Charging and discharging control method of energy storage power station and energy storage power station

Abstract

The embodiment of the invention discloses a charging and discharging control method of an energy storage power station and the energy storage power station, and the target charging and discharging power of the energy storage power station is determined according to the configured charging and discharging power and the grid-connected point power, so that the determined target charging and discharging power of the energy storage power station can meet the requirement for the grid-connected point power. According to the target charging and discharging power of the energy storage power station and the preset power intervals corresponding to the energy storage converters, the operation number of the energy storage converters is controlled so as to control the energy storage converters to operate in the corresponding preset power intervals, and it is guaranteed that all the energy storage converters which are started to operate can work under the power in the corresponding preset power intervals; and the working efficiency of the energy storage converter is improved.

Description

Technical Field

[0001] The present invention relates to the field of energy storage technology, and in particular to a charging and discharging control method of an energy storage power station and an energy storage power station. Background Art

[0002] Energy storage power stations have the advantages of storing a lot of electric energy and charging quickly. Energy storage power stations play an important role in ensuring the power consumption of users.

[0003] In energy storage power stations, the power conversion system (PCS) is a key device. When the battery is charging in the energy storage power station, the PCS supports the conversion of AC power into DC power; and when the battery is discharging, it converts DC power into AC power.

[0004] The power of the PCS will affect the working efficiency of the PCS. In the prior art, there is a problem that the power range of the PCS leads to low working efficiency of the PCS. The working efficiency of the PCS includes the conversion efficiency of the PCS, which is equal to the ratio of the discharge amount to the charge amount of the energy storage converter after the PCS is charged and discharged once. Summary of the invention

[0005] The present invention provides a charge and discharge control method of an energy storage power station and an energy storage power station, so as to enable a PCS to work in a preset power range and improve the working efficiency of the PCS.

[0006] According to one aspect of the present invention, a charge and discharge control method of an energy storage power station is provided. The energy storage power station includes at least two energy storage subsystems, and the energy storage subsystem includes an energy storage converter and a battery connected to the energy storage converter. The charge and discharge control method includes:

[0007] Obtain the configured charging and discharging power of the energy storage power station and the grid connection point power of the energy storage power station;

[0008] Determine the target charging and discharging power of the energy storage power station based on the configured charging and discharging power and the grid connection point power;

[0009] According to the target charging and discharging power of the energy storage power station and the preset power range corresponding to the energy storage converter, the operating number of the energy storage converter is controlled to control the energy storage converter to operate in the corresponding preset power range.

[0010] Optionally, configuring the charge and discharge power includes configuring the charging power, and the target charge and discharge power includes the target charging power;

[0011] Determine the target charging and discharging power based on the configured charging and discharging power and the grid connection point power, including:

[0012] Determine the target charging power based on the relationship between the sum of the configured charging power and the grid connection point power and the preset maximum demand power;

[0013] If the sum of the configured charging power and the grid connection point power is less than or equal to the preset maximum demand power, the configured charging power is determined as the target charging power;

[0014] If the sum of the configured charging power and the grid connection point power is greater than the preset maximum demand power, the difference between the preset maximum demand power and the grid connection point power is determined as the target charging power.

[0015] Optionally, according to the target charging and discharging power of the energy storage power station and the preset power range corresponding to the energy storage converter, the number of running energy storage converters is controlled to control the energy storage converter to operate before the corresponding preset power range, and further includes:

[0016] Determining whether the power of the grid connection point deviates from the first historical curve according to the difference between the power of the grid connection point and the historical power of the grid connection point at the same time on the first historical curve; wherein the first historical curve includes the historical power of the grid connection point at different times in a day;

[0017] If not, continue to execute according to the target charging and discharging power of the energy storage power station and the preset power range corresponding to the energy storage converter, and control the running number of the energy storage converter to control the energy storage converter to operate in the corresponding preset power range;

[0018] If so, within the first preset time period after deviating from the first historical curve, the grid connection point power is continuously obtained and the target charging and discharging power is continuously calculated. When the change in the grid connection point power within the first preset time period is less than the first set threshold, the target charging and discharging power of the energy storage power station and the preset power range corresponding to the energy storage inverter are continued to be executed, and the operating number of the energy storage inverter is controlled to control the energy storage inverter to operate in the corresponding preset power range.

[0019] Optionally, according to the target charging and discharging power of the energy storage power station and the preset power range corresponding to the energy storage converter, the number of running energy storage converters is controlled to control the energy storage converter to operate in the corresponding preset power range, including:

[0020] According to the target charging and discharging power of the energy storage power station and the preset power range corresponding to the currently running energy storage converter, it is determined that if the currently running energy storage subsystem can meet the target charging power, the charging power corresponding to the currently running energy storage converter is adjusted within the preset power range;

[0021] When the currently running energy storage subsystem cannot meet the target charging power, the energy storage converter of at least one other energy storage subsystem is controlled to be turned on or off.

[0022] Optionally, before controlling the number of running energy storage converters according to the target charging and discharging power of the energy storage power station and the preset power range corresponding to the energy storage converter to control the energy storage converter to operate in the corresponding preset power range, the method further includes:

[0023] Obtain the rated power of the energy storage converter of the energy storage subsystem, the rated charging power of the battery connected to the energy storage converter, and the current remaining capacity of the energy storage subsystem;

[0024] Determine the charging priority of the energy storage subsystem according to at least one of the rated power of the energy storage converter of the energy storage subsystem, the rated charging power of the battery connected to the converter, and the current remaining capacity of the energy storage subsystem; the charging priority is negatively correlated with the current remaining capacity, and positively correlated with the rated power of the energy storage converter and the rated charging power of the battery;

[0025] According to the target charging and discharging power of the energy storage power station and the preset power range corresponding to the energy storage converter, a corresponding number of energy storage converters are controlled to start and operate in order of priority from high to low, and the energy storage converters are controlled to operate in the corresponding preset power range.

[0026] Optionally, configuring the charge and discharge power includes configuring the discharge power, and the target charge and discharge power includes the target discharge power;

[0027] Determine the target charging and discharging power based on the configured charging and discharging power and the grid connection point power, including:

[0028] When the power at the grid connection point is greater than or equal to 0, the target discharge power is determined based on the configured discharge power and the energy storage dischargeable power corresponding to the energy storage power station discharging to the connected load;

[0029] If the configured discharge power is greater than the energy storage dischargeable power, the energy storage dischargeable power is determined as the target discharge power;

[0030] If the configured discharge power is less than or equal to the energy storage dischargeable power, the configured discharge power is determined as the target discharge power.

[0031] Optionally, before controlling the number of running energy storage converters according to the target charging and discharging power of the energy storage power station and the preset power range corresponding to the energy storage converter to control the energy storage converter to operate in the corresponding preset power range, the method further includes:

[0032] Determine whether the energy storage dischargeable power deviates from the second historical curve according to the difference between the energy storage dischargeable power and the historical energy storage discharge power at the same time on the second historical curve; wherein the second historical curve includes the historical energy storage discharge power of the energy storage power station at different times of the day;

[0033] If not, continue to execute according to the target charging and discharging power of the energy storage power station and the preset power range corresponding to the energy storage converter, and control the operating quantity of the energy storage converter to control the energy storage converter to operate in the corresponding preset power range;

[0034] If so, within a second preset time period after deviating from the second historical curve, the energy storage dischargeable power is continuously obtained and the target charging and discharging power is continuously calculated. When the change in the energy storage dischargeable power within the second preset time period is less than a second set threshold, the target charging and discharging power of the energy storage power station and the preset power range corresponding to the energy storage inverter are continued to be executed, and the operating number of the energy storage inverter is controlled to control the energy storage inverter to operate in the corresponding preset power range.

[0035] Optionally, the target charging and discharging power is determined according to the configured charging and discharging power and the grid connection point power, including:

[0036] When the power at the grid connection point is less than 0 and the energy storage subsystem is in a discharging state, it is determined that the target discharge power of the energy storage power station is less than the current discharge power of the energy storage power station.

[0037] Optionally, according to the target charging and discharging power of the energy storage power station and the preset power range corresponding to the energy storage converter, controlling the operating quantity of the energy storage converter to control the energy storage converter to operate in the corresponding preset power range includes:

[0038] Determine the power average of the maximum power and the minimum power within the preset power range;

[0039] According to the ratio of the target charging and discharging power to the power average, the value obtained by rounding the ratio is determined as the target operating number of the energy storage converter;

[0040] The target number of energy storage converters is controlled to operate within a preset power range.

[0041] Optionally, obtain the configured charging and discharging power of the energy storage power station and the grid connection point power of the energy storage power station, including:

[0042] Obtain the local configured charge and discharge power of the energy storage power station, or receive the configured charge and discharge power issued;

[0043] Obtain the grid-connected power of the grid-connected electricity meter of the energy storage power station.

[0044] Optionally, the energy storage power station includes at least two substations, and the substation includes at least two energy storage subsystems;

[0045] Before controlling the number of running energy storage converters according to the target charging and discharging power of the energy storage power station and the preset power range corresponding to the energy storage converter to control the energy storage converter to operate in the corresponding preset power range, the charging and discharging control method further includes:

[0046] Obtain the current remaining capacity of the substation and the rated power of the energy storage converter;

[0047] According to the target charging and discharging power of the energy storage power station and the preset power range corresponding to the energy storage converter, the number of running energy storage converters is controlled to control the energy storage converter to operate in the corresponding preset power range, including:

[0048] Determining the priority of charging and discharging the substation according to the current remaining capacity of the substation and / or the rated power of the energy storage converter in the substation;

[0049] According to the target charging and discharging power of the energy storage power station and the preset power range corresponding to the energy storage converter, the energy storage converter in the substation is controlled to start and run in order of priority from high to low, and the energy storage converter is controlled to run in the corresponding preset power range.

[0050] According to one aspect of the present invention, there is provided an energy storage power station, comprising an energy management module and at least two energy storage subsystems, the energy storage subsystem comprising an energy storage inverter and a battery connected to the energy storage inverter; the energy management module is connected to the energy storage inverter, and the energy management module is used to control the energy storage inverter of the energy storage power station according to the charge and discharge control method of the energy storage power station of any embodiment of the present invention.

[0051] The charge and discharge control method of the energy storage power station and the energy storage power station of the embodiment of the present invention determine the target charge and discharge power of the energy storage power station according to the configured charge and discharge power and the grid connection point power, so that the determined target charge and discharge power of the energy storage power station can meet the grid connection point power requirement. According to the target charge and discharge power of the energy storage power station and the preset power range corresponding to the energy storage converter, the number of running energy storage converters is controlled to control the energy storage converter to operate in the corresponding preset power range, ensuring that the energy storage converters that are turned on can operate at the power within the corresponding preset power range, thereby improving the working efficiency of the energy storage converter.

[0052] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0054] Figure 1 It is a graph of the power variation of the energy storage subsystem in the energy storage power station within one day;

[0055] Figure 2 It is a structural schematic diagram of an energy storage power station provided by an embodiment of the present invention;

[0056] Figure 3 is a structural schematic diagram of another energy storage power station provided by an embodiment of the present invention;

[0057] Figure 4 It is a flow chart of a charging and discharging control method of an energy storage power station provided by an embodiment of the present invention;

[0058] Figure 5 is a flow chart of another charging and discharging control method of an energy storage power station provided by an embodiment of the present invention;

[0059] Figure 6 is a flow chart of another charging and discharging control method of an energy storage power station provided by an embodiment of the present invention;

[0060] Figure 7 It is a flow chart of another charging and discharging control method of an energy storage power station provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0061] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings 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 should fall within the scope of protection of the present invention.

[0062] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0063] As described in the background technology, there is a problem that the power range of PCS operation leads to low efficiency of energy storage power stations. Figure 1 This is a diagram of the power change of the energy storage subsystem in the energy storage power station within a day. Figure 1In one day, the battery in the energy storage subsystem is charged in the first time period t1, the third time period t3 and the fifth time period t5, and the power of the energy storage converter is negative; in the second time period t2 and the fourth time period t4, the battery in the energy storage subsystem is discharged, and the power of the energy storage converter is positive. Among them, the first time period t1 and the fifth time period t5 are low-power consumption periods, the third time period t3 is a normal period, and the second time period t2 and the fourth time period t4 are peak power consumption periods. Figure 1 In the time period circled in red, since the electricity demand during normal times is greater than that during off-peak times, when charging the batteries of the energy storage subsystem during normal times, if the energy storage inverters of all the energy storage subsystems in the energy storage power station are turned on and running, the charging power of the energy storage inverter will be low, that is, the energy storage inverter is charged at a low power, which makes the working efficiency of the PCS low in the power range where the energy storage inverter works. As described in the background technology, the working efficiency of the PCS includes the conversion efficiency of the PCS, and the conversion efficiency of the PCS is equal to the ratio of the discharge amount to the charge amount of the energy storage inverter after the PCS is charged and discharged once. Exemplarily, the energy storage inverter in the energy storage power station absorbs 100kWh of electricity from the power grid to charge the battery, but ultimately only discharges 80kWh of electricity, then the conversion efficiency of the energy storage inverter is 80%. An embodiment of the present invention provides a charging and discharging control method for an energy storage power station, Figure 2 is a structural schematic diagram of an energy storage power station provided by an embodiment of the present invention, Figure 3 is a schematic diagram of another energy storage power station provided by an embodiment of the present invention, referring to Figure 2 and Figure 3 , wherein the energy storage power station includes at least two energy storage subsystems 10, the energy storage subsystem 10 includes an energy storage inverter 11 and a battery 12 connected to the energy storage inverter 11, and the energy storage power station can be a user-side energy storage power station. The battery 12 can be in the form of an independent battery cabinet, or it can be one or more battery clusters in a PCS supporting energy storage container. The energy storage power station also includes an energy management module 20, which is communicatively connected to the energy storage inverter 11. The charge and discharge control method can be used to control the charge and discharge state of the energy storage power station, and specifically can be used to control the number of energy storage inverters 11 in the energy storage power station that are turned on and running, and the charge and discharge power of the energy storage inverter 11 that is turned on and running, to ensure that the energy storage inverter 11 operates in a preset power range. The charge and discharge control method can be executed by the energy management module 20. Figure 4 is a flow chart of a charging and discharging control method of an energy storage power station provided by an embodiment of the present invention, with reference to Figure 4 , the charging and discharging control method of the energy storage power station includes:

[0064] S110: Obtain the configured charging and discharging power of the energy storage power station and the grid connection point power of the energy storage power station.

[0065] Among them, the configuration of the charging and discharging power may be the charging and discharging power allocated to the energy storage power station. The configuration of the charging and discharging power may include configuring the charging power and configuring the discharging power. In this step, the configuration of the charging and discharging power and the grid connection point power of the energy storage power station may be obtained in real time. At different time points, the configuration of the charging and discharging power may change or remain unchanged. At different time points, the grid connection point power of the energy storage power station may change or remain unchanged.

[0066] In an optional embodiment, the local configured charge and discharge power of the energy storage power station can be obtained. Specifically, the energy storage power station includes an energy management module, and the energy management module can be configured with an operation strategy, which includes the configured charge and discharge power at different times of the day. Optionally, the configuration charge and discharge power is set according to different time periods in the operation strategy. Optionally, the configuration charge and discharge power at different times in the same time period is the same, and the configuration charge and discharge power in different time periods is different. Exemplarily, the configuration charge and discharge power corresponding to the peak power consumption period and the low power consumption period is different, and the configuration charge and discharge power at each moment in the peak power consumption period is the same. In another optional embodiment of the present invention, the energy management module can receive the configuration charge and discharge power issued from the upper controller, and the upper controller can be a device for issuing instructions from the dispatching center, and the instruction includes the configuration charge and discharge power. The upper controller can issue the corresponding configuration charge and discharge power to the energy storage power station based on the load connected to the dispatched regional power grid and the overall situation of the energy storage power station.

[0067] Optionally, obtaining the grid connection point power of the energy storage power station may include obtaining the grid connection point power of the grid connection point meter of the energy storage power station. Specifically, the energy management module of the energy storage power station may be connected to the grid connection point meter in communication, and then obtain the grid connection point power from the grid connection point meter. Wherein, when the grid connection point power is greater than 0, the energy storage power station absorbs power from the power grid; when the grid connection point power is less than 0, the power generated by the energy storage power station flows back to the power grid.

[0068] S120: Determine the target charging and discharging power of the energy storage power station according to the configured charging and discharging power and the grid connection point power.

[0069] Specifically, when determining the target charge and discharge power of the energy storage power station, determining the target charge and discharge power only based on the configured charge and discharge power may result in the power of the grid connection point not being able to meet the requirements when the energy storage power station is running at the target charge and discharge power. Exemplarily, when the charging power of the energy storage power station is too large, resulting in excessive power at the grid connection point, the user is required to pay additional excess charges. Therefore, when determining the target charge and discharge power, it is possible to ensure that the power at the grid connection point does not exceed the preset maximum demand power as one of the determination conditions. However, when the discharge power of the energy storage power station is too large and exceeds the power required by the load, it will cause the power to flow back to the grid and affect the power quality. Therefore, when determining the target charge and discharge power, it is possible to ensure that the power at the grid connection point is greater than or equal to 0 as one of the determination conditions, that is, to ensure that the power of the energy storage power station does not flow back to the grid. By determining the target charge and discharge power of the energy storage power station based on the configured charge and discharge power and the grid connection point power, the configured charge and discharge power can be determined as the target charge and discharge power when the configured charge and discharge power meets the grid connection point power requirements; when the configured charge and discharge power cannot meet the grid connection point power requirements, the configured charge and discharge power is adjusted to obtain the target charge and discharge power.

[0070] S130. According to the target charging and discharging power of the energy storage power station and the preset power range corresponding to the energy storage converter, control the operating number of the energy storage converter to control the energy storage converter to operate in the corresponding preset power range.

[0071] Among them, the preset power interval corresponding to the energy storage inverter can be set according to the relationship between the power and working efficiency of the energy storage inverter. Optionally, the relationship between the power and working efficiency of the energy storage inverter is obtained through experimental testing of the energy storage inverter, and the power interval corresponding to the higher working efficiency of the energy storage inverter is determined as the preset power interval of the energy storage inverter, and the preset power interval corresponding to the energy storage inverter is stored in the energy management module. Among them, the power interval of the energy storage inverter is related to the type and / or model. The working efficiency of the energy storage inverter includes the conversion efficiency of the energy storage inverter. The power interval with higher working efficiency may include a power interval with a conversion efficiency greater than or equal to a preset percentage. The preset percentage may be 70%, 82%, 90% or other percentages.

[0072] In this step, according to the target charging and discharging power of the energy storage power station and the preset power range corresponding to the energy storage inverter, the target number of energy storage inverters that can be turned on and run so that they can all operate in the corresponding preset power range is determined, and the target number of energy storage inverters is controlled to be turned on and run. By allocating the power of the energy storage inverters that are turned on and run, it is ensured that the energy storage inverters that are turned on and run can all operate at a power within the corresponding preset power range, thereby improving the working efficiency of the energy storage inverter.

[0073] The charge and discharge control method of the energy storage power station according to the embodiment of the present invention can be applied to Figure 2 The energy storage power station shown can also be applied to Figure 3 The energy storage power station shown. Figure 2 The energy management module in the energy storage power station shown can communicate directly with the PCS of the energy storage subsystem, and directly allocate the power of the PCS according to the target charging and discharging power corresponding to the energy storage power station, so that the energy storage converter in the energy storage power station operates in a preset power range. Figure 3 In the energy storage power station shown, the energy storage power station may include at least two substations, and each substation may include at least two energy storage subsystems. The energy management module may include a main management module 21 and a slave management module 22, wherein each substation may be provided with a slave management module 22. The main management module 21 may allocate the substation charge and discharge power corresponding to the substation to the slave management module 22 according to the target charge and discharge power corresponding to the energy storage power station, and the slave management module 22 communicates with the PCS of the energy storage subsystem in the substation and may control the operating status of the PCS. The slave management module 22 may allocate the power of the PCS in the substation according to the substation charge and discharge power allocated by the main management module 21, so that the energy storage converter in the substation operates in a preset power range.

[0074] The charge and discharge control method of the energy storage power station of this embodiment determines the target charge and discharge power of the energy storage power station according to the configured charge and discharge power and the grid connection point power, so that the determined target charge and discharge power of the energy storage power station can meet the grid connection point power requirement. According to the target charge and discharge power of the energy storage power station and the preset power range corresponding to the energy storage converter, the number of running energy storage converters is controlled to control the energy storage converter to operate in the corresponding preset power range, ensuring that the energy storage converters that are turned on can operate at the power within the corresponding preset power range, thereby improving the working efficiency of the energy storage converter.

[0075] In some optional embodiments of the present invention, configuring the charge and discharge power includes configuring the charging power, and the target charge and discharge power includes the target charging power.

[0076] Figure 5 is a flow chart of another charging and discharging control method of an energy storage power station provided by an embodiment of the present invention, with reference to Figure 5 , the charging and discharging control method of the energy storage power station includes:

[0077] S210: Obtain the configured charging and discharging power of the energy storage power station and the grid connection point power of the energy storage power station.

[0078] S220: Determine the target charging power according to the relationship between the sum of the configured charging power and the grid connection point power and the preset maximum demand power.

[0079] Among them, if the sum of the configured charging power and the grid connection point power is less than or equal to the preset maximum demand power, the configured charging power will be determined as the target charging power; if the sum of the configured charging power and the grid connection point power is greater than the preset maximum demand power, the difference between the preset maximum demand power and the grid connection point power will be determined as the target charging power.

[0080] Among them, the preset maximum demand power can be pre-stored in the energy management module. Specifically, in addition to the power that the energy storage station needs to absorb from the power grid for battery charging, the load may also absorb power from the power grid. When the energy storage station is not charging, the grid connection point power can be equal to the power consumption of the energy storage station load. In this step, based on the principle that the total power absorbed by the energy storage station from the power grid does not exceed the preset maximum demand power, the target charging power corresponding to the energy storage station is determined according to the relationship between the sum of the configured charging power and the grid connection point power and the preset maximum demand. It can ensure that the sum of the determined target charging power and the grid connection point power will not exceed the preset maximum demand power, so that the grid connection point power of the energy storage station after the energy storage station in the energy storage station operates at the target charging power will not exceed the preset maximum demand power, thereby ensuring that the power absorbed by the energy storage station from the power grid will not exceed the demand, so that users do not need to pay additional excess electricity charges, while meeting grid compliance, and better economic efficiency.

[0081] S230. According to the target charging power of the energy storage power station and the preset power range corresponding to the energy storage inverter, control the operating number of the energy storage inverter to control the energy storage inverter to operate in the corresponding preset power range.

[0082] Among them, the preset power range includes a preset charging power range corresponding to the energy storage inverter when charging the battery. In S230, according to the target charging power of the energy storage power station and the preset charging power range corresponding to the energy storage inverter, the operating number of the energy storage inverter is controlled and the power of the energy storage inverter is allocated, so that the energy storage inverter can operate in the corresponding preset charging power range to ensure the working efficiency of the energy storage inverter.

[0083] Figure 6 is a flow chart of another charging and discharging control method of an energy storage power station provided by an embodiment of the present invention, with reference to Figure 6 , the charging and discharging control method of the energy storage power station includes:

[0084] S310: Obtain the configured charging and discharging power of the energy storage power station and the grid connection point power of the energy storage power station.

[0085] S320: Determine the target charging power according to the relationship between the sum of the configured charging power and the grid connection point power and the preset maximum demand power.

[0086] S330. Determine whether the grid connection point power deviates from the first historical curve according to the difference between the grid connection point power and the historical power of the grid connection point at the same time on the first historical curve.

[0087] The first historical curve includes the historical power of the grid connection point at different times in a day. The first historical curve can be obtained based on the statistical analysis of the power of the grid connection point over a period of time.

[0088] If not, continue to execute S350;

[0089] If so, within the first preset time period after deviating from the first historical curve, the grid point power is continuously obtained and the target charging and discharging power is continuously calculated, and S340 is executed, and it is determined whether the change in the grid point power is less than the first set threshold value based on the grid point power within the first preset time period. If so, continue to execute S350.

[0090] Specifically, some abnormal situations may occur during the operation of the energy storage power station, such as a sudden power failure of the load. When it is determined that there is no abnormality, the load may be powered on again in a short time. When a large load suddenly loses power, the load power will suddenly drop, and accordingly, the grid power will drop, and the rechargeable power of the energy storage power station will suddenly increase, where the rechargeable power of the energy storage power station is equal to the difference between the preset maximum demand power and the grid power. The fluctuation of the load power will affect the grid power, and then affect the target charging power, and accordingly, it will affect the number of energy storage inverters that are turned on and running in the energy storage power station. Therefore, before S350, it is first possible to judge whether there is an abnormal fluctuation in the grid power. Specifically, it can be determined whether the grid power deviates from the first historical curve based on the difference between the grid power and the historical power of the grid at the same time in the first historical curve corresponding to the grid power. Optionally, whether the grid point power deviates from the first historical curve is determined based on the difference or ratio between the grid point power obtained in real time and the historical power of the grid point at the same time in the first historical curve corresponding to the grid point power. When it does not deviate from the first historical curve, the target charging power can be determined based on the grid point power; when it deviates from the first historical curve, it is necessary to conduct a stability investigation on the grid point power for a period of time to avoid the state transition of a large load in the energy storage power station between power off and power on in a short period of time, resulting in a rapid change in the grid point power, causing the target charging power to change too quickly, resulting in an adverse effect on the energy storage inverter caused by the rapid transition between the on and off states of the energy storage inverter in the energy storage power station, and reducing the frequent on and off state transitions of the energy storage inverter in a short period of time. Among them, the stability inspection of the grid connection point power for a period of time can be based on the grid connection point power within the first preset time to determine the relationship between the change in the grid connection point power and the first set threshold. For example, when the change in the grid connection point power within the first preset time is less than the first set threshold, the grid connection point power is determined to be stable, and then the target charging power can be determined according to the grid connection point power after stabilization, for example, the target charging power can be determined according to the grid connection point power at the last moment of the first preset time; when the change in the grid connection point power within the first preset time is greater than or equal to the first set threshold, it is determined that the grid connection point power is unstable, and the charging and discharging control method can be stopped, and the energy storage power station is checked for failure. Among them, the first set threshold is set and adjusted according to actual needs.

[0091] S350. According to the target charging and discharging power of the energy storage power station and the preset power range corresponding to the energy storage converter, control the operating number of the energy storage converter to control the energy storage converter to operate in the corresponding preset power range.

[0092] Optionally, S230 and S350 may include:

[0093] According to the target charging and discharging power of the energy storage power station and the preset power range corresponding to the currently running energy storage inverter, it is determined that when the currently running energy storage subsystem can meet the target charging power, the charging power corresponding to the currently running energy storage inverter is adjusted within the preset power range; when the currently running energy storage subsystem cannot meet the target charging power, the energy storage inverter of at least one other energy storage subsystem is controlled to be turned on or off.

[0094] The energy storage converter is turned on to start the operation of the energy storage converter and work at a certain power. The energy storage converter is turned off to shut down the energy storage converter.

[0095] Optionally, when the preset power ranges corresponding to the energy storage inverters of each energy storage subsystem in the energy storage power station are the same, it is determined whether the number of currently operating energy storage inverters can meet the target charging power based on the relationship between the target charging power and the product of the number of currently operating energy storage inverters in the energy storage power station and the maximum power within the preset power range, and the relationship between the target charging power and the product of the number of currently operating energy storage inverters in the energy storage power station and the minimum power within the preset power range. When the target charging power is greater than the product of the number of currently operating energy storage inverters in the energy storage power station and the maximum power value in the preset power range, that is, when the number of currently operating energy storage inverters is at the maximum power value in the preset power range, the total charging power of the energy storage power station will still be less than the target charging power, indicating that the number of currently operating energy storage inverters is too small, and at least one other energy storage inverter needs to be controlled to start running to ensure that each operating energy storage inverter can operate within the preset power range; when the target charging power is less than the product of the number of currently operating energy storage inverters in the energy storage power station and the minimum power value in the preset power range, that is, when the number of currently operating energy storage inverters is at the minimum power value in the preset power range, the total charging power of the energy storage power station will still be greater than the target charging power, indicating that the number of currently operating energy storage inverters is excessive, and at least one currently operating energy storage inverter needs to be controlled to be turned off to ensure that the remaining operating energy storage inverters can operate within the preset power range. When the target charging power is less than or equal to the product of the number of currently operating energy storage inverters in the energy storage power station and the maximum power value in the preset power range, and the target charging power is greater than or equal to the product of the number of currently operating energy storage inverters in the energy storage power station and the minimum power value in the preset power range, it means that the number of currently operating energy storage inverters can meet the target charging power, and the charging power corresponding to the currently operating energy storage inverter can be adjusted within the preset power range. Without controlling other energy storage inverters to open and close, the operating energy storage inverter can be guaranteed to operate within the preset power range, thereby ensuring the working efficiency of the energy storage inverter.

[0096] Optionally, before the above S230 or S350, the method further includes:

[0097] Obtain the rated power of the energy storage converter of the energy storage subsystem, the rated charging power of the battery connected to the energy storage converter, and the current remaining capacity of the energy storage subsystem;

[0098] Determine the charging priority of the energy storage subsystem according to at least one of the rated power of the energy storage converter of the energy storage subsystem, the rated charging power of the battery connected to the energy storage converter, and the current remaining capacity of the energy storage subsystem; the charging priority is negatively correlated with the current remaining capacity, and positively correlated with the rated power of the energy storage converter and the rated charging power of the battery;

[0099] According to the target charging and discharging power of the energy storage power station and the preset power range corresponding to the energy storage converter, a corresponding number of energy storage converters are controlled to start and operate in order of priority from high to low, and the energy storage converters are controlled to operate in the corresponding preset power range.

[0100] Among them, the current remaining capacity of the energy storage subsystem can be equal to the product of the rated capacity of the energy storage subsystem and the current battery state of charge (State of Charge, SOC) of the energy storage subsystem. Specifically, due to environmental factors or other factors, the actual power of the energy storage inverter may not reach the rated power, but the larger the rated power of the energy storage inverter, the larger the actual power of the energy storage inverter. In addition, the actual power of the energy storage inverter will also be affected by the rated charging power of the battery connected to the energy storage inverter. When the rated charging power of the battery connected to the energy storage inverter is less than the rated power of the energy storage inverter, the energy storage inverter cannot work at the rated power, and can only work at the rated charging power of the battery at most. When charging the energy storage subsystem, the charging priority of the energy storage subsystem can be determined according to the rated power of the energy storage inverter and / or the rated charging power of the battery connected to the energy storage inverter, so as to ensure that the maximum power that the energy storage inverter can reach is higher, and it is easier to ensure that the energy storage inverter can work in a preset power range, thereby ensuring the working efficiency of the energy storage inverter. In addition, when determining the charging priority of the energy storage subsystem, the remaining capacity of the energy storage subsystem is also taken into account, and the energy storage subsystem with smaller remaining capacity is charged first to ensure that the energy storage subsystem can be kept in a charged state for a longer period of time, so that there is no need to change the on and off state of the energy storage inverter in a short period of time, which is conducive to simplifying the control of the energy storage power station.

[0101] In some optional embodiments of the present invention, configuring the charge and discharge power includes configuring the discharge power, and the target charge and discharge power includes the target discharge power. Figure 7 is a flow chart of another charging and discharging control method of an energy storage power station provided by an embodiment of the present invention, with reference to Figure 7, the charging and discharging control method of the energy storage power station includes:

[0102] S410: Obtain the configured charging and discharging power of the energy storage power station and the grid connection point power of the energy storage power station.

[0103] S420: When the power at the grid connection point is greater than or equal to 0, determine the target discharge power according to the configured discharge power and the energy storage dischargeable power corresponding to the discharge of the energy storage power station to the connected load.

[0104] Among them, if the configured discharge power is greater than the energy storage dischargeable power, the energy storage dischargeable power is determined as the target discharge power; if the configured discharge power is less than or equal to the energy storage dischargeable power, the configured discharge power is determined as the target discharge power.

[0105] Specifically, the energy storage dischargeable power can be determined based on the total power of the loads connected to the energy storage power station and the power of the currently running loads. Among them, the total power of the loads connected to the energy storage power station can be equal to the sum of the rated powers of the loads connected to the energy storage power station, and the power of the currently running loads can be equal to the sum of the rated powers of the currently running loads. In some optional embodiments, the difference between the total power of the loads connected to the energy storage power station and the power of the currently running loads can be determined as the energy storage dischargeable power. In other optional embodiments, the energy storage power station is also connected to a photovoltaic power generation module. In this case, the energy storage dischargeable power can be equal to the difference between the total power of the loads connected to the energy storage power station and the power of the currently running loads minus the power generated by the photovoltaic power generation module.

[0106] In S420, the premise for determining the target discharge power according to the relationship between the configured discharge power and the energy storage dischargeable power is that the power at the grid connection point is greater than or equal to 0, that is, under the premise that no electricity from the energy storage power station flows back to the grid, the target discharge power corresponding to the energy storage power station is determined according to the relationship between the configured discharge power and the energy storage dischargeable power, and discharge can be performed to the load according to the scheduling requirements when no electricity flows back to the grid. By determining the target discharge power corresponding to the energy storage power station according to the relationship between the configured discharge power and the energy storage dischargeable power, it can be ensured that the target discharge power will not exceed the energy storage dischargeable power, and thus when the energy storage power station is operating at the target discharge power, no electricity will flow back to the grid, so that when the energy storage subsystem of the energy storage power station discharges the load, it will not affect the power quality of the grid.

[0107] S430: When the power at the grid connection point is less than 0 and the energy storage subsystem is in a discharging state, determine that the target discharge power of the energy storage power station is less than the current discharge power of the energy storage power station.

[0108] The target discharge power and current discharge power are both for the energy storage power station. For example, the current discharge power is equal to the sum of the current discharge powers of each energy storage subsystem in the energy storage power station. When the power at the grid connection point is less than 0, it means that the energy storage power station has already had electricity flowing back to the grid. In this case, the discharge power corresponding to the energy storage power station needs to be reduced. When the power at the grid connection point is less than 0, if the energy storage subsystem is in a discharging state, it is determined that the target discharge power of the energy storage power station is less than the current discharge power, thereby reducing the total discharge power corresponding to the energy storage power station, eliminating the reverse flow of electricity from the energy storage power station to the grid, and ensuring the quality of electricity.

[0109] On the basis of the above technical solution, optionally, after S420 and S430, it also includes: determining whether the energy storage dischargeable power deviates from the second historical curve according to the difference between the energy storage dischargeable power and the historical energy storage discharge power at the same time on the second historical curve; wherein the second historical curve includes the historical energy storage discharge power of the energy storage power station at different times of the day; if not, continue to execute S440; if yes, within a second preset time after deviating from the second historical curve, continuously obtain the energy storage dischargeable power and continuously calculate the target charge and discharge power, and when the change in the energy storage dischargeable power within the second preset time is less than the second set threshold, continue to execute S440.

[0110] The second historical curve includes the energy storage discharge power at different times of the day. The second historical curve can be obtained based on the statistical analysis of the energy storage discharge power over a period of time.

[0111] As described in the above embodiment, some abnormal situations may occur during the operation of the energy storage power station, such as a sudden power failure of the load. When it is determined that there is no abnormality, the load may be powered on again in a short time. In this case, the load power will first decrease, causing the energy storage dischargeable power to deviate from the second historical curve. The load power will rise again in a short time, causing the energy storage dischargeable power to return to the vicinity of the second historical curve. In this embodiment, before determining the energy storage dischargeable power, it is first possible to determine whether there is an abnormal fluctuation in the energy storage dischargeable power in the energy storage power station. Specifically, it is determined whether the energy storage dischargeable power deviates from the second historical curve based on the difference between the energy storage dischargeable power and the historical energy storage discharge power at the same time on the second historical curve. Optionally, it is determined whether the energy storage dischargeable power deviates from the second historical curve based on the difference or ratio between the energy storage dischargeable power and the historical energy storage discharge power at the same time on the second historical curve and the size relationship of the second set threshold value. In the case of not deviating from the second historical curve, the target discharge power can be determined based on the configured discharge power and the energy storage dischargeable power when the grid connection point power is greater than or equal to 0. In the case of deviation from the second historical curve, it is necessary to conduct a stability inspection on the energy storage dischargeable power for a period of time to avoid abnormal fluctuations in the energy storage dischargeable power caused by changes in load power due to state transitions between power-off and power-on of a large load in the energy storage power station in a short period of time, resulting in frequent fluctuations in the target discharge power, and adverse effects on the energy storage inverter caused by the state transitions of opening and closing the energy storage inverter in a short period of time, thereby reducing the frequent state transitions of opening and closing the energy storage inverter in a short period of time.

[0112] Among them, the stability inspection of the energy storage dischargeable power for a period of time can be based on the energy storage dischargeable power within the second preset time to determine the relationship between the change in the energy storage dischargeable power and the second set threshold. For example, when the energy storage dischargeable power within the second preset time is less than the second set threshold, the energy storage dischargeable power is determined to be stable, and then the target discharge power can be determined according to the energy storage dischargeable power after stabilization, for example, the target discharge power can be determined according to the energy storage dischargeable power at the last moment of the second preset time; when the change in the energy storage dischargeable power within the second preset time is greater than or equal to the second set threshold, it is determined that the energy storage dischargeable power is unstable, and the charging and discharging control method can be stopped, and the energy storage power station is checked for failure. Among them, the second set threshold is set and adjusted according to actual needs.

[0113] S440. According to the target discharge power of the energy storage power station and the preset power range corresponding to the energy storage converter, control the operating number of the energy storage converter to control the energy storage converter to operate in the corresponding preset power range.

[0114] Among them, the preset power range includes a preset discharge power range corresponding to the energy storage inverter when the battery discharges to the load. In S440, according to the target discharge power of the energy storage power station and the preset discharge power range corresponding to the energy storage inverter, the operating number of the energy storage inverter is controlled and the power of the energy storage inverter is allocated, so that the energy storage inverter can operate in the corresponding preset discharge power range to ensure the working efficiency of the energy storage inverter.

[0115] On the basis of the above embodiments, optionally, in the above embodiments, S130, S230, S350 and S440 include: determining the power average of the maximum power and the minimum power within the preset power range; according to the ratio of the target charge and discharge power to the power average, determining the value obtained by rounding the ratio as the target operating number of the energy storage inverter; controlling the target operating number of energy storage inverters to operate within the preset power range.

[0116] The power average of the maximum power and the minimum power within the preset power range can be expressed by the following formula:

[0117] The preset power range is [P best_low ,P best_upper ], P best_upper Indicates the maximum power within the preset power range, P best_low Indicates the minimum power within the preset power range. The power average of the maximum power and the minimum power. Then, according to the target charge and discharge power divided by the power average and rounded, if the quotient of the target charge and discharge power divided by the power average is an integer, the integer quotient is determined as the target operating number of the energy storage converter in the energy storage power station; if the quotient of the target charging power divided by the power average is not an integer, the integer obtained by rounding up or rounding down the quotient of the target charging power and the power average is determined as the target operating number of the energy storage converter in the energy storage power station. Among them, the selection of rounding up or rounding down for the quotient of the target charging power and the power average can be selected according to the actual situation. When the integer obtained by rounding up can satisfy the requirement that all the energy storage converters that are turned on and running work in the preset power range, rounding up is selected, and when the integer obtained by rounding down can satisfy the requirement that all the energy storage converters that are turned on and running work in the preset power range, rounding down is selected. When both rounding up and rounding down can satisfy the requirement that all the energy storage converters that are turned on and running work in the preset power range, either rounding up or rounding down can be selected.

[0118] In this embodiment, by rounding off the ratio of the target charge and discharge power to the power mean, the target operating number of the energy storage inverter is determined as the value obtained by rounding the ratio, so that when the target charge and discharge power changes slightly, the operating number of the energy storage inverter of the energy storage power station does not need to be adjusted. Compared with determining the target operating number of the energy storage inverter according to the ratio of the target charge and discharge power to the maximum power or the minimum power, a certain margin can be left, and the frequency of switching the operating state of the energy storage inverter can be reduced, which is beneficial to ensuring the working reliability of the energy storage inverter.

[0119] like Figure 2 As shown, optionally, the energy storage power station includes at least two substations, and the substation includes at least two energy storage subsystems. Optionally, before S130, S230, S350 and S440, the charge and discharge control method further includes: obtaining the current remaining capacity of the substation and the rated power of the energy storage converter.

[0120] Among them, the remaining capacity of the substation is equal to the sum of the remaining capacities of each energy storage subsystem in the substation.

[0121] S130, S230, S350 and S440 may include: determining the priority of charging and discharging the substation according to the current remaining capacity of the substation and / or the rated power of the energy storage inverter in the substation; according to the target charging and discharging power of the energy storage power station and the preset power range corresponding to the energy storage inverter, controlling the energy storage inverter in the substation to start and operate in order from high to low priority, and controlling the energy storage inverter to operate in the corresponding preset power range.

[0122] Among them, the larger the current remaining capacity of the substation, the lower the priority of the substation for charging, and the higher the priority of the substation for discharging; in this way, it can ensure that the substation maintains the charging or discharging state for a longer time, and reduce the frequent state conversion of the energy storage inverter on and off. The larger the sum of the rated powers of the energy storage inverters in the substation, the higher the charging priority of the substation. According to the determined priority of charging and discharging of the substation, the operation of the energy storage inverter in the substation is controlled in order from high to low priority, and the energy storage inverter is controlled to operate in the corresponding preset power range, so that the energy storage inverter can work in the corresponding preset power range to ensure the working efficiency of the energy storage inverter.

[0123] Combination Figure 2 and Figure 3 The embodiment of the present invention further provides an energy storage power station, including an energy management module 20 and at least two energy storage subsystems 10, the energy storage subsystem 10 including an energy storage inverter 11 and a battery 12 connected to the energy storage inverter 11; the energy management module 20 is connected to the energy storage inverter 11, and the energy management module 20 is used to control the energy storage inverter 11 of the energy storage power station according to the charge and discharge control method of the energy storage power station of any of the above embodiments of the present invention.

[0124] The charge and discharge control method of the energy storage power station of the present invention is described below with specific examples.

[0125] Example 1

[0126] by Figure 2 Taking the energy storage power station shown as an example, the energy storage power station includes four energy storage subsystems, and the energy storage subsystems have the same specifications and configurations (that is, the PCS rated power, energy storage battery capacity and other parameters are the same). For a 2MW / 5MWh energy storage project, the load is at a high level during the afternoon period from 15:00 to 16:00, and there is only 350kW of rechargeable power (that is, the target charging power), otherwise the system will face the risk of over-demand; the rated power of the PCS in this system is 500kW, and the preset power range is [200, 400]kW. In this scenario, the energy management module only notifies one of the PCSs to run, and the other PCSs are in standby mode, so that the running PCS can run within the preset power range to ensure the working efficiency of the PCS.

[0127] During the period of 16:00-17:00, the load power dropped slightly, and the rechargeable power of the energy storage reached around 500kW. At this time, the energy management module notified the two PCSs to start running, so that the running PCSs could run within the preset power range to ensure the working efficiency of the PCSs.

[0128] After 18:00, the electricity price enters the peak period, and the EMS notifies the energy storage subsystem to discharge. If some energy storage subsystems cannot discharge because they are not charged, the EMS will not notify these energy storage subsystems to turn on.

[0129] Example 2

[0130] by Figure 3 Taking the energy storage power station shown in the figure as an example, the energy storage power station includes multiple substations, and each substation has different specifications (such as PCS power and energy storage battery capacity). A 100MW / 500MWh energy storage project is divided into two energy storage substations according to the geographical location of the park, namely substation 1 and substation 2. Substation 1 includes two energy storage subsystems with a battery capacity of 200MWh and a total rated power of 40MW; substation 2 includes three energy storage subsystems with a battery capacity of 300MWh and a total rated power of 60MW.

[0131] During a normal business period, the rechargeable power (also known as the target charging power) is 30 MW, and the preset power range is [10, 20] kW. At this time, the energy management module selects substation 2 with a larger rated power to start operation; based on the rechargeable power of 30 MW, two energy storage subsystems are selected from the energy management module to start operation, so that the energy storage inverter operates in the preset power range.

[0132] When the main management module determines that the target charging power reaches about 40MW according to the first historical curve, it notifies substation 2 to start all energy storage subsystems for charging.

[0133] According to the first historical curve of the power station, the main management module notifies substation 1 to start some or all energy storage subsystems for charging. When the main management module determines that the rechargeable power value of the energy storage power station is narrowing, it will decide to shut down some energy storage subsystems based on the PCS power and the rechargeable power of the battery.

[0134] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0135] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A charging and discharging control method for an energy storage power station, characterized in that: The energy storage power station includes at least two energy storage subsystems, and the energy storage subsystem includes an energy storage converter and a battery connected to the energy storage converter; the charge and discharge control method includes: Obtaining the configured charging and discharging power of the energy storage power station and the grid connection point power of the energy storage power station; Determining the target charging and discharging power of the energy storage power station according to the configured charging and discharging power and the grid connection point power; According to the target charging and discharging power of the energy storage power station and the preset power range corresponding to the energy storage converter, the operating number of the energy storage converter is controlled to control the energy storage converter to operate in the corresponding preset power range.

2. The charge and discharge control method of the energy storage power station according to claim 1, characterized in that: The configuration of the charge and discharge power includes configuring the charging power, and the target charge and discharge power includes a target charging power; The determining the target charging and discharging power according to the configured charging and discharging power and the grid connection point power includes: Determine the target charging power according to the relationship between the sum of the configured charging power and the grid connection point power and the preset maximum demand power; If the sum of the configured charging power and the grid connection point power is less than or equal to the preset maximum demand power, the configured charging power is determined as the target charging power; If the sum of the configured charging power and the grid connection point power is greater than the preset maximum demand power, the difference between the preset maximum demand power and the grid connection point power is determined as the target charging power.

3. The charge and discharge control method of the energy storage power station according to claim 2, characterized in that: The method of controlling the number of running energy storage converters according to the target charging and discharging power of the energy storage power station and the preset power interval corresponding to the energy storage converter, so as to control the energy storage converter to run before the corresponding preset power interval, further includes: Determine whether the grid connection point power deviates from the first historical curve according to the difference between the grid connection point power and the historical power of the grid connection point at the same time on the first historical curve; wherein the first historical curve includes the historical power of the grid connection point at different times in a day; If not, continue to execute the control of the running number of the energy storage converter according to the target charging and discharging power of the energy storage power station and the preset power interval corresponding to the energy storage converter, so as to control the energy storage converter to operate in the corresponding preset power interval; If so, within a first preset time period after deviating from the first historical curve, the grid connection point power is continuously obtained and the target charging and discharging power is continuously calculated, and when the change in the grid connection point power within the first preset time period is less than a first set threshold, the target charging and discharging power of the energy storage power station and the preset power range corresponding to the energy storage inverter are continued to be executed, and the operating number of the energy storage inverter is controlled to control the energy storage inverter to operate in the corresponding preset power range.

4. The charge and discharge control method of the energy storage power station according to claim 2 or 3, characterized in that: According to the target charging and discharging power of the energy storage power station and the preset power range corresponding to the energy storage converter, controlling the running number of the energy storage converter to control the energy storage converter to operate in the corresponding preset power range includes: According to the target charging and discharging power of the energy storage power station and the preset power range corresponding to the currently running energy storage converter, it is determined that if the currently running energy storage subsystem can meet the target charging power, the charging power corresponding to the currently running energy storage converter is adjusted within the preset power range; When the currently running energy storage subsystem cannot meet the target charging power, the energy storage converter of at least one other energy storage subsystem is controlled to be turned on or off.

5. The charge and discharge control method of the energy storage power station according to claim 2 or 3, characterized in that: Before controlling the running number of the energy storage converter according to the target charging and discharging power of the energy storage power station and the preset power interval corresponding to the energy storage converter to control the energy storage converter to operate in the corresponding preset power interval, the method further includes: Acquire the rated power of the energy storage converter of the energy storage subsystem, the rated charging power of the battery connected to the energy storage converter, and the current remaining capacity of the energy storage subsystem; Determine the charging priority of the energy storage subsystem according to at least one of the rated power of the energy storage converter of the energy storage subsystem, the rated charging power of the battery connected to the converter, and the current remaining capacity of the energy storage subsystem; the charging priority is negatively correlated with the current remaining capacity, and positively correlated with the rated power of the energy storage converter and the rated charging power of the battery; According to the target charging and discharging power of the energy storage power station and the preset power range corresponding to the energy storage inverter, a corresponding number of the energy storage inverters are controlled to start and operate in order of priority from high to low, and the energy storage inverters are controlled to operate in the corresponding preset power range.

6. The charge and discharge control method of the energy storage power station according to claim 1, characterized in that: The configured charge and discharge power includes configured discharge power, and the target charge and discharge power includes target discharge power; The determining the target charging and discharging power according to the configured charging and discharging power and the grid connection point power includes: When the grid connection point power is greater than or equal to 0, the target discharge power is determined according to the configured discharge power and the energy storage dischargeable power corresponding to the discharge of the energy storage power station to the connected load; Wherein, if the configured discharge power is greater than the energy storage dischargeable power, the energy storage dischargeable power is determined as the target discharge power; If the configured discharge power is less than or equal to the energy storage dischargeable power, the configured discharge power is determined as the target discharge power.

7. The charge and discharge control method of the energy storage power station according to claim 6, characterized in that: Before controlling the operating quantity of the energy storage converter according to the target charging and discharging power of the energy storage power station and the preset power interval corresponding to the energy storage converter to control the energy storage converter to operate in the corresponding preset power interval, the method further includes: Determine whether the energy storage dischargeable power deviates from the second historical curve according to the difference between the energy storage dischargeable power and the historical energy storage discharge power at the same time on the second historical curve; wherein the second historical curve includes the historical energy storage discharge power of the energy storage power station at different times of the day; If not, continue to execute the control of the running number of the energy storage converter according to the target charging and discharging power of the energy storage power station and the preset power interval corresponding to the energy storage converter, so as to control the energy storage converter to operate in the corresponding preset power interval; If so, within a second preset time period after deviating from the second historical curve, the energy storage dischargeable power is continuously obtained and the target charge and discharge power is continuously calculated, and when the change in the energy storage dischargeable power within the second preset time period is less than a second set threshold, the target charge and discharge power of the energy storage power station and the preset power range corresponding to the energy storage inverter are continued to be executed, and the operating number of the energy storage inverter is controlled to control the energy storage inverter to operate in the corresponding preset power range.

8. The charge and discharge control method of the energy storage power station according to claim 6, characterized in that: The determining the target charging and discharging power according to the configured charging and discharging power and the grid connection point power includes: When the grid connection point power is less than 0 and the energy storage subsystem is in a discharging state, it is determined that the target discharge power of the energy storage power station is less than the current discharge power of the energy storage power station.

9. The charge and discharge control method of the energy storage power station according to claim 1, characterized in that: According to the target charging and discharging power of the energy storage power station and the preset power range corresponding to the energy storage converter, controlling the running number of the energy storage converter to control the energy storage converter to operate in the corresponding preset power range includes: Determine the power average of the maximum power and the minimum power within the preset power range; According to the ratio of the target charge and discharge power to the power average, a value obtained by rounding the ratio is determined as the target operating number of the energy storage converter; The target operating number of energy storage converters is controlled to operate within the preset power range.

10. The charge and discharge control method of the energy storage power station according to claim 1, characterized in that: The obtaining of the configured charging and discharging power of the energy storage power station and the grid connection point power of the energy storage power station includes: Acquire the configured charging and discharging power of the local energy storage power station, or receive the configured charging and discharging power sent down; The grid connection point power of the grid connection point electric meter of the energy storage power station is obtained.

11. The charge and discharge control method of the energy storage power station according to claim 1, characterized in that: The energy storage power station comprises at least two substations, and the substation comprises at least two energy storage subsystems; Before controlling the running number of the energy storage converter according to the target charging and discharging power of the energy storage power station and the preset power interval corresponding to the energy storage converter to control the energy storage converter to operate in the corresponding preset power interval, the charging and discharging control method further includes: Obtaining the current remaining capacity of the substation and the rated power of the energy storage converter; According to the target charging and discharging power of the energy storage power station and the preset power range corresponding to the energy storage converter, controlling the running number of the energy storage converter to control the energy storage converter to operate in the corresponding preset power range includes: Determining the priority of charging and discharging the substation according to the current remaining capacity of the substation and / or the rated power of the energy storage converter in the substation; According to the target charging and discharging power of the energy storage power station and the preset power range corresponding to the energy storage inverter, the energy storage inverter in the substation is controlled to start and operate in order of priority from high to low, and the energy storage inverter is controlled to operate in the corresponding preset power range.

12. An energy storage power station, characterized in that: It includes an energy management module and at least two energy storage subsystems, wherein the energy storage subsystem includes an energy storage converter and a battery connected to the energy storage converter; The energy management module is connected to the energy storage converter, and the energy management module is used to control the energy storage converter of the energy storage power station according to the charge and discharge control method of the energy storage power station according to any one of claims 1-11.

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