment of the peak shaving strategy and optimization of the sodium-ion energy storage operation mode, so as to achieve the optimal peak shaving effect and economy with limited capacity.

[0024] The technical solutions provided by various embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0025] Figure 1 The present invention is a flow chart of a method for peak shaving control of a virtual power plant based on sodium ion energy storage, which specifically includes the following steps:

[0026] S101: Obtain the maximum peak load obtained by load forecasting for the virtual power plant during the target period, and determine the load reduction capacity of the sodium-ion energy storage system, and determine the maximum peak load setting value of the virtual power plant during the target period based on the difference between the maximum peak load and the load reduction capacity.

[0027] S102: During the daily low electricity price period, when the load data of the current control cycle of the virtual power plant is less than or equal to the maximum peak load setting value, the sodium ion energy storage system is charged through the power grid.

[0028] S103: During the daily stable electricity price period, when the load data of the current control cycle of the virtual power plant is less than or equal to the maximum peak load setting value, the sodium ion energy storage system is put into standby mode.

[0029] S104: During the peak electricity price period of each day, when the load data of the current control cycle of the virtual power plant is less than or equal to the maximum peak load setting value, if it is predicted that peak shaving control will be required for the rest of the day, the sodium ion energy storage system will be put into standby mode or charged through the power grid according to its state of charge. If it is predicted that peak shaving control will not be required for the rest of the day, the sodium ion energy storage system will be discharged to the load for arbitrage.

[0030] S105: When it is determined that the virtual power plant is at a peak power consumption according to the load data of the current control cycle and the maximum peak load setting value, the sodium ion energy storage system is used to discharge to the load for peak shaving control and the power grid is charged after the peak shaving control is completed.

[0031] For the convenience of explanation, the following description is only based on the server as the execution subject. The server mentioned in the present invention can be a server set up on the business platform, or a device such as a desktop computer, a notebook computer, etc. that can execute the solution of the present invention.

[0032] Generally, distributed generation, energy storage systems and adjustable loads can be integrated and coordinated in a virtual power plant so that these resources can be regarded as a single, controllable entity to participate in the operation of the electricity market.

[0033] Based on this, when the sodium ion energy storage system is used to serve the peak shaving control process of the virtual power plant, in one or more embodiments of the present invention, the server can set a reasonable threshold value of the state of charge (State of Charge Threshold, SOC) (including: a preset stop charging threshold, a preset trickle charging threshold, a preset trickle discharge threshold, and a preset stop discharge threshold) in combination with the open circuit voltage (OCV curve) of the sodium ion battery pack, thereby protecting the sodium ion battery pack, preventing the sodium ion battery pack from overcharging and over-discharging, improving operational safety and efficiency, and extending the service life of the sodium ion energy storage battery.

[0034] In addition, in one or more embodiments of the present invention, the control decision of the sodium ion energy storage system usually has a hysteresis, which may cause the control effect of the virtual power plant load to be unsatisfactory. Therefore, the control cycle of the virtual power plant load control system should be as small as possible. The control decision used for the sodium ion energy storage system will affect the overall load characteristics of the virtual power plant. Therefore, the input data of the virtual power plant load control system should be the load data of the virtual power plant before the sodium ion energy storage discharge optimization. The output power of the sodium ion energy storage system, the load data after the virtual power plant is optimized, and the load data before the virtual power plant is optimized have the following power balance equation relationship: .

[0035] In the formula, is the power drawn from the grid by the virtual power plant, is the discharge power of the sodium ion energy storage system, is the charging power of the sodium ion energy storage system, is the load power of the virtual power plant.

[0036] Furthermore, in one or more embodiments of the present invention, since the goal of the sodium-ion energy storage system is to manage the load of the virtual power plant at a peak, the maximum peak load of the virtual power grid should not increase due to the charging of the sodium-ion energy storage system; in addition, the discharge of the sodium-ion energy storage system should not cause the load of the virtual power plant to be negative, that is, a reverse flow to the power grid. When the peak load is reduced, the load is high, and although there is a control lag, the optimized virtual power plant load is generally positive; when discharging at peak times for peak-to-valley arbitrage, the control lag at the instantaneous change of the load may cause a reverse flow, so the load maintenance set value can be set. .

[0037] In the formula, The load maintenance set value is set to be greater than zero. By controlling the load of the virtual power plant after discharge optimization to be near the load maintenance set value, reverse flow is prevented.

[0038] In the process of virtual power plant load control, the following constraints need to be followed:

[0039] ;

[0040] ;

[0041] ;

[0042] ;

[0043] ;

[0044] ;

[0045] ;

[0046] ;

[0047] ;

[0048] ;

[0049] ;

[0050] ;

[0051] .

[0052] In the formula, is the ratio of the trickle charging power to the maximum charging power of the sodium ion energy storage system, is the ratio of the trickle discharge power to the maximum discharge power of the sodium ion energy storage system, Charging conversion efficiency for sodium ion energy storage system, is the discharge conversion efficiency of the sodium ion energy storage system, is the peak discharge coefficient of the sodium-ion energy storage system (specifically, it is the ratio of the maximum discharge power of the sodium-ion energy storage system during the peak electricity price period to the maximum discharge power of the sodium-ion energy storage system. The maximum discharge power during the peak electricity price period is usually different from the maximum discharge power of the sodium-ion energy storage system. Taking a 3C discharge battery as an example, the former may be set to a maximum of 1.5C discharge, and the latter (such as during peak shaving) may be set to a maximum of 3C discharge. Short-term 3C discharge is acceptable, but long-term over-temperature protection may occur). is an integer variable that controls peak load reduction, is the initial value of the integer variable, is the peak load duration (usually 15 minutes), is the average load period (s), is a set of natural numbers, For sodium ion energy storage system battery pack The state of charge at the beginning of the time period, is the current available capacity of the sodium-ion energy storage system, is the current maximum capacity of the sodium-ion energy storage system (for example, the rated maximum capacity is 50, the maximum capacity after a period of use is 40, and the available capacity varies between 0 and 40), For sodium ion energy storage system battery pack The health status at the beginning of the period, is the rated capacity of the battery pack of the sodium-ion energy storage system (kWh), , are the lower and upper limits of the state of charge of the battery pack of the sodium ion energy storage system, Control cycle index (1~86400 / ), To control the period index set, , To represent the sodium ion energy storage system A binary variable representing the charge / discharge state of the time period, is the maximum charging power of the sodium-ion energy storage system (kW), is the maximum charging power of the sodium-ion energy storage system converter (kW), is the maximum charging power of the sodium-ion energy storage system battery pack (kW), is the maximum discharge power of the sodium ion energy storage system (kW), is the maximum discharge power of the sodium ion energy storage system converter (kW), is the maximum discharge power of the battery pack of the sodium-ion energy storage system (kW), is the control period (s), is the discharge power of the sodium ion energy storage system in the control period t, is the power drawn from the grid by the virtual power plant in control period t, is the charging power of the sodium ion energy storage system in the control cycle t, is the load power of the virtual power plant during control period t.

[0053] When implementing the peak shaving control method for a virtual power plant based on sodium-ion energy storage, the server can first learn the historical load data of the virtual power plant (multi-time scale load data, second and minute levels) through an artificial intelligence algorithm, and predict the maximum peak load of the virtual power plant during the target period (e.g., next month) based on this data (the data should be: load data when facilities with both source and load characteristics such as sodium-ion energy storage systems are not included), and use the latest predicted value as the maximum peak load declared for the target period. .

[0054] Afterwards, the server can determine the load reduction capacity of the sodium-ion energy storage system by combining the configuration parameters of the sodium-ion energy storage system (such as the energy storage system battery, converter charging and discharging capacity, the energy storage system available capacity, etc.) and setting the load conditions under typical peak-shaving conditions. : .

[0055] In the formula, is the load reduction capability of the sodium-ion energy storage system, is the remaining capacity ratio of the sodium-ion energy storage system battery pack when it is retired, is the rated capacity of the battery pack of the sodium-ion energy storage system, is the upper limit of the state of charge of the battery pack of the sodium ion energy storage system, is the lower limit of the state of charge of the battery pack of the sodium ion energy storage system, is the discharge conversion efficiency of the sodium ion energy storage system, is the maximum discharge power of the energy storage converter of the sodium ion energy storage system, It is the maximum discharge power of the battery pack of the sodium ion energy storage system.

[0056] in, It ensures that the maximum discharge power duration of the sodium-ion energy storage system exceeds the peak load cycle during the entire life cycle of the sodium-ion energy storage system battery pack, effectively avoiding peak shaving failure caused by short-term peak shaving when the battery pack is small in capacity.

[0057] The maximum peak load setting value of the virtual power plant in the target period can be further set accordingly. The control strategy of the sodium ion energy storage system needs to control the charging and discharging scheduling of the energy storage system to achieve the maximum peak load control of the virtual power plant load below the maximum peak load setting value: .

[0058] In the formula, The maximum peak load setpoint proposed for the beginning of the month.

[0059] Furthermore, in one or more embodiments of the present invention, if the actual maximum peak load of the load data of each control period of the virtual power plant after the sodium ion energy storage discharge optimization is still greater than the maximum peak load setting value (for example, due to insufficient capacity or peak shaving failure caused by system failure when the peak time lasts for a long time), the maximum peak load setting value can be updated to the actual maximum peak load by the following formula: .

[0060] In the formula, is the updated maximum peak load setting value, is the peak load data after optimization, is the average load period (s).

[0061] By selecting the maximum peak load iteration cycle as the peak load cycle , which can effectively avoid the problem of unsatisfactory peak load reduction caused by the short scale of peak load change in the subsequent optimal scheduling of peak load reduction, that is, avoid the situation where the rapid iteration of the maximum peak load under special working conditions causes the weakening of peak load reduction.

[0062] After determining all the required data, the server can further establish a regional rule base according to the regional time-of-use electricity price policy, and set up a virtual power plant sodium ion energy storage charging and discharging strategy based on time-of-use electricity prices.

[0063] Specifically, in one or more embodiments of the present invention, during the daily low electricity price period, when the load data of the current control cycle of the virtual power plant is less than or equal to the maximum peak load setting value, the sodium ion energy storage system is charged through the power grid. During the charging process, if the state of charge of the battery pack of the sodium ion energy storage system is lower than the preset trickle charge threshold, the server can determine the fast charging power of the sodium ion energy storage system based on the minimum value of the difference between the maximum peak load setting value and the load data of the current control cycle of the virtual power plant, the maximum charging power of the sodium ion energy storage system converter, and the maximum charging power of the battery pack of the sodium ion energy storage system based on the following formula: .

[0064] Thereby, the server can quickly charge the sodium ion energy storage system through the power grid according to the determined fast charging power.

[0065] If the state of charge of the battery pack of the sodium ion energy storage system is greater than or equal to the preset trickle charging threshold and less than the preset stop charging threshold, the server can determine the trickle charging power of the sodium ion energy storage system based on the following formula according to the minimum value of the difference between the maximum peak load setting value and the current control cycle load data of the virtual power plant and the trickle charging power of the sodium ion energy storage system: .

[0066] Therefore, the server can perform trickle charging on the sodium ion energy storage system through the power grid according to the determined trickle charging power.

[0067] During the daily low electricity price period, when the load data of the current control cycle of the virtual power plant is less than or equal to the maximum peak load setting value, the sodium ion energy storage system is in standby mode: .

[0068] During the daily stable electricity price period, when the load data of the current control cycle of the virtual power plant is less than or equal to the maximum peak load setting value, the sodium ion energy storage system is neither charged nor discharged, that is, it is in standby state: .

[0069] During the peak electricity price period of the day, the server can first determine whether peak shaving is needed for the rest of the day. If peak shaving is needed, the server will be in standby mode or charged through the grid according to the charge state of the sodium ion energy storage system. If peak shaving is not needed, the sodium ion energy storage system will be discharged to the load for peak-valley arbitrage.

[0070] In the peak-valley arbitrage mode, when the state of charge of the battery pack of the sodium-ion energy storage system is greater than the preset trickle discharge threshold, the server can determine the arbitrage fast discharge power of the sodium-ion energy storage system based on the following formula according to the difference between the load data of the current control cycle of the virtual power plant and the load maintenance set value and the maximum value of 0 and the maximum discharge power of the sodium-ion energy storage system during peak-valley arbitrage: .

[0071] in, It is used to prevent reverse flow caused by blind discharge during peak hours. Then, the sodium ion energy storage system can perform arbitrage rapid discharge to the load according to the arbitrage rapid discharge power.

[0072] When the state of charge of the battery pack of the sodium ion energy storage system is less than or equal to the preset trickle discharge threshold and greater than the preset stop discharge threshold, the server can determine the arbitrage trickle discharge power of the sodium ion energy storage system based on the following formula according to the maximum value of the difference between the load data of the current control cycle of the virtual power plant and the load maintenance set value and 0, the peak-to-valley arbitrage peak maximum discharge power of the sodium ion energy storage system, and the trickle discharge power of the sodium ion energy storage system: .

[0073] Afterwards, the sodium ion energy storage system can perform arbitrage trickle discharge to the load according to the determined arbitrage trickle discharge power.

[0074] In other cases of the peak-valley arbitrage model, the sodium-ion energy storage system is in standby mode: .

[0075] When it is determined that the power consumption is at its peak based on the load data of the current control cycle of the virtual power plant and the maximum peak load setting value, the server can discharge to the load through the sodium ion energy storage system to perform peak shaving control and charge through the power grid after completing the peak shaving control.

[0076] Specifically, when the load data of the current control cycle of the virtual power plant is greater than the maximum peak load setting value, it may be a peak in electricity consumption or it may enter a peak in electricity consumption. The server can perform the first-level peak shaving optimization scheduling based on the load data of the current control cycle. Among them, if the state of charge of the battery pack of the sodium ion energy storage system is greater than the preset trickle discharge threshold, the server can determine the rapid discharge power of the sodium ion energy storage system based on the following formula according to the minimum value of the load data of the current control cycle of the virtual power plant before the sodium ion energy storage discharge optimization and the maximum peak load setting value, the maximum discharge power of the sodium ion energy storage system converter, and the maximum discharge power of the sodium ion energy storage system battery pack: Therefore, the sodium ion energy storage system discharges to the load to perform peak shaving control according to the determined rapid discharge power.

[0077] If the state of charge of the battery pack of the sodium ion energy storage system is greater than the preset stop discharge threshold and less than or equal to the preset trickle discharge threshold, the server can determine the trickle discharge power of the sodium ion energy storage system based on the following formula according to the minimum value of the difference between the load data of the virtual power plant before the sodium ion energy storage discharge optimization and the maximum peak load setting value and the trickle discharge power of the sodium ion energy storage system in the current control cycle of the virtual power plant: And according to the determined trickle discharge power, the sodium ion energy storage system discharges to the load to perform peak shaving control.

[0078] Further, in one or more embodiments of the present invention, it is determined whether the average value of the load data of the preset sliding window of the virtual power plant in the preset number of control cycles is greater than the maximum peak load setting value. If so, it is determined that the current control cycle is in the peak power consumption period, and the server can make the sodium ion energy storage system discharge to the load according to the aforementioned fast discharge power or trickle discharge power to perform peak shaving control. If not, it is determined that the current control cycle is in the peak power consumption, and peak shaving control of discharging to the load through the sodium ion energy storage system is not performed.

[0079] For peak power consumption, the server can also add a second layer of peak shaving optimization scheduling to the peak shaving control. Specifically, for each control cycle after the peak power consumption, the server can determine the difference between the load data of the control cycle after sodium ion energy storage discharge optimization and the maximum peak load setting value, and determine the peak shaving deviation of the current control cycle according to the sum of the difference and the peak shaving deviation of the previous control cycle: Among them, the peak-shaving deviation in the first control cycle after the peak of electricity consumption is zero.

[0080] When the peak shaving deviation is less than or equal to zero, the corrected discharge power of the sodium ion energy storage system is determined to be 0; when the peak shaving deviation is greater than zero, the corrected discharge power of the sodium ion energy storage system can be determined based on the following formula according to the minimum value of the load data before the sodium ion energy storage discharge optimization in the control cycle, the maximum discharge power of the sodium ion energy storage system converter, and the maximum discharge power of the sodium ion energy storage system battery pack: , .

[0081] In the formula, The peak shaving deviation is determined, so that the sodium ion energy storage system discharges to the load for peak shaving control according to the determined corrected discharge power.

[0082] Furthermore, the server can also determine when to exit the peak shaving control. Specifically, the server can determine the peak shaving control deviation of the preset sliding window corresponding to each control cycle after the peak power consumption according to the cumulative sum of the differences between the load data after sodium ion energy storage discharge optimization in each control cycle within the preset sliding window corresponding to the control cycle and the maximum peak load setting value.

[0083] The peak shaving control deviation of each control cycle after the peak of electricity consumption is integrated. When the integrated peak shaving control deviation is less than or equal to zero, and at the same time, the load data before the sodium ion energy storage peak shaving control deviation discharge optimization is less than the maximum peak load setting value, the peak shaving control is exited.

[0084] For example, after entering the peak load shaving control, During iteration, the peak clipping control deviation, integral and value:

[0085] , , .

[0086] In the formula, The peak load duration is the period t 1 peak clipping control deviation, is the integral of the peak clipping control deviation.

[0087] The initial value of the integer variable is set to , during the iteration process Limit at ( is an integer), after peak load reduction is triggered, the integer variable In the index It is updated during iteration, thereby covering the peak load reduction to the full cycle range of the peak load.

[0088] The exit conditions for peak load reduction are: .

[0089] After exiting the peak load reduction process, the integer variable Set to initial value , With 0 as the value, the sodium-ion energy storage system receives energy from the grid to cope with the subsequent peak shaving.

[0090] If it is not during the peak period of electricity consumption, it means that the load data of the current control cycle is greater than the maximum peak load setting value and is only a temporary peak in electricity consumption. At this time, the first-level peak-shaving control optimization scheduling can be regarded as a peak discharge decision for the peak electricity consumption. The peak discharge decision within the control cycle of the first-level peak-shaving control optimization scheduling under the time-of-use electricity price strategy can be corrected to 0, that is, standby: .

[0091] based on Figure 1 The virtual power plant peak shaving control method based on sodium ion energy storage shown in the figure, when the virtual power plant is subjected to peak shaving control based on sodium ion energy storage, the maximum peak load setting value of the virtual power plant in the target period is first determined according to the difference between the maximum peak load predicted by the virtual power plant in the target period and the load reduction capacity of the sodium ion energy storage system, and this is used as the peak shaving warning line. Based on this, when the load data of the current control cycle of each day is less than or equal to the maximum peak load setting value, it indicates that the current power consumption pressure is small. Then, based on the economic efficiency of time-of-use electricity prices, the maximum peak load setting value of the virtual power plant in the low electricity price period is further determined. The sodium ion energy storage system is charged and put on standby during stable electricity price periods, and discharged for arbitrage during peak electricity price periods when peak shaving control is not required in the future, thereby ensuring optimal economy. At the same time, by maintaining or replenishing the charge state of the sodium ion energy storage system when it is judged that peak shaving control may be required in the future during peak electricity price periods, and discharging the sodium ion energy storage system to the load for peak shaving control during peak electricity consumption periods, and charging the system in a timely manner through the power grid after the peak shaving control is completed, potential continuous multiple waves of peak electricity consumption can be dealt with, thereby improving the peak shaving effect.

[0092] The present invention provides a peak shaving control method for a virtual power plant based on sodium ion energy storage. By adding real-time control and real-time optimization links on the basis of a pre-energy storage planning model and further refining the energy storage operation time scale, the feasibility and stability of energy storage operation can be effectively improved, while also further increasing the benefits obtained by energy storage users, thereby effectively maximizing the benefits of energy storage users.

[0093] When applying the virtual power plant peak shaving control method based on sodium ion energy storage provided by the present invention, it is not necessary to Figure 1 The steps are executed in the order shown. The specific execution order of the steps can be determined according to needs, and the present invention does not limit this.

[0094] The above is a virtual power plant peak shaving control method based on sodium ion energy storage provided by one or more embodiments of the present invention. Based on the same idea, the present invention also provides a corresponding virtual power plant peak shaving control device based on sodium ion energy storage, such as Figure 3 shown.

[0095] Figure 3 A schematic diagram of a peak shaving control device for a virtual power plant based on sodium ion energy storage provided by the present invention includes:

[0096] An acquisition module 201 is used to obtain a maximum peak load obtained by load forecasting of the virtual power plant in a target period, and determine a load reduction capacity of the sodium-ion energy storage system, and determine a maximum peak load setting value of the virtual power plant in the target period according to a difference between the maximum peak load and the load reduction capacity;

[0097] The valley control module 202 is used to charge the sodium ion energy storage system through the power grid during the daily low electricity price period when the load data of the current control cycle of the virtual power plant is less than or equal to the maximum peak load setting value;

[0098] The normal control module 203 is used to put the sodium ion energy storage system into standby mode when the load data of the current control cycle of the virtual power plant is less than or equal to the maximum peak load setting value during the daily stable electricity price period;

[0099] Peak control module 204 is used for, during the peak period of electricity prices every day, when the load data of the current control cycle of the virtual power plant is less than or equal to the maximum peak load setting value, if it is predicted that peak shaving control will be required for the rest of the day, then the sodium ion energy storage system will be put into standby mode or charged through the power grid according to the charge state of the system; if it is predicted that peak shaving control will not be required for the rest of the day, then the sodium ion energy storage system will be discharged to the load for arbitrage;

[0100] The peak shaving control module 205 is used to discharge the load through the sodium ion energy storage system to perform peak shaving control when it is determined that the power consumption is at a peak according to the load data of the current control cycle of the virtual power plant and the maximum peak load setting value, and to charge through the power grid after the peak shaving control.

[0101] For the specific definition of the peak shaving control device of a virtual power plant based on sodium ion energy storage, please refer to the definition of the peak shaving control method of a virtual power plant based on sodium ion energy storage mentioned above, which will not be repeated here. Each module in the above-mentioned virtual power plant peak shaving control device based on sodium ion energy storage can be implemented in whole or in part by software, hardware and a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules.

[0102] The present invention also provides a computer-readable storage medium, which stores a computer program, which can be used to execute the above Figure 1 A peak shaving control method for a virtual power plant based on sodium ion energy storage is provided.

[0103] The present invention also provides a computer device. At the hardware level, the computer device includes a processor, an internal bus, a network interface, a memory, and a non-volatile memory. Of course, it may also include hardware required for other services. The processor reads the corresponding computer program from the non-volatile memory into the memory and then runs it to achieve the above Figure 1 A peak shaving control method for a virtual power plant based on sodium ion energy storage is provided.

[0104] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided by the present invention can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory or optical memory, etc. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0105] The technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of the present invention.

Claims

1. A virtual power plant peak shaving control method based on sodium ion energy storage, characterized in that: include: Obtain the maximum peak load obtained by load forecasting for the virtual power plant during the target period, determine the load reduction capacity of the sodium-ion energy storage system, and determine the maximum peak load setting value of the virtual power plant during the target period based on the difference between the maximum peak load and the load reduction capacity; During the daily low electricity price period, when the load data of the virtual power plant's current control cycle is less than or equal to the maximum peak load setting value, the sodium-ion energy storage system is charged through the power grid; During the daily stable electricity price period, when the load data of the current control cycle of the virtual power plant is less than or equal to the maximum peak load setting value, the sodium ion energy storage system is put into standby mode; During the peak electricity price period of each day, when the load data of the current control cycle of the virtual power plant is less than or equal to the maximum peak load setting value, if it is predicted that peak shaving control will be required for the rest of the day, the sodium-ion energy storage system will be put into standby mode or charged through the grid according to its state of charge. If it is predicted that peak shaving control will not be required for the rest of the day, the sodium-ion energy storage system will be discharged to the load for arbitrage; When the load data of the current control cycle of the virtual power plant is greater than the maximum peak load setting value, determine whether the average value of the load data of the preset sliding window of the virtual power plant in the preset number of control cycles is greater than the maximum peak load setting value; if so, it is determined that the current control cycle is at the peak of electricity consumption, and the sodium ion energy storage system is used to discharge to the load for peak shaving control and charge through the power grid after completing the peak shaving control; if not, it is determined that the current control cycle is at the peak of electricity consumption, and the peak shaving control of discharging to the load through the sodium ion energy storage system is not performed; The charging of the sodium ion energy storage system through the power grid specifically includes: If the state of charge of the battery pack of the sodium-ion energy storage system is lower than the preset trickle charging threshold, the fast charging power of the sodium-ion energy storage system is determined according to the minimum value of the difference between the maximum peak load setting value and the load data of the current control cycle of the virtual power plant, the maximum charging power of the sodium-ion energy storage system converter and the maximum charging power of the battery pack of the sodium-ion energy storage system; the sodium-ion energy storage system is fast charged through the power grid according to the determined fast charging power; If the state of charge of the battery pack of the sodium-ion energy storage system is greater than or equal to the preset trickle charging threshold and less than the preset stop charging threshold, the trickle charging power of the sodium-ion energy storage system is determined according to the minimum value of the difference between the maximum peak load setting value and the current control cycle load data of the virtual power plant and the trickle charging power of the sodium-ion energy storage system; and the sodium-ion energy storage system is trickle charged through the power grid according to the determined trickle charging power.

2. The peak shaving control method of a virtual power plant based on sodium ion energy storage according to claim 1, characterized in that: The arbitrage through discharging the sodium ion energy storage system to the load specifically includes: When the state of charge of the battery pack of the sodium-ion energy storage system is greater than the preset trickle discharge threshold, the arbitrage fast discharge power of the sodium-ion energy storage system is determined according to the minimum value between the difference between the load data of the current control cycle of the virtual power plant and the load maintenance set value and the maximum value of 0 and the maximum discharge power of the sodium-ion energy storage system during peak-valley arbitrage; the sodium-ion energy storage system is made to perform arbitrage fast discharge to the load according to the arbitrage fast discharge power; When the state of charge of the battery pack of the sodium-ion energy storage system is less than or equal to the preset trickle discharge threshold and greater than the preset stop discharge threshold, the arbitrage trickle discharge power of the sodium-ion energy storage system is determined according to the minimum value of the difference between the load data of the current control cycle of the virtual power plant and the load maintenance set value and 0, the peak-to-valley arbitrage peak maximum discharge power of the sodium-ion energy storage system, and the trickle discharge power of the sodium-ion energy storage system; according to the determined arbitrage trickle discharge power, the sodium-ion energy storage system performs arbitrage trickle discharge to the load; Wherein, the load maintains a set value greater than zero.

3. The peak shaving control method of a virtual power plant based on sodium ion energy storage according to claim 1, characterized in that: The peak shaving control by discharging the sodium ion energy storage system to the load specifically includes: If the state of charge of the battery pack of the sodium-ion energy storage system is greater than the preset trickle discharge threshold, the rapid discharge power of the sodium-ion energy storage system is determined according to the minimum value of the difference between the load data before the sodium-ion energy storage discharge optimization and the maximum peak load setting value in the current control cycle of the virtual power plant, the maximum discharge power of the sodium-ion energy storage system converter, and the maximum discharge power of the battery pack of the sodium-ion energy storage system; and the sodium-ion energy storage system is made to discharge to the load for peak shaving control according to the determined rapid discharge power; If the state of charge of the battery pack of the sodium ion energy storage system is greater than the preset stop discharge threshold and less than or equal to the preset trickle discharge threshold, the trickle discharge power of the sodium ion energy storage system is determined based on the minimum value of the difference between the load data of the virtual power plant before the sodium ion energy storage discharge optimization and the maximum peak load setting value and the trickle discharge power of the sodium ion energy storage system in the current control cycle of the virtual power plant; and the sodium ion energy storage system is discharged to the load for peak shaving control based on the determined trickle discharge power.

4. The peak shaving control method of a virtual power plant based on sodium ion energy storage according to claim 3, characterized in that: The method further comprises: For each control cycle after the peak of electricity consumption, determine the difference between the load data of the control cycle after the sodium ion energy storage discharge optimization and the maximum peak load setting value, and determine the peak shaving deviation of the current control cycle according to the sum of the difference and the peak shaving deviation of the previous control cycle; wherein the peak shaving deviation of the first control cycle after the peak of electricity consumption is zero; When the peak shaving deviation is greater than zero, the corrected discharge power of the sodium ion energy storage system is determined according to the minimum value of the load data before the sodium ion energy storage discharge optimization, the maximum discharge power of the sodium ion energy storage system converter, and the maximum discharge power of the sodium ion energy storage system battery pack in the control cycle; when the peak shaving deviation is less than or equal to zero, the corrected discharge power of the sodium ion energy storage system is determined to be 0; According to the determined corrected discharge power, the sodium ion energy storage system discharges to the load to perform peak shaving control.

5. The peak shaving control method of a virtual power plant based on sodium ion energy storage according to claim 4, characterized in that: The method further comprises: For each control cycle after the peak of electricity consumption, the peak shaving control deviation of the preset sliding window corresponding to the control cycle is determined according to the cumulative sum of the differences between the load data optimized by the sodium ion energy storage discharge in each control cycle in the preset sliding window corresponding to the control cycle and the maximum peak load setting value; The peak shaving control deviation of each control cycle after the peak of electricity consumption is integrated. When the integrated peak shaving control deviation is less than or equal to zero, and at the same time, the load data before the sodium ion energy storage discharge optimization is less than the maximum peak load setting value, the peak shaving control is exited.

6. The peak shaving control method of a virtual power plant based on sodium ion energy storage according to claim 1, characterized in that: Determining the load reduction capacity of the sodium ion energy storage system specifically includes: According to the configuration parameters of the sodium-ion energy storage system, the load reduction capacity of the sodium-ion energy storage system is determined by the following formula: ； in, is the load reduction capability of the sodium-ion energy storage system, is the remaining capacity ratio of the sodium-ion energy storage system battery pack when it is retired, is the rated capacity of the battery pack of the sodium-ion energy storage system, is the upper limit of the state of charge of the battery pack of the sodium ion energy storage system, is the lower limit of the state of charge of the battery pack of the sodium ion energy storage system, is the peak load duration, is the discharge conversion efficiency of the sodium ion energy storage system, is the maximum discharge power of the energy storage converter of the sodium ion energy storage system, It is the maximum discharge power of the battery pack of the sodium ion energy storage system.

7. The peak shaving control method of a virtual power plant based on sodium ion energy storage according to claim 1, characterized in that: The method further comprises: If the actual maximum peak load of the load data of each control cycle of the virtual power plant after optimization of the sodium-ion energy storage discharge is still greater than the maximum peak load setting value, the maximum peak load setting value will be updated to the actual maximum peak load.

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