Energy storage control method, controller, energy storage equipment and micro-grid system

Abstract

The invention discloses an energy storage control method, a controller, energy storage equipment and a micro-grid system, and relates to the technical field of charging. The method is applied to the energy storage equipment, the method is executed by a controller of the energy storage equipment, and the method comprises the steps that power parameters of a plurality of transformer areas are obtained, and the power parameters comprise at least one of the operation power of the energy storage equipment in the transformer areas and the operation power of transformers in the transformer areas; correcting at least one regulation and control parameter based on the power parameter of each transformer area, and determining a control parameter of the energy storage equipment based on the corrected regulation and control parameter; wherein the regulation and control parameters comprise at least one of the operation power of the energy storage equipment, the operation power of the transformer and the power limit value of the energy storage equipment. Therefore, energy storage sharing among a plurality of transformer areas is realized, and the charging and discharging depth of the energy storage equipment is improved.

Description

Technical Field

[0001] The present application relates to the field of charging technology, and in particular to an energy storage control method, a controller, an energy storage device and a microgrid system. Background Art

[0002] With the development of long-range electric vehicles, the high-power demand of charging systems is also increasing. However, large-scale charging infrastructure construction and charging station transformation have brought serious impacts and burdens to the existing power grid. In this case, energy storage equipment, as an adjustable load, has become the first choice for charging stations. By adjusting the output power of energy storage equipment, a basic balance with the energy load can be achieved, alleviating the impact of charging pile electricity consumption on the power grid.

[0003] In actual applications, since charging piles and energy storage devices share the capacity of the transformer, in order to limit the power operating range of the transformer, overload and reverse current control algorithms are usually configured for the energy storage device. The current control algorithms all use the power of a single common connection point as the control target to regulate the operating power of the energy storage device. However, these control algorithms are not suitable for charging stations with multiple transformers, and these control algorithms will limit the charge and discharge depth of the energy storage device. Summary of the invention

[0004] The main purpose of this application is to provide an energy storage control method, a controller, an energy storage device and a microgrid system to achieve energy storage sharing among multiple stations and improve the charging and discharging depth of the energy storage device.

[0005] To achieve the above objectives, the present application provides an energy storage control method, which is applied to an energy storage device, and the method comprises:

[0006] Acquire power parameters of multiple substations, wherein the power parameters include at least one of the operating power of the energy storage device in the substation and the operating power of the transformer in the substation;

[0007] At least one control parameter is corrected based on the power parameters of each of the substations, and the control parameters of the energy storage device are determined based on the corrected control parameters; wherein the control parameters include at least one of the operating power of the energy storage device, the operating power of the transformer, and the power limit of the energy storage device.

[0008] Optionally, the modifying of at least one control parameter based on the power parameters of each of the substations includes: determining an average value of the power parameters of each of the substations based on the power parameters of each of the substations; and modifying the control parameters of the energy storage device based on the average value of the power parameters of each of the substations.

[0009] Optionally, the regulating parameters of the energy storage device are corrected based on the average value of the power parameters of each substation, including: correcting the operating power of the transformer based on the planned energy storage power, the average value of the operating power of each transformer and the operating status of each energy storage device; or correcting the operating power of the energy storage device based on the planned energy storage power, the average value of the operating power of each energy storage device and the operating status of each energy storage device; or correcting the power limit of the energy storage device based on the average value of the operating power of each energy storage device and the operating status of each energy storage device.

[0010] Optionally, the operating power of the transformer is corrected based on the planned energy storage power, the average value of the operating power of each transformer and the operating status of each energy storage device, including: determining the average operating power of each transformer based on the operating power of each transformer and the operating status of each energy storage device; when the planned energy storage power is less than zero, correcting the operating power of the transformer using the average operating power of each transformer; determining the control parameters of the energy storage device based on the corrected regulation parameters includes: determining the control parameters of the energy storage device based on the operating power of the energy storage device, the power limit of the energy storage device and the corrected operating power of the transformer.

[0011] Optionally, the correcting the operating power of the energy storage device based on the planned energy storage power, the average value of the operating power of each of the energy storage devices, and the operating status of each of the energy storage devices includes: determining the average operating power of each of the energy storage devices based on the operating power of each of the energy storage devices and the operating status of each of the energy storage devices; when the planned energy storage power is less than zero, correcting the operating power of the energy storage device using the average operating power of each of the energy storage devices; determining the control parameters of the energy storage device based on the corrected regulation parameters includes: determining the control parameters of the energy storage device based on the operating power of the transformer, the power limit of the energy storage device, and the corrected operating power of the energy storage device.

[0012] Optionally, the power limit of the energy storage device includes a lower power limit, and the power limit of the energy storage device is corrected based on the average value of the operating power of each of the energy storage devices and the operating status of each of the energy storage devices, including: determining the average operating power of each of the energy storage devices based on the operating power of each of the energy storage devices and the operating status of each of the energy storage devices; correcting the lower power limit of the energy storage device using the average operating power, the operating power of the energy storage device and the lower power limit of the energy storage device; determining the control parameters of the energy storage device based on the corrected regulation parameters includes: determining the control parameters of the energy storage device based on the operating power of the transformer, the operating power of the energy storage device and the corrected lower power limit of the energy storage device.

[0013] Optionally, the corrected lower power limit of the energy storage device does not exceed a preset value.

[0014] Optionally, before correcting any control parameter based on the energy storage plan power and the control parameters of each substation, the method also includes: obtaining a control flag and determining a corrected control parameter based on the control flag; correcting any control parameter based on the energy storage plan power and the control parameters of each substation includes: correcting the determined control parameter based on the energy storage plan power and the control parameters of each substation.

[0015] In addition, to achieve the above-mentioned purpose, the present application also provides a controller, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the program, an energy storage control method as described in any one of the above-mentioned methods is implemented.

[0016] The present application also provides an energy storage device, comprising the controller as described above.

[0017] The present application also provides a microgrid system, including multiple parallel substations, each of which includes a transformer, an energy storage device and a charging device. The energy storage device and the charging device are respectively connected to the transformer, and the substation is connected to a power grid via the transformer; the energy storage device includes the controller as described above.

[0018] The energy storage control method of the present application obtains power parameters of multiple substations and corrects at least one control parameter based on the power parameters of each substation. The corrected control parameter can reflect the operating status of each substation. The control parameters of the energy storage device are then determined using the corrected control parameter. This can increase the discharge capacity of the energy storage device corresponding to the low-load transformer, realize energy storage sharing among multiple substations, and improve the charging and discharging depth of the energy storage device. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1This is a scenario example of the energy storage control method of an embodiment of the present application;

[0020] Figure 2 It is one of the flow charts of the energy storage control method of an embodiment of the present application;

[0021] Figure 3 This is the second flow chart of the energy storage control method of the embodiment of the present application;

[0022] Figure 4 This is the third flow chart of the energy storage control method of the embodiment of the present application;

[0023] Figure 5 This is the fourth flow chart of the energy storage control method of the embodiment of the present application;

[0024] Figure 6 It is a schematic diagram of the change of control parameters of a specific example of the present application;

[0025] Figure 7 is a schematic diagram of an energy storage control device according to an embodiment of the present application;

[0026] Figure 8 An example of a physical structure diagram of a controller is shown;

[0027] In the figure, 110, power grid; 120, transformer; 130, charging device; 140, energy storage device; 700, energy storage control device; 710, acquisition module; 720, correction module; 810, processor; 820, communication interface; 830, memory; 840, communication bus.

[0028] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0030] As electric vehicles (EVs) become more popular and their range increases, charging infrastructure must adapt to the growing demand for high-power charging. However, the construction and transformation of large-scale charging stations poses a challenge to the existing power grid, especially during peak hours of power demand. To address this issue, some regions have taken measures to limit the maximum capacity of a single box-type substation to 800kVA. If a higher-power charging station is required, multiple box-type substations will need to be configured.

[0031] In this case, energy storage equipment, as an adjustable load, has become the first choice for charging stations. If energy storage is used in charging stations, on the one hand, charging stations equipped with energy storage equipment can use the "peak shaving and valley filling" model to earn price differences, increase original revenue, and expand the price elasticity of electricity, service fees, etc. On the other hand, by adjusting the output power of energy storage equipment, a basic balance with energy load can be achieved, alleviating the impact of charging pile electricity consumption on the power grid and improving the stability of the power grid.

[0032] Since the energy storage device and the charging pile share the capacity of the transformer, it is necessary to maintain the power balance between the energy storage device and the charging pile so that the transformer operates within a reasonable power range to prevent overload or reverse flow on the grid side. Therefore, control algorithms to prevent overload and reverse flow are usually configured for energy storage devices. The current control algorithms all use the power of a single PCC (common connection point) as the control target to regulate the power of the energy storage device to achieve the effect of preventing overload and reverse flow.

[0033] However, these control algorithms are not suitable for charging stations with multiple transformers. The control targets of these control algorithms do not involve the power operating boundaries of energy storage. In addition, since the operating power limit of the energy storage device is determined only based on a single area, if the charging station includes more than two areas and the charging power of each area is uneven, for areas with low load rates, the discharge depth of the corresponding energy storage device will be greatly restricted. For example, if the power lower limit of a transformer is 0 and the charging power of the charging pile is 10kW, the discharge power of the energy storage device cannot exceed 10kW.

[0034] Based on this, the embodiments of the present application provide an energy storage control method, controller, energy storage device and microgrid system. By considering the operating conditions of the transformers and energy storage devices in each substation, energy storage sharing between multiple substations is achieved. On the basis of ensuring that a single transformer is not overloaded and the total operating power does not exceed the allowed operating range, the charging and discharging depth of each energy storage device is maximized, thereby increasing the charging and discharging capacity.

[0035] For ease of understanding, this specification provides an example scenario of an energy storage control method, which is applied in the following example: Figure 1 In the application environment shown, the scenario example is a charging station scenario, which includes a power grid 110 , multiple transformers 120 , multiple charging devices 130 , and multiple energy storage devices 140 .

[0036] In this scenario example, a transformer 120, a charging device 130 and an energy storage device 140 form a substation, each transformer 120 is connected to the power grid 110 through a bus, and a charging device 130 and an energy storage device 140 are connected to a transformer 120. In addition, a PCC point (common connection point) is set on the bus, and a PCC point is set between each transformer 120 and the bus. It should be noted that the PCC point refers to the specific physical connection point for the exchange of electric energy between the device and the power grid 110; the PCC point can be used to monitor key parameters such as voltage level, frequency, power, harmonic content, etc. to ensure compliance with power quality and safety standards.

[0037] In this scenario example, the charging device 130 may be a charging pile, which is connected to a load (eg, an electric vehicle) and supplies power to the load. The energy storage device 140 may include a battery assembly, a controller, an energy storage converter (ie, an ACDC converter), and the like.

[0038] In actual applications, the controller of the energy storage device 140 modifies its own control parameters by obtaining its own energy storage plan power and the power parameters of each substation. The modified control parameters can reflect the operation status of each substation; the controller of the energy storage device 140 then uses the modified control parameters to determine its own control parameters. The controller of each energy storage device 140 uses the above method to adjust its own control parameters, improve its own charge and discharge depth, and realize energy storage sharing.

[0039] With reference to the scenario example of the energy storage control method in the aforementioned embodiment, the energy storage control method in the embodiment of the present application is described in detail below.

[0040] Figure 2 This is one of the flow charts of the energy storage control method of the embodiment of the present application. The energy storage control method can be applied to energy storage equipment, and the energy storage control method can be executed by the controller of the energy storage equipment. Figure 2 As shown, the energy storage control method may include the following steps:

[0041] Step 210: Acquire power parameters of multiple substations, wherein the power parameters include at least one of an operating power of an energy storage device in the substation and an operating power of a transformer in the substation.

[0042] Step 220: Correct at least one control parameter based on the power parameters of each substation, and determine the control parameters of the energy storage device based on the corrected control parameters; wherein the control parameters include at least one of the operating power of the energy storage device, the operating power of the transformer, and the power limit of the energy storage device.

[0043] It should be noted that the controller of each energy storage device in each substation can execute the energy storage control method of this embodiment to adjust its own control parameters. In addition, the control parameter can be the power limit of the energy storage device, or the operating power of the energy storage device, etc. The control parameter is not specifically limited here.

[0044] The energy storage control method of the embodiment of the present application can be applied in application scenarios such as charging stations, communities, and industrial parks. The embodiment of the present application takes the application in the charging station scenario as an example to introduce the energy storage control method in detail.

[0045] In step 210, the controller of the energy storage device obtains the power parameters of each substation, and the power parameters may include at least one of the operating power of the energy storage device in the substation, the operating power of the transformer in the substation, and the power limit of the energy storage device in the substation. Among them, the power limit of the energy storage device is set in the controller of the energy storage device, so it can also be directly obtained; the controller of the energy storage device can collect the operating power of the transformer in its own substation and its own operating power, and the controller of the energy storage device then sends the operating power of the transformer in its own substation and its own operating power to the bus. The controller of each energy storage device sends the operating power of the transformer in its own substation and its own operating power to the bus, so the controller of an energy storage device can obtain the operating power of the transformer in other substations and the operating power of the energy storage device through the bus.

[0046] In some implementations, the controller of the energy storage device may also obtain its own rated power. During the process of regulating the power limit of the energy storage device, the power limit of the energy storage device cannot exceed the rated power to ensure the normal operation of the energy storage device.

[0047] Furthermore, after obtaining the power parameters of each substation, the controller of the energy storage device can correct any control parameter based on the power parameters of each substation, that is, correct the operating power of the energy storage device, the operating power of the transformer or the power limit of the energy storage device.

[0048] In addition, the power limit of the energy storage device is equal to the operating power of the energy storage device plus the power limit of the energy storage device minus the operating power of the transformer. Therefore, the power limit of the energy storage device is related to the operating power of the energy storage device, the power limit of the energy storage device and the operating power of the transformer. The embodiment of the present application can choose to correct any one of these three parameters to make the corrected control parameters have the operating characteristics of other substations to achieve the purpose of energy storage sharing.

[0049] Finally, the corrected control parameters and the other two control parameters are used to adjust the control parameters of the energy storage device (such as the upper power limit or the lower power limit) to increase the charge and discharge depth of the energy storage device.

[0050] In some embodiments, before modifying any control parameter based on the power parameters of each substation, the energy storage control method may further include: obtaining a control flag, and determining a modified control parameter based on the control flag. Modifying any control parameter based on the power parameters of each substation may include: modifying the determined control parameter based on the power parameters of each substation.

[0051] Specifically, the controller of the energy storage device can obtain a control flag, which is used to indicate which correction algorithm is used to correct the control parameter, and different correction algorithms are used to correct different control parameters. In this embodiment, the control flag can be set by the staff according to actual needs, or it can be automatically set according to power conditions.

[0052] As an example, the control flag bit may include 1, 2, and 3. When the control flag bit is 1, the first correction algorithm is selected to determine that the corrected control parameter is the operating power of the transformer, that is, the first correction algorithm is to correct the operating power of the transformer based on the power parameters of each substation. When the control flag bit is 2, the second correction algorithm is selected to determine that the corrected control parameter is the operating power of the energy storage device, that is, the second correction algorithm is to correct the operating power of the energy storage device based on the power parameters of each substation. When the control flag bit is 3, the third correction algorithm is selected to determine that the corrected control parameter is the power limit of the energy storage device, that is, the third correction algorithm is to correct the power limit of the energy storage device based on the power parameters of each substation.

[0053] In some embodiments, correcting at least one control parameter based on the power parameters of each substation may include: determining an average value of the power parameters of each substation based on the power parameters of each substation; and correcting the control parameters of the energy storage device based on the average value of the power parameters of each substation.

[0054] Specifically, the average value of the power parameters of each area can be calculated first, and then the average value of the power parameters of each area can be used to correct the control parameters of the energy storage device. For example, the average operating power of the energy storage device in each area can be calculated based on the operating power of the energy storage device in each area, and then the operating power of the energy storage device can be corrected using the calculated average operating power.

[0055] In some embodiments, based on the average value of the power parameters of each substation, the control parameters of the energy storage device are corrected, which can include: based on the energy storage planned power, the average value of the operating power of each transformer and the operating status of each energy storage device, the operating power of the transformer is corrected; or, based on the energy storage planned power, the average value of the operating power of each energy storage device and the operating status of each energy storage device, the operating power of the energy storage device is corrected; or, based on the average value of the operating power of each energy storage device and the operating status of each energy storage device, the power limit of the energy storage device is corrected.

[0056] It should be noted that the planned energy storage power refers to the operating power of the energy storage device set by the staff. If the planned energy storage power of the energy storage device is a positive value, it indicates that the energy storage device is charging. If the planned energy storage power of the energy storage device is a negative value, it indicates that the energy storage device is discharging.

[0057] In this embodiment, before using the power parameters of each substation to correct at least one control parameter, the energy storage planned power of the energy storage device can be obtained first. Since the energy storage planned power is set in the controller of the energy storage device, the controller of the energy storage device can directly obtain its own energy storage planned power. Furthermore, at least one control parameter is corrected in combination with the energy storage planned power and the power parameters of each substation.

[0058] It is understandable that the planned energy storage power can be used to know whether the energy storage device is charging or discharging. Usually, the energy storage devices in a charging station are charged or discharged at the same time. If each energy storage device is charging and the power grid needs to output a large amount of power, the PCC point of the bus may exceed the upper limit of its power limit and an overload may occur. At this time, you can choose to adjust the upper limit of the power limit of the energy storage device; if each energy storage device is discharging, the PCC point of the bus may exceed the lower limit of its power limit and a reverse flow may occur. At this time, you can choose to adjust the lower limit of the power limit of the energy storage device.

[0059] In an embodiment of the present application, three control parameter correction algorithms are provided. The first control parameter correction algorithm is to select to correct the operating power of the transformer. Specifically, the controller of the energy storage device corrects the operating power of the transformer in the substation where it is located (i.e., the same substation) based on the planned energy storage power, the average operating power of the transformers in each substation, and the operating status of the energy storage devices in each substation.

[0060] The second control parameter correction algorithm is to select to correct the operating power of the energy storage device. Specifically, the controller of the energy storage device corrects its own operating power based on the energy storage plan power, the average operating power of the energy storage devices in each area, and the operating status of the energy storage devices in each area.

[0061] The third control parameter correction algorithm is to select to correct the power limit of the energy storage equipment. Specifically, the controller of the energy storage equipment corrects the power limit of the energy storage equipment in its area based on the planned energy storage power, the average operating power of the energy storage equipment in each area, and the operating status of the energy storage equipment in each area.

[0062] In the actual application process, you can arbitrarily select a control parameter correction algorithm to correct the corresponding control parameter, or you can select the control parameter correction algorithm according to the obtained control flag bit, and there is no specific limitation here. It is worth mentioning that the first control parameter correction algorithm and the second control algorithm can correct the control parameter to the optimal value at one time, while the third control parameter correction algorithm requires multiple corrections to correct the control parameter to the optimal value; therefore, the first control parameter correction algorithm and the second control algorithm have higher correction efficiency than the third control parameter correction algorithm.

[0063] The three control parameter correction algorithms mentioned above are introduced in detail below.

[0064] Figure 3 This is the second flow chart of the energy storage control method of the embodiment of the present application. Figure 3 As shown, in some embodiments, the first correction algorithm corrects the operating power of the transformer based on the energy storage plan power, the average value of the operating power of each transformer and the operating status of each energy storage device, and may include the following steps:

[0065] Step 310: Determine the average operating power of each transformer based on the operating power of each transformer and the operating status of each energy storage device.

[0066] Step 320: When the planned energy storage power is less than zero, the average operating power of each transformer is used to correct the operating power of the transformer.

[0067] Determining the control parameters of the energy storage device based on the corrected regulation parameters may include: determining the control parameters of the energy storage device based on the operating power of the energy storage device, the power limit of the energy storage device, and the corrected operating power of the transformer.

[0068] It should be noted that the operating status of each energy storage device can also be sent to the bus by the controller of each energy storage device together with other control parameters, and the controller of each energy storage device then obtains the operating status of other energy storage devices through the bus. The operating status of the energy storage device can include an operating state and a non-operating state.

[0069] In this embodiment, the controller of the energy storage device can first calculate the total operating power of a transformer based on the operating power of the transformer in each substation; then determine the total number of energy storage devices currently in operation according to the operating status of the energy storage devices in each substation; and further divide the total operating power of the transformer by the total number of energy storage devices in operation to obtain the average operating power of each transformer.

[0070] After obtaining the average operating power of the transformer, the setting process of the energy storage device control parameters can be further selected according to the planned power of the energy storage. Take the power limit of the energy storage device as an example. Specifically, if the planned power of the energy storage device is greater than or equal to zero, it indicates that the energy storage device is currently in a charging state. At this time, the power grid needs to output a large amount of power, and the PCC point of the bus may exceed the upper limit of its power limit, resulting in an overload. The upper power limit of the PCC point of the bus is a fixed value. Therefore, the controller of each energy storage device can directly use the operating power of the transformer in each substation to regulate the upper power limit of the energy storage device. The lower power limit of the energy storage device remains unchanged (based on the lower power limit of the bus PCC point). The goal of the bus PCC point is not to exceed the upper power limit. If the upper power limit of the energy storage device is recorded as P_des_set_max, the operating power of the energy storage device is recorded as P_des_run, the upper power limit of the energy storage device (i.e., uncorrected) is P_pcc_set_max, and the operating power of the transformer is recorded as P_pcc_run, then the upper power limit of the energy storage device (i.e., corrected) can be calculated by the following formula:

[0071] P_des_set_max=P_des_run+P_pcc_set_max-P_pcc_run

[0072] If the planned energy storage power is less than zero, it indicates that the energy storage device is currently in a discharge state, and the PCC point of the bus may exceed the lower limit of its power limit, resulting in reverse flow. At this time, the average operating power of the transformer can be used to correct the operating power of the transformer, that is, the average operating power of the transformer is used as the operating power of the transformer. The average operating power of the transformer, the operating power of the energy storage device, and the lower power limit of the energy storage device are further used to adjust the lower power limit of the energy storage device to increase the discharge depth of the energy storage device, and the upper power limit of the energy storage device remains unchanged.

[0073] If the lower power limit value (corrected) of the energy storage device is recorded as P_des_set_min, the lower power limit value (uncorrected) of the energy storage device is recorded as P_pcc_set_min, and the average operating power of the transformer is recorded as P_pcc_run_ave, then the lower power limit value of the energy storage device can be calculated by the following formula:

[0074] P_des_set_min=P_des_run+P_pcc_set_min-P_pcc_run_ave

[0075] As an example, if the microgrid system includes two substations, the first substation includes transformer A, charging device A and energy storage device A, and the second substation includes transformer B, charging device B and energy storage device B. The power limits of these two transformers are 400kW to 0kW. If at this time, both energy storage devices are in a discharge state, the charging power of charging device A is 200kW, the operating power of energy storage device A is -100kW, and the operating power of transformer A is 100kW; the charging power of charging device B is 100kW, the operating power of energy storage device B is -50kW, and the operating power of transformer B is 50kW. The controllers of energy storage device A and energy storage device B can calculate respectively: the average operating power of the transformer is 75kW. Because the planned power of energy storage is less than 0, the average operating power of the transformer is used instead of the operating power of the transformer in each substation. Then the controller of energy storage device A can calculate its lower power limit value = -100 + 0-75 = -175 kW. Similarly, the controller of energy storage device B can calculate its lower power limit value = -50 + 0-75 = -125 kW.

[0076] It can be seen that if the existing control method is used, the discharge power of the energy storage device B cannot exceed 100kW. However, through the energy storage sharing of the embodiment of the present application, the discharge power of the energy storage device B can reach 125kW, thereby improving the discharge depth of the energy storage device.

[0077] Figure 4 This is the third flow chart of the energy storage control method of the embodiment of the present application. Figure 4 As shown, in some embodiments, the second correction algorithm corrects the operating power of each energy storage device based on the energy storage plan power, the average value of the operating power of each energy storage device, and the operating state of each energy storage device, and may include the following steps:

[0078] Step 410: Determine the average operating power of each energy storage device based on the operating power of each energy storage device and the operating status of each energy storage device.

[0079] Step 420: When the planned energy storage power is less than zero, the operating power of the energy storage device is corrected using the average operating power of each energy storage device.

[0080] Determining the control parameters of the energy storage device based on the corrected regulation parameters may include: determining the control parameters of the energy storage device based on the operating power of the transformer, the power limit of the energy storage device, and the corrected operating power of the energy storage device.

[0081] In this embodiment, the controller of the energy storage device can first calculate the total operating power of an energy storage device based on the operating power of the energy storage devices in each substation; then determine the total number of energy storage devices currently in operation according to the operating status of the energy storage devices in each substation; and further divide the total operating power of the energy storage device by the total number of energy storage devices in operation to obtain the average operating power of each energy storage device.

[0082] After obtaining the average operating power of the energy storage device, the setting process of the energy storage device control parameters can be further selected according to the planned power of the energy storage. Take the power limit of the energy storage device as an example of the control parameter. Specifically, if the planned power of the energy storage device is greater than or equal to zero, it indicates that the energy storage device is currently in a charging state. At this time, the power grid needs to output a large amount of power, and the PCC point of the bus may exceed the upper limit of its power limit, resulting in an overload. The upper power limit of the PCC point of the bus is a fixed value. Therefore, the controller of each energy storage device can directly use the operating power of the energy storage device in its respective area to regulate the upper power limit of the energy storage device. The lower power limit of the energy storage device remains unchanged (based on the lower power limit of the bus PCC point). The goal during regulation is that the bus PCC point does not exceed its upper power limit. The upper power limit of the energy storage device can be calculated using the formula for the upper power limit of the energy storage device in the above embodiment, which will not be repeated here.

[0083] If the planned energy storage power is less than zero, it indicates that the energy storage device is currently in a discharging state, and the PCC point of the bus may exceed the lower limit of its power limit, resulting in a reverse flow. At this time, the average operating power of the energy storage device can be used to correct the operating power of the energy storage device, that is, the average operating power of the energy storage device is used as the operating power of the energy storage device. The average operating power of the energy storage device, the operating power of the transformer, and the lower power limit of the energy storage device are further used to adjust the lower power limit of the energy storage device to increase the discharge depth of the energy storage device, and the upper power limit of the energy storage device remains unchanged.

[0084] If the average operating power of the energy storage device is recorded as P_des_run_ave, the lower power limit of the energy storage device can be calculated by the following formula:

[0085] P_des_set_min=P_des_run_ave+P_pcc_set_min-P_pcc_run

[0086] As an example, if the microgrid system includes two substations, the first substation includes transformer A, charging device A and energy storage device A, and the second substation includes transformer B, charging device B and energy storage device B. The power limits of these two transformers are 400kW to 0kW. If at this time, both energy storage devices are in a discharge state, the charging power of charging device A is 200kW, the operating power of energy storage device A is -100kW, and the operating power of transformer A is 100kW; the charging power of charging device B is 100kW, the operating power of energy storage device B is -50kW, and the operating power of transformer B is 50kW. The controllers of energy storage device A and energy storage device B can calculate respectively: the average operating power of the energy storage device is -75kW. Because the planned energy storage power is less than 0, the average operating power of the energy storage device is used instead of the operating power of the energy storage device in each substation. Then the controller of energy storage device A can calculate its lower power limit value = -75 + 0-100 = -175 kW. Similarly, the controller of energy storage device B can calculate its lower power limit value = -75 + 0-50 = -125 kW.

[0087] It can be seen that if the existing control method is used, the discharge power of the energy storage device B cannot exceed 100kW. However, through the energy storage sharing of the embodiment of the present application, the discharge power of the energy storage device B can reach 125kW, thereby improving the discharge depth of the energy storage device.

[0088] Figure 5 This is the fourth flow chart of the energy storage control method of the embodiment of the present application. Figure 5 As shown, in some embodiments, the power limit of the energy storage device includes a lower power limit value, and the third correction algorithm corrects the power limit of the energy storage device based on the average value of the operating power of each energy storage device and the operating state of each energy storage device, which may include the following steps:

[0089] Step 510: Determine the average operating power of each energy storage device based on the operating power of each energy storage device and the operating status of each energy storage device.

[0090] Step 520: Correct the lower power limit of the energy storage device using the average operating power, the operating power, and the lower power limit of the energy storage device.

[0091] Determining the control parameters of the energy storage device based on the corrected regulation parameters may include: determining the control parameters of the energy storage device based on the operating power of the transformer, the operating power of the energy storage device and the corrected lower power limit of the energy storage device.

[0092] In this embodiment, the controller of the energy storage device can first calculate the total operating power of an energy storage device based on the operating power of the energy storage devices in each substation; then determine the total number of energy storage devices currently in operation according to the operating status of the energy storage devices in each substation; and further divide the total operating power of the energy storage device by the total number of energy storage devices in operation to obtain the average operating power of each energy storage device.

[0093] After obtaining the average operating power of the energy storage device, the setting process of the energy storage device control parameters can be further selected according to the planned energy storage power. Taking the power limit of the energy storage device as the control parameter as an example, specifically, if the planned energy storage power is greater than or equal to zero, the controller of each energy storage device can directly use the power limit of the energy storage device in its own area to regulate the upper power limit of the energy storage device. The lower power limit of the energy storage device remains unchanged, and the bus PCC point is set as the goal of not exceeding its upper power limit during regulation. The upper power limit of the energy storage device can be calculated by the formula of the upper power limit of the energy storage device in the above embodiment, which will not be repeated here.

[0094] If the planned energy storage power is less than zero, it means that the energy storage device is currently in a discharging state, then the PCC point of the bus may exceed the lower limit of its power limit, resulting in a reverse flow. At this time, the lower power limit of the energy storage device can be corrected by using the average operating power of the energy storage device, the operating power of the energy storage device, and the lower power limit of the energy storage device. Specifically, the power deviation is first calculated using the average operating power of the energy storage device and the operating power of the energy storage device, and then the lower power limit of the energy storage device, the power deviation, and the control factor are used to correct the lower power limit of the energy storage device. It should be noted that the control factor is used to characterize the degree of a single control, and can be set by the staff according to demand. For example, the control factor can be set to 0.5 or 1.

[0095] If the power deviation is recorded as P_des_runerr and the control factor is recorded as pararunerr_des_set, the power lower limit of the energy storage device can be corrected using the following formula:

[0096] P_des_runerr=P_des_run_ave-P_des_run

[0097] P_pcc_set_min=P_pcc_set_min+P_des_runerr*pararunerr_des_set

[0098] As an example, if the microgrid system includes two substations, the first substation includes transformer A, charging device A and energy storage device A, and the second substation includes transformer B, charging device B and energy storage device B. The power limits of these two energy storage devices are 400kW to 0kW. If at this time, both energy storage devices are in the discharge state, the charging power of charging device A is 200kW, the operating power of energy storage device A is -100kW, and the operating power of transformer A is 100kW; the charging power of charging device B is 100kW, the operating power of energy storage device B is -50kW, and the operating power of transformer B is 50kW. The controllers of energy storage device A and energy storage device B can respectively calculate: the average operating power of the energy storage device is -75kW. Assuming the control factor is 1, because the planned energy storage power is less than 0, the controller of energy storage device A can calculate the power lower limit of its substation energy storage device = 0 + (-75 + 100) * 1 = 25kW, then the controller of energy storage device A can calculate its power lower limit = -100 + 25-100 = -175kW.

[0099] Similarly, the controller of energy storage device B can calculate the lower power limit of its energy storage device in the substation = 0 + (-75 + 50) * 1 = -25kW, and the controller of energy storage device A can calculate the lower power limit = -50 - 25 - 50 = -125kW.

[0100] It can be seen that if the existing control method is used, the discharge power of the energy storage device B cannot exceed 100kW. However, through the energy storage sharing of the embodiment of the present application, the discharge power of the energy storage device B can reach 125kW, thereby improving the discharge depth of the energy storage device.

[0101] In some implementations, the corrected lower power limit of the energy storage device does not exceed a preset value. The preset value can be set by a staff member according to actual needs, thereby limiting the lower power limit of the energy storage device.

[0102] Figure 6 Schematic diagram of the change of control parameters of a specific example of the present application. Taking a specific example as an example, the multiple correction process and results of the third correction method are described in detail below.

[0103] If the microgrid system includes two substations, the first substation includes transformer 1, charging device 1 and energy storage device 1, and the second substation includes transformer 2, charging device 2 and energy storage device 2, the upper limit of the grid connection point operating power limit is 800kW, and the lower limit is 5kW. If at this time, energy storage device 1 is in a discharging state, the charging power of charging device 1 is 300kW, the operating power of energy storage device 1 is -100kW, and the operating power of transformer 1 is 200kW; the charging power of charging device 2 is 0kW, the operating power of energy storage device 2 is 0kW, and the operating power of transformer 2 is 0kW.

[0104] from Figure 6 It can be seen that before the energy storage sharing strategy of this embodiment is used (i.e., before 20 seconds), the operating power of energy storage device 1 is -100kW, and the operating power of energy storage device 2 is 0kW. After the energy storage sharing strategy of this embodiment is used (i.e., after 20 seconds), the lower power limits of the energy storage devices in the substations where energy storage devices 1 and 2 are located are adjusted. Among them, the lower power limit of the energy storage device corresponding to energy storage device 1 is adjusted from 5kW to 100kW, and the lower power limit of the energy storage device corresponding to energy storage device 2 is adjusted from 5kW to -100kW; after several cycles of adjustment, the operating power of energy storage device 2 is adjusted to -100kW.

[0105] In addition, from Figure 6 It can be seen that the third correction method corrects the lower power limit of the energy storage device in a step-like manner, that is, through multiple cycles of adjustment, the lower power limit of the energy storage device is corrected to the optimal value.

[0106] Through the above experimental verification, it can be seen that the energy storage control method of the embodiment of the present application can maximize the charging and discharging depth of each energy storage device on the basis that the total operating power does not exceed the allowable operating range, thereby increasing the charging and discharging amount, which is of great practical significance for improving the energy storage "peak shaving and valley filling" mode to earn price difference and increase profits.

[0107] Based on the above embodiments, the embodiments of the present application also provide an energy storage control device. Figure 7 is a schematic diagram of an energy storage control device according to an embodiment of the present application. Figure 7 As shown, the energy storage control device 700 may include an acquisition module 710 and a correction module 720 that are connected to each other.

[0108] Among them, the acquisition module 710 is used to obtain power parameters of multiple substations, wherein the power parameters include at least one of the operating power of the energy storage device in the substation and the operating power of the transformer in the substation; the correction module 720 is used to correct at least one control parameter based on the power parameters of each of the substations, and determine the control parameters of the energy storage device based on the corrected control parameters; wherein the control parameters include at least one of the operating power of the energy storage device, the operating power of the transformer, and the power limit of the energy storage device.

[0109] Therefore, by obtaining the power parameters of each substation and correcting at least one control parameter based on the power parameters of each substation, the corrected control parameter can reflect the operating status of each substation, and then the control parameters of the energy storage device are determined using the corrected control parameter, which can increase the discharge capacity of the energy storage device corresponding to the low-load transformer, realize energy storage sharing among multiple substations, and improve the charging and discharging depth of the energy storage device.

[0110] In some implementations, the correction module 720 is specifically used to: determine an average value of the power parameters of each of the substations based on the power parameters of each of the substations; and correct the control parameters of the energy storage device based on the average value of the power parameters of each of the substations.

[0111] In some embodiments, the correction module 720 is specifically used to: correct the operating power of the transformer based on the planned energy storage power, the average value of the operating power of each transformer, and the operating status of each energy storage device; or, correct the operating power of the energy storage device based on the planned energy storage power, the average value of the operating power of each energy storage device, and the operating status of each energy storage device; or, correct the power limit of the energy storage device based on the average value of the operating power of each energy storage device and the operating status of each energy storage device.

[0112] In some embodiments, the correction module 720 is further specifically used to: determine the average operating power of each transformer based on the operating power of each transformer and the operating status of each energy storage device; when the planned energy storage power is less than zero, use the average operating power of each transformer to correct the operating power of the transformer; the control parameters of the energy storage device based on the corrected regulation parameters are determined, including: determining the control parameters of the energy storage device based on the operating power of the energy storage device, the power limit of the energy storage device and the corrected operating power of the transformer.

[0113] In some embodiments, the correction module 720 is further specifically used to: determine the average operating power of each of the energy storage devices based on the operating power of each of the energy storage devices and the operating status of each of the energy storage devices; when the planned energy storage power is less than zero, correct the operating power of the energy storage device using the average operating power of each of the energy storage devices; the control parameters of the energy storage device based on the corrected regulation parameters are determined, including: determining the control parameters of the energy storage device based on the operating power of the transformer, the power limit of the energy storage device and the corrected operating power of the energy storage device.

[0114] In some embodiments, the power limit of the energy storage device includes a lower power limit, and the correction module 720 is further specifically used to: determine the average operating power of each energy storage device based on the operating power of each energy storage device and the operating status of each energy storage device; correct the lower power limit of the energy storage device using the average operating power, the operating power and the lower power limit of the energy storage device; determine the control parameters of the energy storage device based on the corrected regulation parameters, including: determine the control parameters of the energy storage device based on the operating power of the transformer, the operating power of the energy storage device and the corrected lower power limit of the energy storage device.

[0115] In some implementations, the corrected lower power limit of the energy storage device does not exceed a preset value.

[0116] In some embodiments, the acquisition module 710 is also used to obtain the control flag and determine the modified control parameters based on the control flag; the correction module 720 is also specifically used to correct the determined control parameters based on the energy storage plan power and the power parameters of each substation.

[0117] It should be noted that for details not disclosed in the energy storage control device of this embodiment, please refer to the details disclosed in the embodiment of the energy storage control method in the embodiments of this specification, and no further details will be given here.

[0118] Based on the above embodiments, the embodiments of the present application also provide a controller. Figure 8 An example of a physical structure diagram of a controller is shown below: Figure 8As shown, the controller may include: a processor 810, a communication interface 820, a memory 830 and a communication bus 840, wherein the processor 810, the communication interface 820 and the memory 830 communicate with each other through the communication bus 840. The processor 810 may call the logic instructions in the memory 830 to execute the energy storage control method, which includes: obtaining power parameters of multiple substations, wherein the power parameters include at least one of the operating power of the energy storage device in the substation and the operating power of the transformer in the substation; modifying at least one control parameter based on the power parameter of each of the substations, and determining the control parameter of the energy storage device based on the modified control parameter; wherein the control parameter includes at least one of the operating power of the energy storage device, the operating power of the transformer and the power limit of the energy storage device.

[0119] In addition, the logic instructions in the above-mentioned memory 830 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program code.

[0120] Based on the above embodiments, an embodiment of the present application further provides an energy storage device, which may include the controller as described above.

[0121] On the basis of the above embodiments, on the other hand, the present invention further provides a non-transitory computer-readable storage medium having a computer program stored thereon, which is implemented when the processor executes the energy storage control method provided by the above methods, the method comprising: obtaining power parameters of multiple substations, wherein the power parameters include at least one of the operating power of the energy storage device in the substation and the operating power of the transformer in the substation; correcting at least one control parameter based on the power parameter of each of the substations, and determining the control parameter of the energy storage device based on the corrected control parameter; wherein the control parameter includes at least one of the operating power of the energy storage device, the operating power of the transformer, and the power limit of the energy storage device.

[0122] On the basis of the above embodiments, an embodiment of the present application further provides a microgrid system, characterized in that it includes multiple parallel substations, each of which includes a transformer, an energy storage device and a charging device. The energy storage device and the charging device are respectively connected to the transformer, and the substation is connected to the power grid through a transformer; the energy storage device includes the controller as described above.

[0123] It should be noted that for details not disclosed in the microgrid system of this embodiment, please refer to the details disclosed in the embodiment of the energy storage control method in the embodiment of this specification, and no further details will be given here.

[0124] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0125] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0126] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for controlling energy storage, characterized in that: Applied to energy storage equipment, the method comprises: Acquire power parameters of multiple substations, wherein the power parameters include at least one of the operating power of the energy storage device in the substation and the operating power of the transformer in the substation; At least one control parameter is corrected based on the power parameters of each of the substations, and the control parameters of the energy storage device are determined based on the corrected control parameters; wherein the control parameters include at least one of the operating power of the energy storage device, the operating power of the transformer, and the power limit of the energy storage device.

2. The energy storage control method according to claim 1, characterized in that: The modifying of at least one control parameter based on the power parameter of each of the stations includes: Determine an average value of the power parameters of each of the stations based on the power parameters of each of the stations; Based on the average value of the power parameters of each of the substations, the control parameters of the energy storage device are corrected.

3. The energy storage control method according to claim 2, characterized in that: The modifying of the control parameters of the energy storage device based on the average value of the power parameters of each of the substations includes: Based on the planned energy storage power, the average value of the operating power of each transformer and the operating status of each energy storage device, the operating power of the transformer is corrected; or, Based on the planned energy storage power, the average value of the operating power of each of the energy storage devices and the operating status of each of the energy storage devices, the operating power of the energy storage devices is corrected; or, The power limit of the energy storage device is corrected based on an average value of the operating power of each of the energy storage devices and an operating state of each of the energy storage devices.

4. The energy storage control method according to claim 3, characterized in that: The correcting the operating power of the transformer based on the energy storage plan power, the average value of the operating power of each transformer and the operating state of each energy storage device includes: Determining the average operating power of each transformer based on the operating power of each transformer and the operating status of each energy storage device; When the planned energy storage power is less than zero, the operating power of the transformer is corrected by using the average operating power of each transformer; The step of determining the control parameters of the energy storage device based on the corrected regulation parameters includes: A control parameter of the energy storage device is determined based on the operating power of the energy storage device, the power limit of the energy storage device, and the corrected operating power of the transformer.

5. The energy storage control method according to claim 3, characterized in that: The correcting the operating power of the energy storage device based on the energy storage planned power, the average value of the operating power of each of the energy storage devices, and the operating state of each of the energy storage devices includes: Determining an average operating power of each of the energy storage devices based on the operating power of each of the energy storage devices and the operating status of each of the energy storage devices; When the planned energy storage power is less than zero, the operating power of the energy storage device is corrected by using the average operating power of each of the energy storage devices; The step of determining the control parameters of the energy storage device based on the corrected regulation parameters includes: A control parameter of the energy storage device is determined based on the operating power of the transformer, the power limit of the energy storage device, and the corrected operating power of the energy storage device.

6. The energy storage control method according to claim 3, characterized in that: The power limit of the energy storage device includes a lower power limit, and the power limit of the energy storage device is corrected based on the average value of the operating power of each of the energy storage devices and the operating state of each of the energy storage devices, including: Determining an average operating power of each of the energy storage devices based on the operating power of each of the energy storage devices and the operating status of each of the energy storage devices; Correcting the lower power limit of the energy storage device using the average operating power, the operating power and the lower power limit of the energy storage device; The step of determining the control parameters of the energy storage device based on the corrected regulation parameters includes: Based on the operating power of the transformer, the operating power of the energy storage device and the corrected lower power limit of the energy storage device, a control parameter of the energy storage device is determined.

7. The energy storage control method according to claim 6, characterized in that: The corrected lower power limit of the energy storage device does not exceed a preset value.

8. A controller, comprising a memory and a processor, wherein a computer program is stored in the memory, characterized in that: When the processor executes the program, the energy storage control method according to any one of claims 1 to 7 is implemented.

9. An energy storage device, characterized in that: Comprising a controller as claimed in claim 8.

10. A microgrid system, characterized in that: It includes a plurality of parallel substations, each of which includes a transformer, an energy storage device and a charging device, wherein the energy storage device and the charging device are respectively connected to the transformer, and the substation is connected to a power grid through the transformer; The energy storage device comprises the controller as claimed in claim 8.

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